Chapter 20 HEART and Chapter 21 BLOOD VESSELS AND CIRCULATION Flashcards

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1. Where are the base and the apex of the heart?

Apex of the heart

The apex of the heart is the lowest superficial part of the heart.

It is directed downward, forward, and to the left, and is overlapped by the left lung and pleura.


2. Which “end” of the heart has vessels attached to it?

The base of the heart is the superior end where the major vessels are attached.


What is the pericardial sac? What type of tissue makes up the sac?

pericardial sac—>stabilizes the heart and associated vessels within the mediastinum

The heart is surrounded by the tough fibrous pericardial sac that is lined with serous membrane. Contains 15-50 ml pericardial fluid which Lubricates and reduces friction.


4. Describe the Parietal and Visceral Pericardia. Location, purpose, composition

Visceral pericardia- Layer of serous membrane adjacent to the heart tissue.

Parietal- Layer of serous membrane adjacent to the fibrous pericardial sac


5. What is pericarditis and what types of problems does it cause?

Pericarditis- Inflammation of the pericardium. Trama. Infection. Post-sergical. Increase in serous fluid. Blood. Increase pressure around heart. Interferse with beating.


6. What is cardiac tamponade and what problems does it cause?

Cardiac tamponade is a clinical syndrome caused by the accumulation of fluid in the pericardial space, resulting in reduced ventricular filling and subsequent hemodynamic compromise. The condition is a medical emergency, the complications of which include pulmonary edema, shock, and death.


7. Name and describe the three layers of the heart. Include the type of tissue each is made of and any unique or important features.

Epicardium, Myocardium, Endocardium

Epicardium- the visceral pericardium attached to heart via a layer of loose connective tissue

Myocardium- concentric layers of cardiac muscle and CT arranged in circular or spiral bundles

CT forms the fibrous skeleton of the heart

The connective tissues function:

1) limit the amount of stretch of the myocardium (particularly where the great vessels enter the heart

2) function as an internal skeleton

3) limit the spread of electrical activity between the atria and ventricles (non-conducting tissue)

Endocardium- Simple squamous epithelium, continuous with the endothelial lining of the blood vessels.


8. What is the cardiac skeleton made of and what are its functions?

The cardiac skeleton, sometimes called the fibrous skeleton of the heart, is the structure of dense connective tissue in the heart that separates the atria from the ventricles.

The cardiac skeleton establishes electrically impermeable boundaries to autonomic influence within the heart.

Connective tissue framework _ CT

Anchors valves

Internal support


9. Describe the atria - include location, size, vessels attached to each one.

Atria- Superior chambers, known as the "receiving chambers", receive blood from the great veins

Right- - Receives blood from vena cava. , Deoxygenated

Left- Receives blood from pulmonary veins. Oxygenated

Right atrium-

- Superior vena cava - blood draining from the superior body
- Inferior vena cava - blood draining from the inferior body
- Coronary sinus - blood draining from the heart

Left atrium - 4 entrances

- 2 right pulmonary veins - drains blood from the right lung lobes
- 2 left pulmonary veins - drains blood from the left lung lobes


10. Define: Interatrial septum, fossa ovalis, foramen ovale, coronary sulcus

Fossa ovalis- Indentation after foramen ovale closes.

Forman ovale- Hole in septum; pre- birth

Coronary sulcus- The atria of the heart are separated from the ventricles by the coronary sulcus ,this contains the trunks of the nutrient vessels of the heart, and is deficient in front, where it is crossed by the root of the pulmonary artery. On the posterior surface of the heart, the coronary sulcus contains the coronary sinus.


11. Describe the ventricles - include location, size, and the vessels each pumps into

- Lower chamber
- Pump blood from heart
- Left ventricle outer wall much thicker


12. Define/describe these structural terms:
interventricular septum, anterior and posterior interventricular sulci

interventricle septum- The wall between the ventricles of the heart.

Anterior interventricular sulci- The anterior interventricular sulcus is one of two grooves that separate the two ventricles of the heart from each other. It is located on the anterosuperior surface of the heart.

Posterior interventricular sulci- The posterior interventricular artery (PIV) (or posterior descending artery (PDA)) is an artery running in the posterior interventricular sulcus to the apex of the heart where it meets with the anterior interventricular artery.


13. What structures are found in the sulci?

Coronary blood vessels and adipose tissue.


14. What is endocarditis and what types of problems are associated with it?

Endocarditis is an infection of the heart's valves or its inner lining (endocardium). It is most common in people who have a damaged, diseased, or artificial heart valve.

Endocarditis is caused by bacteria (or in rare cases, by fungi) that enter the bloodstream and settle on the inside of the heart, usually on the heart valves. Bacteria can invade your bloodstream in many ways, including during some dental and surgical procedures.

If endocarditis is not treated, the bacteria that cause endocarditis can form growths on or around the heart valves. The growths prevent the heart valves from opening and closing properly. This interrupts the normal blood flow through the valves and interferes with the heart's pumping action. Blood can leak backwards instead of being pumped forward. Over time, heart failure can develop, because your heart may not be able to pump enough blood to meet your body's needs.


15. What structure does the coronary circulation serve?

Blood supply to hearts own tissues.


16. What are the main structures of the coronary circulation?

The coronary circulation consists of the coronary arteries, which branch off of the aorta and carry oxygen-rich blood to the heart muscle; and coronary veins, which carry deoxygenated blood to the coronary sinus, which empties into the right atrium.


17. Where do the coronary arteries get their blood (which vessel feeds them)?

Coronary arteries get their blood from an expensive network of coronary blood vessels.


18. What structure does the blood drain before returning to the right atrium?

The anterior cardiac veins drain the anterior surface of the R ventricle and empty directly into the R atrium.


19. Define, Compare and contrast pulmonary and systemic circulation.

Pulmonary: Pumps blood through lungs, get O2 and removes CO2

Systemic: Delivers O2 through the rest fo the body, and picks up CO2


20. Trace a drop of blood passing through the heart from the vena cava to the aorta.
Include all chambers, valves, vessels and organs that it has to travel through.
Indicate where the blood is oxygenated or deoxygenated in each structure.

