21. Blood Flashcards
Overall functions of blood
Transports food, waste products and hormones.
Transport heat and helps maintain a constant body temperature.
Transport oxygen.
Defend against diseases
Composition of blood
Liquid part
Solid part
Liquid: Plasma- pale (55%)
Solid: Red blood cells, white blood cells, platelets (45%)
Compositon of plasma
90% water
3% dissolved substances
7% proteins (antibodies and clotting proteins)
Role of plasma
Transport dissolved substances (glucose, urea, amino acids, vitamins and minerals)
Carries heat
Red Blood cell Shape Also known as Main functions Contains Produced
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)
Red Blood Cell shape benefits
Biconcave: Increased surface area so more oxygen transported
RBC vs. Normal body cell
RBC- no nucleus when mature
RBC- no mitochondria (more room for oxygen transport
RBC have haemoglobin
White Blood cell Shape and ratio Also known as Main function Types Produced Where they mature
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
How WBC fight infection
monocytes
Surround bacteria and engulfs them. Known as phagocytosis and become known as phagocytes
How WBC fight infection
lymphocytes
produce antibodies
RBC vs. WBC
WBC-larger, irregular shape, has nucleus
RBC- smaller, biconcave, no nucleus
What is anaemia
When body has low level of iron. Less RBCs so less O2 transported. Person weaker, more tired.
What is haemophilia
When blood doesnt clot properly
Platelets Shape Main function Produced Ratios
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
Name 3 types of blood vessels
and their function
Types: Artery, Vein, Capillary
Function: Transport blood around the body
Arteries and Veins never connect. Capillary connects them,
Structure of a blood vessel (diagram)
Outside–>In
- Inelastic protein called collagen- prevents over expansion (tough)
- Muscle (allows vessel to expand) and Elastic fibres (allow vessel to return to original shape)
- Endothelium cells- line the vessels
- Lumen- where the blood flows
Artery Main function Valves Wall Lumen Blood Blood flow
Main function: Transports blood away from heart Valves: No Wall: Thick Lumen: Small Blood:High pressure, Rich in oxygen Blood flow: in pulses
Vein Main function Valves Wall Lumen Blood Blood flow
Main function: transport oxygen to heart Valves: yes Wall: Thin Lumen: Wide Blood: Low Pressure, No oxygen Blood flow: Smooth
Capillary
Main Function
Structure
Walls
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
Why does the artery have a thick wall and the vein doesn’t
Artery has to pump blood all over body
Vein only has to pump blood to one place (heart)
Why does vein have valves and arteries dont
Artery: Blood is under high pressure so not needed.
Vein: Low pressure so needs to prevent backflow
How capillaries are adapted for exchange of materials
They are branched and numerous so more efficient
Wall is 1 cell thick so less distance for material to travel.
