Vocab 3 Temme

Question 0

no-slip condition

Answer 0

as a fluid flows across a solid surface, the fluid molecules at the interphase stay put (velocity equals zero), while the remaining fluid flows past by continually changing shape.

Question 1

chamber-and-valve pump

Answer 1

the coupling of a means to generate convective flow generating pressure gradients within a tube, with a means to steer the flow in one direction. The basic structure is comprised of two one way valves—oriented in the same direction—and some means to alternatingly compress and expand the space or chamber in between.
relative pressure

Question 2

hematocrit

Answer 2

the percentage of total blood volume that is cellular.

cardiac output

Question 3

total peripheral resistance

Answer 3

the total resistance to flow generated by all the capillary beds in systemic circulation.

Question 4

sympathetic chain ganglia

Answer 4

sympathetic chain ganglia – a series (or chain) of connected sympathetic postganglionic cell body clusters positioned along each side of the vertebral column adjacent to the major body wall branches of the aorta.

Question 5

sympathetic tone

Answer 5

the tonic (basal) rate of activity of the sympathetic component of the nervous system—which is generally around 1/2 to 2 impulses or action potentials per second. This tonic rate maintains all innervated smooth muscles (found largely wrapped around arterioles) in a partial state of contraction and the heart beating faster than it would otherwise.

Question 6

medullary cardiovascular control center

Answer 6

the hindbrain region that through integration of various sources of inputs plays a role in regulating arterial blood pressure by adjusting the overall pace of sympathetic and some parasympathetic (i.e., vagal connections to the heart) outputs —which in turn adjusts heart rate and total peripheral resistance.

Question 7

baroreceptor

Answer 7

a sensor or monitor that detects changes in pressure

Question 8

alpha-adrenergic receptors

Answer 8

a class of G-protein linked receptors generally found on smooth muscle that binds with norepinephrine or epinephrine (although not as well), and when bound triggers contraction (or vasoconstriction when the smooth muscle is wrapped around blood vessels).

Question 9

beta1-adrenergic receptors

Answer 9

beta1-adrenergic receptors – a class of G-protein linked receptors found on the heart (SA node, AV node, cardiac muscle) that binds equally well with either norepinephrine or epinephrine, and when bound triggers increases in both heart rate and the strength of heart contractions.

Question 10

beta2-adrenergic receptors

Answer 10

a class of G-protein linked receptors found on smooth muscle that that binds with epinephrine or norepinephrine (although not as well), and when bound inhibits contraction (or promotes vasodilation when the smooth muscle is wrapped around blood vessels).

Question 11

adrenal medulla

Answer 11

the inner part of the adrenal gland, which is derived from postganglionic sympathetic cells, and when stimulated secretes epinephrine (and to a lesser extent norepinephrine).

Question 12

diastole

Answer 12

the relaxation phase of the cardiac cycle, which is when the heart fills with blood and the arterial pressure is at its minimum.

Question 13

sinoatrial node

Answer 13

a mass of specialized cardiac tissue in the wall of the right atrium that spontaneously (and rhythmically) depolarizes and thus initiates the action potentials that trigger each new cardiac cycle. (The SA node
is sometimes referred to as the pacemaker of the heart. In humans it tends to initiate about 100 action potentials per minute.)

Question 14

intercalated disks

Answer 14

the structures that connect individual cardiac muscle cells. They are composed largely of desmosomes (the strongest form of cell-cell junction) and gap junctions (which form a cytoplasmic connection between cells).

Question 15

A-V fibrous barrier

Answer 15

a layer of connective tissue that separates the interconnected cardiac muscle cells making up the atria, from the interconnected cardiac muscle cells making up the ventricles. By acting as an insulating layer, it prevents action potentials from spreading directly from the atria to the ventricles, or vice versa.

Question 16

Frank-Starling mechanism

Answer 16

Frank-Starling mechanism – the mechanism by which the heart responds to more blood filling its ventricles with a stronger contraction . (Which within physiological limits, results in the heart pumping all the blood that returns to it.)

Question 17

capillary bed

Answer 17

a network of 10 to 100 capillaries that arise from a single arteriole.

