Animal Physiology Chapter 12 Vocab

Front 1

Hemolymph

Back 1

The blood of invertebrates with open circulatory systems

Front 2

Microcirculation

Back 2

Capillary systems

Front 3

Ultra filtration

Back 3

The process of separating colloid or molecular particles from a solute by filtration, using suction or pressure, through a colloidal filter or semipermeable membrane

Front 4

Sinus venosis

Back 4

Where pacemaker is located in fish

Front 5

Sinoatrial node

Back 5

Where pacemaker is located in vertebrates besides fish

Front 6

Pacemaker

Back 6

Consists of a group of small, weakly contractile, specialized muscle cells capable of spontaneous activity.

Front 7

Neurogenic heart (invertebrate)

Back 7

Heart where pacemaker is nerve cells

Front 8

Myogenic heart (vertebrate)

Back 8

Heart where pacemaker is made of muscle cells

Front 9

Ectopic pacemaker

Back 9

Pacemaker situated outside area where normally found

Front 10

Pacemaker potential

Back 10

The spontaneous and rhythmic depolarizations produced by pacemaker tissue

Front 11

electrocardiogram

Back 11

(ECG) A record of electrical events associated with contractions of the heart; typically obtained with electrodes placed on the surface of the body.

Front 12

Atrioventricular node

Back 12

Specialized conduction tissue in the heart that, along with Purkinge fibers, forms a bridge of electrical conduction of excitation waves from the atria to the ventricles

Front 13

Bundle of his

Back 13

The conduction tissue within the interventricular septum of the mammalian heart.

Front 14

Purkinje fibers

Back 14

Junctional fibers that convey the wave of excitation from the bundle of His after it branches and that extend into the myocardium of the two ventricles

Front 15

Endocardium

Back 15

Internal lining of the heart wall

Front 16

Epicardium

Back 16

External covering of the heart wall

Front 17

Negative chronotropic effect

Back 17

When acetylcholine is released from parasympathetic fibers it slows heart rate. This decrease in heart rate is the negative chronotropic effect.

Front 18

Atrioventricular block

Back 18

When high levels of actylcholine completely block conduction through the atrioventricular node.

Front 19

Positive chronotropic effect

Back 19

Catacholamines epinephrine and norepinephrine increase the rate of myocardial contractions, or heart rate.

Front 20

Positive inotropic effect

Back 20

Catacolamine epinephrine and norepinephrine increase the force of myocardial contraction.

Front 21

Positive dromotropc effect

Back 21

Catacolamine epinephrine and norepinephrine increase the force of myocardial contraction

Front 22

Efficiency of contraction

Back 22

The mechanical work done by the heart, expressed as a fraction of the total energy expended.

Front 23

Pericardium

Back 23

The sac of connective tissue that encloses the heart.

Front 24

Bulbus

Back 24

A heart chamber

Front 25

Brady cardia

Back 25

A reduction in heart rate from a normal level.

Front 26

Ductus arteriosis

Back 26

The vessel connecting the pulmonary artery and the aorta in fetal mammals.

Front 27

Foramen ovale

Back 27

A hole in the interatrial septum covered by a flap valve, which directs oxygenated blood returning to the heart via the inferior vena cava into the left atrium.

Front 28

Chorioallantois

Back 28

In a bird egg, a network of blood vessels called the chorioallantoid lies just under the shell. This is a site of oxygen exchange.

Front 29

Laminar flow

Back 29

A pattern of turbulence free flow of fluid in a vessel or past a moving object; a gradient of relative velocity exists in which the fluid layers closest the wall have the lowest relative velocity.

Front 30

Viscosity

Back 30

A physical property of fluids that determines the ease with which layers of a fluid move past each other

Front 31

Turbulent flow

Back 31

A flow pattern in which sharp gradients and inconsistencies in velocity and direction of fluid flow exist.

Front 32

Reynold’s number (Re)

Back 32

A unitless number; the tendency of a flowing gas of liquid to become turbulent in proportion to its velocity and density and in inverse proportion to its viscosity.

Front 33

Kinematic viscosity

Back 33

Viscosity divided by density; gases of equal kinematic viscosity will become turbulent at equal flow rates in ideal airways.

Front 34

Hematocrit

Back 34

Volume of red blood cells per unit volume of blood.

Front 35

Poiseuille’s law

Back 35

The principle that, in laminar flow, the flow is directly proportional to the driving pressure, and resistance is independent of flow.

Front 36

Fahraeus-lindqvist effect

Back 36

The reduction in the apparent viscosity of blood as it flows into small arterioles.

Front 37

Plasma skimming

Back 37

The separation of plasma from blood within the circulation.

Front 38

Compliance

Back 38

The change in length or volume per unity change in the applied force.

Front 39

Endothelium

Back 39

A single cell layer forming the internal lining of blood vessels.

Front 40

Vasa vasorum

Back 40

The tiny arteries and veins that supply nutrients to and remove waste products from the tissues in the walls of large blood vessels.

Front 41

Pressure pulse

Back 41

The difference between the systolic and diastolic pressures.

Front 42

Rete mirabile

Back 42

The countercurrent arrangement of small arterioles and venules is referred to as a rete mirabile.

Front 43

Pericyte cells

Back 43

A few elongated cell with the ability to contract, called pericyte cells, are found wrapped around capillaries.

