Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Y1 - CVS > Special Circulations > Flashcards

Special Circulations Flashcards

1
Q

What are the 2 circulations to the lungs?

A

Bronchial circulation

Pulmonary circulation

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

What is Bronchial circulation?

A

Part of systemic circulation which supplies Oxygen to the parts of the lungs NOT CLOSE to thee alveoli

It meets the metabolic requirements of the lungs

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

What is the pulmonary circulation to the lungs?

A

Blood supplied to the alveoli for gas exchange

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

What is the normal cardiac output for the typical 70kg male at rest?

A

5 L/min

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

What physiological situation does Cardiac Output increase with?

A

Exercise

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

What chamber of the heart is the pressure of the pulmonary artery equal to during SYSTOLE?

A

Right Ventricle

(Pulmonary artery pressure = Right ventricular pressure in diastole)

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

Is the pressure of the pulmonary artery less than, equal to or greater than the right ventricle in DIASTOLE?

Why?

A

Pulmonary artery pressure > RV pressure

Elastic recoil of artery makes it greater

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

What is the relative pressure of the right atrium compared to the right atrium during DIASTOLE?

A

Pressures equal

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

What chamber of the heart is the pressure of the aorta equal to during SYSTOLE?

A

Left ventricle

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

Is the pressure of the aorta less than, equal to or greater than the Left ventricle in DIASTOLE?

Why?

A

Aorta pressure greater than LV in diastole

Elastic recoil or aorta makes it a greater pressure

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

In terms of pressures, how are the atrial and ventricular pressures related in DIASTOLE?

A

Pressure of ATRIA = Pressure of Ventricles

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

What relative pressure and resistance does the pulmonary circulation/right side of the heart work at?

A

Low pressure
Low resistance

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

What relative pressure and resistance does the systemic circulation/left side of the heart work at?

A

High pressure
Higher resistance

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

What contributes to the low pressure of the pulmonary circulation?

A

Low Mean Arterial Pressure
Low Mean Capillary Pressure
Low Mean Venous Pressure

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

What contributes to the low resistance of the pulmonary circulation?

A

Short + wide vessels
Lots of capillaries (lots of parallel elements)
Arterioles have relatively little smooth muscle

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

What contributes to the High pressure of systemic circulation?

A

High Mean Arterial Pressure
HighMean Capillary Pressure
High Mean Venous Pressure

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

What contributes to the High resistance of systemic circulation?

A

Long + Narrow vessels
Variable blood flow to capillaries
Arterioles have relatively thick smooth muscle walls

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

What are the 2 adaptations to promote efficient gas exchange at the lungs?

A

High capillary density in Alveolar wall(Large SA)

Short diffusion distance

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

What needs to match the rate of ventilation of alveoli for efficient gas exchange?

A

Ventilation of alveoli = Perfusion of alveoli

Ventilation must match perfusion

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

What is the optimal perfusion ratio (V/Q ratio)?

A

V/Q = 0.8

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

How may mucus build up affect Perfusion ratio (V/Q ratio)?

A

Mucus prevents ventilation so means any perfused blood is not oxygenated

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

How is blood diverted away from alveoli that are not well ventilated to maintain an optimal V/Q ratio?

A

Hypoxic pulmonary vasoconstriction

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

What is hypoxic pulmonary vasoconstriction?

A

When the pulmonary blood vessels constrict in a response to hypoxia

Ensures that perfusion matches ventilation so that poorly ventilated alveoli get less perfused (maximising gas exchange)

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

How is hypoxic pulmonary vasoconstriction different to the response of hypoxia in the systemic circulation?

