CARDIOVASCULAR

Question 1

▪ Pericardium—a double-walled sac
▪ Fibrous pericardium is loose and superficial
▪ Serous membrane is deep to the fibrous pericardium and composed of two layers
1. Parietal pericardium: outside layer that lines the inner surface of the fibrous pericardium
2. Visceral pericardium: next to heart; also known as the epicardium
▪ Serous fluid fills the space between the layers of pericardium, called the pericardial cavity

Answer 1

Coverings of the heart

Question 2

WHAT ARE THE Walls of the heart

Answer 2

1. Epicardium
   ▪ Outside layer; the visceral pericardium
2. Myocardium
   ▪ Middle layer
   ▪ Mostly cardiac muscle
3. Endocardium
   ▪ Inner layer known as endothelium

Question 3

WHAT ARE THE Four chambers of the heart

Answer 3

Atria (right and left)
▪ Receiving chambers
▪ Assist with filling the ventricles
▪ Blood enters under low pressure
•Ventricles (right and left)
▪ Discharging chambers
▪ Thick-walled pumps of the heart
▪ During contraction, blood is propelled into circulation

Question 4

▪ Separates the two atria longitudinally

Answer 4

Interatrial septum

Question 5

▪ Separates the two ventricles longitudinally

Answer 5

Interventricular septum

Question 6

Heart functions as a double pump
▪ Arteries carry blood away from the heart
▪ Veins carry blood toward the heart
Double pump
▪ Right side works as the pulmonary circuit pump
▪ Left side works as the systemic circuit pump

Answer 6

•Heart functions as a double pump
▪ Arteries carry blood away from the heart
▪ Veins carry blood toward the heart
Double pump
▪ Right side works as the pulmonary circuit pump
▪ Left side works as the systemic circuit pump

Question 7

▪ Blood flows from the right side of the heart to the lungs
and back to the left side of the heart
▪ Blood is pumped out of right side through the pulmonary trunk, which splits into pulmonary arteries and takes oxygen-poor blood to lungs
▪ Oxygen-rich blood returns to the heart from the lungs via pulmonary veins

Answer 7

Pulmonary circulation

Question 8

WHAT TYPE OF CIRCULATION
▪ Oxygen-rich blood returned to the left side of the heart
is pumped out into the aorta
▪ Blood circulates to systemic arteries and to all body tissues
▪ Left ventricle has thicker walls because it pumps blood to the body through the systemic circuit
▪ Oxygen-poor blood returns to the right atrium via systemic veins, which empty blood into the superior or inferior vena cava

Answer 8

Systemic circulation

Question 9

•Heart Valves
▪Allow blood to flow in only one direction, to prevent backflow
▪ Atrioventricular (AV) valves—between atria and ventricles
▪ Left AV valve: bicuspid (mitral) valve
▪ Right AV valve: tricuspid valve
▪ Semilunar valves—between ventricle and artery
▪ Pulmonary semilunar valve
▪ Aortic semilunar valve

Answer 9

•Heart Valves
▪Allow blood to flow in only one direction, to prevent backflow
▪ Atrioventricular (AV) valves—between atria and ventricles
▪ Left AV valve: bicuspid (mitral) valve
▪ Right AV valve: tricuspid valve
▪ Semilunar valves—between ventricle and artery
▪ Pulmonary semilunar valve
▪ Aortic semilunar valve

Question 10

•AV valves - ATRIOVENTRICULAR
▪ Anchored the cusps in place by chordae tendineae to
the walls of the ventricles
▪ Open during heart relaxation, when blood passively fills the chambers
▪ Closed during ventricular contraction
•Semilunar valves
▪ Closed during heart relaxation
▪ Open during ventricular contraction
▪Valves open and close in response to pressure changes in the heart

Answer 10

AV valves
▪ Anchored the cusps in place by chordae tendineae to
the walls of the ventricles
▪ Open during heart relaxation, when blood passively fills the chambers
▪ Closed during ventricular contraction

Semilunar valves
▪ Closed during heart relaxation
▪ Open during ventricular contraction
▪Valves open and close in response to pressure changes in the heart

