chapter 9 transport in humans Flashcards
what makes up plasma (4)
- 90% water = acts as a solvent to soluble proteins like fibrinogen, prothrombin and antibodies
- Dissolved mineral salts
- Food substances like glucose, amino acids, fats and vitamins
- Excretory products like urea, uric acid, creatinine, carbon dioxide (present as hydrogencarbonate ions)
function of red blood cells
- contains haemoglobin: combines reversibly with oxygen
- To transport oxygen from lungs to all cells to the body
adaptations of RBCs
- Has a circular biconcave shape: increase SAVR = contains more haemoglobin = higher rate of absorption and release of oxygen
- Does not have a nucleus: increase in space = carry more haemoglobin
- Elastic and bellshaped: can squeeze through blood vessels smaller than itself
what are white blood cells (feature + types)
feature: able to change its shape and squeeze through the walls of thin blood capillaries into spaces among tissue cells = mobile to fight bacteria
types:
1. lymphocytes: produce antibodies = protect body from disease causing microorganisms
2. phagocytes: able to ingest foreign particles like bacteria
how does agglutination happen
happens when plasma contains antibody (in plasma) and antigen (on surface of RBC) of same letter:
antibody a binds to antigen A,
antibody b binds to antigen B
donation: involves only blood (only antigens) - if agglutination occurs it is due to plasma in recipient
features of blood type A
- can receive A and O
- plasma/serum has antibody b
- RBC has antigen A
features of blood group B
- can receive B and O
- Plasma has antibody a
- RBC has antigen B
features of blood group AB
- can receive A, B, AB and O (universal acceptor)
- Plasma has no antibody
- RBC has antigen A and B
features of blood group O
- can receive O (universal donor)
- Plasma has antibody a and b
- RBC has no antigen
how does blood clotting occur when there is an open wound (4 steps)
- Damaged blood vessels release enzyme thrombokinase
- stimulates conversion of protein prothrombin into thrombin in presence of calcium ions
- Thrombin catalyses conversion of soluble protein fibrinogen to insoluble fibrin threads (will not dissolve in water present in plasma)
- Fibrin threads form mesh which trap blood cells and seals wound = microorganisms like bacteria cannot enter
what is phagocytosis
definition: process of engulfing/ingesting foreign particles by white blood cells (phagocytes)
process: Phagocyte engulfs bacteria by flowing over them and enclosing them = digests ingested bacteria
how do lymphocytes protect our body (3)
- Destroying bacteria: attaches to them, causing bacterial surface membrane to rupture
- Causing bacteria to clump together = easily ingested by phagocytes
- Neutralising harmful substances produced by bacteria
how to reduce risk of rejection in a transplant
- Tissue match = must be genetically close to the recipient as possible (either from same person or family member)
- Use immunosuppressive drugs: inhibit responses of recipient’s immune system = antibodies will not be produced and attack the tissue
what are arteries (function, structure, blood pressure, speed of blood flow)
function: Transports blood away from the heart→ carry oxygenated blood (except pulmonary artery)
structure: Thick muscular walls, Small lumen, no valves
BP: high = more blood flowing per unit time in a smaller space
speed of blood flow: fast
adaptations of arteries
- Thick muscular walls = withstand immense pressure of blood forced out from the heart
- Walls with much elastic tissue: able to stretch and recoil under high pressure to push blood along the artery