unit 8 - circulatory system

Question 1

primary functions of the circulatory system (7)

Answer 1

1. transports oxygen to the body cells
2. transports nutrients from the digestive system to body cells
3. transports hormones to body cells
4. transports wastes from body cells to excretory organs
5. distributes heat
6. helps maintain constant PH
7. prevents infection

Question 2

blood is supplied to 3 separate sections of the body

Answer 2

1. systematic system: carries blood through the body
2. pulmonary system: carries blood from the right side of the heart to the lungs
3. coronary system: provides blood to the hear

Question 3

layers of the heart

Answer 3

Pencardium: a thin closed sac surrounding the heart to reduce friction
Myocardium: the middle layer, the thickest part of the wall
Endocardium: the inner lining of the chambers

Question 4

human hearts have 4 chambers consisting of

Answer 4

2 atria: act as holding chambers for the blood

2 ventricles: pump blood

Question 5

the chambers are separated by valves (AV)

Answer 5

the right side - triscupid valve

the left side - biscupud valve

Question 6

Semilunar Valves

Answer 6

found in the areas where the blood vessels attach to the ventricles

Question 7

arteries

Answer 7

• carry blood away from the heart (oxygenated blood)
• have thick walls
• stretch to accommodate blood
• the largest is the aorta
• smaller sized ones are called arterioles which then branch off into capillaries

Question 8

veins

Answer 8

• carry blood back to the heart (deoxygenated)
• capillaries merge and from venues which then from viens
• walls are thin
• use valves to move blood upwards
• the largest veins are the superior and vena cava

Question 9

capillaries

Answer 9

• where gas exchange happens
• very thin walls so its easy to diffuse gases through them
• permeable to many substances

Question 10

vasoconstriction and vasodilation

Answer 10

vasoconstriction - the narrowing of blood vessels

vasodilation - the widening of blood vessels

Question 11

heart beat and pulse

Answer 11

systole: Systole occurs when the heart contracts to pump blood out
diastole: occurs when the heart relaxes after contraction

average is 120/80

Question 12

electrical system of the heart

Answer 12

1. SA node
2. AV node
3. Bundle of his
4. Bundle branches
5. purkinje fibers

Question 13

electrocardiogram - ECG

Answer 13

a recording of the electrical events/changes during a cardiac cycle

• arrhythmia: irregular
• Bradycardia: slow heart rate
• Tachycardia: fast heart rate

Question 14

what are 2 purposes of a defibrillator

Answer 14

1. restores a normal rhythm

2. starts a heart that has been stopped

Question 15

hypertension

Answer 15

thick blood