Question 11

▪Blood in the heart chambers does not nourish the myocardium
▪The heart has its own nourishing circulatory system consisting of:

Answer 11

▪ Coronary arteries—branch from the aorta to supply the heart muscle with oxygenated blood
▪ Cardiac veins—drain the myocardium of blood
▪ Coronary sinus—a large vein on the posterior of the
heart; receives blood from cardiac veins

Blood also empties into the right atrium via the coronary sinus

Question 12

—branch from the aorta to supply the heart muscle with oxygenated blood

Answer 12

▪ Coronary arteries

Question 13

—drain the myocardium of blood

Answer 13

▪ Cardiac veins

Question 14

—a large vein on the posterior of the
heart; receives blood from cardiac veins

Answer 14

Coronary sinus

Question 15

▪Intrinsic conduction system of the heart
▪ Cardiac muscle contracts spontaneously and
independently of nerve impulses
▪ Spontaneous contractions occur in a regular and continuous way
▪ Atrial cells beat 60 times per minute
▪ Ventricular cells beat 20−40 times per minute
▪ Need a unifying control system—the intrinsic conduction system (nodal system)

Answer 15

▪Intrinsic conduction system of the heart
▪ Cardiac muscle contracts spontaneously and
independently of nerve impulses
▪ Spontaneous contractions occur in a regular and continuous way
▪ Atrial cells beat 60 times per minute
▪ Ventricular cells beat 20−40 times per minute
▪ Need a unifying control system—the intrinsic conduction system (nodal system)

Question 16

▪Intrinsic conduction system of the heart (continued)
▪ Two systems regulate heart activity
▪ Autonomic nervous system
▪ Intrinsic conduction system, or the nodal system
▪ Sets the heart rhythm
▪ Composed of special nervous tissue
▪ Ensures heart muscle depolarization in one direction only (atria to ventricles)
▪ Enforces a heart rate of 75 beats per minute

Answer 16

▪Intrinsic conduction system of the heart (continued)
▪ Two systems regulate heart activity
▪ Autonomic nervous system
▪ Intrinsic conduction system, or the nodal system
▪ Sets the heart rhythm
▪ Composed of special nervous tissue
▪ Ensures heart muscle depolarization in one direction only (atria to ventricles)
▪ Enforces a heart rate of 75 beats per minute

Question 17

▪Intrinsic conduction system of the heart (continued) ▪Components include:
▪ Sinoatrial (SA) node
▪ Located in the right atrium
▪ Serves as the heart’s pacemaker
▪ Atrioventricular (AV) node is at the junction of the atria and ventricles
▪ Atrioventricular (AV) bundle (bundle of His) and bundle branches are in the interventricular septum
▪ Purkinje fibers spread within the ventricle wall muscles

Answer 17

▪Intrinsic conduction system of the heart (continued) ▪Components include:
▪ Sinoatrial (SA) node
▪ Located in the right atrium
▪ Serves as the heart’s pacemaker
▪ Atrioventricular (AV) node is at the junction of the atria and ventricles
▪ Atrioventricular (AV) bundle (bundle of His) and bundle branches are in the interventricular septum
▪ Purkinje fibers spread within the ventricle wall muscles

Question 18

rapid heart rate, over 100 beats per minute

Answer 18

▪ Tachycardia—

Question 19

▪—slow heart rate, less than 60 beats per minutes

Answer 19

Bradycardia

Question 20

Cardiac cycle and heart sounds
▪ The cardiac cycle refers to one complete heartbeat, in
which both atria and ventricles contract and then relax ▪ Systole = contraction
▪ Diastole = relaxation
▪ Average heart rate is approximately 75 beats per minute
▪ Cardiac cycle length is normally 0.8 second

Answer 20

Cardiac cycle and heart sounds
▪ The cardiac cycle refers to one complete heartbeat, in
which both atria and ventricles contract and then relax ▪ Systole = contraction
▪ Diastole = relaxation
▪ Average heart rate is approximately 75 beats per minute
▪ Cardiac cycle length is normally 0.8 second

Question 21

▪ Heart is relaxed
▪ Pressure in heart is low
▪ Atrioventricular valves are open
▪ Blood flows passively into the atria and into ventricles ▪ Semilunar valves are closed

