Chapter 06 - Transport in Humans Flashcards
What is blood made up of?
1) Plasma
2) Red blood cells
3) White blood cells
4) Platelets
Describe plasma
Plasma is a yellowish pale liquid that consists of water and other dissolved substances (glucose, salts, proteins, amino acids, fats, vitamins, hormones, excretory products, red blood cells and white blood cells)
Describe the functions of plasma
1) Transports RBC and WBC around the body
2) Transports nutrients from the small intestine to other parts of the body
3) Transports excretory products from their production organs to excretory organs for removal
4) Transports hormones from endocrine glands to target organs
What are the 4 adaptations of red blood cells?
1) Circular, biconcave shape – Increase SA:V
2) Contains haemoglobin – binds readily and reversibly with oxygen
3) No nucleus – More space for more haemoglobin
4) Flexible – Squeeze through narrow capillaries
What is the main function of red blood cells?
To transport oxygen molecules from the lungs to the rest of the body
What happens to the concentration of oxygen in the air at higher altitudes?
The concentration is lower resulting in a less steep concentration gradient between the lungs and the air causing the oxygen to diffuse more slowly into the lungs, reducing the amount of oxygen absorbed into the blood
What does the body do in response to lesser oxygen absorbed into the bloodstream?
To compensate for this, the body produces more RBC for more haemoglobin to increase the oxygen carrying capacity of the blood to ensure an adequate supply of oxygen for aerobic respiration to provide sufficient energy to meet the body’s needs
What are the 2 types of white blood cells?
1) Phagocytes
2) Lymphocytes
Describe the structure of white blood cells
White blood cells are irregular in shape, phagocytes have a lobed nucleus while lymphocytes have a round nucleus
What are the main 2 functions of white blood cells?
1) Antibody production
2) Phagocytosis
What do lymphocytes produce and what are the functions?
Antibodies can
1) recognise foreign particles
2) destroy disease causing organisms such as bacteria and viruses
3) cause bacteria to clump together for easy ingestion by phagocytosis
4) neutralises toxins produced by bacteria
What process do phagocytes carry out?
Phagocytosis - the process by which a white blood cell engulfs and destroys foreign particles. This process is to destroy bacteria by taking them into the cytoplasm through ingestion
What are platelets made of?
Fragments of cytoplasm
What do platelets do?
Platelets prevent excessive blood loss and the invasion of harmful organisms into the bloodstream
Describe the process of blood clotting
1) When blood is exposed to air, an enzyme is released by the platelets from the damaged tissues to activate the thombrin in the plasma
2) Thombrin catalyses the conversion of soluble fibrinogen into insoluble fibrin threads
3) Fibrin threads entangle to blood cells and the entire mass becomes a clot/scab
4) A clot prevents foreign/harmful substances from entering the bloodstream
What is tissue/organ transplant?
Replacement of damaged/diseased tissue/organ by a healthy one from a donor
Why would a recipient’s (receiving an organ/tissue) immune system reject the transplanted organ?
The recipient’s immune system treats the donor’s tissue/organ as a foreign entity, causing white blood cells to produce antibodies to destroy the transplanted organ/tissue
What are 3 measures to overcome the problem of tissue/organ rejection?
1) If a person suffers skin burns, healthy skin from another part of the same person’s body can be used to replace the damaged skin
2) A tissue match can be performed to ensue the tissues of the donor and recipient are highly genetically similar
3) Use drugs that can suppress the responses of the recipient’s immune system towards the foreign tissue
What do red blood cells have on their surface and in their plasma?
Antigens on the surface, antibodies in plasma (both contain special proteins in our body)
What are the 4 blood groups?
A, B, AB, O
What kind of letters are used to represent antigens and antibodies
Antigen: Caps
Antibody: no caps
What are the antigen(s) and antibody(ies) present in blood group A?
Antigen A, Antibody b
What are the antigen(s) and antibody(ies) present in blood group B?
Antigen B, Antibody a
What are the antigen(s) and antibody(ies) present in blood group AB?
Antigen A&B, no antibodies
What are the antigen(s) and antibody(ies) present in blood group O?
No antigens, Antibody a&b
If the antigen A binds with antibody a, what would the effect be?
Clumping of red blood cells
If the antigen A binds with antibody b, what would the effect be?
No clumping of red blood cells
If the antigen B binds with antibody a, what would the effect be?
No clumping of red blood cells
If the antigen B binds with antibody b, what would the effect be?
Clumping of red blood cells
Why is agglutination (clumping) dangerous?
The clumps can block small blood vessels and obstruct blood flow. Hence, matching blood types is important in blood transfusions to avoid clumping and potential health risks
What is transfusion?
Transfusion is the process of transferring fluid into a vein or an artery
What blood group can AB give to and receive from?
AB can only give to AB
but receive from AB, A, B and O (AB is greedy)
What blood group can A give to and receive from?
A can give to A and AB
and receive from A and O
What blood group can B give to and receive from?
B can give to B and AB
and receive from B and O
What blood group can O give to and receive from?
O can give to AB, A, B, O
and receive from O
(overly generous)
What is the heart and what happens when it relaxes and contracts?
A heart is a muscular organ that is responsible for pumping blood throughout the body
When the heart contracts, the blood is forced out with high pressure
When the heart relaxes, the heart chambers fill up with blood
What are arteries?
Arteries are blood vessels that carry blood away from the heart
What is the name of the large artery that leaves the left side of the heart?
Aorta, it branches to form smaller arteries
What kind of walls do arteries have and why?
Thick and muscular - withstand high blood pressure (because arteries receives blood directly from heart and blood is forced out)
Elastic - Stretch and recoil/spring back to propel blood in spurts along the artery (pulse)
What is constriction and dilation of the artery caused by?
The contraction and relaxation of muscles in the arterial wall
What happens to the lumen of the artery when the muscles in the wall of the arterial wall contract?
The lumen becomes narrower when it constricts, so less blood flows through it per unit time
What happens to the lumen of the artery when the muscles in the wall of the arterial wall relax?
The lumen becomes wider when it, so more blood flows through it per unit time
What kind of blood do arteries carry?
Oxygenated blood (except pulmonary arteries)
What are the smaller arteries called?
Arteries branches to form arterioles