Vena Cavas- R Atrium- Tricuspid Valve- R ventricle- Pulmonary semilunar valve- Pulmonary trunk- Pulmonary arteries-Lungs-Pulmonary Veins....

L Atrium-Bicuspid valve- L Ventricle- Aortic Semilunar valve- aorta


21. List and describe the fetal circulatory shortcut.

22. What would happen if these shortcuts did not close up about the time of birth? Why can fetal blood bypass the lungs?

The foramen ovale is a hole in the Interatrial Septum, allowing the blood skips from right atrium to left atrium

The ductus arteriosis goes from the aorta to the pulmonary trunk

Fetal blood bypasses the lungs because the lungs are not yet expanded.

The blood would continue to skip the lungs, and as a result would not be oxygenated.


23. Describe the heart valves - what they’re made of, which have chordae tendineae.

They are strong, flexible and stress resistant. Covered by endocardium and made of dense irregular connective tissue. Only the atrioventicular valves have chordae tendineae.


24. What is the major function of the heart valves and why is it important?

The major function of the valves is to regulate the flow of blood and prevent the backflow of blood. It is important because id the valves can’t maintain adequate circulation, it can lead to Valvular Heart Disease, resulting in carditis (inflammation of the heart) and rheumatic fever.


25. Where are each of the valves located?

Atrioventicular: Between the atria and ventricles. Tricuspid valve is in the right ventricle and Bicuspid valve in the left ventricle.

Semilunar: valves are located between the ventricles and arteries. The aortic semilunar valves is between the left ventricle and aorta, the pulmonary semilunar valve is below the pulmonary trunk and aorta.


26. What do the chordae tendineae and papillary muscles do? Why is this important?

The chordae tendineae and papillary muscles anchor the heart valves in place.


27. What is a heart murmur?

Heart murmurs are abnormal heart sounds that can be caused by stenosis, prolapsed valves or an open foramen ovale.


28. What is stenosis of a heart valve? What is a valve prolapse? What problems does each cause?

Stenosis is narrowing of the valves and it makes it harder to eject blood. It can occur at any valve in the heart. Valve prolapse is when the vales go past the closed position which leads to backflow of blood.


29. Describe the contractile fibers of the heart in terms of both basic structure and function.

They are specialized muscle cells of the conducting system control and coordinate the heartbeat. It generates pressure and moves blood.


30. What are the electrical phases for an action potential in the heart muscle?

Permeability changes due to voltage-gated
channels opening and closing during an action
potential in cardiac muscle:

1. Depolarization phase
• Na+ channels open.
• K+ channels close.
• Ca2+ channels begin to open.

2. Early repolarization and plateau phases
• Na+ channels close.
• Some K+ channels open, causing early
• Ca2+ channels are open, producing the
plateau by slowing further repolarization.

3. Final repolarization phase
• Ca2+ channels close.
• Many K+ channels open.


31. Describe each of these electrical phases for an action potential and what happens during them.



32. How does the refractory period for cardiac muscle compare to that of skeletal muscle and why is this important to heart function?

* Skeletal muscle: Rapid AP & Rapid contraction.
* Short refractory period & short contraction
* Contractions can summate- produce Tetany


33. What type of tissue makes up the conducting system of the heart and what is its purpose?

Contraction of the atria and ventricles is coordinated by specialized cardiac muscle cells in the wall of the heart that form the conduction system of the heart.


34. Diagram and explain the electrical conduction system. Include the location and a description of the roles of the sino-atrial node, atrioventricular node, Bundle of His, bundle branches, Purkinje or conducting fibers.
How does the direction and timing of electrical conduction in the heart effect contractions and the ability to pump blood?

1) SA node- just below the Superior Vena Cava. It is the pacemaker and gets input from the Sympathetic and Parasympathetic nerves
2) AV node- is located at the Interatrial Septum. It is a relay station the ventricles and is a secondary pacemaker.
3) Bundle of His- is located in the interventricular septum. It is the only route from atria to ventricles. Carry signals to right and left ventricles.
4) Right and left bundle branches- are located in the interventricular septum and fans out deep to the endocardial surface. Moves impulse down the interventricular septum to the heart’s apex.
5) Purkinje Fibers- Located in the walls of the ventricles or the endocardium. Pick up impulse at apex and moves it up the along the sides of the ventricle. Triggers ventricular contractions.
Direction is important because if any of the atrial pathways are damaged, the heart beats at a slower rate and blood is not pumped as effectively. Timing must be synchronized for a stronger contraction that proples the blood.


35. What is an ECG/EKG and what can it tell us about the heart? What are the ECG leads?

Diagnostic of heart. A 360 picture of electrical events of the heart.

12 or 3 leads placed on the body.


36. Describe what happens during the:
P wave QRS complex T wave P-R interval and Q-T interval

P wave = Trigger atrial contraction . Atrial depolarization.

QRS complex- -Depolarization of the ventricles “sharp and fast”- Triggers ventricular contractions

T wave – Repolarize ventricles. Occur after ventricles contract . Ventricles relax.

P-R interval – Time it takes for the electrical signal to go from Atria to the verticals.

Q-T interval- Time for ventricle to depolarize.


37. Define systole and diastole.

Fibers shorten
Chamber pressure rising
Moves blood forward
Atrial and ventricular
Systole- seperate

Relaxation phase
Fibers lengthen
Chamber pressure falling/ low
Chambers re-fill
Atrial and Vintricular
Diastole seperate


38. Why are atrial and ventricular systole and diastole separate events?

Need separate events in order to allow time for chambers to fill and to maintain pressure. To move blood.


39. What is the cardiac cycle?

The period between the start of one heartbeat and the beginning of the next.


. Name the phases of the cycle and describe what is happening during each phase.

