Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

ESA2 Callum's Cards - Complete > CVS S1 - Introduction to CVS + Anatomy of CVS + DR Work > Flashcards

CVS S1 - Introduction to CVS + Anatomy of CVS + DR Work Flashcards

1
Q

Where does exchange of substances between the blood and tissues occur?

A

Capillaries

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

What is the major mechanism of substance exchange between the blood and tissues?

A

Diffusion (98%)

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

Diffusion is affected by what 3 factors?

A

Area available for exchange

Diffusion resistance

Concentration gradient

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

How is area for exchange of substances through capillaries determined?

A

Determined by ‘Capillary density’ - Capillaries per unit volume

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

Where is capillary density highest?

Are all capillaries always perfused?

A

In tissues with the highest metabolic activity

Nope

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

What is meant by diffusion resistance and how is it determined?

A

The difficulty of movement through the barrier formed by the capillaries

Determined by:

The nature of the barrier and the nature of the molecules that are diffusing

The distance over which the diffusion occurs
i.e.’Path length’

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

What effect does concentration gradient between the blood and tissues have on diffusion?

A

Larger concentration gradient means a greater rate of diffusion, the opposite is also true

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

How is concentration gradient between blood and tissues determined?

A

Gradient depends on concentration of substances in blood

Which is in turn affected by the rate of flow, unless blood is supplied at an adequate rate the gradient will dissipate

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

How much blood must the cardiovascular system supply to the body as a whole?

A

between 5 and 25L of blood per minute

5L at rest

Up to 25L in strenuous conditions

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

What is the minimum and maximum rate of blood flow (per minute) to the following organs/systems?

Brain
Heart
Kidneys
Gut
Muscle
Skin
Other
A

Brain, 0.75L - 0.75L

Heart, 0.3L - 1.2L

Kidneys, 1.2L - 1.2L

Gut, 1.4L - 2.4L

Muscle, 1.0L - 16.0L

Skin, 0.2L - 2.5L

Other, 0.2L - 0.2L

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

What is meant by ‘Perfusion rate’?

A

Rate of blood flow

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

Apart from the brain, where else must the cardiovascular system maintain a contant perfusion of?

A

Heart Muscle

Kidneys

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

What are the 4 main functional components of the cardiovascular system?

A

A Pump (The heart)

Distribution vessels (Arteries)

Flow Control

Capacitance

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

What is meant by ‘Flow control’ in terms of the cardiovacsular system?

How is this control achieved?

A

Flow control is the control of cardiac output, so that it might be distributed appropriately

Flow is restricted in parts of the body that are easy to perfuse, driving blood to areas that are not so easy to perfuse

This is achieved with resistance vessels, namely arterioles and pre-capillary sphincters

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

What is meant by ‘Capacitance’ in terms of the cardiovascular system?

A

Capacitance is the ability to cope with changes in cardiac output

This is a store of blood that can be called on to cope with temporary imbalance in the amount of blood returning to the heart and the required cardiac output.

This store is the veins

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

How is the blood distributed between:

Arteries and arterioles
Capillaries
Heart and lungs
Veins

What is the total blood volume?

A

Arteries and arterioles - 0.55L (11%)

Capillaries - 0.25L (5%)

Heart and lungs - 0.85L (17%)

Veins - 3.35L (67%)

Total volume of ~5L

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

Where is the heart located in the body?

A

The middle mediastinum

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

What is the pericardium?

Describe its location and function

A

A fibroserous sac surrounding the heart and the roots of the great vessels

It is made up of 2 serious membranes, the visceral (lies against the heart) and the parietal layer

The space between is filled with serous fluid, allowing relatively frictionless motion of the heart

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

What relationship do the phrenic nerves have with the heart?

A

Phrenic nerves are responsible for innervation of the pericardium

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

What is pericarditis?

What is the major problem associated with pericarditis?

A

Inflammation of the pericardium

Commonly due to infection or post infarct

Accumulation of fluid in the pericardium (pericardial effusion) can lead to cardiac tamponade.

Cardiac tamponade is a condition in which there is so much fluid in the pericardium it restricts inflow of blood into the heart.

