Heart - Circulatory System 3

Question 1

Anatomy of the heart

Answer 1

• lies in thoracic cavity between lungs
• has a base and apex and lies obliquely
  Organs associated with the heart:
• diaphragm
• oesophagus
• trachea
• L&R bronchus
• vertebrae
• ribs
• intercostal muscles

Question 2

Layers of tissue which compose the heart?

Answer 2

• pericardium
• myocardium
• endocardium

Question 3

Pericardium

Answer 3

2 sacs:
- outer sac = consists of fibrous tissue = prevents over distension of heart
- inner sac = double serous membrane = allows smooth movement between layers when heart beats

Question 4

Myocardium

Answer 4

• composed of specialised cardiac muscle
• sheet of muscle instead of individual cells
• impulses spread across whole sheet causing contraction

Question 5

Endocardium

Answer 5

• flattened epithelial cells- continuous with endothelium lining blood vessels
• lines chambers and valves of heart
• smooth membrane = allows smooth flow of blood through heart

Question 6

Interior of heart

Answer 6

• divided into right and left by septum
• each side divided into upper chamber and lower ventricle by atrioventricular valves
• right valve = 3 semilunar cusps
• left valve = 2 semilunar cusps
• they ensure blood flows in one direction only
• valves open and close with changes in blood pressure within chambers

Question 7

2 largest veins

Answer 7

• 2 largest veins - superior vena cava and the inferior vena cava - empty deoxygenated blood into right atrium.
• travels via right tricuspid atrioventricular valve into right ventricle - from here then pumped into pulmonary artery (only artery to carry deoxygenated blood)

Question 8

Approximate number of heartbeats in each minute

Answer 8

72 BPM

Question 9

What divides the heart into the right and left side?

Answer 9

Median septum

Question 10

2 chambers on each side of the heart - name them

Answer 10

Upper = atrium
Lower = ventricle

Question 11

Name the valves which blood passes through

Answer 11

• tricuspid valve
• mitral valve
• aortic valve

Question 12

Tricuspid valve

Answer 12

Blood passes from 1 right chamber to the other right chamber

Question 13

Mitral valve

Answer 13

Blood passes from 1 left chamber to the other left chamber

Question 14

Aortic valve

Answer 14

Blood passes from heart to the arterial system of the body

Question 15

What are the layers that make up a wall of an artery

Answer 15

• tunica intima
• tunica media
• tunica adventitia

Question 16

Tunica intima

Answer 16

Thin endothelial layer of simple squamous cells

Question 17

Tunica media

Answer 17

Layer of elastic fibres and smooth muscle

Question 18

Tunica adventitia

Answer 18

Outer layer of fibrous connective tissue together with nutrient blood vessels to artery wall

Question 19

Veins vs arteries

Answer 19

Veins have:
- thinner walls
- valves - ensure blood flows in 1 direction

Question 20

What blood vessels carry oxygenated blood?

Answer 20

• hepatic artery
• renal artery

Question 21

Why are superficial veins visible through skin as dark lines

Answer 21

• oxyhaemoglobin is present in oxygenated blood - it’s brought red but becomes darker when oxygen is given up - as has happened to venous blood

Question 22

Approximate volume for blood in the average adult body?

Answer 22

• between 5 and 6 litres of blood

Question 23

Blood is made up of a liquid portion, called ________, and various types of cells

Answer 23

Plasma

Question 24

True or false - the liquid portion of blood is roughly 90% water?

Answer 24

True