Structure of the Cardivascular System Flashcards Preview

Higher Biology Unit 2: Physiology & Health > Structure of the Cardivascular System > Flashcards

Flashcards in Structure of the Cardivascular System Deck (52)
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1
Q

What is the cardiovascular system composed of?

A

heart
blood
blood vessels

2
Q

Give the 5 functions of the cardiovascular system?

A

Transporting oxygen and removing carbon dioxide
Transporting nutrients (e.g. glucose) and removing wastes (e.g. urea)
Fighting disease (A mode of transport for WBC)
Transporting hormones
Regulating body temperature

3
Q

What do arterial branches of the aorta supply?

A

oxygenated blood to all parts of the body

4
Q

What does deoxygenated blood leave the organs in and what do they unite to form and where does this lead to?

A

Leaves in the veins . These unite to form the vena cava, which returns blood to the heart.

5
Q

Describe what happens to blood pressure as blood moves away from the heart?

A

a decrease in blood pressure

6
Q

What are the 3 types of blood vessels?

A

Arteries (and arterioles)
Veins (and venules)
Capillaries

7
Q

Describe the structure of an artery?

A

Outer layer of connective tissue containing elastic fibre.
Middle layer - thick smooth muscular layer
Inner layer - elastic fibres
Lining of endothelium
Narrow lumen

8
Q

Describe the structure of a vein?

A

Outer layer of connective tissue containing elastic fibre.
Middle layer - thin smooth muscular layer
Inner layer - elastic fibres
Lining of endothelium
Wide lumen
Valves

9
Q

Give 3 structural differences between an artery and a vein?

A

An artery has a narrower lumen whereas a vein has a wider lumen
An artery has a thick muscular layer whereas a vein has a thin muscular layer
An artery doesn’t have valves whereas a vein does

10
Q

Give 2 functional differences between an artery and a vein?

A

An artery carries blood away from the heart
A vein carries blood back to the heart
(Arteries mainly carry oxygenated blood.)
(Veins mainly carry deoxygenated blood.)

11
Q

What do valves do?

A

prevent the backflow of blood

12
Q

What do arteries branch into ?

A

smaller arteries called arterioles

13
Q

What is blood returned to veins from?

A

smaller veins called venules

14
Q

When does vasoconstriction occur?

A

when the smooth muscle in the walls of the arterioles contract which reduces blood flow.

15
Q

When does vasodilation occur?

A

when the smooth muscle relaxes which increases blood flow to an area

16
Q

What are capillaries composed of?

A

endothelial cells

17
Q

Describe the walls of capillaries?

A

the walls are only one cell thick

18
Q

What do capillaries allow?

A

the exchange of substances between blood and living tissues through their thin walls.

19
Q

In terms exchange of materials in a capillary bed, what does blood arrive in?

A

arteriole at higher pressure than the blood in the capillaries

20
Q

As blood is forced into the narrow exchange vessels, what does it undergo?

A

a form of pressure filtration and much of the plasma (containing small dissolved molecules like glucose, amino acids and essential ions) is squeezed through the thin walls. The liquid is called tissue fluid.

21
Q

How does tissue fluid differ from blood plasma ?

A

it contains little or no plasma protein

22
Q

What is tissue fluid?

A

the liquid which forms around cells after the process of pressure filtration. It contains all the same components of blood plasma other than plasma proteins.

23
Q

In terms exchange of materials in a capillary bed, what does blood leave in?

A

venule at low pressure

24
Q

What happens after the exchange of materials with the body cells?

A

the tissue fluid to blood/circulatory system by OSMOSIS

25
Q

Compare the plasma and tissue fluid?

A
Plasma
Protein plasma
RBC
WBC
(PLATELETS)

Tissue Fluid
Little or no plasma protein
WBC

26
Q

What does tissue fluid supply cells with?

A

glucose (other soluble food molecules), dissolved oxygen and other substances such as ions

27
Q

What does tissue fluid receive to be excreted?

A

carbon dioxide and other metabolic wastes diffuse out of the cells and into the tissue fluid to be excreted

28
Q

What do lymphatic vessels do?

A

absorb excess tissue fluid and return the lymph fluid to the circulatory system i.e. bloodstream

29
Q

What is excess tissue fluid within the lymphatic vessels known as?

A

lymph

30
Q

Describe how lymph in a lymph vessel is forced along the lymphatic system?

A

Flow of lymph through the lymphatic system is brought about mainly by the vessels being periodically compressed when muscles contract during breathing, locomotion and other body movements.

31
Q

What is the importance of the presence of valves in lymphatic vessels?

A

prevent the back flow of lymph

32
Q

Which structures enable lymph to return to the blood circulatory system?

A

the 2 lymphatic ducts, which enters the veins coming from the arms

33
Q

State 2 reasons why the lymphatic system is regarded as a specialised part of the cardiovascular system?

A

It consists of:
lymph fluid that is derived from blood
a system of vessels that returns lymph to the bloodstream

34
Q

What is the job of the heart?

A

to pump blood around the body

35
Q

What happens to the blood at each contraction?

A

it is ejected from the right and left ventricle at the same time

36
Q

Where does the right ventricle send blood to and through what vessel?

A

to the lungs via the pulmonary artery

37
Q

Where does the left ventricle send blood to and through what vessel?

A

to the rest of the body via the aorta

38
Q

Describe the pathway of blood through the heart?

A

Vena cava > Right Atrium> right ventricle> pulmonary artery> lungs > pulmonary vein> Left atrium> left ventricle> aorta

39
Q

Why is the left ventricle wall much thicker than the right?

A

The left ventricle needs to contract to create more pressure so that it can pump blood over a longer distance to the rest of the body. Whereas the right ventricle only has to pump a short distance to the lungs

40
Q

Where does the heart muscle get its blood supply from?

A

coronary artery

41
Q

What are the functions of the heart valves?

A

prevent the backflow of blood

42
Q

Where are the atrio-ventricular valves found?

A

situated between the atria and the ventricles

43
Q

Where are the semi-lunar valves found?

A

situated at the origins of the pulmonary artery and aorta

44
Q

What is cardiac output?

A

the volume of blood pumped be each ventricle per minute

45
Q

What is heart rate?

A

the number of times the heart beats each minute

46
Q

What is stroke volume?

A

the volume of blood pumped by each ventricles during each heart beat

47
Q

How do you calculate cardiac output?

A

HRxSV

48
Q

How do you calculate heart rate?

A

CO/SV

49
Q

How do you calculate stroke volume?

A

CO/HR

50
Q

What are the units for CO?

A

l/min

51
Q

What are the units for HR?

A

beats/min

52
Q

What are the units for SV?

A

ml