Atrial Systole-
“atrial kick”
In response to P wave events
Atria contract
Increase pressure
Blood to ventricals

Atrial Diastole-
Atria depolarize
Muscle cell relax
Decrease in pressure
Begin to refill with blood

Ventricular systole
Triggered by ventriclas Depolarization (QRS)
a) Isovolumetric phase- Contraction has started to increase pressure, all 4 valves closed blood not leaving yet.
b) Ejection phase- Continule contraction, increase pressure, now open semilunar valves, blood leaves ventricles “ejected”

Venticular systole continued:
Pressure in ventricles must exceed pressure in arteries, SL valves open (blood ejected)

Ventricular Diastole- early
Allows repolarization “t-wave”
Decrease pressure in ventricles
All valves closed
No blood moving
No volumetric phase

Ventricular Diastole- Late
Continue to decrease pressure
Av valves open
Blood flows passively to ventricles


Define: Contractility

Contractility- Amount of force produced during a contraction, at a given preload. Based on how much (ca+2) is available

Increase (ca+2) increase contractility, increase force, increase sv
Decrese (ca+2) decrease contractility, decrease force, decrease sv


Define: End Systolic Volume,
End Diastolic Volume, Stroke volume,

End Systolic volume- amount of blood left in the ventricles at the end of systole (ml). After contraction.

End Diastolic Volumne- The amount of blood in the ventricles just before contraction begins. How full is the ventricle is prior to contraction – measured in ml.

Stroke volumne- Amount of blood ejected from each ventical during contraction


* Define Isovolumetric Contraction

Isovolumetric Contraction- Heart valves closed , volumes of ventricals change, increase in pressure


41. Define: Ventricular ejection

Ventricular ejection- Pressure in ventrical exceeds that – muscle cells of atrial trunk, sl valves open, tention production remain constant.


42. How do we determine stroke volume for someone?

End diatoilic volume – end systolic volume= sv

- Body size, age, gender, all factors


43. What are the 4 normal heart sounds and what causes each one?

S1- Tri/bicuspid
S-> AV valves close as ventricles begin contracting. “Lubb”

S2- SL valves close
Ventrical begins to relax

S3- AV valves open
Blood passively fills ventricles

S4- Atria contraction
Force/push last of blood decrease inbto venticles “atrial kick”
Active filling of ventricles.


44. ???What is the stroke volume formula and what does it mean?

The amount of blood ejected from each ventrical during a contraction.


45. What is cardiac output? 46. Be able to use the CO = SV x HR formula if given data!

The amount of blood pumped by the left ventricle in 1 min. HR X SV => CO


47. What is cardiac reserve and why is it important?

The period between the start of one heartbeat and the beginning of the next.


48. What are the three major factors that influence stroke volume?

Preload – Contractility – Afterload


49. Describe each factor of stroke volume and explain its influence on the stroke volume.

-PRELOAD: based on EDV= Increase EDV => increase preload
-Ventricle wall stretch
- How much blood in ventricles before it contracts.

-CONTRACTILITY: Strength of contraction of any given period.
- Based on Ca+2
-increase ca+2= increased force, contractility, and SV
-decrease ca+2= decreased force, contractility, and SV

-AFTERLOAD: The amount of pressure (Aortic trunk/Pulmonary trunk) needed to get the blood out of the arteries. “the amount of pressure the heart is working against.
- Force need to open SL valves.
- Decrease afterload = easier to eject blood => lower Bp
- Increase afterload = harder to eject blood => higher Bp


50. What are some things that influence each of these stroke volume factors?

Blood loss, blocked blood flow, an increase or decrease in both Bp
and Hr.


51. How does the autonomic nervous system influence heart rate?
Include - cardiovascular center, sympathetic and parasympathetic effects,

Through sympathetic and parasympathetic: ANS helps heart
Adjust to bodies needs.

Include - cardiovascular center, sympathetic and parasympathetic effects,
- Cardiovascular center: MEDULLA OBLONGATA – involuntary
- Influenced by Anticipation, Proprioceptors, Chemoreceptoers, and Baroreceptors.
- Sympathetic : increases Hr; stressful “fight or flight”
- SA, AV nodes receive rapid signals
-A) increase Hr
-B) increase contractility
- increase Ca+2 in cardiac muscle
- Dilates or constricts vessels
- Parasympathetic: decrease Hr
- Vagus nerve
- NO EFFECT on contractility or vessles
- returns system to normal


52. Define Tachycardia and Bradycardia

Tachycarida – Heart rate above 100 beats/ min
Normal: exercise or stress situations
Abmormal: at rest may indicate increase serious problems.

Bradycardia- Heart rate typically bellow 50 beats/min. Normal: well trained athletes some sleeping. Abnormal: most individuals in average to poor condition.


53. What hormones influence the heart rate and ability to contract?

Epi and Ne; T3 and T4; Glucagon


54. What are some of the other factors that influence your heart rate?
Include baroreceptors, proprioceptors, chemoreceptors, anticipation

Baroreceptors=> BP
Monitor internal receptors ex: stomach full

Ex: Sudden drop in BP Baroreceptors signal>CNS>CV Center>increase HR

Position, activity

decrease in O2 or increase in CO2


55. What role does exercise play in CV health?

- Increases SV
- Lower blood cholesterol
- Decrease risk of heart attack


56. Name factors that increase your risk of developing heart disease or other CV disorders?

Body size, genetics, age, gender, Fitness level, Body temperature, heart disease or damage, meds and drugs


57. Define and describe: Arrhythmia, atrial flutter, atrial fibrillation, ventricular fibrillation.

Arrhythmia- Irregular beating patterns.

Atrial flutter-Atrial flutter (AFL) is an abnormal heart rhythm that occurs in the atria of the heart

Atrial Fibrillation- (A-Fib) Decrease stroke volumne

Ventricular fibrillation- (V-Fib)- Stop circulation


58. Which is the most serious arrhythmia and why?

- Ventricular fibrillation V-Fib: Heart not pumping blood to the body.


60. What does MI stand for? What does this mean?

Myocardial infarction (MI). Commonly known as Heart Attack, interruption of blood supply to a part of the heart, causing heart cells to die. This is most commonly due to occlusion (blockage) of a coronary artery.


Define: Angina

Angina: is chest pain or discomfort you get when your heart muscle does not get enough blood.


Define Angioplasty

Angioplasty: is a procedure to restore blood flow through the artery.