A

Response is opposite

In systemic vasodilation happens to maximise blood flow to area

In pulmonary vasoconstriction happens to keep blood away from areas that it wont get oxygenated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What negative effects can happen as a result of Chronic hypoxic vasoconstriction?
Chronic increase in vascular resistance causing Chronic Pulmonary Hypertension High AFTERLOAD on RV, leads to RV Hypertrophy and eventually RV HEART FAILURE (this is called cor pulmonale)
26
How does gravity effect the lower pressure blood vessels of the pulmonary circulation?
Strongly
27
How does pressure affect the status of the vessels in the lungs during diastole at the Apex of the lungs, level of the heart and base of the lungs?
Apex vessels - Collapse during diastole, open in systole Level of Heart vessels - Continuously open Base of lung vessels - Vessels constantly distended/swollen
28
How does hydrostatic pressure in blood vessels change as you go down the body?
Increased pressure More fluid above
29
What happens to pulmonary blood flow in exercise?
Inc Cardiac output In Pulmonary arterial pressure opening apical capillaries Inc O2 uptake by lungs Capillary transit time reduces
30
What 2 types of pressure contribute to formation of tissue fluid
Hydrostatic pressure of blood in capillary Oncotic pressure
31
What is oncotic pressure?
Pressure exerted by plasma proteins in the capillary drawing fluid back into the blood
32
What influences capillary hydrostatic pressure more, venous pressure or arterial pressure in the systemic circulation?
Venous pressure
33
What increase in pressure leads to peripheral oedema ?
Inc Central Venous Pressure Hypertension doesn’t usually result in peripheral oedema
34
What factor causes a low amount of lymph/tissue fluid produced in the lungs?
LOW capillary hydrostatic pressure of capillaries in lungs
35
What is the primary cause of oedema causing capillary pressure to increase?
Increased Venous pressure
36
What may lead to Venous pressure increasing leading to pulmonary oedema?
Mitral valve stenosis Left ventricular failure
37
How can Mitral valve stenosis lead to pulmonary oedema?
Pressure builds up in Left Atrium Leads to pressure build up in the pulmonary veins leading to the left atria Increased pulmonary venous pressure leads to increased capillary/hydrostatic pressure leading too more tissue fluid being filtered out than reabsorbed
38
How can left ventricular failure lead to peripheral oedema?
Pressure builds up in the Left Ventricle Leads to increased pressure in the Left Atrium Leads to increases pressure in the pulmonary veins Increased Pulmonary Venous Pressure leads to pulmonary oedema
39
How does Pulmonary Oedema affect gas exchange?
Impairs gas exchange
40
How does pulmonary oedema change when standing up and lying down?
Changes with hydrostatic pressure (due to gravity) Forms at bases when standing Forms throughout lungs when lying down
41
What symptoms does pulmonary oedema cause?
Breathlessness
42
How can the symptoms of pulmonary oedema be relieved?
Diuretics to minimise fluid retention
43
How does the Cerebral circulation meet the high O2 demand for the brain?
High capillary density High basal flow rate High O2 extraction
44
Why is a secure blood supply to the brain vital?
Neurones very sensitive to hypoxia Irreversible damage to neurones after 4 mins without oxygen
45
What is an anastomoses?
An alternate pathway for blood to flow through in case of a blockage in one of the vessels
46
Structurally how is a secure blood supply to the brain ensured?
Anastomoses between basilar and internal carotid arteries
47
What is the main anastomotic structure of the cerebral circulation?
Circle of Willis
48
Functionally how is a secure blood supply to the brain ensured?
Myogenic auto regulation maintains perfusion during hypotension Metabolic factors Brainstem regulating other circulations
49
What is hypercapnia and hypocapnia?
High or low partial pressure of CO2
50
How do metabolic factors help secure blood flow to the brain?
Cerebral vessels are very sensitive to changes in arterial partial pressure of CO2
51
What happens to cerebral blood vessels in hypercapnia?
Vasodilation
52
What happens to cerebral blood vessels in Hypocapnia?
Vasoconstriction
53
Why does panic hyperventilation lead to dizziness or fainting?
Can cause hypocapnia by expelling lots of CO2 Causes cerebral blood vessels to vasoconstriction reducing blood flow to brain
54
What is the myogenic auto regulated response of the cerebral blood vessels when blood pressure increases?
