circulatory system

Question 1

why do multi-cellular organisms need a circulatory system?

Answer 1

• small SA:V
• high metabolic rate
• high respiration rate

Question 2

double circulatory system

Answer 2

the blood passes through heart twice before one circuit is completed (different in fish)

Question 3

open circulatory system

Answer 3

blood flows freely through body cavity
transported back to heart through valves
blood in this case not used for oxygen supply

Question 4

arteries

Answer 4

• thick and muscular walls
• elastic tissue to stretch and recoil when heart beats
• endothelium folded –> arteries can expand

Question 5

arterioles

Answer 5

= smaller arteries

• less elastic tissue
• layer of smooth muscle

Question 6

capillaries

Answer 6

• walls one cell thick –> easier diffusion

Question 7

venules

Answer 7

small veins

Question 8

space where blood flows through

Answer 8

lumen

Question 9

veins

Answer 9

• wider lumen
• little muscular/elastic tissue
• valves to prevent backward flow

Question 10

capillary bed

Answer 10

the network of capillaries in an area of tissue

Question 11

tissue fluid

Answer 11

surrounds cells in tissue

Question 12

how is the fluid pushed in and moved out of space between tissues?

Answer 12

pressure filtration

out: also lymphatic system

Question 13

why are no red blood cells in the tissue fluid/ lymph

Answer 13

too big to get through capillary walls

Question 14

when do white blood cells enter tissue fluid?

Answer 14

when there is an infection

Question 15

when are platelets in the tissue fluid

Answer 15

when capillaries are damaged

Question 16

systemic circuit

Answer 16

body circuit

Question 17

pulmonary circuit

Answer 17

circuit of blood that flows through the lungs

Question 18

What makes red blood cells so perfect for oxygen transport?

Answer 18

• high SA:V
• no nucleus
• small & flexible –> move through capillaries easily

Question 19

white blood cells function

Answer 19

phagocytosis

lymphocytes: production of antibodies

Question 20

platelets

Answer 20

cell fragments

make blood clot

Question 21

plama transports:

Answer 21

heat, hormones, blood cells, CO2, digested food, urea

Question 22

which chamber of the heart receives blood from the lungs?

Answer 22

the left side

Question 23

myogenic

Answer 23

cardiac muscle can contract and relax without receiving signals from the nerves

Question 24

why do the ventricles contract after the atria?

Answer 24

the AVN has a slight delay before it reacts to the signal of the SAN

Question 25

conduction system of the heart

Answer 25

SAN
AVN
bundle of His
Purkyne tissue

Question 26

Why does the electric signal not spread through the whole muscle straight away?

Answer 26

non-conduction collagen tissue

Question 27

How can an electrocardiograph monitor heart activity?

Answer 27

the heart muscle depolarizes when it contracts and repolarizes when it relaxes

Question 28

Where is the greatest blood pressure in the body?

Answer 28

Aorta –> blood just ejected from heart

Question 29

How high is the blood pressure in capillaries?

Answer 29

largely dissipated (zerstreut) (large number of capillaries)

Question 30

What kind of vessels have capillaries on both sides?

Answer 30

vessels connecting two organs (like the hepatic vein)