Blood Flashcards
(13 cards)
name any four types of cells that comprise the formed elements of blood:
red blood cells, platelets, T lymphocytes and basophils
describe the structure and function of red blood cells:
biconcave disc structure, increases surface area; red blood cells use haemoglobin to transport oxygen throughout the body
describe the structure and function of platelets:
fragments of cells lacking nucleus; promote blood clotting at the site of damaged vessels
describe the structure and function of T lymphocytes:
agranular leukocytes; attack viruses, fungi, transplanted cells, cancer cells, and some bacteria
describe the structure and function of basophils:
granular leukocytes; which intensify inflammatory response and are involved in hypersensitivity (allergic) reactions
name the three mechanisms involved in reducing blood loss:
vascular spasm, platelet plug formation and coagulation
explain vascular spasm
vascular spasm involves contraction of smooth muscles lining the vessel wall, to narrow the lumen size; reduces blood loss while heamostatic mechanisms begin operation
explain platelet plug formation
platelets contact and stick to parts of a damaged blood vessel; due to adhesion, the platelets become activated; they extend many projections and begin to release their contents; accumulation and adherence of platelets forms the platelet plug at site of damage
explain coaggulation
coagulation can be intrinsic or extrinsic and involves enzymatic reactions which results in the formation of fibrin threads at the site of damage
Type A
A antigen found on blood cell
Anti-B antibody found in plasma
cannot receive blood from type B or type AB
Type B
B antigen found on blood cell
Anti-A antibody found in plasma
cannot receive blood from type A or type AB
Type AB
A antigen and B antigen found on blood cell
no antibodies found in plasma
can receive blood from any donor
Type O
no antigens found on blood cell
Anti-A and Anti-B antibodies found in plasma
can only receive blood from Type O donors
