Heart Structure And Function Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

The compartment labeled “A” in the above diagram is the __ . It receives venous (deoxygenated) blood from the body

A

Right atrium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

The compartment labeled “B” in the above diagram is the___. it contracts to send blood to the lungs for gas exchange

A

Right ventricle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The compartment labeled “D” in the above diagram is the ___. It
contracts to send blood to the entire body.

A

Left ventricle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The vessel labeled “E” in the above diagram is the ______. It is the initial conduit for deoxygenated blood to pass to the lungs.

A

Pulmonary artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The vessel labeled “F” in the above diagram is the ______. It is the initial conduit for all oxygenated blood to pass to the entire body.

A

Aorta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The valve labeled “H” is generally called a _______. Don’t worry about left or right on this one. These one-way valves prevent back-flow of blood from adjacent vessels when the bottom chambers relax.

A

Semilunar valve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

. Let’s talk more about the myocardial cells. Cardiac muscle cells are held together, end-to-end, at complex junctions called ________ that consist of interdigitated membrane

A

Intercalated disks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Within the junctions mentioned in the previous question, the cells are physically tethered by these strong connections that allow force created in one cell to be transferred to the adjacent cell.

A

Desmosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

These components of the junctions mentioned in Question 9 allow cardiac muscle cells to be electrically connected. These direct conduits between myocardial cells allow waves of depolarization of to pass rapidly between cells, causing them to contract almost simultaneously

A

Jap junctions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

These specific myocardial cells make up ~99% of the heart, are striated muscle, and have thick and thin filaments organized into sarcomeres

A

Contractile cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

These specific myocardial cells make up ~1% of the heart, and mostly lack thick and thin filaments. Rather they are specialized for passing electrical signals around the heart.

A

Autorhythmic cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

This general category of vessel directly returns blood back to the heart atria.

A

Veins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

This general category of vessels directly receives blood from the heart ventricles.

A

Arteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

These blood vessels are the primary site of vasoconstriction and vasodilation because they contain large amounts of smooth muscle.

A

Arterioles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

These blood vessels are where gas, nutrient, and waste exchange occurs in body tissues.

A

Capillary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

These blood vessels receive deoxygenated blood from the vessels named in the previous question.

A

Venules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

The circuit of the cardiovascular system that conducts deoxygenated blood from the heart to the lungs and returns oxygenated blood back to the heart is called the _______.

A

Pulmonary circuit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

The circuit of the cardiovascular system that conducts oxygenated blood from the heart to body tissues and returns deoxygenated blood back to the heart is called the _______

A

Systemic circuit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

______ defines the amount of blood that is pumped by one ventricle during a single contraction

A

Stroke volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

______ is a term that describes all the electrical and physical events that happen in the heart during one contraction-relaxation cycle.

A

Cardiac cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

If we count the number of contraction – relaxation cycles that happen in 1 minute, that defines a person’s _______

A

Heart rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

The volume of blood entering the heart from the venous circulation at any given moment is technically called ______

A

Venous return

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

______ defines the volume of blood left in a ventricle at the end of its contraction phase.

A

End systolic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

______ defines the maximum amount of blood that a ventricle can hold when it is fully relaxed.

A

End diastolic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

______ describes the time when a heart chamber (atria or ventricles) are contracting and pumping blood.

A

Systole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

______ describes the time when a heart chamber (atria or ventricles) are relaxing and filling with blood.

A

Diastole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

This concept explains that the heart must pump all the blood that returns to it AND theforce of heart contraction is determined by the volume of blood returning to it at any given moment.

A

Frank starling law

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

The total volume of blood pumped by one ventricle during a given period of time ( usually 1 minute) is called

A

Cardiac output

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

These blood vessels have the smallest diameter. They are also the site of exchange for nutrients, wastes, and signal molecules between the blood and body tissues since they are composed only of a single layer of loosely connected endothelial cells.

A

Capillaries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

These blood vessels deliver blood to specific tissues and the smooth muscle cells embedded in their walls give them variable resistance. These characteristics make them ideal for fine tuning blood flow to meet the metabolic demands of different tissues around the body.

A

Arterioles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

These blood vessels collect blood just after it has had a chance to exchange nutrients, wastes, and signal molecules with body tissues and start its return journey to the heart.

