Vocab 3 Temme Flashcards
(44 cards)
no-slip condition
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.
chamber-and-valve pump
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
hematocrit
the percentage of total blood volume that is cellular.
cardiac output
total peripheral resistance
the total resistance to flow generated by all the capillary beds in systemic circulation.
sympathetic chain ganglia
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.
sympathetic tone
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.
medullary cardiovascular control center
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.
baroreceptor
a sensor or monitor that detects changes in pressure
alpha-adrenergic receptors
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).
beta1-adrenergic receptors
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.
beta2-adrenergic receptors
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).
adrenal medulla
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).
diastole
the relaxation phase of the cardiac cycle, which is when the heart fills with blood and the arterial pressure is at its minimum.
sinoatrial node
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.)
intercalated disks
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).
A-V fibrous barrier
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.
Frank-Starling mechanism
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.)
capillary bed
a network of 10 to 100 capillaries that arise from a single arteriole.
intercellular (endothelial) clefts
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
colloid osmotic pressure
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
albumin
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
lymphatic system
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.)
multipotent progenitor cell
a stem cell that can develop into all the different types of blood cells.
megakaryocyte
a large bone marrow cell that gives rise to platelets.