This can be rapidly fatal

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

What are the major vessels entering and leaving the heart?

A

Entering:

Inferior and superior vena cavae to the right atrium

Pulmonary enter the left atrium

Leaving:

Pulmonary artery from the right ventricle

Aorta from the left ventricle

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

Where do the coronary arteries originate from?

A

The right and left aortic sinus found branching from the ascending aorta

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

Describe briefly the course of the Right coronary artery and list the major branches.

A

Originates from right aortic sinus

Passes anteriorly between the right auricle and the pulmonary trunk

Passes through the coronary sulcus between the right ventricle and atrium until it reaches the base of the heart

Branches:

Right marginal branch
Posterior interventricular artery

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

Describe briefly the course of the Left coronary artery and list the major branches

A

Originates from the left aortic sinus

Passes between the pulmonary trunk and the left auricle before entering the coronary sulcus

While still posterior to the pulmonary trunk, it divides.

Divisions are:

Anterior interventricular branch - Descends towards apex

Circumflex branch - Courses towards the left through the coronary sulcus, gives off the left marginal branch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Where is the coronary sinus found and what are its major tributaries?
Found inferior to the left atrium Tributaries are the great, middle, small and posterior cardiac veins
26
Where is the great cardiac vein found?
Originates from the apex Travels up the anterior interventricular sulcus as the 'anterior interventricular vein' Upon reaching the coronary sulcus the great cardiac vein turns to the left and continues on in the coronary sulcus until it reaches the coronary sinus
27
What is the function of arteries?
Carry blood away from the heart to the capillary beds
28
Outline the progression in types of artery from the heart to the capillary beds
Heart Large elastic arteries Medium muscular arteries Arterioles Meta-arterioles Capillaries
29
What is the basic structure of an artery or vein?
Tunica intima - Next to lumen Tunica media Tunica adventitia - Outer layer
30
Describe in detail the structure of Elastic arteries
Tunica intima: Endothelial cells have long axis parallel with long axis of artery Narrow sub endothelium of connective tissue and discontinuous elastic lamina Tunica Media: 40-70 fenestrated elastic membranes (elastin) with smooth muscle cells and collagen between these lamellae Thin external elastic lamina may be present Tunica adventitia: ``` Layer of fibroelastic connective tissue Vasa vasorum (Lymphatic vessels and nerve fibres) ```
31
What is the function of elastic arteries?
Expand slightly during systole
32
Describe in detail the structure of muscular arteries
Tunica intima: - Endothelium with thick internal elastic lamina Tunica media: - 40 layers of smooth muscle connected by gap junctions for coordinated contraction - Prominent external elastic lamina with fenestrations Tunica adventitia: - Thin layer of fibroelastic connective tissue - Contains vasa vasorum (not very prominent) - Also contains lymphatic vessels and (unmyelinated) nerve fibres
33
What are the vasa vasorum? Why might an artery contain vasa vasorum?
Smaller blood vessels contained within the tunica adventitia of an artery Diffusion of nutrients through the endothelium is not sufficient to supply the tissues of the vessel
34
What is the function of the unmyelinated nerves in the tunica adventitia of a muscular artery?
Nerve endings release noradrenaline (sympathetic nerve fibres) Diffuses through fenestration in the tunica media's external elastic lamina and into the superficial tunica media Creates a depolarisation of the smooth muscle cells which propagates to all muscle cells via gap junctions causing vasocontriction
35
As muscular arteries diminish in diameter, what happens to their structure?
Number of smooth muscle layers in the tunica media decreases
36
How do arterioles differ from muscular arteries in terms of size and their tunica media?
Arterioles are less than 0.1mm diameter, arteries are larger than 0.1mm diameter Arterioles have 1-3 layers of smooth muscle cells in the tunica media
37
Would you ever find arterioles with thin internal elastic lamina?
Yes, but only those of larger diameter
38
What are the main features of small arterioles?
No internal or external elastic lamina Tunica media is composed of a single smooth muscle cell encircling the endothelial cells Tunica adventitia is scant
39
By what percentage can arterioles perform sustained dilation or contraction? Why is this useful? Give an example of this process