A

Venules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

These blood vessels have the widest diameters and therefore hold more than half of the blood in our bodies. They also typically run close to the surface of our skin, so they must have both fibrous tissue for strength and elastic tissue for flexibility.

A

Veins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

These blood vessels are structurally reinforced with elastic and fibrous tissue, since they must withstand the highest blood pressures.

A

Arteries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

When considering blood pressure, two values are always recorded. The ________ pressure represents the maximum pressure that occurs in an artery near the heart and follows ventricular contraction.

A

Systolic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

The ________ pressure represents the minimum pressure in an artery near the heart and coincides with ventricular relaxatio

A

Diastolic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

There are three main factors that determine your blood pressure at any given moment (i.e., when resting, exercising, etc.). One factor, referred to as _______, focuses on how hard your heart is working at that moment. This factor combines the number of beats per minute and the volume of blood pumped per ventricular contraction, both of which are controlled by autonomic efferent pathways.

A

Cardiac output

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Another key factor in determining blood pressure is the water content of the blood plasma. This factor is referred to as _______ and is regulated primarily by the kidneys with guidance from both autonomic and hormonal efferent pathways

A

Total blood volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

A third factor that influences your blood pressure, called ________, is determined by the variable diameter (or radius) of the arterioles. This factor is mostly under tonic sympathetic control and strategically diverts more blood flow to hard-working areas and sends less blood flow to less-essential organs at any given time.

A

Total peripheral resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

With this last point in mind, it should (hopefully) seem logical that the skeletal muscles, liver, and heart muscle itself will all receive _______ blood flow during exercise due to increased metabolic demands. (Choose from “More” or “Less”)

A

More

40
Q

By contrast, it should also (hopefully) seem logical that the digestive system, urinary system, and reproductive organs will all receive ______ blood flow during exercise, since these organs will have lower metabolic activity at that time. (Choose from “More” or “Less”)

A

Less

41
Q

When high-levels of nitric oxide is released as a paracrine signal molecule by neurons, that will cause ________ blood flow to those neurons.

A

Increase

42
Q

We will learn later that an infection or irritation in the skin stimulates immune cells to release high levels of histamine and bradykinin. It should come as no surprise then that the area around the infection will become red and swollen due to _______ blood flow.

A

Increased

43
Q

By contrast, when you have a cut in the skin, thrombocytes (platelets) in the blood will be attracted to the area and release high levels of serotonin. This signal molecule stimulates _______ blood flow in the damaged area to limit its loss from the body as the injury is repaired.

A

Decreased

44
Q

When body tissues (e.g., skeletal muscles) have very high levels of oxygen present, this gas acts as a paracrine signal, leading to _______ blood flow to that area. This change allows cells in the area to use up the surplus oxygen and return conditions to homeostasis.

A

Decreased

45
Q

When body tissues (e.g. skeletal muscles) are very active, they will increase their production of ATP. This in turn causes more production of carbon dioxide and H+ ions, which ultimately decreases the pH of those tissues. Under these conditions, the carbon dioxide and H+ ions will act as paracrine signals to cause _______ blood flow through that area to help return conditions to homeostasis.

A

Increase

46
Q

Vasopressin is a neurohormone released by the posterior pituitary. It is released at high levels when the body becomes dehydrated and has drop in total blood volume, which leads to a drop in blood pressure. Vasopressin therefore acts as a _________ to increase peripheral resistance around the body and help to bring blood pressure back up.

A

Vasoconstrictor

47
Q

Low levels of hormone called angiotensin II are produced when the body is overhydrated and has high blood volume, leading to elevated blood pressure. Under these conditions, angiotensin II functions as a ______ to help bring blood pressure back down.

A

Vasodilator

48
Q

Natriuretic peptides are hormones that are produced at high levels when blood volume and blood pressure are high. Therefore, under these conditions, these hormones function as a ________ to help bring blood pressure back down.

A

Vasodilator

49
Q

There are two main types of capillaries scattered around the body. _______ are located in areas that need maximum exchange between the blood and interstitial fluid, such as in capillaries passing through the kidneys or around the small intestines. These capillaries are extremely leaky, due to their loose junctions between endothelial cells and pores in their plasma membrane.

