Lecture Test 2

Question 1

What are the three classes of arteries based on size?

Answer 1

Conducting (elastic), distributing (muscular), and resistance (small) arteries.

Question 2

What is the function of conducting arteries?

Answer 2

They expand during systole and recoil during diastole to maintain blood flow and pressure.

Question 3

Name two examples of conducting arteries.

Answer 3

Aorta and common carotid arteries.

Question 4

What characterizes distributing arteries?

Answer 4

They distribute blood to specific organs and have thick smooth muscle layers.

Question 5

What is the diameter of arterioles?

Answer 5

Approximately 200 mm.

Question 6

What is the tunica externa?

Answer 6

The outermost layer of a blood vessel, consisting of loose connective tissue.

Question 7

What is the role of the tunica media?

Answer 7

It strengthens vessels and controls blood vessel diameter through smooth muscle contraction.

Question 8

What percentage of blood is contained in veins at rest?

Answer 8

About 64%.

Question 9

What is the average blood pressure in veins?

Answer 9

Approximately 10 mm Hg.

Question 10

What is the simplest route for blood circulation?

Answer 10

Heart → arteries → arterioles → capillaries → venules → veins.

Question 11

What causes varicose veins?

Answer 11

Blood pooling in veins due to valve failure and increased pressure.

Question 12

What is edema?

Answer 12

Accumulation of excess fluid in tissue due to increased filtration or reduced reabsorption.

Question 13

What are the primary causes of edema?

Answer 13

Increased capillary filtration, reduced capillary reabsorption, and obstructed lymphatic drainage.

Question 14

What is the pressure gradient’s role in venous return?

Answer 14

It is the most important force, with venous pressure averaging 7 to 13 mm Hg toward the heart.

Question 15

What is hypovolemic shock?

Answer 15

A condition caused by loss of blood volume due to trauma, burns, or dehydration.

Question 16

What is septic shock?

Answer 16

A condition triggered by bacterial toxins causing vasodilation and increased capillary permeability.

Question 17

What is the skeletal muscle pump?

Answer 17

A mechanism where contracting muscles squeeze blood out of veins, aiding venous return.

Question 18

What is the role of aldosterone in blood pressure regulation?

Answer 18

It promotes kidney retention of sodium and water, increasing blood volume and pressure.

Question 19

What is the function of natriuretic peptides?

Answer 19

They increase kidney excretion, reducing blood volume and pressure.

Question 20

What is the significance of colloid osmotic pressure (COP)?

Answer 20

It draws fluid into capillaries, resulting from blood plasma proteins like albumin.

Question 21

What happens to blood flow during polycythemia?

Answer 21

Blood flow declines due to increased viscosity.

Question 22

What are hemorrhoids?

Answer 22

Varicose veins of the anal canal.

Question 23

What is the difference between hydrostatic pressure and colloid osmotic pressure?

Answer 23

Hydrostatic pressure drives fluid out of capillaries, while COP draws fluid back in.

Question 24

What is the function of vasa vasorum?

Answer 24

Small vessels that supply blood to the outer half of the walls of larger blood vessels.

Question 25

What variable has the greatest control over blood flow?

Answer 25

Vessel radius

Question 26

How does blood flow (F) relate to vessel radius (r)?

Answer 26

Blood flow is proportional to the fourth power of the radius.

Question 27

What is vasomotion?

Answer 27

The collective term for vasoconstriction (narrowing of vessels) and vasodilation (widening of vessels).

Question 28

What is reactive hyperemia?

Answer 28

Increased blood flow above normal after blood supply is cut off and then restored.

Question 29

What is angiogenesis?

Answer 29

The growth of new blood vessels, allowing hypoxic tissue to increase its own perfusion.

Question 30

What triggers the medullary ischemic reflex?

Answer 30

A drop in perfusion of the brain.

Question 31

What is hypertension?

Answer 31

Chronic resting blood pressure higher than 130/80, which can weaken arteries and promote atherosclerosis.

Question 32

What is hypotension?

Answer 32

Chronic low resting blood pressure caused by factors such as blood loss or dehydration.

Question 33

What is the role of angiotensin II in blood pressure regulation?

Answer 33

It is a potent vasoconstrictor that raises blood pressure.

Question 34

How does antidiuretic hormone (ADH) affect blood pressure?

Answer 34

It promotes water retention and raises blood pressure; at high concentrations, it acts as a vasoconstrictor.

Question 35

What is circulatory shock?

Answer 35

A state in which cardiac output is insufficient to meet the body's metabolic needs.

Question 36

What are the two categories of circulatory shock?

Answer 36

Cardiogenic shock and low venous return (LVR) shock.

Question 37

What is the function of natural killer (NK) cells?

Answer 37

They patrol the body for pathogens and diseased host cells, attacking and destroying them.

Question 38

What are perforins?

Answer 38

Proteins released by NK cells that create holes in the plasma membranes of infected cells.

Question 39

What is the role of macrophages in the immune system?

Answer 39

They are large phagocytic cells that present antigens to alert other immune cells.

Question 40

What is the thymus responsible for?

Answer 40

Housing developing T cells and secreting hormones that regulate their activity.

Question 41

What distinguishes innate immunity from adaptive immunity?

Answer 41

Innate immunity is nonspecific and lacks memory, while adaptive immunity is specific and has memory.

Question 42

What are the two types of adaptive immunity?

Answer 42

Cellular (cell-mediated) immunity and humoral (antibody-mediated) immunity.

Question 43

What is the function of antibodies?

Answer 43

They tag pathogens for destruction and do not directly destroy them.

Question 44

What is an antigen?

Answer 44

Any molecule that can bind an antibody, often with large molecular weights.

Question 45

What are haptens?

Answer 45

Incomplete antigens that are too small to be antigenic by themselves but can trigger an immune response when combined with a host molecule.

Question 46

What is the structure of an antibody?

Answer 46

Composed of four polypeptide chains linked by disulfide bonds, with variable and constant regions.

Question 47

What is the role of helper T cells in the immune response?

Answer 47

They coordinate both cellular and humoral immunity by secreting interleukins.

Question 48

What is the significance of memory cells in the immune system?

Answer 48

They are long-lived and respond more rapidly upon re-exposure to the same pathogen.

Question 49

What is anaphylaxis?

Answer 49

A severe, immediate type 1 hypersensitivity reaction that can lead to bronchoconstriction and circulatory shock.

Question 50

What is the role of epinephrine in anaphylactic shock?

Answer 50

It dilates bronchioles, increases cardiac output, and restores blood pressure.

Question 51

What are the characteristics of autoimmune diseases?

Answer 51

Failures of self-tolerance where the immune system attacks the body's own tissues.