Circulatory System

Question 1

What’s the function of the circulatory system?

Answer 1

It provides oxygen, nutrients and hormones to muscles and tissues throughout the body and also removed waste from cells and organs so the body can dispose of it

Question 2

Main parts of the circulatory system

Answer 2

Blood, the heart, veins, arteries, capillaries

Question 3

What is blood made out of in vertebrates?

Answer 3

Erythrocytes (red blood cells), leukocytes (white blood cells), thrombocytes (platelets), plasma

Question 4

Structure of / information on erythrocytes

Answer 4

Disc-shaped, think and sunken centre, thick around outside, can survive around 120 days, can bend fold and squeeze through small spaces

Question 5

Functions of erythrocytes

Answer 5

To pick up oxygen from the lungs and take it to the tissues and to pick up carbon dioxide from the tissues and take it to the lungs

Question 6

Structure of / information on leukocytes

Answer 6

Appear granulated, live for 3-4 days, found in blood and lymphatic system, formed in bone marrow

Question 7

What are the 5 types of leukocytes and what do they do?

Answer 7

Neutrophils - ingest and destroy pathogens
Eosinophils - attack pathogens, cause allergic reactions
Basophils - also plays a role in allergies
Monocytes - clean up dead cells , identifies invaders for lymphocytes
Lymphocytes - part of adaptive immune system, creat antibodies

Question 8

Functions of leukocytes

Answer 8

Help destroy bacteria, help disable pathogens, destroy allergens and inflammatory chemicals

Question 9

Structure of / information on thrombocytes

Answer 9

Very small fragments of bone marrow, no nucleus - they aren’t cells, irregularly-shaped

Question 10

Functions of thrombocytes

Answer 10

Form temporary platelet plugs to stop bleeding, promote and then dissolve blood clots, digest and destroy bacteria, maintain linings of blood vessels

Question 11

Structure of / information on plasma

Answer 11

Largest component in blood - 55%, clear extracellular fluid, a liquid in which erythrocytes / leukocytes / thrombocytes are suspended

Question 12

Blood plasma of a mixture of …?

Answer 12

Water - 91%, proteins - 77%, nutrients - 2%, hormones - <1%, electrolytes - <1%

Question 13

Functions of plasma

Answer 13

Carries proteins, transports nutrients, waste materials, water, enzymes and hormones around the body and regulates bleeding

Question 14

What is hemoglobin?

Answer 14

it is a protein found in erythrocytes that loads and transports oxygen. it contains iron which binds the oxygen to the erythrocyte. it has a high affinity for oxygen - can carry 4 oxygen molecules. animals that live in areas of low oxygen content have an increased amount of hemoglobin in their blood. hemoglobin will also take up oxygen at a lower concentration due to the change in amino acids which dictate how the protein folds

Question 15

Function of arteries

Answer 15

to deliver oxygenated blood away from the heart and to the rest of the body - one exception is the pulmonary artery which takes deoxygenated blood to the lungs

Question 16

Structure of arteries

Answer 16

thick walls made of elastic fibers and smooth muscle - allows them to stretch so they don’t burst/rupture. have a small/narrow lumen

Question 17

Arterioles

Answer 17

large artery splits into smaller vessels called arterioles. they branch further into capillaries when it reaches the tissue cells. they slow down blood flow which causes a drop in blood pressure so that the capillaries dont get damaged

Question 18

Function of veins

Answer 18

carry deoxygenated blood back to the heart - exception is pulmonary vein which takes oxygenates blood from the lungs to the heart

Question 19

Structure of veins

Answer 19

thin walls that are less elastic and less muscular than arteries, wide/large lumen, have valves to keep blood flowing in the same direction and prevent blood flowing backwards

Question 20

Venules

Answer 20

smaller blood vessels that pass to larger veins , are porous - fluid/waste substances can filter back into the bloodstream

Question 21

Structure of capillaries

Answer 21

a network of tiny blood vessels that sit between veins and arteries, wall is one cell thick

Question 22

Function of capillaries

Answer 22

supply tissues and organs of the body with components of the blood such as oxygen, remove waste from surrounding cells

Question 23

what is diffusion

Answer 23

the movement of molecules from a high concentration to a low concentration

Question 24

What’s an closed circulatory system

Answer 24

internal organs aren,t in direct contact with the blood, blood flow can be regulated and blood is enclosed within the heart and blood vessels

Question 25

Whats an open circulatory system

Answer 25

the body cavity is filled with blood and blood flow cannot be regulated, organs and tissues are bathed in a fluid called haemolymph, the heart pumps the haemolymph so it can reach the rest of the body, haemolympoh transports the necessary nutrients to the cells of the body

Question 26

whats a single circulatory system

Answer 26

blood passes through the heart once and the heart has two chambers (one atrium and one ventricle), blood receives oxygen after being pumped from the heart, the heart only receives oxygenated blood, blood pressure is lower than double circulatory system.