A

Fenestrated capillary

50
Q

All other areas of the body that just need regular levels of exchange between the blood and interstitial fluid have _______. These capillaries are only moderately leaky at the junctions between endothelial cells.

A

Continuous capillaries

51
Q

These porous blood vessels are not technically capillaries, but they do allow for exchange of blood cells and plasma proteins with surrounding tissues. They are also much wider than standard capillaries. These kinds of vessels are found only in the bone marrow, liver, and spleen.

A

Sinusoids

52
Q

Levels of oxygen, glucose, amino acids, and hormones are higher in the blood plasma passing through capillaries, relative to the interstitial fluid around nearby body cells. By contrast, metabolic wastes, such as carbon dioxide, creatinine, or urea, are released by cells. The level of these molecules is higher in the interstitial fluid than in the blood plasma passing through nearby capillaries. Movement of these solutes into or out of the leaky capillaries occurs down their individual concentration gradients by the process of _____

A

Diffusion

53
Q

Large proteins that are too bulky to pass through loose junctions between endothelial cells or fenestrations use a different mechanism to leave the blood plasma. They enter capillary endothelial cells by endocytosis, get trafficked across the cytoskeleton in vesicles, and then leave these cells by exocytosis to join the interstitial fluid of tissue cells. This membrane transport mechanism is called ______

A

Transcytosis

54
Q

When water leaves capillaries and enters the interstitial fluid around tissue cells, that process is called ____

A

Filtration

55
Q

When water enters capillaries and leaves the interstitial fluid around tissue cells, that process is called _______.

A

Absorption

56
Q

Two pressures dictate how much water leaves a capillary and how much enters it. This pressure drives absorption and uses osmotically- active solutes to pull water from the interstitial fluid into the capillaries.

A

Colloid osmotic pressure

57
Q

This pressure drives filtration and describes the pressure pushing out against the inner walls of the capillaries. This pressure is also typically synonymous with “blood pressure”, at least for the intents and purposes of this class.

A

Hydrostatic pressure

58
Q

When more water leaves a capillary network than enters it, tissue swelling, more technically called ______, will occur in that localized area.

A

Edema

59
Q

This is the term for the liquid matrix of the blood. It is made up of 92% water, 7% dissolved proteins, and 1% other dissolved biomolecules.

A

Plasma

60
Q

The liquid matrix mentioned in the previous question is identical to
interstitial fluid, except for the presence of ______ in blood

A

Plasma proteins

61
Q

This is the most abundant protein in the liquid matrix of the blood. It
makes up about 60% of the total protein content of that fluid

A

Albumin

62
Q

This protein dissolved in the liquid matrix of the blood is essential for
creating clots after an injury to the vascular system occurs

A

Fibrinogen

63
Q

The technical name for red blood cells is _______. They lose their nucleus by the time they enter the bloodstream, where they carry
oxygen and carbon dioxide. They also only live for about 4 months.

A

Erythrocyte

64
Q

The technical name for white blood cells is _______. They are cells of
the immune system and defend the body against pathogens

A

Leukocytes

65
Q

These cellular elements, commonly called platelets, also lack a nucleus
and are critical for blood clotting after a vascular injury

A

Thrombocytes

66
Q

The larger cell type that platelets split off from during development is
called a __________.

A

Megakaryocyte

67
Q

All the cellular elements in blood are descended from a single
precursor cell type known as a __________ stem cell.

A

Pluripotent hematopoietic

68
Q

The cell type noted in the previous question resides in the _______ ,
and can develop into many different cell types.

A

Bone marrow

69
Q

_______ is the term for the synthesis of blood cells, which begins
during embryonic development and continues throughout a person’s
life.

A

Hematopoiesis

70
Q

Signal molecules in this general category control the process named in
the previous question. They are made on-demand (not stored in
vesicles) by any nucleated cell and travel through the blood stream.

A

Cytokines

71
Q

This specific signal molecule stimulates hematopoietic stem cells to grow and differentiate into all types of blood cells, especially white
blood cell

A

Colony stimulating factors

72
Q

This specific signal molecule influences the growth and differentiation
of red blood cells specifically. It is produced by the kidney.

A

Erythropoietin

73
Q

This specific signal molecule influences the growth and differentiation
of the parent cell for platelets.

A

Thrombopoïetin

74
Q

The ratio of red blood cells to plasma is indicated clinically by the _____ and is expressed as a percentage of the total blood volume.