Most arterioles can dilate up to 60-100% resting diameter Or can constrict up to 40% This directs blood to where it might be needed During strenuous physical activity, arterioles in the gut will constrict to allow greater blood flow to the skeletal muscles
40
What are meta-arterioles and how do they differ from arterioles?
Meta-arterioles supply blood to capillary beds Their smooth muscle layer is not continuous Instead, smooth muscle cells are spaced apart and each encircles the endothelium of a capillary arising from the meta-arteriole (pre-capillary sphincter)
41
What is the function of smooth muscle cells in meta-arterioles?
Function as pre-capillary sphincters Allow the arterioles and meta-arterioles to serve as flow regulators for the capillary beds They control whether a capillary bed is perfused or bypassed
42
Describe the structure of capillaries
Made up of a single layer of endothelium and a basement membrane 7-10um in diameter
43
How much of the total blood volume is contained within capillaries? What is the total exchange surface area of all capillary beds in the body?
5% Estimated 600m2
44
What features of capillary structure aid in exchange of substances through the capillary wall?
Narrow lumen is almost completely filled by an RBC, minimising the diffusion path length As velocity is inversely proportional to cross sectional area, velocity is very low in capillaries compared to the rest of the vasculature, this allows more time for exchange
45
What are the three types of capillary?
Continuous Fenestrated Sinusoidal
46
Describe the structure of continuous capillaries
Endothelium with basement membrane Pericytes form a branching network around the outer surface
47
What are pericytes? What processes are they involved in?
Cells capable of dividing into smooth muscle cells or fibroblasts Divide during angiogenesis, wound healing or tumour growth
48
How does the structure of fenestrated capillaries vary from continuous capillaries?
Pores (fenestrations) in the endothelium
49
Describe the structure of sinusoidal capillaries
Fenestrated endothelium with large holes Discontinuous basal lamina (basement membrane) Associated pericytes Some do not have tight junctions and are called 'discontinuous sinusoidal capillaries' Generally larger in diameter than continuous or fenestrated capillaries
50
What does the unique structure od sinusoidal capillaries allow for? Where are sinusoidal capillaries normally found and why?
Allows RBCs and WBCs to pass through the capillary wall Normally found in the liver and spleen, where greater amount of movement of materials is necessary
51
List the progression of vascular structures that the blood passes through from the capillaries to the heart (in order)
Capillaries Post-capillary venules Venules Veins Large veins Heart
52
How does the structure of veins differ from that of arteries?
Thinner wall with more connective tissue and less elastic fibres or smooth muscle Lumen wider and irregular (than accompanying arteries) Paired semilunar valves that prevent retrograde travel of blood
53
Describe the structure of post-capillary venules
Structure much like capillaries (endothelium and associated pericytes) Generally more permeable than capillaries 10-30um diameter No valves as in larger venules/veins
54
What do the structural features of a post-capillary venule allow for? How is this relevant to inflammatory response?
Because pressure is lower (larger diameter) than in capillaries fluid tend to drain into them Except in inflammatory response where fluid and leukocytes emigrate out (these venules are the preferred location for leukocyte emigration)
55
How will low blood pressure affect veins?
Veins may collapse if blood pressure isn't maintained
56
What apart from blood pressure determines blood flow in veins?
Moving blood towards the heart: - 'Muscle pump' action of the lower limb - Pressure factors in the abdominal and thoracic cavities Preventing retrograde flow: - Valves
57
In what diameter range will muscle fibres begin appearing in venules?
50um - 1mm
58
How do the superficial veins of the legs differ from other small or medium sized arteries? Why is this difference necessary?
Most small/medium arteries have a well defined tunica adventitia In superficial veins of the leg, there is a well defined muscular wall This may be to resist distension by gravity
59
Give some examples of large veins
``` Vena Cavae Pulmonary Portal Renal Internal jugular Iliac Azygous ```
60
How do large veins differ from small/medium veins?
Have well developed longitudinal smooth muscle in the tunica adventitia in addition to the circularly arranged smooth muscle in the tunica media

ESA2 Callum's Cards - Complete (36 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions