Mcat Biology (Chapter 7)

Front 1

pulmonary circulation

Back 1

the right side of the heart accepts deoxygenated blood returning from the body and moves it to the lungs by way of the pulmonary arteries

Front 2

systemic circulation

Back 2

the left side of the hearts receives oxygenated blood from the lungs by way of the pulmonary veins and forces it out of the body through the aorta

Front 3

atria

Back 3

thin-walled structures where blood is received from either the venae cavae or pulmonary veings

Front 4

venae cavae

Back 4

deoxygenated blood entering the right heart

Front 5

pulmonary veins

Back 5

oxygenated blood entering the left heart

Front 6

ventricles

Back 6

blood is pushed there from the atria; they contract to send blood to the lungs and the systemic circulation

Front 7

atrioventricular valves

Back 7

separate the atria from the ventricles

Front 8

semilunar valves

Back 8

separate the ventricles from the vasculature

Front 9

tricuspid valve (three leaflets)

Back 9

valve between the right atrium and the right ventricle

Front 10

mitral or bicuspid valve (two leaflets)

Back 10

valve between the left atrium and the left ventricle

Front 11

pulmonary valve

Back 11

valve that separates the right ventricle from the pulmonary circulation

Front 12

aortic valve

Back 12

valve that separates the left ventricle from the aorta

Front 13

pathway of blood

Back 13

right atrium

(tricuspid valve)

right ventricle

(pulmonary valve)

pulmonary artery

lungs

pulmonary veins

left atrium

(mitral valve)

left ventricle (aortic valve)

aorta

arteries

arterioles

capillaries

venules

veins

venae cavae

right atrium

Front 14

electrical impulse pathway

Back 14

sinoatrial (SA) node

atrioventricular (AV) node

bundles of His (AV bundle) and its branches

Purkinje fibers

Front 15

atrial systole (contraction)

Back 15

results in an increase in atrial pressure that forces a little more blood into the ventricles than the one based solely on ventricular relaxation

Front 16

atrial kick

Back 16

additional volume of blood caused by atrial systole (contraction)

Front 17

interventricular septum

Back 17

wall of the heart where the bundle of His and its branches are embedded

Front 18

intercalated discs

Back 18

connect muscle cells of the heart; contain many gap junctions directly connecting the cytoplasm of adjacent cells, thereby allowing for coordinated ventricular contraction

Front 19

myogenic activity

Back 19

describes the cardiac muscle which can contract without any neural input; SA node generates about 60-100 beats/minute without neural input

Front 20

systole

Back 20

ventricular contraction and closure of the AV valves occurs and blood is pumped out of the ventricles

Front 21

diastole

Back 21

the heart is relaxed, the semilunar valves are closed, and blood from the atria fills the ventricles

Front 22

cardiac output

Back 22

total blood volume pumped by a ventricle in a minute; product of heart rate (RH, beats per minute) and stroke volume (SV, volume of blood pumped per beat)

Front 23

three major types of blood vessels

Back 23

arteries, veins and capillaries

Front 24

arteries

Back 24

carry blood away from the heart; the largest is the aorta

Front 25

arterioles

Back 25

what arteries branch into

Front 26

capillaries

Back 26

what arterioles ultimately lead to; perfuse the tissues

Front 27

venules

Back 27

on the venus side, what capillaries join together into

Front 28

veins

Back 28

what venules join to form

Front 29

endothelial cells

Back 29

what all blood vessels are lined with; maintain the vessels by releasing chemicals that aid in vasodilation and vasoconstriction; can allow white blood cells to pass through the vessel wall and into the tissues during an inflammatory response; release chemicals when damaged that are necessary in the formation of blood clots to repair the vessel and stop bleeding

Front 30

arteries which contain deoxygenated blood

Back 30

pulmonary and umbilical arteries (only two!)

