Chapter 21 Blood Vessels
Arteries are sometimes called the _______ vessels of the cardiovascular system because they have a strong-resilient tissue structure.
________ have the thickest tunica media.
The outermost wall of an artery or vein is called the _________, and in large arteries and veins contains the _____________.
tunica exerna; vasa vasorum
Most blood is in the ___________.
Vasomotion is associated with the presence of ___________.
smooth muscle in the tunica media
Varicose veins are caused by __________.
failure of the venous valves
What is the mean arterial pressure for a person with 110 and 65 mm Hg as systolic and diastolic pressure, respectively?
80 mm Hg
The velocity of blood flow decreases when ______________.
The medullary ischemic reflex results in ________________.
increased circulation to the brain.
___________ has the most important effect on blood velocity.
Reactive hyperemia is a result of ____________ to increase perfusion in a tissue.
Blood pressure does not increase by ________.
atrial natriuretic peptide.
The vasomotor center of the __________ controls blood vessels throughout the body.
Hypertension is commonly considered to be a chronic resting blood pressure higher than __________.
_____________ are powerful vasoconstrictors, and _________________ also increases heart rate.
epinephrine and angiotensin II; epinephrine
____________ is not a mechanisms of movement through the capillary wall.
The most important force driving filtration at the arterial end of a capillary is ____________________.
blood colloid osmotic pressure
___________________ by the capillaries at their venous end.
Waste products are taken up
The most important force driving reabsorption at the venous end of a capillary is _____________________.
blood colloid osmotic pressure
________________ do not lead to edema.
________________ would not increase capillary filtration.
A mean arterial pressure (MAP) below 60 mm Hg can cause _____________, whereas a MAP above 160 mm Hg can cause _________.
syncope; cerebral edema
_______________ does not contribute to venous return.
______________ shock can be produced by hemorrhage, severe burns, or dehydration.
__________ shock occurs when bacterial toxins trigger vasodilation and increase capillary permeability.
A bee sting can trigger a massive release of histamine, which causes __________ and a(n) ___________ in arterial blood pressure.
Myocardial infarction can lead to _________ shick.
The most important force in venous flow is _______________.
the pressure generated by the heart
Blood flow to the ____________ remains quite stable even when mean arterial pressure (MAP) fluctuates from 60 to 140 mm Hg.
Pulmonary arteries have ________ blood pressure compared to systemic arteries.
How many pulmonary arteries empty into the right atrium of the heart?
The lungs receive a systemic blood supply by way of the _______________.
There are no ______________ in humans.
right and left brachiocephalic arteries
The _______________ supplies 80% of the cerebrum.
internal carotid artery
The cerebral arterial circle (Circle of Willis) is ______________.
an anastomosis surrounding the pituitary gland
From the superior to inferior, the major branches of the abdominal aorta are:
celiac trunk, superior mesenteric artery, renal arteries, gonadal arteries, inferior mesenteric artery, and common iliac arteries.
The principal venous drainage of the thoracic organs is accomplished by way of ______________.
the azygos system
The _________ are not a contributor of the inferior vena cava.
The _________________ is the longest vein, and portions of this vein are commonly used as grafts in coronary bypass surgery.
great saphenous vein
What are the 3 layers of the blood vessel:
tunica interna, tunica median tunica externa
The innermost layer, adjacent to lumen
The middle layer, smooth muscle and elastic fibers
The outermost layer, adjacent to surrounding tissue
thick-walled, muscular, and elastic, conduct blood at high pressure, and have a pulse
thin-walled, conduct at low pressure, contain many valves to prevent backflow, have no pulse
_____________ carry blood away from the heart to the tissues
Elastic, which allows them to absorb the pressure created by ventricles of the heart as they pump blood into the arteries.
the walls of arteries
Arteries can regulate their diameter because of the _______________ in the tunica media.
Name the types of arteries
elastic arteries, muscular arteries, and arterioles
Features of the elastic arteries (conducting arteries) are
large diameter, more elastic fibers, less smooth muscle, function as pressure reserviors
Features of the muscular arteries (distributing arteries) are
medium diameter, more smooth muscle, fewer elastic fibers, distribute blood to various parts of the body
Features of the arterioles are
abundant microscopic, vessels that regulate the flow of blood into the capillary networks of the body's tissues.