Answer 21

)
Atrial diastole (ventricular filling)

Cardiac cycle and heart sounds (continued

Question 22

▪ Ventricles remain in diastole
▪ Atria contract
▪ Blood is forced into the ventricles to complete ventricular filling

Answer 22

▪Atrial systole

Cardiac cycle and heart sounds (continued)

Question 23

▪ Atrial systole ends; ventricular systole begins
▪ Intraventricular pressure rises
▪ AV valves close
▪ For a moment, the ventricles are completely closed chambers

Answer 23

Isovolumetric contraction

Question 24

▪ Ventricles continue to contract
▪ Intraventricular pressure now surpasses the pressure in the major arteries leaving the heart
▪ Semilunar valves open
▪ Blood is ejected from the ventricles
▪ Atria are relaxed and filling with blood

Answer 24

Ventricular systole (ejection phase)

Cardiac cycle and heart sounds

Question 25

▪ Ventricular diastole begins ▪ Pressure falls below that in the major arteries ▪ Semilunar valves close ▪ For another moment, the ventricles are completely closed chambers ▪ When atrial pressure increases above intraventricular pressure, the AV valves open

Answer 25

Isovolumetric relaxation

Question 26

▪ ▪—longer, louder heart sound caused by the closing of the AV valves

Answer 26

Lub - Heart sounds

Question 27

▪—short, sharp heart sound caused by the closing of the semilunar valves at the end of ventricular systole

Answer 27

Dup Heart sounds

Question 28

What do u call the ▪ Amount of blood pumped by each side (ventricle) of the heart in 1 minute

Answer 28

Cardiac output (CO)

Question 29

What do u call the ▪ Volume of blood pumped by each ventricle in one contraction (each heartbeat) ▪ About 70 ml of blood is pumped out of the left ventricle with each heartbeat

Answer 29

Stroke volume (SV)

Question 30

▪ Typically 75 beats per minute

Answer 30

Heart rate (HR)

Question 31

▪Cardiac output is the product of the heart rate (HR) and the stroke volume (SV) ▪CO = HR × SV ▪ CO = HR (75 beats/min) × SV (70 ml/beat) ▪ CO = 5250 ml/min = 5.25 L/min

Answer 31

▪Cardiac output is the product of the heart rate (HR) and the stroke volume (SV) ▪CO = HR × SV ▪ CO = HR (75 beats/min) × SV (70 ml/beat) ▪ CO = 5250 ml/min = 5.25 L/min

Question 32

▪Regulation of stroke volume ▪ 60 percent of blood in ventricles (about 70 ml) is pumped with each heartbeat ▪ Starling’s law of the heart ▪ The critical factor controlling SV is how much cardiac muscle is stretched ▪ The more the cardiac muscle is stretched, the stronger the contraction ▪ Venous return is the important factor influencing the stretch of heart muscle

Answer 32

▪Regulation of stroke volume ▪ 60 percent of blood in ventricles (about 70 ml) is pumped with each heartbeat ▪ Starling’s law of the heart ▪ The critical factor controlling SV is how much cardiac muscle is stretched ▪ The more the cardiac muscle is stretched, the stronger the contraction ▪ Venous return is the important factor influencing the stretch of heart muscle

Question 33

▪Factors modifying basic heart rate 1. Neural (ANS) controls ▪ Sympathetic nervous system speeds heart rate ▪ Parasympathetic nervous system, primarily vagus nerve fibers, slow and steady the heart rate 2. Hormones and ions ▪ Epinephrine and thyroxine speed heart rate ▪ Excess or lack of calcium, sodium, and potassium ions also modify heart activity 3. Physical factors ▪ Age, gender, exercise, body temperature influence heart rate

Answer 33

▪Factors modifying basic heart rate 1. Neural (ANS) controls ▪ Sympathetic nervous system speeds heart rate ▪ Parasympathetic nervous system, primarily vagus nerve fibers, slow and steady the heart rate 2. Hormones and ions ▪ Epinephrine and thyroxine speed heart rate ▪ Excess or lack of calcium, sodium, and potassium ions also modify heart activity 3. Physical factors ▪ Age, gender, exercise, body temperature influence heart rate