Question 18

intercellular (endothelial) clefts

Answer 18

gaps found between neighboring cells within the single-celled endothelium that
forms a capillary. These gaps occur in regions where adjacent cells are not held together by tight junctions

Question 19

colloid osmotic pressure

Answer 19

the osmotic gradient between the outside and inside of a capillary that forms due to the
presence of larger solutes, mainly proteins, that do not readily pass through a capillary’s intercellular clefts

Question 20

albumin

Answer 20

the most abundant plasma protein, which as a consequence plays an important role in generating the colloid
osmotic pressure needed to maintain blood volume. (It also plays a role in transporting certain low water solubility
molecules, such as fatty acids, in the blood stream.)
lymph

Question 21

lymphatic system

Answer 21

the network of vessels through which excess interstitial fluid (including even large solutes) is
collected, transported, and eventually returned to the circulatory system. (Along the way, all fluid also passes through
lymph nodes.)

Question 22

multipotent progenitor cell

Answer 22

a stem cell that can develop into all the different types of blood cells.

Question 23

megakaryocyte

Answer 23

a large bone marrow cell that gives rise to platelets.

Question 24

platelets

Answer 24

cell fragments of megakaryocytes that are involved in patching small tears or holes that form within injured
blood vessels.

Question 25

thrombin

Answer 25

the enzyme that when activated initiates blood clot formation by catalyzing the conversion of fibrinogen into
fibrin.

Question 26

fibrinogen

Answer 26

a plasma protein that is the precursor to the formation of the polymer fibers found in blood clots.

Question 27

coagulation cascade

Answer 27

a series of enzyme-driven reactions triggered by injury to a blood vessel (along with surrounding
tissue) that ultimately activates thrombin, which in turn triggers the formation of a blood clot.

Question 28

transpulmonary pressure

Answer 28

the pressure gradient between the inside of the lung and the pleural cavity.

Question 29

tidal volume

Answer 29

the volume of air entering or leaving the lungs (along with the connecting tubing) during a single normal
or quiet ventilation cycle.

Question 30

partial pressure

Answer 30

the proportion of the total atmospheric pressure contributed by a particular type of gas.

Question 31

alveoli

Answer 31

the small air sacs across which molecular oxygen (O2) and carbon dioxide (CO2) are exchanged between the blood and air in the lungs

Question 32

erythropoietin

Answer 32

the hormone (cytokine) released by the kidney in response to hypoxia (low molecular oxygen levels) that stimulates production of red blood cells.

Question 33

hemoglobin

Answer 33

a large iron-bearing protein found in red blood cells able to bind with and release oxygen molecules (O2) in a way that greatly facilitates their transport between the lungs and body tissues. (It also involved in the transport of carbon dioxide (CO2) from the tissues to the lungs.)

Question 34

oxygen dissociation curve

Answer 34

a plot of the relationship between the amount of oxygen in the surrounding environment (measured in terms of the partial pressure of molecular oxygen) and the percent saturation of hemoglobin.

Question 35

carbonic anhydrase

Answer 35

an enzyme that catalyzes the conversion of carbon dioxide (CO2) and water (H2O) bicarbonate (HCO3-) and hydrogen ions (H+), or vice versa. (That is, it catalyzes the reaction in either direction.)

Question 36

chloride shift

Answer 36

the process in which red blood cells transport one bicarbonate (HCO3-) in exchange for one chloride ion
(Cl-) across the cell membrane.

Question 37

proximal tubule

Answer 37

the initial segment of a kidney tubule where most reabsorption takes place.

Question 38

renin

Answer 38

an enzyme secreted by juxtaglomerular (JG) cells in response to low arterial blood pressure or volume that
catalyzes the conversion of a certain plasma protein (angiotensinogen) into angiotensin I.

Question 39

aldosterone

Answer 39

a steroid hormone produced in the adrenal cortex that promotes both increased sodium ion (Na+)
reabsorption and increased potassium ion (K+) secretion in the kidney. Both angiotensin II and high plasma potassium
ion levels promote its release.

Question 40

osmoregulation

Answer 40

an organism maintaining an osmotic balance between its interstitial fluid and its cells.

Question 41

anti-diuretic hormone (ADH)

Answer 41

hormone released by the posterior pituitary that stimulates an increase in the water permeability of each kidney’s collecting tubules (and vasoconstriction of arterioles). (Note: It is also called vasopressin).

Question 42

concentrated urine

Answer 42

when the osmolarity of the kidney filtrate exiting the body is greater than 300 mOsm.

Question 43

urea

Answer 43

a nontoxic molecular form by which some animals (especially mammals) use to get rid of excess nitrogenous
wastes (especially, ammonia (NH3)). Urea is formed in the liver by joining two ammonia molecules (NH3) with one carbon dioxide (CO2)