59. Define: By-pass surgery

By-pass surgery: a blood vessel is removed or redirected from one area of the body and placed around the area of narrowing to "bypass" the blockages and restore blood flow to the heart muscle.


61. What is ischemia and why is it a problem?

An inadequate blood supply to an organ or part of the body, especially the heart muscles. Since oxygen is carried to tissues in the blood, insufficient blood supply causes tissue to become starved of oxygen. In the highly aerobic tissues of the heart and brain, irreversible damage to tissues can occur in as little as 3–4 minutes at body temperature. The kidneys are also quickly damaged by loss of blood flow.


1. Describe the three layers of tissue found in artery and vein walls.

Externa, Media and Interna.


2. How are the layers of tissues found in artery and vain walls similar and how are they different?
Define: elasticity, contractility, vasoconstrict, and vasodilate

Externa: FB connective tissue

Media: Artery Smooth Muscle and Elastic fibers. For veins smooth muscle only.

Interna: Simple squamous endothelium

Define: elasticity, contractility, vasoconstrict, and vasodilate

Elasticity: The condition or property of being elastic; flexibility

Contractility: contractility represents the intrinsic ability of the heart/myocardium to contract

Vasoconstrict: Vasoconstriction is the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels

Vasodilate: Vasodilation refers to the widening of blood vessels resulting from relaxation of smooth muscle cells within the vessel walls.


3. What are some of the major characteristics of arteries?



4. What are the three categories of arteries – how are they alike and how do they differ?

Arteries don't have valves while veins have valves and the blood flows slower,smoother and at low pressure in veins than in arteries. All arteries except pulmonary artery carry oxygenated blood while all veins except pulmonary vein carry deoxygenated blood. Arteries carry blood away from the heart to the rest of the body while veins carry blood to the heart away from the rest of the body.


Define: Coronary artery disease

Blockage in arteries that feed the heart- often few symptoms in early stages.


Define: Aneurysm

An aneurysm is an abnormal widening or ballooning of a portion of an artery due to weakness in the wall of the blood vessel.

Common locations for aneurysms include:
•The major artery from the heart (the aorta)

•The brain (cerebral aneurysm)

•In the leg behind the knee popliteal artery aneurysm)

•Intestine (mesenteric artery aneurysm)

•An artery in the spleen (splenic artery aneurysm)

High blood pressure, high cholesterol, and cigarette smoking may raise your risk of certain types of aneurysms. High blood pressure is thought to play a role in abdominal aortic aneurysms.


5. Define: arteriosclerosis

Hardening of the arteries, also called atherosclerosis, is a common disorder. It occurs when fat, cholesterol, and other substances build up in the walls of arteries and form hard structures called plaques.


6. Name and describe the different varieties of arteriosclerosis and list some contributing factors to their development.

Over time, these plaques can block the arteries and cause problems throughout the body.

Hardening of the arteries is a process that often occurs with aging. As you grow older, plaque buildup narrows your arteries and makes them stiffer. These changes make it harder for blood to flow through them.

Clots may form in these narrowed arteries and block blood flow. Pieces of plaque can also break off and move to smaller blood vessels, blocking them.

Either way, the blockage starves tissues of blood and oxygen, which can result in damage or tissue death.This is a common cause of heart attack and stroke.


7. Describe the structure of a capillary wall.
Why is this structure important to the function of the capillaries?
Describe and contrast continuous capillaries and fenestrated capillaries.

Wall- Single squamous cell thick
Very permeable
Exchange vessels

Continuous: More common simple squamous endothelium. Controlled movement in/out

Fenetrated: live & kidneys, more permeable, greater exchange


8. What is a pre-capillary sphincter and what does it do?

The precapillary sphincter is a band of smooth muscle that adjusts the blood flow into each capillary. At the point where each true capillary originates from an arteriole, a smooth muscle fiber usually encircles the capillary. This is called the precapillary sphincter. This sphincter can open and close the entrance to the capillary. Blood flow in a capillary changes as vasomotion occurs


9. Define the terms: arterial anastomosis, sinusoid and venous sinus

Arterial anastomosis: is a connection (an anastomosis) between two blood vessels, such as between arteries (arterio-arterial anastomosis), between veins (veno-venous anastomosis) or between an artery and a vein (arterio-venous anastomosis). Such anastomoses occur normally in the body in the circulatory system, serving as backup routes for blood to flow if one link is blocked or otherwise compromised, but may also occur pathologically.

Sinusoid: is a small blood vessel that is a type of capillary similar to a fenestrated endothelium. Sinusoids are actually classified as a type of Open Pore Capillary (aka discontinuous) as opposed to fenestrated

Venous sinus: (also called dural sinuses, cerebral sinuses, or cranial sinuses) are venous channels found between layers of dura mater in the brain.[1] They receive blood from internal and external veins of the brain, receive cerebrospinal fluid (CSF) from the subarachnoid space, and ultimately empty into the internal jugular vein.


10. Describe the structure and function of the veins and venules.

Veins are blood vessels which carry deoxygenated (or very low levels of oxygen) blood back to the heart. The exception to this rule is the pulmonary vein, which carries oxygenated blood, from the lungs, back to the heart, ready to be pumped around the rest of the body.

Venules: Venules are blood vessels that drain blood directly from the capillary beds. Venules very small blood vessel in the microcirculation that allows blood to return from the capillary beds to the larger blood vessels called veins.


11. Why do some of the larger veins have valves in them?

Larger Veins have valves because venous pressure is often not great enough (as the blood must overcome gravity and other forces) to return the blood to the heart. To prevent the back flow to the heart then It might cause Heart attack. Usually Larger veins have higher pressure and without back flow it could cause us heart attack.