Question 34

▪ Vessels that carry blood away from the heart ▪

Answer 34

Arteries and arterioles

Question 35

▪ Vessels that play a role in exchanges between tissues and blood

Answer 35

▪ Capillary beds

Question 36

Vessels that return blood toward the heart

Answer 36

▪ Venules and veins

Question 37

▪Three layers (tunics) in blood vessels (except the capillaries)

Answer 37

1.Tunica intima forms a friction-reducing lining ▪ Endothelium 2.Tunica media ▪ Smooth muscle and elastic tissue ▪ Controlled by sympathetic nervous system 3. Tunica externa forms protective outermost covering ▪ Mostly fibrous connective tissue ▪ Supports and protects the vessel

Question 38

Structural differences in arteries, veins, and capillaries ▪ Arteries have a heavier, stronger, stretchier tunica media than veins to withstand changes in pressure ▪ Veins have a thinner tunica media than arteries and operate under low pressure ▪ Veins also have valves to prevent backflow of blood ▪ Lumen of veins is larger than that of arteries ▪ Skeletal muscle “milks” blood in veins toward the heart

Answer 38

Structural differences in arteries, veins, and capillaries ▪ Arteries have a heavier, stronger, stretchier tunica media than veins to withstand changes in pressure ▪ Veins have a thinner tunica media than arteries and operate under low pressure ▪ Veins also have valves to prevent backflow of blood ▪ Lumen of veins is larger than that of arteries ▪ Skeletal muscle “milks” blood in veins toward the heart

Question 39

Structural differences in arteries, veins, and capillaries (continued) ▪ Only one cell layer thick (tunica intima) ▪ Allow for exchanges between blood and tissue ▪ Form networks called capillary beds that consist of: ▪ A vascular shunt ▪ True capillaries ▪ Blood flow through a capillary bed is known as microcirculation

Answer 39

▪ Capillaries

Question 40

WHAT DO U CALL THE ▪ Branch off a terminal arteriole ▪ Empty directly into a postcapillary venule ▪ Entrances to capillary beds are guarded by precapillary sphincters

Answer 40

▪ True capillaries ▪Structural differences in arteries, veins, and capillaries (continued)

Question 41

Major arteries of systemic circulation Aorta ▪ Largest artery in the body ▪ Leaves from the left ventricle of the heart Regions ▪ Ascending aorta—leaves the left ventricle ▪ Aortic arch—arches to the left ▪ Thoracic aorta—travels downward through the thorax ▪ Abdominal aorta—passes through the diaphragm into the abdominopelvic cavity

Answer 41

Major arteries of systemic circulation Aorta ▪ Largest artery in the body ▪ Leaves from the left ventricle of the heart Regions ▪ Ascending aorta—leaves the left ventricle ▪ Aortic arch—arches to the left ▪ Thoracic aorta—travels downward through the thorax ▪ Abdominal aorta—passes through the diaphragm into the abdominopelvic cavity

Question 42

WHAT DO U CALL THE BRANCHES THAT ▪ Right and left coronary arteries serve the heart

Answer 42

Arterial branches of the ascending aorta ▪Major arteries of systemic circulation (continued) ▪

Question 43

Major arteries of systemic circulation (continued) =Arterial branches of the aortic arch •Brachiocephalic trunk splits into the: ▪ Right common carotid artery ▪ Right subclavian artery =Left common carotid artery splits into the: ▪ Left internal and external carotid arteries =Left subclavian artery branches into the: ▪ Vertebral artery ▪ In the axilla, the subclavian artery becomes the axillary artery → brachial artery → radial and ulnar arteries

Answer 43

Major arteries of systemic circulation (continued) =Arterial branches of the aortic arch •Brachiocephalic trunk splits into the: ▪ Right common carotid artery ▪ Right subclavian artery =Left common carotid artery splits into the: ▪ Left internal and external carotid arteries =Left subclavian artery branches into the: ▪ Vertebral artery ▪ In the axilla, the subclavian artery becomes the axillary artery → brachial artery → radial and ulnar arteries

