cardovascular system

Question 1

location of the heart

Answer 1

between lungs, the sternum and thoracic vertebra;

surrounded by ribs in a space called mediastinum.

Question 2

what tissue type is it made out of

Answer 2

dense fibrous connective tissue bag called the pericardial sac;

Question 3

Pericardium

Answer 3

double walled sac enclosing the heart. It is anchored to the diaphragm

Question 4

2 types of pericardium

Answer 4

1- fibrous

2- serous

Question 5

coronary vessels

Answer 5

Left coronary artery gives rise to the anterior interventricular branch.
- Right coronary artery gives rise to the posterior interventricular branch

Question 6

heart skeleton

Answer 6

• dense fibrous tissue with some fibrocartilage
• provides and anchor for the heart muscle
• provides electrical insulation

Question 7

blood vessles (2 types)

Answer 7

Arteries carry blood away from the heart. Veins carry blood towards it.

Question 8

3 layers of blood vessels

Answer 8

• Tunica interna: always has a layer of endothelium. May also have connective tissue and elastin.
  • Tunica media: has smooth muscle, collagen and variable amount of elastic tissue (thicker in arteries).
  • Tunica externa (adventitia): connective tissue and collagen fibres (thicker in veins).

Question 9

3 different types of arterties

Answer 9

• conducting large arteries
• distrabuting musuclar arteries
• resistance with small arteries

Question 10

3 different types of veins

Answer 10

• large veins
• medium veins
• venules

Question 11

capillaries

Answer 11

Capillaries join arteries and veins. It is where the exchange between the tissues occurs

Question 12

the cardiac cycle

Answer 12

• ventricular disatole
• isovolumetric contraction
• ventriciular ejection
• isvolumetric relaxation

Question 13

control of the heart

Answer 13

• Cardiac muscle is involuntary. It has large amounts of mitochondria
• Cardiac muscle cells do not need stimulation for contraction, it works as single unit. The cells have a longer refractory period

Question 14

contraction of the heart

Answer 14

• sinoatrial node cell depolarises
• The fibrous skeleton insulates the atria from the ventricles
• Purkinje fibres distribute the excitation through the
  ventricular myocardium and into the papillary muscle which
  contract
• ventricles contract from the bottom up forcing blood
  into the vessels

Question 15

Electrocardiogram

Answer 15

finds the heart rate. Waves represent electrical activity

in the heart.

Question 16

P wave

Answer 16

depolarisation of the atrium. Atria contracts after the P wave

Question 17

QRS wave

Answer 17

depolarisation of the ventricles and atria. Ventricles contract after the QRS wave

Question 18

T wave

Answer 18

repolarisation of ventricles. Ventricles relax after the T wave

Question 19

Cardiac output

Answer 19

= stroke volume (volume of blood leaving the ventricle) x heart rate (beats per minute).

Question 20

Respiratory pump

Answer 20

the diaphragm contracts, drops and squashes the veins in the abdomen pushing blood back up to the heart therefore increases venous return

Question 21

Skeletal muscle pump

Answer 21

when skeletal muscles contract they get shorter and fatter causing squashing of the vein so blood is pushed back towards the heart. It ensure blood travels in one direction