12. Define the terms varicose veins and hemorrhoids.

Varicose veins: Varicose veins are swollen, twisted, and sometimes painful veins that have filled with an abnormal collection of blood. Symptoms: Fullness, heaviness, aching, and sometimes pain in the legs; Visible, swollen veins

Hemorrhoids: Hemorrhoids are painful, swollen veins in the lower portion of the rectum or anus. Symptoms of hemorrhoids include: Anal itching; Anal ache or pain, especially while sitting; Bright red blood on toilet tissue, stool


13. What is the pattern of distribution of blood in the different vessels?

Pulmonary Circuit (10-20%)
Pick up O2 Deoxygenated
Remove Co2 Oxygenated

Sytemic Circuit (80-90%)
Drop off O2 Deoxygentaed
Pick up co2 Deploarize


14. What do we mean by venous reserve?

Ability to shift blood from systemic veins to other parts of circulatory pathway when needed.


15. What does the term hemodynamics mean and why is it important?

Hemodynamics means movement of blood.

Hemodynamics is an important part of cardiovascular physiology dealing with the forces the pump (the heart) has to develop to circulate blood through the cardiovascular system. Adequate blood circulation (blood flow) is a necessary condition for adequate supply of oxygen to all tissues, which, in return, is synonymous with cardiovascular health, survival of surgical patients, longevity and quality of life.


Define: blood pressure

Force against walls of systemic arteries. Measured in mmHg.Arterial pressure.


Define: resistance (R)

The force opposing blood flow.


Define: Stroke volume

Stroke volume: stroke volume (SV) is the volume of blood pumped from one ventricle of the heart with each beat


16. Define : heart rate

Heart rate: is the number of heartbeats per unit of time, typically expressed as beats per minute (bpm)


17. Cardiac Output is influenced by stroke volume, heart rate, blood pressure and resistance.
18. How does each of these influence the cardiac output?
19. How do these factors interact with each other?

Cardiac output (Q or CO ) is the volume of blood being pumped by the heart, in particular by a left or right ventricle in the time interval of one minute. Q is furthermore the combined sum of output from the right ventricle and the output from the left ventricle during the phase of systole of the heart


20. Define, compare and contrast: Hydrostatic pressure, blood pressure, and circulatory pressure

hydrostatic pressure (hdr-sttk)-
The pressure exerted by a fluid at equilibrium at a given point within the fluid, due to the force of gravity. Hydrostatic pressure increases in proportion to depth measured from the surface because of the increasing weight of fluid exerting downward force from above.

Blood pressure (BP-,
Sometimes referred to as arterial blood pressure, is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs.

Circulatory Pressure-

•Circulatory pressure is divided into three components

•Blood pressure (BP)

•Capillary hydrostatic pressure (CHP)

•Venous pressure


21. Name the 4 major factors that influence resistance to blood flow and describe each one.

22. Which of these factors is typically the most important in influencing the blood pressure?

1. Blood viscosity-
- thickness
Changes gradually
Increase viscosity (thickness)
Increase to Resistance

Example #2:
-add more cells
Decrease Viscosity
Decrease Resitance

2. Turbulence- (think water-rafting)

Example 1: Smooth vessel, Low turbulence, Low resistance

Example 2: Increase turbulence, Increase in resistance- *Change gradual

3. Total blood vessel length = 70,000 miles

Example 1: Increase weight-> Increase blood vessel length ->then increase resistance.

Example 2: Lower weight->Decrease blood vessels
->Decrease resistance (gradual)

4. Blood vessel radius-

R= Resistance r=radius

R= 1/r4 Inverse relationship
Artery starting r=1mm

R=1/14 =1/1= 1< starting resistance level

Artery dialates r=2mm
R=1/2 (power of 4 { 2*2*2*2}) =1/16 <R is 1/16th Starting level (easier to move then)

Artery contricts= r=1/2 mm
R=1/ ½ (power of 4)= 1/ 1/10 = 16< R is 16 times the starting level (harder to move threw.)

The variable with the greatest effect on resistance is the diameter (or radius, 1/2 the diameter) of a particular vessel - resistance drops exponentially as the radius increases.
Radius, Controls how big or small


23. Which blood vessels provide the most resistance and why?

A. They distribute blood to various parts of the body.
B. They contain a large quantity of elastic tissue.
C. The contraction and relaxation of the smooth muscle in their walls can change their diameter.
D. Their prime function is the exchange of nutrients and wastes between the blood and tissue cells.


24. What units do we use when measuring blood pressure? How do we write them out?

Blood pressure is measured in millimeters of mercury (mmHg) and recorded as two numbers -- systolic pressure "over" diastolic pressure. For example, the doctor or nurse might say "130 over 80" as a blood pressure reading. This is written as 130/80.


25. Define Systolic pressure and Diastolic pressure.

Diastolic blood pressure- the minimum level of blood pressure measured between contractions of the heart.

It may vary with age, gender, body weight, emotional state, and other factors.

Systolic- the pressure exerted on the bloodstream by the heart when it contracts, forcing blood from the ventricles of the heart into the pulmonary artery and the aorta.


26. Blood pressure when the heart is resting between beats.

Resting Heart Rate (RHR) is the rate at which your heart beats when you are at rest. The best time to measure RHR is right after you naturally wake up in the morning, without an alarm. Generally, the lower a person's RHR is, the more fit that person is because the heart doesn't have to work as hard. The heart usually beats between 60-80 times per minute while at rest.


27. How do we determine pulse pressure (formula)? What is pulse pressure?

Systolic Pressure (mmHg)
- Diastolic Pressure (mmHg)
Pulse Pressure (mmHg)

Answer: 118-70= 48 mmHg pulse pressure

• Example: 30-50 mmHg good pulse pressure


28. How do we determine Mean Arterial Pressure (formula)?

It is calculated by adding one-third of the pulse pressure to the diastolic pressure.


29. Why is mean arterial pressure clinically important?

Because when pressures shift outside the normal range, clinical problems can develop.


30. What is hypertension and why is it clinically important?

31. What types of problems does it cause for people who have it?

32. What diseases or problems does it increase the risk of?

Hypertension is abnormally high blood pressure and it is clinically important because it increases the workload on the heart, enlarging the left ventricle, resulting in multiple problems.

The heart demands a greater need for oxygen, coronary circulation cannot keep pace, signs and symptoms of coronary ischemia appear. Increased arterial pressure also stresses the walls of blood vessels through the body. This stress promotes the development of arteriosclerosis.