Question 44

▪ Intercostal arteries supply the muscles of the thorax wall ▪ Other branches of the thoracic aorta (not illustrated) supply the: ▪ Lungs (bronchial arteries) ▪ Esophagus (esophageal arteries) ▪ Diaphragm (phrenic arteries)

Answer 44

▪ Arterial branches of the thoracic aorta Major arteries of systemic circulation (continued)

Question 45

▪ Celiac trunk is the first branch of the abdominal aorta. Three branches are: 1. Left gastric artery (stomach) 2. Splenic artery (spleen) 3. Common hepatic artery (liver) ▪ Superior mesenteric artery supplies most of the small intestine and first half of the large intestine

Answer 45

▪ Arterial branches of the abdominal aorta ▪Major arteries of systemic circulation (continued)

Question 46

▪ Left and right renal arteries (kidney) ▪ Left and right gonadal arteries ▪ Ovarian arteries in females serve the ovaries ▪ Testicular arteries in males serve the testes ▪ Lumbar arteries serve muscles of the abdomen and trunk

Answer 46

▪Major arteries of systemic circulation (continued) ▪ Arterial branches of the abdominal aorta (continued)

Question 47

▪ Inferior mesenteric artery serves the second half of the large intestine ▪ Left and right common iliac arteries are the final branches of the aorta ▪ Internal iliac arteries serve the pelvic organs ▪ External iliac arteries enter the thigh → femoral artery → popliteal artery → anterior and posterior tibial arteries

Answer 47

▪ Arterial branches of the abdominal aorta (continued) ▪Major arteries of systemic circulation (continued)

Question 48

▪Major veins of systemic circulation ▪ Superior vena cava and inferior vena cava enter the right atrium of the heart ▪ Superior vena cava drains the head and arms ▪ Inferior vena cava drains the lower body

Answer 48

▪Major veins of systemic circulation ▪ Superior vena cava and inferior vena cava enter the right atrium of the heart ▪ Superior vena cava drains the head and arms ▪ Inferior vena cava drains the lower body

Question 49

▪Major veins of systemic circulation (continued) ▪ Veins draining into the superior vena cava ▪ Radial and ulnar veins → brachial vein → axillary vein ▪ Cephalic vein drains the lateral aspect of the arm and empties into the axillary vein ▪ Basilic vein drains the medial aspect of the arm and empties into the brachial vein ▪ Basilic and cephalic veins are joined at the median cubital vein (elbow area)

Answer 49

▪Major veins of systemic circulation (continued) ▪ Veins draining into the superior vena cava ▪ Radial and ulnar veins → brachial vein → axillary vein ▪ Cephalic vein drains the lateral aspect of the arm and empties into the axillary vein ▪ Basilic vein drains the medial aspect of the arm and empties into the brachial vein ▪ Basilic and cephalic veins are joined at the median cubital vein (elbow area)

Question 50

▪Major veins of systemic circulation (continued) ▪ Veins draining into the superior vena cava (continued) ▪ Subclavian vein receives: ▪ Venous blood from the arm via the axillary vein ▪ Venous blood from skin and muscles via external jugular vein ▪ Vertebral vein drains the posterior part of the head ▪ Internal jugular vein drains the dural sinuses of the brain

Answer 50

▪Major veins of systemic circulation (continued) ▪ Veins draining into the superior vena cava (continued) ▪ Subclavian vein receives: ▪ Venous blood from the arm via the axillary vein ▪ Venous blood from skin and muscles via external jugular vein ▪ Vertebral vein drains the posterior part of the head ▪ Internal jugular vein drains the dural sinuses of the brain

Question 51

▪ Veins draining into the superior vena cava (continued) ▪ Left and right brachiocephalic veins receive venous blood from the:

Answer 51

▪ Subclavian veins ▪ Vertebral veins ▪ Internal jugular veins

Question 52

▪ Brachiocephalic veins join to form the superior vena cava → right atrium of heart ▪ Azygos vein drains the thorax

Answer 52

▪ Brachiocephalic veins join to form the superior vena cava → right atrium of heart ▪ Azygos vein drains the thorax