Front 44

Continuous calipillaries

Back 44

Continuous capillaries, which are the least permeable, are located in muscle, neuronal tissue, the lungs, connective tissue, and exocrine glands.

Front 45

Fenestrated capillaries

Back 45

Fenestrated capillaries, which exhibit intermediate permeability, are found in the renal glomerulus intestines, and endocrine glands.

Front 46

Sinusoidal capillaries

Back 46

Sinusoidal capillaries, which are the most permeable, are present in the liver, bone marrow, spleen, lymph nodes, and adrenal cortex.

Front 47

Colloid osmotic pressure

Back 47

High pressures inside a capillary result in the filtration of fluid from the blood plasma into the interstitial space. This filtration pressure is opposed by the colloid osmotic pressure of the plasma, which results largely from the higher concentration of proteins in the blood plasma than in the interstitial fluid.

Front 48

Starling hypothesis

Back 48

The net movement of fluid at any point along the capillary is determined by two factors: (a) the difference between blood pressure and colloid osmotic pressure and (b) the permeability of the capillary wall, which tends to increase toward the venous end. This concept is sometimes referred to as the starling hypothesis.

Front 49

Edema

Back 49

Retention of interstitial fluid in organs or tissues.

Front 50

Lymph

Back 50

The plasma like fluid collected from interstitial fluid and returned to the bloodstream via the thoracic duct; contains white, but not red, blood cells.

Front 51

Thoracic duct

Back 51

A duct through which fluid from the lymphatic system returns to the bloodstream.

Front 52

Villi

Back 52

Small, fingerlike projections (e.g., on the intestinal epithelium).

Front 53

Central lacteal

Back 53

A small, blind-ended lymph vessel in the center of an intestinal villus that functions in the uptake of fats and some vitamins.

Front 54

Lymphocytes

Back 54

White blood cells produced in lymphoid tissue that lack cytoplasmic granules and have a large, round nucleus.

Front 55

Baroreceptors

Back 55

A sensory receptor that is stimulated by changes in pressure, as in the walls of blood vessels.

Front 56

Medullary cardiovascular center

Back 56

A group of neurons in the medulla involved in the integration of information used in the control and regulation of circulation.

Front 57

A-fiber

Back 57

Myelinated A-fiber afferents respond to changes in heart rate and appear to relay information on heart rate to cardiovascular control centers located in the medulla oblongata..

Front 58

B-fiber

Back 58

Myelinated B-fiber afferents respond to increases in the rate of filling and volume of the atria.

Front 59

C-fiber

Back 59

The third type of atrial mechanoreceptor comprises unmyelinated C-fiber afferents innervating the junction of the veins and atria.

Front 60

Diuresis

Back 60

An increase in urine production.

Front 61

Atrial natriuretic peptide (ANP)

Back 61

(ANP) One of a family of peptide hormones cleaved from a single precursor peptide and produced in the cardiac atria; its physiological effects in clued increased urine output, increased sodium excretion, and receptor-mediated vasodilation, the net result of which is lowered blood pressure.

Front 62

Natriuresis

Back 62

As the name indicates, ANP causes an increase in Na+ excretion (natriuresis) and in urine production.

Front 63

Chromaffin cells

Back 63

Epinephrine-secreting cells of the adrenal medulla; named for their high affinity for chromium salt stains.

Front 64

Neuropeptide Y

Back 64

A 36-animo-acid peptide, co-localized with norepinephrine in sympathetic ganglia and adrenergic nerves and localized in some nonadrenergic fibers, the physiolocical effects of which include reduction in the action of catecholamines on the mammalian heart and potentiation of the action of catecholamines on fish hearts.

Front 65

Hyperemia

Back 65

Increased blood flow to a tissue or an organ.

Front 66

Ischemia

Back 66

The absence of blood flow to an organ or a tissue.

Front 67

Active hyperemia

Back 67

The increase in blood flow during and after increased activity in a tissue, particularly skeletal muscle.

Front 68

Reactive hyperemia

Back 68

Higher than normal blood flow that occurs following a brief period of ischemia.

Front 69

Nitric oxide (NO)

Back 69

A gas that functions as intercellular messenger, including neurotransmitters; is endothelium-derived relaxing factor; destroys intracellular microbes.

Front 70

Endothelins

Back 70

Family of peptides secreted by many tissues that can act as a paracrine or hormonal signal; one major action is vasoconstriction.

Front 71

Prostacyclin

Back 71

Eicosanoid that inhibits platelet aggregation in bloodclotting; also called prostaglandin I2 (PGI2)

Front 72

Thromboxane A2

Back 72

Thromboxane that, among other effects, stimulates platelet aggregation in blood clotting.

Front 73

Histamine

Back 73

The base formed from histidine by decarboxylation; responsible for dilation of blood vessels.

Front 74

Plasma kinins

Back 74

Peptide hormones formed in the blood after injury – for example, bradykinin.

Front 75

Extrinsic cascade

Back 75

Extrinsic clotting pathway – formation of fibrin clots by pathway using tissue factor on cells in interstitium; once activated, it also recruits the intrinsic clotting pathway beyond factor XII.

Front 76

Intrinsic pathway

Back 76

Intrinsic clotting pathway – intravascular sequence of fibrin clot formation initiated by factor XII or, more usually, by the initial thrombin generated by the extrinsic clotting pathway.

Front 77

Thrombus

Back 77

A clot in the circulation that blocks blood flow.