The Heart and Blood Vessles

Question 1

the need for a circulatory system

Answer 1

larger organisms require a circulatory system to transport materials to and
from cells

small organisms such as amoeba, fungi etc have no need for one as diffusion is adequate

Question 2

diffusion definition

Answer 2

movement of molecules from one area of high concentration to an area of low concentration.

Question 3

Closed circulatory system

Answer 3

heart pumps blood through a network of vessels
materials are exchanged between the blood and cells through thin walled capillaries
eg: humans, rabbits, earthworm

Question 4

Advantages of a closed circulatory system

Answer 4

1. Blood can be pumped faster, speeds up the delivery and removal of materials (animals can have a higher metabolic rate
2. It allows for control over the distribution of blood

Question 5

Open circulatory system

Answer 5

Heart pumps blood into open ended vessels
blood flows through tissues and bathes cells
blood flows back to heart
Eg: insects and spiders

Question 6

Parts of Artery and Vein

Answer 6

Collagen
Muscle and elastic fibre
Endothelium
LUMEN

Question 7

Arteries

Answer 7

carry blood away from heart
blood is under high pressure
thick wall
small lumen
valves absent
Pulses**
blood high in O2

Question 8

Veins

Answer 8

carry blood to heart
low pressure
large lumen
thick wall
valves
smoothly**
blood low in O2

Question 9

Capillaries: parts

Answer 9

lumen
endothelium

Question 10

Capillary

Answer 10

one cell thick
where exchange of materials to the cells (o2, co2, urea)

Question 11

purpose of valves

Answer 11

to prevent back flow of blood
control direction of blood flow

Question 12

Blood pressure

Answer 12

is the force the blood exerts against the wall of a blood vessel

Question 13

The heart location

Answer 13

between two lungs above diaphragm
slightly tilted to the left
protected by rib cage
chest cavity, thoracic

surrounded by pericardium

Question 14

Atria

Answer 14

pump blood into lower chambers (ventricles)
thin walls as pump blood short distance

Question 15

Ventricles

Answer 15

pump blood out of the heart - right to the lungs left to the head and body (thick)

Question 16

what holds valves in place

Answer 16

tendons heart strings

Question 17

Valves

Answer 17

prevent back flow
tricuspid
bicuspid
semilunar valves (half moons) in pulmonary artery and aorta - prevent blood returning to the heart

Question 18

LORD

Answer 18

left
oxygenated
right
deoxygenated

Question 19

deoxygenated blood

Answer 19

blood that’s low in oxygen enters heart through the vena cava
blood enters the right atrium, goes through tricuspid valve to enter right ventricle
blood is forced to the lungs through the semilunar valve in the pulmonary artery

Question 20

oxygenated blood

Answer 20

oxygenated blood returns to the heart from the lungs
it enters the left atrium through the pulmonary veins
pumped down through the bicuspid valve to left ventricle
blood is pumped out to the body through semilunar valve in aorta

Question 21

What separates oxygenated and deoxygenated

Answer 21

septum

Question 22

double circulation

Answer 22

heart is a double pump
pulmonary circuit
systemic circuit

Question 23

advantages of a double circulatory system

Answer 23

allows oxygenated and deoxygenated blood to be kept separate
ensures that the blood pressure is high enough to reach all parts of the body

Question 24

single circulatory system.

Answer 24

can only produce low blood pressure around most of the body which restricts activities of an animal
eg:fish

Question 25

portal system

Answer 25

blood pathway that begins and ends in capillaries

vessels do not connect directly to the heart
Eg: Heptic portal vein

Question 26

pulmonary circuit

Answer 26

deoxygenated blood pumped from right side of heart to lungs
oxygenated blood returns to left side of the heart

Question 27

systemic circuit

Answer 27

oxygenated blood pumped from left side of heart to all various parts of the body and returns as deoxygenated blood to the right side of heart