Some diseases of increased risk are: Arteriosclerosis, coronary ischemia, aneurysms, heart attacks and strokes.


33. Distinguish between primary hypertension and secondary hypertension.

Primary: For most adults, there's no identifiable cause of high blood pressure. This type of high blood pressure, called essential hypertension or primary hypertension, tends to develop gradually over many years.

Secondary: Some people have high blood pressure caused by an underlying condition. This type of high blood pressure, called secondary hypertension, tends to appear suddenly and cause higher blood pressure than does primary hypertension.


34. What is hypotension and why is clinically important?
What are some of its causes?

Hypotension is abnormally low blood pressure. Important because systems may not get enough O2 or nutrients delivered to tissues and is usually associated with high volume blood loss.


35. What is orthostatic hypotension?

Orthostatic hypotension is a form of hypotension in which a person's blood pressure suddenly falls when standing up or stretching. The symptom is caused by blood pooling in the lower extremities upon a change in body position. Also known as a head rush or a dizzy spell.


36. What is capillary exchange?

37. What are some of the different ways that materials are exchanged (give examples for each)

Exchange of nutrients, gases, waters, ions, etc.

Blackboard: Materials in/out of blood.
Interstitial fluid
ECI- of tissues

• Exchange between blood & interstitial fluid.
• Critical to normal body functioning.

Some exchange uses active transport  Burn ATP

Most exchange – Passive Transport
 Energy needed, Not ATP
 NOT from cells.


38. Compare and contrast filtration and reabsorption. Why is each important?

Filtration- out of blood
Reabsorption- back into blood


39. How does material that isn’t reabsorbed end up being returned to the vessels?



40. What is net filtration pressure? Why does it change from one end of a capillary bed to the other? What does this change cause?



41. Define edema and give examples of situations that might cause it.

Build up of interstitial fluid producing swelling.

Ex: think swelling in foot or/and legs

Increased BP, Blocked lymph flow, Histamine (inflamation, swelling), kidney damage


42. Define venous return.

Help us to bring blood back

*Bring to R atrium
*Pressure gradients
*Skeletal muscle pumps
*Respitory pump


43. Explain how the skeletal muscle and respiratory pumps assist venous return.

Venous valves: Prevent backflow, minimize pooling, keep blood moving back to heart.

The Order:
1. valves, fail/weaken
2. blood pools
3. vein expands


44. What roll do pressure differences play in venous return?



45. What is autoregulation of blood flow?

Autoregulation is a manifestation of local blood flow regulation. It is defined as the intrinsic ability of an organ to maintain a constant blood flow despite changes in perfusion pressure. For example, if perfusion pressure is decreased to an organ (e.g., by partially occluding the arterial supply to the organ), blood flow initially falls, then returns toward normal levels over the next few minutes. This autoregulatory response occurs in the absence of neural and hormonal influences and therefore is intrinsic to the organ. When perfusion pressure (arterial minus venous pressure, PA-PV) initially decreases, blood flow (F) falls because of the following relationship between pressure, flow and resistance:


46. What are some of the factors that influence autoregulation mechanisms?



47. What are Vasodilators? What are some of the triggers that promote their release?

Increase local circulation. Open pre-capillary sphincters.

Triggers: decrease O2 and increase in CO2, Warmth

Example on Board:
Vasodilation-> open
Increase vessel diameter & Flow thru vessel
decrease resistance & decrease BP, making it easier.


48. What are Vasoconstrictors? What are some of triggers that promote their release?

Decrease local circulation ->> below normal range

Example on Board:
Decrease vessel diameter & flow thru vessel.
Increase resistance & increase BP


49. Where is the cardiovascular control center in the brain?

Medulla Oblongata


50. What type(s) of nerve fibers run to the heart? What does each type do?



51. What type(s) of nerve fibers run to the blood vessels? What do they do?



52. How do nerve signals effect heart rate, contractility, vessel diameter and resistance to flow?



53. . What is a baroreceptor? Where are they located? What do they do?

Baroreceptors monitor pressure changes sensitive to stretching of vessels of heart chambers.

Increase pressure -> Increase stretching-> Signal CNS -> Increase BP

Decrease in pressure-> Decrease stretching -> signal CNS -> Decrease BP

Sense stretching changes= pressure changes.
• Aortic baroreceptors: Systemic BP
• Carotid baroreceptors: BP to brain
• R. Atrium, Vena Cavae baroreceptors

Also baroreceptors on end of systemic pathway


54. What chemicals do chemoreceptors associated with cardiovascular control monitor?

Chemoreceptors alert CNS to:
Increase or decrease CO2
Increase or decrease H+


* Increase CO2 and Increase H+ --> Acidosis Decrease PH -> Increase in HR

* Decrease and Decrease in H+ --> Alkalosis --> Increase PH--> Decrease in HR


54. Where are some of the chemoreceptors located?
What are they more sensitive to - low O2 or high CO2?

Chemoreceptors Alert CNS to change in the levels in CO2, O2 AND H+. Receptors in Medulla Oblongata. High CO2 + High H+= Acidoss Low PH
Low CO2 + H+ = Alkalosis High PH. Decreased O2 would cause Hypoxia.


55. Which hormones are involved with controlling the blood pressure?
For each: Give targets and list effects the hormone has on blood pressure or blood flow.

1. Epinephrine & Norepinephrine
2. Antidiuretic Hormone (ADH)/Vasopressin (AVP)
3. Angiotensin 2
4. Aldosterone
For each: Give targets and list effects the hormone has on blood pressure or blood flow.

1. Epinephrine & Norepinephrine: Raise BP COMES from (Medulla) Effects of increased sympathetic stimulation Activates cardiac muscle. Turn on Vasomotor units it dilates lungs muscles and constricts
2. Antidiuretic Hormone helps to raise BP. Posterior Pituitary gland. Low H2O in urine Antidiuretic. Return H20 blood Raise Blood volume that Raise BP
3. Angiotensin 2: Hypothalamus, HighThirst, Drink High Blood volume then High BP.
4. Aldosterone: Adrenal Cortex, Action Signal Kidneys Return NA+ h20 follow NA+ back into blood High Blood volume High BP.


