Cardiovascular Physiology Flashcards Preview

Human Physiology > Cardiovascular Physiology > Flashcards

Flashcards in Cardiovascular Physiology Deck (25)
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1
Q

P wave (ECG)

A

Result of depolarisation from SA node to AV node

2
Q

QRS complex (ECG)

A

Result of the ventricular depolarisation and precedes ventricular contraction

3
Q

T wave (ECG)

A

Caused by ventricular repolarisation

4
Q

Stroke Volume influenced by:

A
  • Volume of blood in ventricles
  • Changes in sympathetic nervous system
  • Changes in arterial pressure
5
Q

Regulation of HR

A
  • If blood volume drops, then SV declines and CO is maintained by increasing HR
    * Chronotropic factors
  • Controlled by nervous system affecting ion channels
    * Sympathetic increases HR
    * Parasympathetic decreases HR
6
Q
  • Respond to changes in arterial pressure
  • Highly sensitive to stretch/distortion
  • Degree of stretching is directly proportional to blood pressure
  • An increase in pressure leads to increase in AP firing
  • Short term changes in blood pressure
A

Arterial baroreceptors

7
Q
  • Network of connected neurons
  • Medulla oblongata
  • Input from various baroreceptors
  • Input determines AP frequency CV centre
  • Increased firing of baroreceptors, decreased sympathetic outflow, increased parasympathetic outflow
  • Decreased arterial pressure, increased plasma concentrations of hormones, which increases arterial pressure by constricting arterioles
A

Medullary CV Centre

8
Q
  • Norepinephrine acts on beta-adrenergic receptors to increase ventricular contractility
  • Increased contractility results in greater SV due to a more complete ejection of the end-diastolic volume
A

SV - Contractility

9
Q
  • The ventricle contracts more forcefully during systole when it has been filled to a greater degree during diastole
  • Due to length-tension relationship
  • End-diastolic volume is determined by how stretched the ventricular sarcomeres are before contraction
  • The greater the end-diastolic volume, the more the muscles are stretched and thus greater the contraction
A

SV - Frank Marlin Mechanism

10
Q

Muscular sack enclosing heart

A

Pericardium

11
Q

Fixes inner layer of pericardium to heart

A

Epicardium

12
Q

Muscular wall of the heart formed from cardiac muscle cells

A

Myocardium

13
Q

Muscular wall separating the ventricles

A

Atrioventricular Septum

14
Q

Limit movement to prevent backward flow of blood

A

Papillary muscles

15
Q
  • Permit flow from atrium to ventricle
  • Left valve - bicuspid
  • Right valve - tricuspid
A

Atrioventricular Valves

16
Q

Blood from right ventricle to pulmonary trunk

A

Pulmonary semi-lunar valve

17
Q

Blood from left ventricles into aorta

A

Aortic semi-lunar valve

18
Q

Fasten AV valves to papillary muscles

A

Chordae tendinae

19
Q

Precapillary sphincter

A

The site at which a capillary exits from a metarteriole, surrounded by ring of muscle

20
Q

Angiogenesis, and where are factors produced?

A
  • Capillary develop and growth

- Vascular endothelial cells

21
Q

Continuous capillaries

A

Skin and muscle

22
Q

Fenestrated capillaries

A
  • More permeable

- Intestines, kidneys

23
Q

Sinusoidal capillary

A

Liver, bone marrow, lymphoid tissues

24
Q

Things that contribute to resistance

A
  • Blood viscosity
  • Total blood vessel length
  • Blood vessel diameter
25
Q

Percentage of blood volume that is erythrocytes

A

Haematocrit