THE BLOOD Flashcards
What are erythrocytes? (1)
Red blood cells
What are leucocytes? (1)
White blood cells
What does plasma carry? (6)
Plasma carries; -nutrients from gut to liver to all cells
-excretory products
-hormones from the endocrine gland to all tissues and organs
-dissolved proteins that have a role in regulating the osmotic concentration of the blood
-dissolved proteins that are antibodies
-heat to all tissues.
What are the functions of plasma? (4)
-carry water-soluble materials around the body
-help maintain body temperature
-acts as a buffer to pH changes
-contains platelets
What does the blood carry? (3)
-erythrocytes
-leucocytes
-plasma
What are the several types of white blood cells? (4)
-neutrophils
-monocytes
-eosinophils
-lymphocytes
What is the function of neutrophils and monocytes? (1)
They engulf and digest pathogens by phagocytosis
What is the function of eosinophils? (2)
Involved in allergic responses and protection against viruses and parasitic worms.
What is the function of lymphocytes, type B? (1)
To make antibodies.
What is the function of lymphocytes, type T? (1)
Help kill tumour cells and help control immune responses.
What is the function of platelets? (1)
They are involved in blood clotting.
What is the function of red blood cells? (2)
-oxygen from the lungs to respiring tissues
-carbon dioxide from respiring tissues to the lungs
What is the main need for high blood pressure? (1)
To drive the blood around the body to the tissues and organs.
What happens during systole (heart contraction)? (1)
Blood is pumped through the aorta and other arteries at high pressure. The elastic fibres of the arteries enable them to expland and allow blood through.
What happens during diastole (heart relaxation)? (1)
The blood pressure in the arteries drops, the elastic recoil of the artery walls help forced the blood on.
What are varicose veins? (2)
When a vein wall becomes weakened, valves may no longer close properly which allows back flow of blood causing the vein to become enlarged and bumpy (varicose).
Where do varicose veins usually occur? (1)
In superficial veins near the skin surface in lower legs.
How are varicose veins usually treated? (1)
They can be surgically removed without affecting blood flow as most blood is returned to the heart by deep veins.
What are the functions of the blood? (4)
-transport
-defence
-thermoregulation
-maintaining pH of body fluids
How are red blood cells specialised? (4)
-have a flattened bioconcave shape
-large amount of haemoglobin
-no nucleus or organelles
-diameter of 6-8 micrometers larger than a capillary diameter
Why does a red blood cell having a flattened bioconcave shape help it to perform its function? (1)
Ensures a large surface area to volume ratio for efficient gas exchange.
Why does a red blood cell having a large amount of haemoglobin help it to perform its function? (1)
For transporting oxygen, it binds to it.
Why does a red blood cell having no nucleus or organelles help it to perform its function? (1)
Maximises space for haemoglobin so more oxygen can be transported.
Why does a red blood cell having a -diameter of 6-8 micrometers larger than a capillary diameter help it to perform its function? (1)
Slows blood flow to allow diffusion of oxygen.
which out of the three blood vessels have an outer layer (tonica externa)? (3)
Artery- present
Capillary- absent
Veins- present
which out of the three blood vessels have an middle layer (tunica media)? (3)
Artery- thick layer
Capillary- absent
Veins- thin layer
which out of the three blood vessels have an endothelium (tunica intima)? (3)
Artery- absent
Capillary- absent
Veins- present
What is a tunica intima? (1)
‘Pavement epithelium’ or valves.
What is a tunica media? (1)
Smooth involuntary muscle.
What is pulmonary circulation? (1)
The pathway of arteries, veins and capillaries carrying blood from the heart to the lungs and back to the heart.
What is systemic circulation? (1)
The pathway of arteries, veins and capillaries carrying blood from the heart to all the bodies tissues and back to the heart.
What route does pulmonary circulation take? (6)
Pulmonary artery - artériole - capillary - venule - vein - pulmonary vein
What route does systematic circulation take? (6)
Aorta - artériole - capillary - venule - vein - vena cava
What is meant by elastic arteries? (2)
Elastic fibres and smooth muscle in the walls of arteries are stretched when the blood is at high pressure, some of the energy in the blood is stored at potential energy in the elastic walls, when the pressure of the blood falls this energy is used to maintain the flow until the ventricles contract.
