Physiology

Question 1

When the blood leaves the arteries is it under high or low pressure?

Answer 1

High

Question 2

As the blood moves through the circulatory system does the pressure increase or decrease?

Answer 2

Decrease

Question 3

Define stroke volume

Answer 3

The volume of blood ejected from the heart in one beat

Question 4

What is the desired stroke volume at rest?

Answer 4

70 ml

Question 5

Define heart rate

Answer 5

The number of times the heart beats per minutes

Question 6

What is the desired resting heart rate?

Answer 6

60-85 bpm

Question 7

Define cardiac output

Answer 7

The volume of blood ejected from the heart in one minute

Question 8

What is the usual cardiac output when at rest?

Answer 8

Around 5L per minute

Question 9

How do you calculate cardiac output?

Answer 9

Heart rate x stroke volume

Question 10

Define mean arterial blood pressure (MABP)

Answer 10

The average pressure exerted by the blood on the walls of the major arteries

Question 11

What is the usual MABP?

Answer 11

<107 mmHg

Question 12

How do you calculate MABP?

Answer 12

MABP = Cardiac output x Peripheral resistance

Question 13

How many factors affect arterial blood pressure and what are they?

Answer 13

4;
~circulatory volume
~force of ventricular contraction
~elasticity of the arteries
~peripheral reistance

Question 14

What is the biggest/most common factor that effects arterial blood pressure?

Answer 14

circulatory volume

Question 15

What is circulatory volume?

Answer 15

Associated with the stroke volume. If you have an increase blood volume, you have an increased pressure and therefore increased blood pressure.

Question 16

How does ventricular force effect blood pressure?

Answer 16

If you are pumping the blood at a higher force then your over all blood pressure is going to be increased.

Question 17

How does the elasticity of the arteries effect blood pressure?

Answer 17

If the arteries are inelastic then you have a smaller diameter which means the blood will be travelling at high pressures meaning high blood pressure.

Question 18

How does peripheral resistance effect blood pressure?

Answer 18

The higher the resistance in the arteries the higher the blood pressure

Question 19

What is the biggest factor that effects resistance in the arteries?

Answer 19

The radius of the arteries

Question 20

What type of nerves travel all around the body and can effect lots of things in the body?

Answer 20

Vagus nerves

Question 21

What effect do the vagus nerves have on the heart?

Answer 21

They slow down the heart beat

Question 22

What effect does the cardiac accelerator do to the heart rate?

Answer 22

Accelerates the heart rate

Question 23

What type of receptors are baroreceptors?

Answer 23

Pressure receptors

Question 24

How can the nerves signal the blood vessels?

Answer 24

They can tell them to either dilate or constrict

Question 25

When does atrial stretch occur?

Answer 25

It happens when venous return is raised eg when the circulatory volume has increased.

Question 26

What are atrial myocytes?

Answer 26

Heart muscle cells

Question 27

What is an atrial natriuretic peptide (ANP)?

Answer 27

It is a vasodilator

Question 28

What two things does ANP do?

Answer 28

Promotes sodium excretion and inhibits the secretion of ADH

Question 29

What effect does inhibiting ADH have on BP?

Answer 29

By inhibiting ADH you decrease the reabsorption of sodium and hence water too, which increases urination and therefore decreases your BP

Question 30

What is the NICE guidelines for diagnosing hypertension?

Answer 30

If they have a consistent systolic measurement of over 140 mmHg or a diastolic reading of over 90 mmHg.

Question 31

What are the two different types of hypertension that can be diagnosed?

Answer 31

Primary and secondary hypertension

Question 32

What is classed as primary hypertension?

Answer 32

When there is no clear cause of the hypertension (is around 97% of cases)

Question 33

What is classed as secondary hypertension?

Answer 33

When the hypertension is caused by another disease, such as kidney problems

Question 34

How many ways can the endocrine system effect blood pressure and what are they?

Answer 34

4 ways, which are ~adrenaline release ~antidiuretic hormone (ADH) ~atrial natriuretic peptide (ANP) ~renin angiotensin aldosterone system.

Question 35

Where is adrenaline released from?

Answer 35

The adrenal medulla

Question 36

When is adrenaline released?

Answer 36

When a low BP has been detected

Question 37

What are the effects that adrenaline has on BP?

Answer 37

It speeds up the heart rate and increases ventricular contraction. It dilates the skeletal muscle and constricts splenic vascular beds

Question 38

Does adrenaline increase or decrease cardiac output and systolic BP?

Answer 38

Increases

Question 39

Does adrenaline have a big effect on MABP and if so what effect does it have?

Answer 39

Little effect on MABP

Question 40

What is ADH also known as?

Answer 40

Vasopressin

Question 41

Where is ADH released from?

Answer 41

The posterior pituitary

Question 42

When will ADH be released?

Answer 42

When there has been a reduction in BP or when there has been increased plasma osmality.

Question 43

What are the effects of ADH?

Answer 43

It promotes reabsorption of water in the kidneys and constricts blood vessels if present at a high enough concentration

Question 44

What effect does ADH have on stroke volume and thoracic peripheral?

Answer 44

It increases these

Question 45

When it is released, does ADH keep BP up or down?

Answer 45

Keeps it up

Question 46

When will atrial natriuretic peptides be released?

Answer 46

When the walls of the atria are stretched.

Question 47

How many effects does ANP have on BP and what are they?