* Describe the following circulatory sub-systems: (Inc. structures, purpose and unique features)
Pulmonary circulation,

Pulmonary Circulation: Designed to oxygenate the blood 10-20% blood in circulation.


*56. Describe the following circulatory sub-systems: (Inc. structures, purpose and unique features)
systemic circulation

Systemic Circulation: Carries O2 and nutrients to tissues, removes CO2 and wastes. 80-90% blood in circulation.


56. Describe the following circulatory sub-systems: (Inc. structures, purpose and unique features)
hepatic portal circulation

Hepatic Portal Circulation: Collects venous blood from the G1 tract and spleen routes through liver before returning to heart.


56. Describe the following circulatory sub-systems: (Inc. structures, purpose and unique features)
cerebral circulation

Cerebral Circulation:
2 Vertebral Arteries – brainstem, cerebellum, occipital lobe
2 internal Carotid – anterior portions of brain and eyes
Shunt (anastomosis) at base of cerebrum
Venous blood leaves brain: Venous sinuses into Internal Jugular veins


Action potentials generated by the autorhythmic cells spread to the contractile cells through what structures in the membrane?

gap junctions

^Yes, action potentials generated by the autorhythmic cells spread waves of depolarization to contractile cells through gap junctions. If the depolarization causes the contractile cells to reach threshold, they will in turn generate an action potential.


The pacemaker potential (unstable resting membrane potential) in the SA node (an autorhythmic cell) is due to a decreased efflux of what ion?


^Yes, if there is a decreased efflux of potassium while there is a normal influx of sodium, the inside of the cell would become less negative. Thus, threshold would be reached. The ability of these autorhythmic cells to spontaneously depolarize is what results in the pacemaker potential.


When threshold is reached at the SA node (an autorhythmic cell), what channels open causing further depolarization of the membrane?

fast calcium

^Yes, unlike nerve cells or cardiac muscle cells, fast calcium channels are responsible for the depolarization phase of the autorhythmic cell action potential. When the fast calcium channels open, calcium rushes into the cell making it less negative (or more positive).


Repolarization of an autorhythmic cell is due to the opening of which channels?

voltage-gated potassium channels

^Yes, opening of voltage-gated potassium channels causes positive potassium ions to move out of the cell. This efflux of potassium causes the cell to become more negative inside thus, repolarizing the cell.


In order to cause cardiac muscle contraction, the contractile cells must also depolarize. What causes the depolarization of the contractile cells?

the flow of positive ions from adjacent cells

^Yes, the flow of positive ions from the autorhythmic cells (or adjacent cells) brings the membrane to threshold initiating depolarization of the contractile cell.


Which part of the conduction system initiates the depolarizing impulse, which spreads throughout the heart?

SA node

^Yes, the SA Node spontaneously depolarizes, causing the wave of depolarization that spreads through the rest of the conduction system and heart.


Contraction of the atria results from which wave of depolarization on the ECG tracing?

P wave

^Yes, the P wave represents atrial depolarization, which leads to atrial contraction.


Which part of the intrinsic conduction system delays the impulse briefly before it moves on to the ventricles?

AV node

^Yes, the AV node slows down the impulse giving the atria time to contract before the ventricles contract.


What is the relaxed state of the ventricle called?


^The resting state of the atrium or ventricle is referred to as diastole. The heart chambers are in diastole for the majority of the cardiac cycle.


The one-way nature of the left AV valve prevents blood flow from _________.

the left ventricle to the left atrium

^The atrioventricular valves are one-way valves that allow blood to flow into the ventricle but prevent blood flow back into the atrium. This maintains the movement of blood forward, toward the systemic circulation.


The closing of the left AV valve occurs near the beginning of __________.

ventricular systole

^Ventricular systole is the contraction of the ventricle. This causes the pressure within the ventricle to quickly rise above that in the atrium, which in turn causes the AV valve to close. The closed AV valve ensures that blood is ejected into the aorta and not back into the atrium.


The majority of ventricular filling occurs while the ventricles and atria are in what state(s)?

ventricular and atrial diastole

^The majority of ventricular filling occurs while both the ventricle and atrium are relaxed - while both chambers are in diastole. Ventricular filling also occurs during atrial systole, but this phase only contributes about 30 percent to ventricular filling.


The volume of the ventricle when it is most full ?

describes end-diastolic volume

^The end-diastolic volume is the ventricular volume at the end of ventricular diastole. At this point, all ventricular filling (including that from atrial systole) has occurred, and the ventricular volume is maximal.


Left ventricular filling occurs __________.

while the AV valve is open

^The AV valve allows blood to flow in one direction - from the atrium to the ventricle. Because the ventricle is filled with blood from the atrium, this valve must be open to fill the ventricle.


Heart valves are in what state during isovolumetric contraction?

The AV valves and semilunar valves are closed.

^Isovolumetric contraction is the brief period of time at the beginning of ventricular systole where both the AV valves and semilunar valves are closed. Because these closed valves prevent blood from exiting the ventricles, the volume of the ventricles stays the same despite contraction of the heart muscle. This period of contraction is quite brief - lasting less than 20 msec or about 2 percent of the full cardiac cycle.


The decrease in left ventricular pressure at the end of ventricular systole causes __________.

the semilunar valve to close

^The semilunar valve closes when left ventricular pressure drops below aortic pressure. This occurs at the end of ventricular systole and marks the end of ventricular ejection. Blood in the aorta collects in the cusps of the semilunar valve and holds the valve shut while pressure in the ventricle continues to decrease and ventricular diastole begins.


Ventricular diastole begins with the closing of the semilunar valves. What phase of the cardiac cycle happens between this event and the later opening of the AV valves?

isovolumetric relaxation

^The prefix iso- means "same" so this is a period of "same volume". While the semilunar valve and AV valve are both closed, blood may not enter nor exit the ventricle. Therefore ventricular volume remains constant during this time. This period of relaxation is quite brief - lasting less than 20 msec or about 2 percent of the full cardiac cycle.