Arterioles play a key role in _______________ blood flow from arteries into capillaries by regulating _________.
The transfer of substances (by-products and waste) between interstitial fluid surrounding each cell and the blood flowing past the cells in the capillaries
Microscopic vessels that usually connect arterioles and venules
Composed of a single layer of cells and a basement membrane
The exchange of nutrients and wastes between blood and tissue cells happen because the
capillary walls are so thin
___________ branch to form an extensive capillary network throughout the tissues and are found near almost every cell in the body
Name the types of capillaries
continuous, fenestrated, sinusoids
___________ are small vessels that are formed by the union of several capillaries
____________ drain blood from the _____________ in the veins
An ___________ is the union of the branches of 2 or more arteries supplying the same region of the body
Anastomes union provides an _______________ for blood flow
Arteries that do not form anastomosis are known as
When an end artery is blocked, blood cannot get to that particular region of the body. What can occur?
Necrosis is _________ of a segment that blood doesn't reach
Veins are formed from union of several _________.
Compared to arteries, veins have thinner tunica interna and media and ____________ tunica externa.
Veins have less ___________ tissue and less ________ muscle than arteries
Veins contain __________
At rest, the largest portion of the blood is in ___________________ and ________________, which are considered "blood reservoirs".
systemic veins; venules
Blood flow during exercise _______________ perfusion of the lungs, myocardium, and skeletal muscles, and _____________ perfusion of the kidneys and digestive tract.
During capillary exchange, substance cross capillary walls by
diffusion, transcytosis, and bulk flow
The most important mechanism of the capillary exchange is
4 bulk flow factors are
blood hydro-static pressure, blood colloid osmotic pressure, interstitial fluid osmotic pressure and interstitial fluid hydro-static pressure
The difference between net hydrostatic pressure and net osmotic pressure is
net filtration pressure
An abnormal buildup of fluid in the capillary results in swelling known as
Substances such as oxygen, cardon dioxide, glucose, amino acids, and some hormones cross capillary walls via
Large, lipid-insoluble molecules (like insulin) cross capillary walls in vesicles via
Bulk flow is a passive process in which large numbers of _______, _______, or ________ in a fluid move together in the same direction
ions, molecules or particles
Bulk flow occurs from an area of __________ pressure to an area of _______ pressure, and it continues as long as a pressure difference exists.
Filtration is a _________________ movement of fluid and solutes from blood capillaries into interstitial fluid.
_____________ is pressure-driven movement of fluid and solutes from the interstitial fluid into blood capillaries.
Interstitial fluid hydrostatic pressure (IFHP) and blood colloid osmotic pressure (BCOP) promote
Under normal conditions, the volume of fluid and solutes reabsorbed is almost as large as the volume filtered is called
Starling's Law of the capillaries
___________ is the volume of blood that flows through any tissue in a given time period (in mL/min)
Total blood flow is
cardiac output (CO)
Cardiac output equation
heart rate (hr) x stroke rate (sv)
Contraction of the ventricles generates
blood pressure (BP)
___________________ is the opposition to blood flow due to friction between blood and the walls of blood vessels
Vascular resistance (R)
________ the volume of blood flowing back to the heart through the systemic veins
Venous Return (VR)
___________ is an inadequate CO (cardiac output) that results in failure of the CV system to meet the metabolic demands of body cells
Name the types of shock
hypovolemic, cardiogenic, vascular, obstructive
Shock resulting from blood or fluid loss
Shock caused by inadequate function of the heart, or pump failure
Shock from extreme vasodilation and decreased peripheral resistance
Shock that occurs when there is a block to blood flow in the heart or great vessels, causing an insufficient blood supply to the body's tissues
Activation of the renin-angiotensin-aldosterone system; secretion of anti-diuretic hormone; activation of the sympathetic division of the ANS; release of local vasodiliators
Homeostasis response to shock
Blood vessels develop from isolated masses of ____________ in the mesoderm called _________________
mesenchyme; blood islands
Normal blood pressure
less than 120/80 mm Hg
Pre hypertension blood pressure
120-139/80-89 mm Hg
Stage 1 hypertension
140-159/90-99 mm Hg
Stage 2 hypertension
greater than 160/100 mm Hg