Answer 47

4 effects. ~ promotes sodium (and therefore water) excretion in the kidneys ~ inhibits ADH and aldosterone secretion ~ acts as a vasodilator ~ can slow renin release

Question 48

What effect does ANP have on stroke volume and thoracic peripheral?

Answer 48

Decreases it

Question 49

Does ANP release keep BP up or down?

Answer 49

Keeps BP down

Question 50

Where is renin released from?

Answer 50

Afferent arterioles, in the glomerulus of the kidneys

Question 51

When is renin released?

Answer 51

When the perfusion pressure in the kidneys is low, hence related to low BP

Question 52

What protein does renin act on?

Answer 52

Angiotensinogen

Question 53

When renin cleaves angiotensinogen what is created?

Answer 53

Angiotensin 1

Question 54

What enzyme is needed to convert angiotensin 1 to angiotensin 2?

Answer 54

Angiotensin converting enzyme

Question 55

What are the 4 properties of angiotensin 2?

Answer 55

~ potent vasoconstrictor through AT receptors ~ dipsogenic ~ stimulates ADH secretion ~ activates aldosterone

Question 56

What is aldosterone?

Answer 56

An absorbing salt

Question 57

How does aldosterone secretion become activated?

Answer 57

By angiotensin 2

Question 58

Where is aldosterone secreted from?

Answer 58

Adrenal cortex

Question 59

What is the effect of aldosterone?

Answer 59

It increases the reabsorption of sodium (and therefore water) in the kidneys and therefore keeps blood volume up.

Question 60

Does aldosterone keep BP up or down?

Answer 60

Keeps BP up

Question 61

What is Conn’s disease also known as?

Answer 61

Primary Aldosteronism

Question 62

What is a common result to see for patients with Conn’s disease?

Answer 62

High plasma level of aldosterone and a normal level of plasma renin.

Question 63

What are the causes of Conn’s disease?

Answer 63

Adrenal cortex tumour or hyperplasia

Question 64

What clinical feature may a patient with Conn’s disease present with?

Answer 64

Polydipsia, polyuria and persistent hypokalaemia

Question 65

Are cardiac and skeletal muscle striated or not?

Answer 65

They are

Question 66

What does striated mean?

Answer 66

When you look at them under a microscope they look like stripes

Question 67

When the muscles contract do they get longer or shorter?

Answer 67

Shorter

Question 68

What cause contraction in the striated muscle?

Answer 68

The thick filaments are pulling the thin filaments towards the centre of the sacromere

Question 69

What is the shortening of the muscles dependent on?

Answer 69

Calcium, as it binds to the regulatory proteins

Question 70

Are skeletal muscle movements involuntary or voluntary movements?

Answer 70

Voluntary

Question 71

Are the cardiac muscles Voluntary or involuntary movements?

Answer 71

Involuntary

Question 72

At the myosin binding site what is bound?

Answer 72

The myosin head is bound to actin filaments

Question 73

What happens in the sarcoplasmic reticulum?

Answer 73

It is specially adapted for calcium to be sucked into when muscles are relaxed

Question 74

What takes up the 30-40% of the cell volume in cardiac cells?

Answer 74

Mitochondria

Question 75

What's the function of gap junctions within the cell?

Answer 75

They act as electrically leaky junctions or boundaries between the cardiac muscles

Question 76

What do the gap junctions allow for?

Answer 76

~communications rapidly between the cells through plasma protein membranes ~Small ions can more freely from one cell to another

Question 77

Is the resting membrane potential of a cell always positive or negative?

Answer 77

Electronegative

Question 78

What controls the movement of ions in and out of the cells?

Answer 78

The sodium potassium pump

Question 79

When the permeability of the membrane to sodium and potassium is increased is this depolarisation or repolarisation?

Answer 79

Depolarisation

Question 80

When the permeability of the membrane to sodium and potassium is decreased is this depolarisation or repolarisation?

Answer 80

Repolarisation

Question 81

What do cardiac action potentials lead to?

Answer 81

Muscle contraction

Question 82

What do action potentials need to pass before an action potential can be fired?

Answer 82

The Threshold

Question 83

Are cardiac action potentials and non-cardiac action potentials the same?

Answer 83

No, the cardiac action potential is depolarised longer

Question 84

Why does the heart contract differently to other muscles?

Answer 84

Because the heart has to completely empty of blood before the next contraction so there has to be a refractory period where the heart cannot contract

Question 85

What is known as the pacemaker of the heart?

Answer 85

The Sino Atrial node (SA node)

Question 86

What node centralises the electrical information to pass it down to the bundle of His?

Answer 86

The Atrio ventricular node

Question 87

What side of the heart gets the electrical impulse first?

Answer 87

Right side

Question 88

When you have a positive deflection does the line move up or down? And what does this tell you about the direction of the electrical activity?

Answer 88

Up, therefore the electrical activity is moving towards the electrode

Question 89

When you have a negative deflection does the line move up or down? And what does this tell you about the direction of the electrical activity?

Answer 89

Down, the electrical activity is moving away from the electrode

Question 90

What are the 3 types of bipolar leads?

Answer 90

Lead 1, 2 and 3

Question 91

Where does lead 1 cross?

Answer 91

Horizontally across the body

Question 92

Where does lead 2 cross?

Answer 92

Diagonally across the body from left to right

Question 93

Where does lead 3 cross?

Answer 93

Diagonally across the body from right to left

Question 94

What are your unipolar leads?

Answer 94

aVr, aVL and aVf