Isovolumetric relaxation and ventricular filling (two phases of the cardiac cycle) take place during __________.

ventricular diastole

^Yes, both occur during ventricular diastole when the ventricles are not actively contracting and ejecting blood.


Describe the pressures in the atria and ventricles that would cause the opening of the AV valves.

Pressure in the atria would be greater than the pressure in the ventricles.

^Yes, higher pressure in the atria than in the ventricles forces the AV valves to open and blood moves into the ventricles.


What causes the aortic semilunar valve to close?

greater pressure in the aorta than in the left ventricle

^Yes, backflow of blood in the aorta (towards the left ventricle) closes the aortic semilunar valve.


Put the phases of the cardiac cycle in the correct order, starting after ventricular filling.

isovolumetric contraction, ventricular ejection, isovolumetric relaxation

^Yes, the ventricles must contract and eject blood before they relax and fill again.


Increased pressure in the ventricles would close what valve(s)?

AV valves only

^Yes, increased pressure in the ventricles would close the AV valves.


Which of the following would increase cardiac output to the greatest extent?

increased heart rate and increased stroke volume

^Yes, cardiac output = heart rate x stroke volume.


Which of the following would increase heart rate?

epinephrine and norepinephrine

^Yes, secreted by the adrenal medulla as a result of sympathetic stimulation, these hormones act as part of the sympathetic response, increasing heart rate.


How would an increase in the sympathetic nervous system increase stroke volume?

increased contractility

^Yes, an increase in sympathetic nervous system activity would increase contractility (by increasing available calcium), thus increasing stroke volume. Contractility causes an increase in stroke volume by decreasing end systolic volume; it does not change end diastolic volume.


By what mechanism would an increase in venous return increase stroke volume?

increased end diastolic volume

^Yes, an increase in venous return increases the end diastolic volume. The fibers are stretched more, resulting in an increase in the force of contraction (preload, or the Frank-Starling Mechanism).


How would a decrease in blood volume affect both stroke volume and cardiac output?

decreased stroke volume and no change in cardiac output

^Yes, a decreased blood volume would decrease the end diastolic volume, thus lowering the stroke volume. Although this would initially lead to a decrease in the cardiac output, heart rate would increase because of increased activity of the sympathetic nervous system in an effort to maintain cardiac output.


In the capillaries, hydrostatic pressure (HP) is exerted by __________.

blood pressure

^Yes, blood pressure is the driving force for filtration.


The net hydrostatic pressure (HP) is the hydrostatic pressure in the __________ minus hydrostatic pressure in the __________.

capillary; interstitial fluid

^Yes, the capillary hydrostatic pressure (HPC; caused by blood pressure) is much higher than the interstitial hydrostatic pressure (HPI). The interstitial fluid is forced out of the capillaries.


The colloid osmotic pressure in the capillary is caused by __________.

proteins in the blood

^Yes, the non-diffusible proteins in the plasma exert the colloid osmotic pressure, which pulls fluid into the capillary.


Which net pressure draws fluid into the capillary?

net osmotic pressure

^Yes, the proteins exert colloid osmotic pressure, which draws fluid into the capillary.


Reabsorption of fluid into the capillary takes place at the arterial end or venous end of the capillary?


^Yes, because the hydrostatic pressure of blood (which favors filtration out of the capillary) is lowest in the venous end of the capillary.


Arteries __________.

carry blood away from the heart


The innermost layer of an artery or vein is called the __________.

tunica intima or tunica interna


Fenestrated capillaries are found __________.

in the choroid plexus and kidneys


Capillaries __________.

function as parts of a capillary plexus


The pattern of blood flow through a capillary bed is influenced by __________.

both sympathetic innervation and parasympathetic innervation


Chemical and gaseous exchange takes place __________.

only across capillary walls


In general, the walls of arteries are thinner than the walls of veins. True or False?



Capillaries that have small pores in their endothelium are called __________.

fenestrated capillaries


Small intestines contributes to the venous reserve True or false? __________.



A new recruit in the armed forces stands at attention on a hot afternoon. He decides to lock his knees, thinking it will make the standing easier. After a short while, he faints. What has occurred?

He did not use muscular compression to help return blood to the heart; thus, his brain did not receive enough oxygenated blood, causing him to pass out.


Arteries demonstrate a pattern of _____________, whereas veins demonstrate ________________.

divergence; convergence


What does NOT affect the resistance found in arteries? __________.

presence of valves


The pulse pressure of an artery is __________.

the difference between systolic and diastolic pressures


Mean arterial pressure __________ as arterial branches become smaller.



The process by which materials leave the capillary at the arterial end is called ______________, and the entry of materials into the capillary at the venous end is called ________________.

filtration; reabsorption


The blood colloid osmotic pressure drives the process of __________.



Pulmonary veins carry blood ____________ the heart, and this blood is _________________.

toward; oxygenated


The three large arteries originating from the aortic arch are the __________.

brachiocephalic, left common carotid, and left subclavian arteries


The internal carotid arteries supply blood to the __________.



The superior sagittal sinus is located in the __________ and drains blood from the __________.

falx cerebri; brain


Blood that drains from the brain into the transverse sinus flows into the __________.

internal jugulars


The popliteal vein is a ___________ vein that passes blood into the ______________ vein.

deep; femoral


In which of the following locations is the pulse NOT commonly taken?

external jugular vein


In fetal development, the connection between the right atrium and left atrium, which closes by birth, is called the __________.

foramen ovale


What structures close or constricts at birth?

foramen ovale and ductus arteriosus


As you proceed from the aorta toward the capillaries, blood pressure falls rapidly as the result of an increase in __________. (Use three words.)

cross-sectional area


The driving force for filtration at the capillaries is __________. (Use two words.)

hydrostatic pressure


Baroreceptor reflexes respond to changes in blood pressure and __________ reflexes monitor changes in the chemical composition of arterial blood.



If a capillary is damaged, and dissolved proteins and formed elements leak into the interstitial fluid, the ICOP would be raised. This elevation of the ICOP would produce localized __________.




The pituitary hormone released in response to a decrease in blood volume and an increase in osmotic pressure is __________.

ADH- Antidiretic hormone