Question 53

▪Major veins of systemic circulation (continued) ▪ Veins draining into the inferior vena cava ▪ Anterior and posterior tibial veins and fibial veins drain the legs ▪ Posterior tibial vein → popliteal vein → femoral vein → external iliac vein ▪ Great saphenous veins (longest veins of the body) receive superficial drainage of the legs ▪ Each common iliac vein (left and right) is formed by the union of the internal and external iliac vein on its own side

Answer 53

▪Major veins of systemic circulation (continued) ▪ Veins draining into the inferior vena cava ▪ Anterior and posterior tibial veins and fibial veins drain the legs ▪ Posterior tibial vein → popliteal vein → femoral vein → external iliac vein ▪ Great saphenous veins (longest veins of the body) receive superficial drainage of the legs ▪ Each common iliac vein (left and right) is formed by the union of the internal and external iliac vein on its own side

Question 54

▪Major veins of systemic circulation (continued) ▪ Veins draining into the inferior vena cava (continued) ▪ Right gonadal vein drains the right ovary in females and right testicle in males ▪ Left gonadal vein empties into the left renal vein ▪ Left and right renal veins drain the kidneys ▪ Hepatic portal vein drains the digestive organs and travels through the liver before it enters systemic circulation ▪ Left and right hepatic veins drain the liver

Answer 54

▪Major veins of systemic circulation (continued) ▪ Veins draining into the inferior vena cava (continued) ▪ Right gonadal vein drains the right ovary in females and right testicle in males ▪ Left gonadal vein empties into the left renal vein ▪ Left and right renal veins drain the kidneys ▪ Hepatic portal vein drains the digestive organs and travels through the liver before it enters systemic circulation ▪ Left and right hepatic veins drain the liver

Question 55

▪Arterial supply of the brain and the circle of Willis ▪ Internal carotid arteries divide into: ▪ Anterior and middle cerebral arteries ▪ These arteries supply most of the cerebrum ▪ Vertebral arteries join once within the skull to form the basilar artery ▪ Basilar artery serves the brain stem and cerebellum

Answer 55

▪Arterial supply of the brain and the circle of Willis ▪ Internal carotid arteries divide into: ▪ Anterior and middle cerebral arteries ▪ These arteries supply most of the cerebrum ▪ Vertebral arteries join once within the skull to form the basilar artery ▪ Basilar artery serves the brain stem and cerebellum

Question 56

Hepatic portal circulation is formed by veins draining the digestive organs, which empty into the hepatic portal vein

Answer 56

▪Digestive organs ▪ Spleen ▪ Pancreas

Question 57

▪ Measurements of arterial pulse, blood pressure, respiratory rate, and body temperature

Answer 57

Vital signs

Question 58

▪ Alternate expansion and recoil of a blood vessel wall (the pressure wave) that occurs as the heart beats ▪ Monitored at pressure points in superficial arteries, where pulse is easily palpated ▪ Pulse averages 70 to 76 beats per minute at rest, in a healthy person

Answer 58

▪Arterial pulse

Question 59

▪ The pressure the blood exerts against the inner walls of the blood vessels ▪ The force that causes blood to continue to flow in the blood vessels

Answer 59

▪Blood pressure

Question 60

▪ When the ventricles contract: ▪ Blood is forced into elastic arteries close to the heart ▪ Blood flows along a descending pressure gradient ▪ Pressure decreases in blood vessels as distance from the heart increases ▪ Pressure is high in the arteries, lower in the capillaries, and lowest in the veins

Answer 60

▪Blood pressure gradient

Question 61

▪Measuring blood pressure ▪ Two arterial blood pressures are measured ▪ Systolic—pressure in the arteries at the peak of ventricular contraction ▪ Diastolic—pressure when ventricles relax ▪ Expressed as systolic pressure over diastolic pressure in millimeters of mercury (mm Hg) ▪ For example, 120/80 mm Hg ▪ Auscultatory method is an indirect method of measuring systemic arterial blood pressure, most often in the brachial artery

Answer 61

▪Measuring blood pressure ▪ Two arterial blood pressures are measured ▪ Systolic—pressure in the arteries at the peak of ventricular contraction ▪ Diastolic—pressure when ventricles relax ▪ Expressed as systolic pressure over diastolic pressure in millimeters of mercury (mm Hg) ▪ For example, 120/80 mm Hg ▪ Auscultatory method is an indirect method of measuring systemic arterial blood pressure, most often in the brachial artery

