Many hours after a meal, alpha (α) cells in the pancreatic islets (islets of Langerhans) secrete
glucagon, which raises blood glucose.
Even a small quantity of hormone can have a strong effect on its target cell because of
Neither follicle stimulating (FSH) hormone nor testosterone alone can stimulate significant sperm production, whereas when they act together, the testes produce some 300,000 sperm per minute. This exemplifies
the synergistic effect
These statements about diabetes mellitus (DM) are correct except
both type I and type II DM are characterized by lack of, or low levels of, insulin.
Choose the correct statement(s) regarding the composition of plasma.
Water represents 92% by weight.
Albumin is 60% of the total protein portion.
The most abundant nitrogenous waste is urea
Choose the accurate statement(s) about the two reaction pathways to coagulation
The intrinsic mechanism uses only clotting factors found in the blood itself.
In most cases of bleeding, both the extrinsic and intrinsic mechanisms work simultaneously to contribute to hemostasis
The extrinsic mechanism is initiated by clotting factors released by the damaged blood vessel and perivascular tissues.
How is hemophilia characterized
It has sex-linked recessive mechanism of heredity
Most hemophilia occurs predominantly in males.
The lack of factor VIII causes classical hemophilia (hemophilia A), which accounts for about 83% of cases.
Lack of factor IX causes hemophilia B, which accounts for 15% of cases.
Which of the following characteristics of a red blood cell increases its ability to carry oxygen to the tissues?
Lacking mitochondria, RBCs rely exclusively on anaerobic fermentation to produce ATP.
The cytoplasm of an RBC consists mainly of a 33% solution of hemoglobin.
? RBCs lose nearly all organelles during their development.
?Lacking a nucleus and DNA, RBCs also are incapable of protein synthesis and mitosis.
Choose the statement(s) associated with hemolytic disease of the newborn.
It occurs when an Rh- woman carries an Rh+ fetus
The first pregnancy is likely to be uneventful because the placenta normally prevents maternal and fetal blood from mixing
At the time of birth, or if a miscarriage occurs, placental tearing exposes the mother to Rh+ fetal blood and she begins to produce anti-D antibodies.
If she becomes pregnant again with an Rh+ fetus, her anti-D antibodies may pass through the placenta and agglutinate the fetal erythrocytes.
Identify the components of the circulatory system.
All of the choices are correct ( heart, blood vessels, blood)
Viscosity and osmolarity will both increase if the amount of ____________ in the blood increases
The first and second choices are correct. ( RBC and proteins)
Choose the correct statement regarding the function of platelets.
They secrete procoagulants, or clotting factors, which promote blood clotting
Factor XII catalyzes the formation of a plasma enzyme called kallikrein, that in turn converts an inactive protein into _________, a fibrin-dissolving enzyme that breaks up the clot
_____________ is the enzyme responsible for promoting the formation of more kallikrein, completing the positive feedback loop in dissolving clots.
In healthy blood vessels, platelets do not adhere because the smooth, endothelium is coated with
The two principal functions of the erythrocytes are:
The second and third choices are correct. (to pick up oxygen from the lungs and deliver it to tissues and to pick up carbon dioxide from the tissues and unload it in the lungs.
Identify the INCORRECT statement regarding blood groups other than ABO and Rh.
They frequently cause transfusion reactions.
Identify the correct statement regarding leukocytes.
Leukocytes spend only a few hours in the bloodstream, then migrate through the walls of the capillaries.
Choose the correct statement(s) associated with the metabolism of cardiac muscle.
Cardiac muscle depends almost exclusively on aerobic respiration to make ATP.
It is very rich in myoglobin (a source of stored oxygen) and glycogen (for stored energy).
Choose the correct statements that accurately explain impulse conduction to the myocardium
Firing of the SA node excites atrial cardiocytes and stimulates the two atria to contract almost simultaneously.
In the AV node, the signal slows down to about 0.05 m/sec because the cardiocytes have fewer gap junctions over which the signal can be transmitted.
Signals travel through the AV bundle and Purkinje fibers at a speed of 4 m/sec, the fastest in the conduction system.
The delay at the AV node is essential because it gives the atria time to fill with blood before they begin to contract.
Exercise has the following effects on cardiac output.
The main reason the heart rate increases at the beginning of exercise is that proprioceptors in the muscles and joints transmit signals to the cardiac centers.
As the exercise progresses, muscular activity increases venous return.
A sustained program of exercise causes hypertrophy of the ventricles, which increases their stroke volume.
Heart sound ____________ is thought to result from the transition from expansion of the empty ventricles to their sudden filling with blood.
Given that cardiac output equals ____________, you can see that there are only two ways to change it: change the heart rate or change the stroke volume
HR X SV
has a strong, positive inotropic effect, meaning it increases the strength of each contraction of the heart.
If the right ventricle begins to pump an increased amount of blood, this soon arrives at the left ventricle, stretches it more than before, and causes it to increase its stroke volume and match that of the right. This is and example of ________________.
As the exercise progresses, muscular activity __________ venous return. This increases the _________ on the right ventricle.
Obstruction of the ___________ will cause a more severe myocardial infarction (MI) than the obstruction of any of the others
left coronary artery (LCA)
The long plateau in the action potential observed in cardiocytes is probably related with _____________ staying longer in their cytosol.
Mitral valve stenosis causes blood to leak back into the ___________ when the ventricles contract.
Mitral valve prolapse (MVP) generates a murmur associated with the _____ heart sound that occurs when the ____.
lubb (S1); ventricles contract
Cardioinhibitory centers in the _____________ receive input from __________.
medulla oblongata; chemoreceptors in the aortic arch
The Frank-Starling law of the heart states that stroke volume is proportional to
the end-diastolic volume.
During periods of exercise
the sympathetic nervous system can increase perfusion of the skeletal muscles
metabolite accumulation in a tissue can stimulate local vasodilation.
the parasympathetic nervous system can selectively reduce blood flow to the kidneys and digestive tract.
Choose the accurate statements regarding the effects of edema
Cerebral edema can produce headaches, nausea, and sometimes delirium, seizures, and coma.
As the tissues become congested with fluid, oxygen delivery and waste removal are impaired and the tissues may begin to die.
Pulmonary edema presents a threat of suffocation as fluid replaces air in the lungs.
Muscle perfusion during exercise increases dramatically. Perfusion is increased via
-arterioles dilating in response to epinephrine and norepinephrine.
- precapillary sphincters dilating in response to muscle metabolites such as lactic acid, CO2, and adenosine.
-muscular contraction compressing the blood vessels.
-blood being diverted from other organs such as the digestive tract and kidneys to meet the needs of the working muscles.
The advantage(s) of there being a much lower blood pressure in the pulmonary circuit include
- blood flows more slowly through the pulmonary capillaries and therefore has more time for gas exchange
-it prevents fluid accumulation in the alveolar walls and lumens, which would compromise gas exchange.
-oncotic pressure overrides hydrostatic pressure, so pulmonary capillaries are engaged almost entirely in absorption.
Blood usually passes through one network of capillaries from the time it leaves the heart until the time it returns, but there are exceptions, notably ______________.
The second and third choices are correct. (portal systems and anastomoses)
Choose the accurate statement(s) about how materials get from the blood to the surrounding tissues.
The first, second, and third choices are correct.
Identify the INCORRECT statement regarding the fundamental causes of edema.
Capillary reabsorption does not depend on oncotic pressure.
Which of the following is NOT a mechanism that assists venous return?
Central venous pressure being greater than pressure in the venules