Front 31

smooth musclee

Back 31

arteries have more than veins

Front 32

deep vein thrombosis (DVT)

Back 32

a clot in the deep veins of the leg

Front 33

pulmonary embolus

Back 33

a life-threatening condition caused by a deep vein thrombosis clot becoming dislodged and traveling through the right heart to the lungs

Front 34

portal systems

Back 34

hepatic portal system

hypophyseal portal system

renal portal system

blood will pass through two capillary bed in series before returning to the heart

Front 35

hepatic portal system

Back 35

blood leaving capillary beds in the walls of the gut passes through the hepatic portal vein before reaching the capillary beds in the liver

Front 36

hypophyseal portal system

Back 36

blood leaving capillary beds in the hypothalamus travels to a capillary bed in the anterior pituitary to allow for paracrine secretion of releasing hormones

Front 37

renal portal system

Back 37

blood leaving the glomerulus travels through an efferent arteriole before surrounding the nephron in a capillary network called the vasa recta

Front 38

blood composition

Back 38

55% liquid (plasma)

45% cells (erythrocytes, leukocytes and platelets)

Front 39

plasma

Back 39

liquid portion of blood, an aqueous mixture of nutrients, salts, respiratory gases, hormones, and blood proteins

Front 40

erythrocytes, leukocytes and platelets

Back 40

blood cells; all formed from hematopoietic stem cells which originate in the bone marrow

Front 41

erythrocyte

Back 41

red blood cell; specialized cell designed for oxygen transport; contains about 250 million molecules of hemoglobin; can carry approximately 1 billion molecules of oxygen; lack mitochondria, nucleus and organelles

Front 42

hemoglobin

Back 42

part of erythrocyte; can bind 4 molecules of oxygen; binding occurs at the heme group's central iron atom which can undergo changes in its oxidation state (oxidation-reduction reaction)

Front 43

hematocrit

Back 43

measurement of how much of the blood sample consists of red blood cells, given as a perentage

Front 44

leukocytes

Back 44

white blood cells; less than 1% of blood volume

2 classes:

granulocytes (neutrophils, eosinophils, and basophils)

agranulocytes (lymphocytes and monocytes)

Front 45

granular leukocytes or granulocytes

Back 45

neutrophils, eosinophils and basophils; so named because of they contain toxic cytoplasmic granules; involved in inflammatory reactions, allergies, pus formation and destruction of bacteria and parasites

Front 46

agranulocytes

Back 46

lymphocytes and monocytes; don't contain granules

Front 47

lymphocytes

Back 47

important in the specific immune response; primary responders against infection and maintain a memory bank of pathogens

Front 48

B-cells

Back 48

lymphocytes that mature in the spleen or in lymph nodes; responsible for antibody generation

Front 49

T-cells

Back 49

lymphocytes that mature in the thymus; kill virally infected cells and activate other immune cells

Front 50

monocytes

Back 50

phagocytize foreign matter such as bacteria

Front 51

macrophages

Back 51

this is what monocytes are called once they leave the bloodstream and enter an organ

Front 52

microglia

Back 52

this is what the macrophage population is called in the central nervous system

Front 53

Langerhans cells

Back 53

this is what the macrophage population is called in the skin

Front 54

osteoclasts

Back 54

this is what the macrophage population is called in the bone

Front 55

thrombocytes or platelets

Back 55

cell fragments or shards released from cells in bone marrow known as megakaryocytes; function is to assist in blood clotting; detect collagen and then begin clotting process

Front 56

megakaryocytes

Back 56

cells in the bone marrow which release thrombocytes and platelets

Front 57

hematopoiesis

Back 57

production of blood cells and platelets; triggered by a number of hormones, growth factors, and cytokines; all cellular elements of blood originate in the bone marrow

Front 58

erythropoietin

Back 58

secreted by the kidney; stimulates mainly red blood cell development

Front 59

thrombopoietin

Back 59

secreted by the liver and kidney; stimulates mainly platelet development

Front 60

hemolysis

Back 60

occurs when a blood recipient is given the wrong blood type

Front 61

Rh factor

Back 61

also a surface protein expressed on red blood cells; Rh+ or Rh- refers to the presence or absence of a specific allele called D; Rh+ is dominant; issue when mother is Rh- and has an Rh+ baby (the issue is with the second baby if they are also Rh+)

Front 62

erythroblastosis fetalis

Back 62

result of pregnancy of a second Rh+ baby to an Rh- mother; anti-Rh antibodies cross the placenta and attack fetal blood cells resulting in hemolysis of fetal cells

Front 63

sphygmomanometer

Back 63

measures blood pressure; measure gauge pressure in the systemic circulation which is the pressure above and beyond atmospheric pressure (760 mmHg at sea level)

Front 64

blood pressure

Back 64

force per unit area exerted on the wall of blood vessels; expressed as a ratio of the systolic (ventricular contraction) to diastolic (ventricular relaxation) pressures; normally between 90/60 and 120/80

Front 65

circulation equation (equivalent to Ohm's law)

