21. Blood

Question 1

Overall functions of blood

Answer 1

Transports food, waste products and hormones.
Transport heat and helps maintain a constant body temperature.
Transport oxygen.
Defend against diseases

Question 2

Composition of blood
Liquid part
Solid part

Answer 2

Liquid: Plasma- pale (55%)
Solid: Red blood cells, white blood cells, platelets (45%)

Question 3

Compositon of plasma

Answer 3

90% water
3% dissolved substances
7% proteins (antibodies and clotting proteins)

Question 4

Role of plasma

Answer 4

Transport dissolved substances (glucose, urea, amino acids, vitamins and minerals)
Carries heat

Question 5

Red Blood cell
Shape
Also known as
Main functions
Contains
Produced

Answer 5

Shape:Round, very small, biconcave
Also known as: Erythrocytes
Main functions: Transport oxygen
Contains: Haemoglobin which gives blood red colour and transports oxygen. A red pigment
Produced: Bone marrow (rib and breastbone)

Question 6

Red Blood Cell shape benefits

Answer 6

Biconcave: Increased surface area so more oxygen transported

Question 7

RBC vs. Normal body cell

Answer 7

RBC- no nucleus when mature
RBC- no mitochondria (more room for oxygen transport
RBC have haemoglobin

Question 8

White Blood cell
Shape and ratio
Also known as
Main function
Types
Produced
Where they mature

Answer 8

Shape and ratio: Larger than RBC, irregular shape, RBC:WBC 700:1
Also known as: leucocytes
Main function: fight infection
Types: Lymphocytes and Monocytes
Produced: Bone marrow
Where they mature: Lymphatic system

Question 9

How WBC fight infection

monocytes

Answer 9

Surround bacteria and engulfs them. Known as phagocytosis and become known as phagocytes

Question 10

How WBC fight infection

lymphocytes

Answer 10

produce antibodies

Question 11

RBC vs. WBC

Answer 11

WBC-larger, irregular shape, has nucleus

RBC- smaller, biconcave, no nucleus

Question 12

What is anaemia

Answer 12

When body has low level of iron. Less RBCs so less O2 transported. Person weaker, more tired.

Question 13

What is haemophilia

Answer 13

When blood doesnt clot properly

Question 14

Platelets
Shape
Main function
Produced
Ratios

Answer 14

Shape: Tiny fragments of cells
Main Function: Clot blood which prevents blood loss and forms scabs which stops the entry of infection
Produced: Bone Marrow
Ratios: RBC: WBC: Platelets, 700:1:40

Question 15

Name 3 types of blood vessels

and their function

Answer 15

Types: Artery, Vein, Capillary
Function: Transport blood around the body
Arteries and Veins never connect. Capillary connects them,

Question 16

Structure of a blood vessel (diagram)

Answer 16

Outside–>In

1. Inelastic protein called collagen- prevents over expansion (tough)
2. Muscle (allows vessel to expand) and Elastic fibres (allow vessel to return to original shape)
3. Endothelium cells- line the vessels
4. Lumen- where the blood flows

Question 17

Artery
Main function
Valves
Wall
Lumen
Blood
Blood flow

Answer 17

Main function: Transports blood away from heart
Valves: No
Wall: Thick
Lumen: Small
Blood:High pressure, Rich in oxygen
Blood flow: in pulses

Question 18

Vein
Main function
Valves
Wall
Lumen
Blood
Blood flow

Answer 18

Main function: transport oxygen to heart
Valves: yes
Wall: Thin
Lumen: Wide
Blood: Low Pressure, No oxygen
Blood flow: Smooth

Question 19

Capillary
Main Function
Structure
Walls

Answer 19

Main Function: Exchange of materials between the cells and the blood. Connect arteries and veins
Structure: Branched in a network
Walls: Thin and one cell thick

Question 20

Why does the artery have a thick wall and the vein doesn’t

Answer 20

Artery has to pump blood all over body

Vein only has to pump blood to one place (heart)

Question 21

Why does vein have valves and arteries dont

Answer 21

Artery: Blood is under high pressure so not needed.
Vein: Low pressure so needs to prevent backflow

Question 22

How capillaries are adapted for exchange of materials

Answer 22

They are branched and numerous so more efficient

Wall is 1 cell thick so less distance for material to travel.