Vasoconstriction Reduce the blood flow to the brain
55
What is the myogenic auto regulated response of the cerebral blood vessels when blood pressure decreases?
Vasodilation Increase blood flow to brain
56
If there is high activity in the brain what affect does this have on blood flow?
Areas with increased neuronal activity = increased blood flow
57
What is metabolic hyperaemia?
Increased blood flow to a highly metabolically active area
58
What metabolites act as vasodilators?
Increased: -Partial pressure of CO2 -[K+] -Adenosine (From ATP breakdown) Decreased: -Partial pressure of O2
59
If intercranial pressure increases how is cerebral blood flow affected?
Impaired
60
What happens if blood flow to the vasomotor control regions of the brainstem is impaired?
Increased sympathetic vasomotor activity Increases arterial BP (This helps maintain cerebral blood flow)
61
What baroreceptor reflex is stimulated when blood pressure increases?
Reflex bradycardia
62
What does bradycardia + acute hypertension indicate and why?
Hall mark of space occupying lesion in brain Cerebral tumour increases intracranial pressure. This impairs cerebral blood flow. Blood flow to vasomotor control region in brainstem impaired leading to vasoconstriction which increases the BP. This stimulates the bradycardic response
63
What are the 3 main coronary arteries?
Right Coronary artery Left Coronary artery branches into 2: -Circumflex (Posteriorly) -Left Anterior Descending (Front) LAD
64
Where do the coronary arteries come from?
First branches of aorta
65
When does the left coronary artery mainly flow with blood, systole or diastole?
Diastole
66
Why does angina come on during exercise but is relieved by rest?
In exercise Diastole period decreases. Left coronary artery mainly has blood flow during diastole, so less blood supplied to heart in exercise causing hypoxia to heart muscle, transient ischaemia causing pain
67
How is the coronary circulation maximised for blood flow?
High capillary density (Facilitates efficient O2 delivery) Very short diffusion distance
68
What factors of the coronary blood vessels help cope with increases myocardial O2 demand?
Increased coronary blood flow (proportional up until a point) Small increase in amount of Oxygen extracted
69
What causes the vasodilation of coronary arteries when demand for oxygen by the heart is high?
Metabolic hyperaemia Adenosine, increased [K+] and lower pH are vasodilators
70
What is a problem with the structure of the coronary arteries?
They are end arteries therefore have very few anastomoses Means if theres a blockage any tissue downstream will die since no alternate route for blood flow
70
What is a problem with the structure of the coronary arteries?
They are end arteries therefore have very few anastomoses Means if theres a blockage any tissue downstream will die since no alternate route for blood flow
71
How do narrowed coronary arteries lead to angina on exercise?
Blood flows mostly through coronaries during diastole Diastole in exercise reduced This combined with increased demand causes the pain due to hypoxic heart tissue
72
How is skeletal muscles circulation controlled?
Capillary density depends on muscle type Very high vascular tone Only 1/2 capillaries perfused at rest (means more can be recruited when needed)
73
What metabolites act as vasodilators in skeletal muscle causing metabolic hyperaemia?
Inc [K+] Inc osmolarity Inorganic phosphates Adenosine Inc [H+] Adrenaline acts on B2 receptors
74
What it’s the special role of cutaneous circulation?
Temperature regulation
75
How does cutaneous circulation play a role in temperature regulation?
Skin = Main heat dissipating surface Arterovenous anastomoses
76
What are arterovnous anastomoses?
Shunts/blood vessels that pass from arteries to veins to avoid blood flowing close to the surface of the skin
77
What is the main regulator of blood flow through thee cutaneous circulation?
Sympathetic stimulation NOT metabolites Blood flows mainly through arteriovenous anastomoses
78
What happens in terms of sympathetic tone in arterovenous anastomoses when core body temperature decreases?
Increased sympathetic tone in arterovenous anastomoses Decreases blood flow to apical skin
79
What happens in terms of sympathetic tone in arterovenous anastomoses when core body temperature increases?
Decreased sympathetic tone in arterovenous anastomoses Opens the anastomoses allowing blood to divert near to veins near the skin

Y1 - CVS (21 decks)

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