A

Hematocrit

75
Q

Because each red blood cell has lost its _____, they cannot synthesize new proteins to maintain their membrane or enzymes to carry out other repair processes. This contributes to their short, 4-month lifespan.

A

Nucleus

76
Q

Because red blood cells lack ___, they must rely on glycolysis for their ATP production.

A

Mitochondria

77
Q

In some red blood cell disorders, the shape or ______ of the cells can give clues as to the specific disease.

A

Morphology

78
Q

In some red blood cell disorders, the shape or ______ of the cells can give clues as to the specific disease.

A

Morphology

79
Q

For example, in this disorder, the red blood cells change shape to resemble a crescent. This abnormal shape causes these cells to jam up in small blood vessels, blocking blood flow to tissues, which causes tissue damage and sometimes extreme pain.

A

Sickle cell disease

80
Q

When red blood cells are microcytic, often due to an iron deficiency, their _____ is abnormally small

A

Mean corpuscular volume

81
Q

This protein is the main component of red blood cells and is best known for its role in transporting oxygen. We will also see in lecture that it also transports carbon dioxide as well as hydrogen ions.

A

Hemoglobin

82
Q

When blood cells are removed from circulation, the liver converts remnants of the molecule named in the previous question into a colored pigment called ______.

A

Bilirubin

83
Q

The pigment mentioned in the previous question is then used to synthesize _____, which is an important part of the digestive process.

A

Bile

84
Q

If a person has very low levels of hemoglobin in their blood, they have a condition called _____. This condition can be caused by accelerated
red blood cell loss or decreased red blood cell production.

A

Anemia

85
Q

This term includes all the physiological mechanisms engaged to keep blood within a damaged vessel

A

Hemostasis

86
Q

As soon as vessel damage occurs, the first step in repair is a reflex that causes release of paracrine signal molecules that cause _____ in the immediate area, which minimizes blood loss. Putting pressure on a bleeding wound also aids in this underlying process.

A

Vasoconstrict

87
Q

Exposed collagen fibers at the site of damage will cause ______ to adhere and start the process of clotting.

A

Platelets

88
Q

When the cells mentioned in the previous question adhere to the collagen, they become activated and release ____ into the area around the injury. Two specific examples are serotonin and thromboxane A2, which are localized vasoconstrictors to again help minimize blood loss.

A

Cytokines

89
Q

The secretion of the specific signal molecules mentioned in the previous question, along with another called platelet-activating factor (PAF), stimulate more platelet aggregation and more secretion of these signal molecules. This is an example of a (positive or negative) feedback loop.

A

Positive

90
Q

The final hemostatic mechanism is called the ______ and occurs when a fibrin protein mesh ensnares erythrocytes and stabilizes the platelet plug to form a clot (see Figure 16.11b for a visual).

A

Coagulation cascade

91
Q

Once the damaged vessel is repaired through the process of mitosis, the clot retracts when the fibrin mesh is slowly dissolved by an enzyme called ___

A

Plasmin

92
Q

Hemostasis is a delicate balance between too little response (which can lead to excessive bleeding) or too much, which could create a ____ that can block blood flow in an undamaged vessel and deprive all its tissues of vital nutrients.

A

Thrombus

93
Q

_____ are chemicals released by endothelial cells that prevent coagulation from taking place.

A

Anticoagulants

94
Q

The body naturally produces three of the molecules mentioned in the previous question. Two of these have fairly obscure names, like protein C and antithrombin III, but the third is commonly used in a clinical setting to prevent a blood sample from clotting prior to analysis. It is called______.

A

Heparin

95
Q

People who are at risk of developing small blood clots are sometimes told to take one ____ tablet every other day to thin the blood. However, this chemical does not really affect blood viscosity. It actually prevents platelet plug formation and therefore helps to inhibit clot formation and prevent heart attacks or strokes.

A

(  A sprin l l . _ . . )

96
Q

This is the best-known coagulation disorder where one of the factors in the coagulation cascade is either defective or lacking, leading to excessive bleeding.

A

Hemophilia

97
Q

Another important category of protein that is dissolved in the liquid
matrix is _________, which provide defense from foreign invaders by
binding to their surface and “tagging” them for destruction.

A

Immunoglobulin