Transport Flashcards
(22 cards)
What is the composition of blood?
Plasma
Platelets
Red blood cells
White blood cells
What is plasma
Pale yellow liquid carrying substances around the body
What does plasma carry around the body?
red/white blood cells
platelets
digested food products
carbon dioxide
urea
hormones
heat
What are platelets
Small fragments of cells that help blood clot.
What do platelets do?
They stop bleeding
Barrier for microbes
What are the adaptations of red blood cells?
no nucleus (space for haemoglobin)
biconcave shape (squeeze through holes)
SA:VR
What do red blood cells do
Transport oxygen from lungs to all cells in body
oxygen + haemoglobin <-> oxyhaemoglobin
What type of nucleus do phagocytes have? Why?
Lobed
Squeeze through small holes
What do phagocytes do?
Detect things foreign to body
Engulf and digest (enzymes)
Non-specific
What do lymphocytes do?
Detects new antigens
Produces new antibodies
New antibodies lock onto new antigens (marked out for destruction by phagocytes)
Memory cell produced
What are antigens?
Unique molecules on surface of pathogens
Describe vaccination
vaccination stimulates the immune system to create memory cells to protect against future infections without causing the disease
Describe blood clotting
Platelets plug damaged area
Held together by mesh of protein fibrin
Why does heart rate increase during exercise?
- Muscles require more energy so respire more
- Carbon Dioxide concentration in blood increases
- Detected by receptors in aorta and carotid artery. Signal to brain
- Brain signals to heart.
Why does heart rate increase due to adrenaline?
- Adrenaline released from adrenal glands
- Adrenaline binds to specific receptors in heart
What is coronary heart disease?
When the coronary arteries (that supply blood to heart muscle) get blocked by build up of fatty material
Lack of oxygen to heart muscle -> heart attack
What are arteries?
Blood vessels that carry oxygenated blood away from the heart
What are veins?
Blood vessels that carry deoxygenated blood towards the heart
What are capilleries?
Blood vessels where gas exchange (oxygen and carbon dioxide) and nutrient exchange occur between blood and tissues
What is the structure of arteries?
High pressure ->
walls are strong + thick+ elastic
small lumen
What is the structure of veins?
Low pressure ->
thin walls
bigger lumen to help blood flow
valves stop backflow
What is the structure of capilleries?
Arteries branch into capillaries
Very small
Permeable walls (1 cell thick)