Question 62

▪Measuring blood pressure ▪ Two arterial blood pressures are measured

Answer 62

▪ Systolic—pressure in the arteries at the peak of ventricular contraction ▪ Diastolic—pressure when ventricles relax

Question 63

is an indirect method of measuring systemic arterial blood pressure, most often in the brachial artery

Answer 63

▪ Auscultatory method

Question 64

Neural factors: the autonomic nervous system

Answer 64

▪ Parasympathetic nervous system has little to no effect on blood pressure ▪ Sympathetic nervous system promotes vasoconstriction (narrowing of vessels), which increases blood pressure

Question 65

Renal factors: the kidneys ▪ Kidneys regulate blood pressure by altering blood volume ▪ If blood pressure is too high, the kidneys release water in the urine ▪ If blood pressure is too low, the kidneys release renin to trigger formation of angiotensin II, a vasoconstrictor ▪ Angiotensin II stimulates release of aldosterone, which enhances sodium (and water) reabsorption by kidneys

Answer 65

Renal factors: the kidneys ▪ Kidneys regulate blood pressure by altering blood volume ▪ If blood pressure is too high, the kidneys release water in the urine ▪ If blood pressure is too low, the kidneys release renin to trigger formation of angiotensin II, a vasoconstrictor ▪ Angiotensin II stimulates release of aldosterone, which enhances sodium (and water) reabsorption by kidneys

Question 66

▪Effects of various factors on blood pressure (continued) ▪Temperature ▪ Heat has a vasodilating effect ▪ Cold has a vasoconstricting effect ▪ Chemicals ▪ Various substances can cause increases or decreases in blood pressure ▪ Epinephrine increases heart rate and blood pressure

Answer 66

▪Effects of various factors on blood pressure (continued) ▪Temperature ▪ Heat has a vasodilating effect ▪ Cold has a vasoconstricting effect ▪ Chemicals ▪ Various substances can cause increases or decreases in blood pressure ▪ Epinephrine increases heart rate and blood pressure

Question 67

pressure ranges from 110 to 140 mm Hg

Answer 67

▪ Systolic pressure

Question 68

▪ pressure ranges from 70 to 80 mm Hg

Answer 68

Diastolic pressure

Question 69

▪ Low systolic (below 100 mm Hg) ▪ Often associated with illness ▪ Acute hypotension is a warning sign for circulatory shock

Answer 69

▪ Hypotension (low blood pressure)

Question 70

▪ ▪ Sustained elevated arterial pressure of 140/90 mm Hg ▪ Warns of increased peripheral resistance

Answer 70

Hypertension (high blood pressure)

Question 71

▪In an embryo ▪ The heart develops as a simple tube and pumps blood by week 4 of pregnancy ▪ The heart becomes a four-chambered organ capable of acting as a double pump over the next 3 weeks

Answer 71

▪In an embryo ▪ The heart develops as a simple tube and pumps blood by week 4 of pregnancy ▪ The heart becomes a four-chambered organ capable of acting as a double pump over the next 3 weeks

Question 72

▪ Carries nutrients and oxygen from maternal blood to fetal blood ▪ Fetal wastes move from fetal blood to maternal blood ▪ Houses: ▪ One umbilical vein, which carries nutrient- and oxygen- rich blood to the fetus ▪ Two umbilical arteries, which carry wastes and carbon dioxide–rich blood from the fetus to placenta

Answer 72

▪Umbilical cord

Question 73

▪Age-related problems associated with the cardiovascular system include: ▪ Weakening of venous valves ▪Varicose veins ▪Progressive arteriosclerosis ▪ Hypertension resulting from loss of elasticity of vessels ▪ Coronary artery disease resulting from fatty, calcified deposits in the vessels

Answer 73

▪Age-related problems associated with the cardiovascular system include: ▪ Weakening of venous valves ▪Varicose veins ▪Progressive arteriosclerosis ▪ Hypertension resulting from loss of elasticity of vessels ▪ Coronary artery disease resulting from fatty, calcified deposits in the vessels