Back 65

ΔP = CO x TPR

ΔP is pressure differential across circulation

CO is cardiac output

TPR is total peripheral (vascular) resistance

Front 66

baroreceptors

Back 66

specialized neurons that regulate blood pressure

Front 67

atrial natriuretic peptide (ANP)

Back 67

a hormone secreted by specialized atrial cells within the heart; aids in the loss of salt within the nephron acting as a natural diuretic with loss of liquid

Front 68

capillaries

Back 68

where oxygen and nutrients diffuse out of the blood into tissues while waste products like carbon dioxide, hydrogen ions, urea and ammonia diffuse into the blood in addition to hormones

Front 69

PaO2

Back 69

level of oxygen in the blood which is often measured as the partial pressure within the blood; approximately 70-100 mmHg; inconvenient because blood sample has to be taken from artery

Front 70

oxygen saturation

Back 70

percentage of hemoglobin molecules carrying oxygen; easily measured using a finger probe; normally 97%

Front 71

cooperative binding

Back 71

a form of allosteric regulation; results in the classic sigmoidal (S-shaped) oxyhemoglobin dissociation curve; referring to hemoglobin's affinity for oxygen increasing after one oxygen has bonded and decreasing after one oxygen has been removed

Front 72

bicarbonate ion (HCO3-)

Back 72

form through which vast majority of CO2 exists in the blood when it is leaving

Front 73

carbonic anhydrase

Back 73

catalyzes the combination reaction between carbon dioxide and water to form carbonic acid (H2CO3); carbonic acid is a weak acid and dissociates into a proton and the bicarbonate ion; this reaction is reversed when the alveolar capillaries in the lungs are reached so we can breathe out carbon dioxide

CO2 (g) + H2O (aq) <--- carbonic anhydrase --->

H2CO3 (aq) <---> H+ (aq) + HCO3- (aq)

Front 74

Starling forces

Back 74

the balance between hydrostatic pressure and osmotic (oncotic) pressure

Front 75

hydrostatic pressure

Back 75

pressure (force per unit area) that the blood exerts against the vessel walls; pushes fluid out of the bloodstream and into the interstitium through the capillary walls

Front 76

osmotic pressure

Back 76

the "sucking" pressure generated by solutes as they attempt to draw water into the bloodstream; forces fluid out at the arteriolar end of a capillary bed

Front 77

oncotic pressure

Back 77

osmotic pressure due to plasma proteins; draws fluid back in at the venule end

Front 78

right shift in the oxyhemoglobin dissociation curve

Back 78

caused by high PaCO2 (carbon dioxide partial pressure within the blood), high [H+], low pH, high temperature and high concentration of 2,3-BPG; reflects a decreased affinity for oxygen in hemoglobin which means more oxygen in tissues

Front 79

2,3-bisphosphoglycerate (2,3-BPG)

Back 79

side product of glycolysis in red blood cells

Front 80

left shift in the oxyhemoglobin curve

Back 80

caused by decreased PaCO2, decreased [H+], decreased temperature and decreased 2,3-BPG; more affinity for oxygen in hemoglobin which means less oxygen in tissues; fetal hemoglobin (HbF) has a higher affinity for oxygen than adult hemoglobin (HbA)

Front 81

renal system

Back 81

urinary system

Front 82

interstitium

Back 82

cells surrounding the blood vessels

Front 83

edema

Back 83

accumulation of excess fluid in the interstitium results in this condition

Front 84

lymph

Back 84

lymphatic fluid (made of white blood cells)

Front 85

thoracic duct

Back 85

channel which returns lymphatic fluid (lymph) to the central circulatory system

Front 86

clots

Back 86

composed of both coagulation factors (proteins) and platelets; prevent (or at least minimize) blood loss

Front 87

collagen and tissue factor

Back 87

contained in the connective tissue and exposed when the endothelium of a blood vessel is damaged

Front 88

coagulation factors

Back 88

secreted by the liver; sense tissue factor and initiate a complex activation cascade in order to make a clot; endpoint of the cascade is the activation of prothrombin to form thrombin by thromboplastin

Front 89

thrombin

Back 89

convert fibrinogen into fibrin

Front 90

fibrin

Back 90

ultimately forms small fibers that aggregate into a woven structure, like a net, that captures red blood cells and other platelets, forming a stable clot over the area of damage

Front 91

plasmin

Back 91

breaks down clots

Front 92

plasminogen

Back 92

generates plasmin