Question 28

general path of blood

Answer 28

1. heart
2. arteries
3. arterioles
4. capillaries (exchange)
5. venules
6. veins

Question 29

heart is made of…

Answer 29

cardiac muscle which is involuntary and slow to fatigue
pericardium prevents friction

Question 30

hepatic portal vein

Answer 30

capillaries on both ends which connects the digestive system to the liver

Question 31

Ventral surface

Answer 31

front
curved
coronary artery runs from left to right

Question 32

Dorsal surface

Answer 32

back
flat

Question 33

systole

Answer 33

id when the heart chambers contract

Question 34

diastole

Answer 34

is when the heart chambers relaz

Question 35

SA node

Answer 35

sino atrial node
pacemaker

Question 36

AV node

Answer 36

atrio ventricular node

Question 37

Cardiac cycle

Answer 37

refers to events which take place during one heartbeat

Question 38

What ensures the constant movement of blood

Answer 38

the alternate systole and diastole of the heart muscle

Question 39

Heartbeat is controlled by…

Answer 39

specialised tissue called sino-atrial node (SA)
pacemaker

Question 40

pacemaker location

Answer 40

found embedded in the wall of the right atrium near where the superior vena cava enters the heart

Question 41

factors that affect the rate of heartbeat

Answer 41

exercise
temperature
emotions
shock
drugs

Question 42

Stages of heart beat 1

Answer 42

1. Atrial diastole (atria and ventricles are relaxed— blood enters left and right atrium)

Question 43

Stage of heartbeat 2.

Answer 43

2. Atrial systole (sa node sends electrical impulses across the muscles of both atria
   This causes both atria to contract (systole) and pump blood down into ventricles
   as impulses pass through atria they reach AV node (bottom of right atrium against septum)

Question 44

Stages of heart beat 3

Answer 44

Ventricular systole

AV nose passes impulses down through septum to the walls of the ventricles causing them to contract
forces blood out of the heart and into pulmonary artery and aorta

Question 45

Cardiac blood supply

Answer 45

coronary arteries branch out of the aorta and carry oxygen and nutrients to muscle cells of the heart

—> blockage of coronary arteries, common cause of heart attack (angina)

Question 46

Pulse

Answer 46

a wave of vibrations taht passes down the walls of the arteries when the aorta expands following a ventricular contraction

Question 47

Effects of Smoking on circulatory system

Answer 47

major cause of CHD
tobacco contains harmful substances
nicotine (blood pressure)
carbon monoxide (hardens arteries)
smoking increases risk of thrombosis (clot)

Question 48

Effect of exercise of circulatory system

Answer 48

regular exercise makes heart stronger and more efficient at pumping
improves supply of oxygen to cardiac muscle and reduces blood pressure

Question 49

Effect of diet on circulatory system

Answer 49

Excessive salt: increases blood volume and pressure
Sat Fat/cholesterol: block arteries
Fibre: reduces absorption of cholesterol and decreases risk of heart disease
Lack of Protein: lowers blood pressure
Lack of iron: anaemia

Question 50

EXPERIMENT: Dissect, display and identify parts of the heart

Answer 50

1. Rinse, board
2. distinguish ventral and dorsal
3. Identify four major blood vessels
4. Locate four chambers (using scalpel)
5. Cut open left ventricle (thick wall, strings, bicuspid valve)
6. Cut Right ventricle (thin wall, strings, tricuspid valve)
7. Cut Atria (thin walls, bicuspid and tricuspid valves)
8. Cut pulmonary artery (semilunar valve)
9. Cut aorta (semilunar valve, beginning of coronary artery)
10. Identify septum
11. Used small labels to identify all
12. clean and sanitise

Question 51

EXPERIMENT: to investigate the effect of exercise on the pulse rate of a human

Answer 51

1. Locate pulse
2. count number of pulses per min at rest
3. repeat twice more, calculate average
4. walk for five mins and repeat
5. briskly walk and repeat
6. exercise and repeat