UNIT 3: book review
List 2 protective functions of blood:
- preventing blood loss- platelets and plasma proteins initiate clot formation stopping blood loss
- preventing infection- leukocytes and antibodies attack foreign invaders
What is hematocrit? What is the normal value?
hematocrit = % of RBC in blood volume
normal value = 45%
Suppose you are caring for a patient in liver failure due to chronic alcoholism. What problems would you expect the reduced synthesis of plasma proteins to cause in this patient?
Plasma proteins maintain the correct osmotic pressure and water balance in the blood. With reduced synthesis, more water will enter the tissues causing edema. Some of the plasma proteins are clotting proteins and with reduced synthesis, a person would be less capable of clotting blood when injured.
How many molecules of oxygen can each hemoglobin molecule transport? What part of the hemoglobin binds the oxygen?
heme portion binds the oxygen
Patients with advanced kidney disease often have anemia. Explain the connection.
The kidneys synthesize erythropoietin to increase red blood cell production to increase blood oxygen. When the kidneys are damaged, they cannot produce erythropoietin (EPO). Without EPO, red blood cell count decreases and anemia occurs.
Categorize each cell:
- are or become important phagocytes
- abundant in lymph nodes & in spleen
- granule contents similar to those of mast cells
- neutrophils and monocytes
- eosinophils, basophils and neutrophils
Amos has leukemia. Even though his WBC count is abnormally high, Amos is prone to severe infections, bleeding and anemia. Why?
Amos's red bone marrow is generating abnormal WBCs which are inhibiting the production of normal bone marrow elements. The lack of normal WBCs allows for infections, low number of platelets fails to stop bleeding, and lack of erythrocytes causes anemia.
Because of the blood brain barrier, brain tissue is somewhat less accessible to circulating macrophages. Because of this, one type of CNS cell can become phagocytotic. Which one?
Nigel is told he has type A blood. Which ABO antibodies does he have in his plasma? Which agglutinogens are on his RBCs? Could he donate blood to an AB recipient? Could he receive blood from an AB donor?
Type A: A agglutinogens on RBC and anti-B antibodies in plasma
He could donate blood to an AB recipient but cannot receive blood from AB donor because the anti-B antibodies would reject the blood
Emily, 17, is brought to the ER with a fever, headache, and stiff neck. You suspect bacterial meningitis. Would you expect to see an elevated neutrophil count in a differential WBC count? Explain.
If she has bacterial meningitis, there would be an increased neutrophil count because neutrophils are a major defense against bacteria.
The heart is in the mediastinum. What is that?
medial cavity of the thorax
From inside to outside, list the layers of the heart wall and the coverings of the heart.
layers: endocardium, myocardium, and epicardium (visceral layer of serous pericardium)
coverings: visceral layer of serous pericardium, parietal layer of serous pericardium, fibrous pericardium
What is the purpose of the serous fluid inside the pericardial cavity?
the fluid decreases friction as the heart moves
Label the structures. Which heart chamber receives oxygen-poor blood from veins? Which chamber pumps blood into the systemic circulation? Which blood vessel transports blood towards the lungs?
B. pulmonary trunk
C. left atria
D. right atria
E. left ventricle
F. right ventricle
G. inferior vena cava
right atria, left ventricle, pulmonary trunk
What is the function of the papillary muscles and chordae tendinae?
They work together to close the atrioventricular valves while the ventricles are constricting so there is no backflow of blood.
Name the valve with just two cusps.
Mitral valve (Bicuspid valve)
Which side of the heart acts as the pulmonary pump? The systemic pump?
pulmonary = right side
systemic = left side
Which of the following is true?
a) the left ventricle wall is thicker than the right ventricle wall
b) the left ventricle pumps blood at a higher pressure than the right ventricle
c) the left ventricle pumps more blood with each beat than the right ventricle
a) true. the muscle is bigger because the blood needs to be pumped further
b) true. the systemic circuit is a higher pressure system than the pulmonary circuit
c) false. each ventricle pumps the same amount of blood per beat.
Name the two main branches of the right coronary artery.
right marginal artery and posterior inter-ventricular artery
For each of the following, state whether it applies to skeletal muscle, cardiac muscle or both:
a) refractory period is almost as long as the contraction
b) source of Ca2+ for contraction is only SR
c) has troponin
d) has triads
a) cardiac muscle
b) skeletal muscle
d) skeletal muscle
Cardicac muscle cannot go into tetany. Why?
absolute refractory period is almost as long as the contraction
Describe the electrical event in the heart that occurs during each of the following:
a) QRS complex of ECG
b) T wave of ECG
c) P-R interval of ECG
a) ventricular depolarization
b) ventricular repolarization
c) atrial depolarization and conduction of AP through the rest of the intrinsic conduction system
In skeletal muscle, every muscle fiber must be innervated so it can contract. In cardiac muscle the intrinsic conduction system does not connect ot every cardiac myocyte. Why is this not necessary? Which part of the intrinsic conduction system directly excites ventricular myocardial cells? In which direction does the depolarization wave travel across the ventricles?
- cardiac myocytes are connected via gap junctions and are depolarized when an adjacent myocyte depolarizes
- the subendocardial conducting network excites ventricular muscle cells
- Depolarization of ventricles travels upwards from apex towards atria
After running to catch a bus, Josh noticed that his heart was beating faster than normal and was bounding forcefully in his chest. How did this increase HR and SV come about
Exercise activates the sympathetic nervous system. Increase in sympathetic activity during exercise directly increases HR, increases venous return which increases end diastolic volume which increases stroke volume, and increases contractile strength which decreases end systolic volume and increases stroke volume.
What problem of cardiac output might ensue if the heart beats far too rapidly for an extended period, that is, if tachycardia occurs? Why?
If the heart is beating very rapidly, the amount of time for ventricular filling between contractions is decreased. This decreases venous return and EDV which decreases stroke volume
Which branch of the ANS innervates blood vessels? Which layer of the blood vessel wall do these nerves innervate? What are the effectors (cells that carry out the response)?
sympathetic; tunica media; smooth muscle cells in tunica media
When vascular smooth muscle contracts, what happens to the diameter of the blood vessel? What is this called?
diameter decreases = vasoconstriction
Where are capillaries found?
tunica intima of blood vessels