Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology 1 > Lecture 18- Circulatory system > Flashcards

Lecture 18- Circulatory system Flashcards

1
Q

What does a circulatory system consist of?

A

A muscular pump (heart)
A fluid (blood)
A series of conduits (blood vessels)

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

What is the heart, blood and blood vessels known collectively as?

A

Cardiovascular system

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

What is the function of circulatory systems?

A

To transport things around the body- heat, hormones, respiratory gases, blood cells, platelets, immune system, nutrients, waste products

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

What organisms do not have circulatory systems?

A

Single celled organisms, multicellular organisms with cells close to the external environment

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

Why do some animals not need circulatory systems?

A

Exchange can occur directly with the external environment due to structures and body shapes (such as gastrovascular cavities)

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

What are gastrovascular cavities?

A

Highly branched central cavities

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

In larger animals, what environment do cells exchange with?

A

The extracellular fluid

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

What does the extracellular fluid consist of?

A

Fluid in the circulatory system (blood plasma)

Fluid around the cells (interstital fluid)

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

What is an open circulatory system?

A

Where extracellular fluid combines with fluid of the circulatory system and squeezes through intercellular spaces when the animal moves.

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

How does fluid return to the heart in an open circulatory system?

A

In arthropods- through ostia

In mollusks- open vessels

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

What is a closed circulatory system?

A

Where blood is kept separate from the interstital fluid

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

How does blood move through a closed circulatory system?

A

Blood is pumped through the vascular system by one or more hearts

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

What are the three main advantages of a closed circulatory system?

A
  • Faster transport through vessels than intercellular spaces
  • Blood directed to specific tissues
  • Specialized carriers travel in vessels and transport hormones or nutrients to specific sites
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does the right side of the heart do?

A

Pumps blood through the pulmonary circuit

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

What does the left heart do?

A

Pumps blood through the systemic circuit

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

What are the two types of chambers?

A

Atria, ventricles

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

What is the purpose of valves in the heart?

A

To prevent backflow of blood

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

What valve lies between the atria and ventricles?

A

Atrioventricular valves

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

What do atrioventricular valves do?

A

Prevent backflow when ventricles contract

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

What valves lie between the ventricles and major arteries?

A

The pulmonary valve

The aortic valve

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

What is the purpose of the pulmonary valve and the aortic valve?

A

Prevent backflow when ventricles relax

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

What are the three steps of blood flow through the right side of the heart?

A

Deoxygenated blood from tissues enters the right atrium
Flows through atrioventricular valve into right ventricle
Right ventricle pumps blood through pulmonary valve into pulmonary circuit

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

What veins does the right atrium receive blood from?

A
  • Superior vena cava (from upper body)

- Inferior vena cava (from lower body)

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

What veins does oxygenated blood return to the heart in?

A

Pulmonary veins

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

What are the two phases of of the cardiac cycle?

A

Systole

Diastole

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

What is systole?

A

When ventricles contract

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

What is diastole?

A

When ventricles relax

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

What is the 1st step in the cardiac cycle?

A

The atria contract

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

What is the next step after the atria contract?

A 
'lub'
Ventricles contract
AV valves close
Pressure in ventricle builds
Pulmonary/aortic valve opens
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What happens after the ‘lub’ stage?

A

Blood is pumped out of the ventricles, into the aorta and pulmonary artery.

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

What happens after blood is pumped out of the ventricles into the aorta and pulmonary arteries?

A

‘Dup’
Ventricles relax
Pressure in ventricle falls at the end of sytole
Aortic/pulmonary arteries shut

The the ventricles fill with blood again

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

How are blood pressure changes measured?

A

Sphygmomanometer and a stethoscope

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

What is the systolic value?

A

The pressure needed to compress an artery so blood does not flow

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

What is diastolic value?

A

Pressure needed to allow intermittent flow through the artery

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

What are healthy blood pressure values?

A

120 mm Hg over 70 mm Hg

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

What is blood?

A

A connective tissue made of cells in a liquid extracellular matrix called plasma

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

What is the name of the part of the blood made up of cells?

A

Packed cell volume or hematocrit

38
Q

What are most of the cells in the hematocrit?

A

Erythrocytes- red blood cells- that transport gases

39
Q

Where are red blood cells generated?

A

Bone marrow

40
Q

What is hypoxia?

A

Deficiency in the amount of oxygen reaching tissues

41
Q

What is produced in response to hypoxia?

A

Erythropoietin- a hormone released by the kidneys

42
Q

What activates the genes for erythropoietin in the kidneys?

A

Hypoxia-inducible factor 1 (HIF-1) a transcription factor

43
Q

How are red blood cells formed?

A

Immature red blood cells divide and produce hemoglobin while in the bone marrow,
At 30% hemoglobin the organelles break down
The cell enters circulation

44
Q

How long do red blood cells circulate?

A

About 120 days

45
Q

What happens to red blood cells after 120 days?

A

They rupture as the pass through narrow capillaries, as in the spleen

46
Q

Other than red blood cells, what else does bone marrow produce?

A

Megakaryocytes

47
Q

What do megakaryocytes do?

A

Break off cell fragments called platelets

48
Q

What do platelets do?

