Circulatory System

Question 1

What makes up blood?

Answer 1

Plasma
Erythrocytes (red blood cells)
Leukocytes (white blood cells)
Thrombocytes (platelets)

Question 2

What is plasma made up of?

Answer 2

90% water
10% ions, proteins, nutrients, waste and dissolved gases
Albumin - most abundant protein found in plasma

Question 3

What does plasma do?

Answer 3

Transports hormones and antibodies
Works with the platelets to cause the blood to clot

Question 4

How do Erythrocytes form?

Answer 4

The formation of RBCs is called erythropoiesis.
It is done in bone marrow through hemocytoblast (a type of stem cell)
They take 2 days to form and 2,000,000 are made every second
More are made when a hormone called erythropoietin is secreted

Question 5

What is an erythrocyte and what does it do?

Answer 5

Red blood cell
Transports oxygen and carbon dioxide

Question 6

What is the structure of an erythrocyte?

Answer 6

Biconcave - increases the surface area
No mitocondria so the cell doesn’t use up all the oxygen it’s transporting
No nucleus so there’s more space for the haemoglobin (what oxygen binds to)

Question 7

What are the blood vessels?

Answer 7

Arteries
Veins
Capillaries

Question 8

What are leukocytes and what is their function?

Answer 8

White blood cells
Immune response

Question 9

What is the structure of a leukocyte?

Answer 9

Larger than erythrocytes (rbcs)
Contains a nucleus and mitochondria
5 different types with their own roles

Question 10

What are veins?

Answer 10

A type of blood vessel that carries deoxygenated blood towards the heart.

Question 11

What is the structure of a vein?

Answer 11

Thin walls as the blood pressure is low
Contains valves to prevent back flow from low pressure

Question 12

What is a thrombocyte and what does it do?

Answer 12

A platelet
Blood clotting

Question 13

What is a thrombocytes structure?

Answer 13

No nucleus
0.1% of blood composition

Question 14

What is an artery?

Answer 14

Arteries are a kind of blood vessel that carries oxygenated blood away from the heart
- except the pulmonary artery which carries deoxygenated blood to the lungs

Question 15

What is the structure of an artery?

Answer 15

It has thick walls as the blood is tight pressure. (Coming away from the heart so blood is being pumped)

Question 16

What do capillaries do?

Answer 16

They exchange gas and nutrients from arteries and veins to the surrounding tissue.

Question 17

What is the structure of a capillary?

Answer 17

They’re the smallest blood vessel
They’re one cell thick and very permeable so gas and liquids exchange through it easily

Question 18

What does the heart do?

Answer 18

Pumps blood around the body
Controls the heart rate
Controls the blood pressure

Question 19

Structures of the heart

Question 20

What is the atria?

Answer 20

The first chamber of the heart
The right side goes to the lungs
The left side goes to the body
The myocardial (cardiac muscle) is thin as it doesn’t have to pump blood very far

Question 21

What are the ventricles?

Answer 21

The right pumps blood into the lungs
The left pumps blood into the body
Thick myocardium (cardiac muscle) as it pumps blood a long distance
The left pumps blood at a higher temperature so is thicker

Question 22

What is the aorta?

Answer 22

The main artery
Pumps blood to the body

Question 23

What is the vena cava?

Answer 23

Main vein
carries deoxygenated blood to the heart
Superior carries blood from the chest and up
Inferior carries blood from below the chest

Question 24

What are the pulmonary veins?

Answer 24

There are four
They carry oxygenated blood from the lungs to the left atrium

Question 25

What are the pulmonary arteries?

Answer 25

Carries deoxygenated blood from the right ventricle to the lung
There are two - each supplies deoxygenated blood to a lung

Question 26

What are the valves in the heart called?

Answer 26

Bicuspid
Tricuspid

Question 27

Where are the bicuspid and tricuspid valves located?

Answer 27

Between the atria and ventricles

Question 28

What do the bicuspid and tricuspid valves do?

Answer 28

Allows blood flow between the atria and ventricles
Attaches to papillary muscles with strong chords called chordae tendinaes

Question 29

Where is the bicuspid valve located

Answer 29

Between the left atrium and ventricle
- also called the mitral valve

Question 30

Where is the tricuspid valve located?

Answer 30

Between the right atrium and ventricle

Question 31

What are the structures involved in the heartbeat?

Answer 31

Sino-atrial node
Atrioventricular node
Bundle of his
Purkynje fibres

Question 32

Where does the heart beats electrical impulse start?

Answer 32

The sinoatrial node

Question 33

What connects the atrium and ventricle?

Answer 33

The atrioventricular node

Question 34

What is the bundle of his?

Answer 34

Carries the electrical signal from the atrioventricular node to the purkynje fibres

Question 35

What does the purkinje fibres do?

Answer 35

divides and spreads the impulses to the ventricular muscles

Question 36

What is the journey of the electrical signal that causes the heartbeat?

Answer 36

Begins in sinoatrial node
Activates the atria
Reaches the atrioventricular node
Sends impulse down the bundle of his
Divides into purkynje fibres
Contraction of ventricles

Question 37

What is a closed circulatory system?

Answer 37

The blood is contained inside of blood vessels and travels around a unidirectional circuit back to the heart
Vertibrates and some invertebrates have theses

Question 38

What is an open circulatory system?

Answer 38

The blood flows freely through the cavities (hemoceol)
Generally invertebrates have these