Circulatory / Cardiovascular System

Question 1

What is the role of the capillaries ?

Answer 1

Enable exchange of water , nutrients , and waste products between the blood and the tissues!

Question 2

What is the circulatory system made up of ?

Answer 2

• The heart
• Blood vessels
• Blood

Question 3

What does the arteries do?

Answer 3

Carry blood away from the heart under high pressure

Question 4

Where is the heart located ?

Answer 4

In the thoracic cavity and the mediastinum
Left of the midline
Anterior to the vertebrate column
Posterior to the sternum

Question 5

What are the three layer of the heart wall ?

Answer 5

• Pericardium
• Myocardium
• Endocardium

Question 6

What attaches the atrioventricular valves to the heart to prevent them collapsing into the atria ?

Answer 6

The Chordae Tendinae

Question 7

What is the inner most layer of the heart called ?

Answer 7

The endocardium

Question 8

What’s the middle layer of the heart called and what tissue is it made up of ?

Answer 8

Myocardium + Cardiac tissue

Question 9

What is the outer layer of the heart called ?

Answer 9

The pericardium

Question 10

How many sections does the pericardium have ? Name each section starting with the layer closest to the heart.

Answer 10

3 layers
1 - Visceral layer of serious pericardium OR epicardium
(Then the pericardial cavity , made of fluid)
2-Parietal layer of serious pericardium
3- Fibrous pericardium

Question 11

What are the three functions of the fibrous pericardium ?

Answer 11

1- Helps anchor heart to surrounding structures
2- To protect the heart , as it’s a thick connective tissue
3- Prevents the heart from over filling with blood and therefore over stretching.

Question 12

The visceral pericardium and the parietal pericardium are both made of serious membranes , what does this mean ?

Answer 12

They are double layered membranes that produce serious fluid between the two layers to provide lubrication.

Question 13

What is the endocardium made of?

Answer 13

A single layer of epithelial cells continuous with the inner most layer of the vessels.

Question 14

What are the two things coronary circulation is mainly made up from ?

Answer 14

Coronary Arteries and Veins

Question 15

What’s does coronary circulation do ?

Answer 15

Supply the cells of the heart with oxygen and nutrients

Question 16

What is the conduction system ?

Answer 16

The hearts ability to generate its own electrical impulses

Question 17

What is the conduction system made up of ?

Answer 17

The SA node ( sino atrial node)

The AV node ( Atrio ventricular node)

Question 18

What does SA node stand for ?

Answer 18

• Sino atrial node

Question 19

What is the SA node made of and where is it located ?

Answer 19

• Group of cardiomyocytes

- Located in the right atrium of the heart

Question 20

What does the SA node do ?

Answer 20

The SA node spontaneously depolarises and generate a cardiac action potential 100 times per minute.

It’s the natural pace maker of the heart and makes both atria contract simultaneously.

Question 21

What does AV node stand for?

Answer 21

Atrioventricular node

Question 22

What is the AV node made up of ?

Answer 22

Conducting cells

Question 23

What does the AV node do ? What is it’s part in the conduction system?

Answer 23

Once the action potential from the SA node reaches here it slows , enabling the atria to empty their blood into the ventricles.

Question 24

What system are the SA and AV node part of ?

Answer 24

Then conduction system

Question 25

Explain the conduction system pathway

Answer 25

Starts at the node SA, cardiac action penitential makes both atria contact simultaneously .Once at the AV node the action potential slows enabling the atria to empty their blood into the ventricles. The atrio ventricular bundle begins at the AV node and passes to the inter-ventricular septum. Right and left bundle branches action potential now enter the R and L bundle branched towards the apex of the heart . Purkinje fibre rapidly conduct the action potential beginning at the apex upwards to the remainder of the ventricular myocardium.Then the ventricles contract pushing blood up toward the semi lunes valves .

Question 26

What’s the equation to find the cardiac output of the heart ?

Answer 26

Cardiac output = Stroke volume X Heart rate

Question 27

What does the renin-angiotensin -aldosterone system (RAAS) do ?

Answer 27

Raises blood pressure

Question 28

What do chemoreceptors do ?

Answer 28

Chemoreceptors monitor chemical changes In the blood , they monitor O2 , CO2 and PH of the blood

Question 29

Where are chemo receptors located?

Answer 29

In the aorta and carotid arteries

Question 30

When chemoreceptors detects a chemical change in the blood where is this information sent to ?

Answer 30

The cardiovascular centre in the medulla oblongata

Question 31

What do baroreceptors do ?

Answer 31

Monitor the stretch of the arteries by the blood flowing through them

Question 32

How is blood pressure monitored ?

Answer 32

Baroreceptors and chemoreceptors

Question 33

What is vasoconstriction

Answer 33

Narrowing of the blood vessels = increases blood pressure

Question 34

What is vasodilation ?

Answer 34

Widening of the blood vessels = decrease in blood pressure

Question 35

What is venous return?

Answer 35

The volume of blood returning to the right atrium/ ventricles

Question 36

In addition to the heart muscle 2 other mechanisms “pump” blood from the lower body back to the heart what are they ?

Answer 36

Skeletal muscle pump

Respiratory pump

Question 37

Explain the skeletal muscle pump

Answer 37

Muscles in the lower half of the body compress the veins to help increase blood flow back up to the heart .

Question 38

Explain the respiratory pump

Answer 38

During inhalation the diaphragm moves downwards causing pressure in the thoracic cavity to decrease , whilst the pressure in the abdominal cavity increases - this compresses the abdominal veins and sends blood back to the heart