A

Initiate blood clotting when activated by collagen exposed in damaged blood vessels

49
Q

What do platelets do once activated?

A

Release chemical clotting factors which activate other platelets

50
Q

What are the 4 main steps in blood clotting?

A
  • Cell damage and platelet activation
  • Inactive enzyme prothrombin converts to active form, thrombin
  • Thrombin cleaves fibrinogen and forms fibrin
  • Fibrin threads form mesh that clots blood and seals vessels
51
Q

Where is prothrombin and fibrinogen found?

A

Circulating in the plasma

52
Q

What does plasma contain?

A 
Gases
Ions
Nutrients
Proteins
Other molecule: hormones, vitamins
53
Q

What type of vessel are arteries and arterioles?

A

Resistance vessels because their resistance can vary

54
Q

How does the resistance of arteries and arterioles vary?

A
  • Walls have elastin and collagen- stretch and recoil

- Smooth muscle cells in the walls allow them to dilate/constrict.

55
Q

What other feature of a resistance vessel can change its resistance?

A

Its diameter

56
Q

How is the resistance of an artery or arteriole controlled?

A

By neuronal and hormonal mechanisms by influencing smooth muscle cells

57
Q

Why is pressure reduced in smaller vessels such as capillaries?

A
  • Arterioles are highly branched

- Capillaries contribute an enormous surface area

58
Q

What is the structure of a capillary?

A

Walls are a single layer of endothelial cells, tiny holes called fenestrations

59
Q

What are capillary beds permeable to?

A

Water, ions, small molecules

Not large proteins

60
Q

What are Starling’s forces?

A

Two opposing forces that maintain water balance in capillaries

61
Q

How do starling’s forces work?

A
  • Blood pressure: forces water and small solutes out

- (Colloidal) Osmotic pressure: created by large molecules that cannot leave

62
Q

Explain how blood pressure changes across a capillary bed.

A

Blood pressure is higher at the arterial end and drops at the venous end

63
Q

How does osmotic pressure change across a capillary?

A

It does not change- it is constant

64
Q

How does blood pressure and osmotic pressure work together in a capillary?

A

Blood pressure is higher than osmotic pressure: fluid leaves

Blood pressure is lower than osmotic pressure: fluid returns

65
Q

What is Edema?

A

An accumulation of fluid in the extracellular space.

66
Q

What can cause edema?

A
  • Fall in blood protein levels (disease)
  • Histamine release: increases capillary permeability, relaxes smooth muscle in arterioles, raises blood pressure in capillaries
67
Q

Other than changes in blood pressure, what else draws water back into capillaries?

A

Bicarbonate ions (HCO3-) converted from CO2 contribute to the osmotic pressure- more at the venous end raises osmotic pressure.

68
Q

What is the blood-brain barrier?

A

Highly selective brain capillaries which do not have fenestrations

69
Q

What are veins also known as?

A

Capacitance vessels

70
Q

Why are veins called capacitance vessels?

A

Because they are very expandable so blood will accumulate in them

71
Q

How is blood returning from below the heart assisted?

A

Skeletal muscle contractions that squeeze the veins

72
Q

How is backflow prevented in veins?

A

One-way valves

73
Q

What is the Frank-Starling law?

A

A property of cardiac muscle cells that increases cardiac output

74
Q

What are the implications of the Frank-Starling law?

A

Cells contract more forcefully if stretched by an increase in the volume of returning blood

75
Q

What does the lymphatic system do?

A

Returns interstital fluid to the blood

76
Q

What is it called when fluid enters the vessels?

A

lymph

77
Q

Where do lymphatic capillaries go?

A

Merge into thoracic ducts- they empty into veins in the neck

78
Q

What are lymph nodes?

A

Sites of lymphocyte production

79
Q

What do lymph nodes do?

A

Remove microorganisms and foreign material by phagocytosis and act as filters.

80
Q

What is atherosclerosis?

A

Hardening of the arteries

81
Q

How does atherosclerosis form?

A

-Endothelial lining is damaged by high blood pressure, smoking, diet, microorganisms
Plaque forms at site of damage
Damaged cells attract migration of smooth muscle cells

82
Q

What happens once smooth muscle cells have been attracted to damaged cells?

A

Smooth muscle cells have cholesterol deposits to make the plaque fatty
Connective tissue and calcium deposits make the artery wall less elastic

83
Q

What can happen if platelets stick to plaque on artery walls?

A

A thrombus may form

84
Q

What do coronary arteries do?

A

Supply blood to the heart muscle

85
Q

What are the symptoms of atherosclerosis?

A

Chest pain, shortness of breath (reduced blood flow in coronary arteries)

86
Q

What happens if a thrombus forms in the coronary artery?

A

Coronary thrombus: myocardial infarction (heart attack)

87
Q

What is an embolus?

A

A piece of thrombus

88
Q

what can an embolus cause?

A

Embolism if it lodges in a blood vessel

89
Q

What happens if the embolism is in the brain?

A

Cells fed by that artery die: a stroke

90
Q

What are some of the causes of atherosclerosis?

A
  • Genetic predisposition
  • Age
  • Environmental risk (smoking, high-fat diet, sedentary)
  • Medical conditions (hypertension, obesity, diabetes)

Biology 1 (16 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions