mod 5 Blood Flashcards
what blood type is considered the universal donor?
O
what blood type is considered the universal recipient?
AB
which of the following would be an expected hematocrit for a healthy adult female? 98% 84% 65% 58% 42%
42%
Any substance, eg a broken off section of a blood clot that is transported via the blood vessels is termed a... embolus thrombus infarct anticoagulant all of the above
embolus
which plasma protein is the most common and name 2 roles it plays…
albumin
acts as a carrier protein
adds pH buffering capacity to blood
important component in maintaining vascular COP and fluid balance in the vasculature
Albumin- 60% of plasma proteins, produced by liver , main contributor to osmotic pressure
there are 3 main processes by which the body prevents loss of blood from traumatised tissues, what are these? indicate sequence of events.
haemostasis
1) vascular spasm
2) platelet plug formation
3) coagulation
what does clot retraction mean and how does it occur?
within first 30 - 60 minutes, a platelet induced process called clot retraction stabilizes the clot.
platelets contain contractile proteins, actin and myosin
contraction of actin and myosin in the platelets pull on surrounding fibrin strands, squeezing serum and compacting the clot.
how does foetal Hb differ from adult Hb in terms of function?
= fetal Hb is the main oxygen transport protein in the fetus during the last 7 months if development in the uterus and in the newborn.
= fetal haemoglobin binds oxygen with greater affinity than the adult Hb.
=allows fetus better access to oxygen from the mother’s bloodstream
= fetal haemoglobin has different globin molecules
= beta chains are replaced with gamma polypeptide chains in fetal Hb.
what do the terms oxyhaemoglobin and carboxyhaemoglobin refer to?
oxyhaemoglobin- oxygen bound to iron ont eh heme group (lungs to blood)
20% of CO2 transported in blood combines with Hb.
CO2 binds to globins amino acids rather than heme group = carboaminohaemoglobin (tissues to lungs)
occurs more readily when Hb in reduced state (deoxyhaemoglobin)
CO (carbon monoxide) binds to heme group = carboxyhaemoglobin
describe 3 types of anaemia
anaemia, insufficient O2 carrying capacity of blood, duw to either insufficient RBC or insufficient Hb or both. leads to fatigue, breathlessness, chills paleness.
1) insufficient RBC - haemorrhagic anaemia, haemolytic anaemia, aplastic anaemia.
2) insufficient Hb - dietary iron deficiency (microcytes) lack of intrinsic factor Vit B12 percicious anaemia (macrocytes)
3) abnormal Hb- thalassemias, globin chain abnormalities, cells are fragile and block capillaries
what does the Hb molecule consist of ?
2 alpha and 2 beta polypeptide chains (make up globin).
contains 4 heme groups, each containing an iron ion.
which vitamin is especially important to the production of blood clotting factors?
vit K
which ion is absolutely crucial to the clotting cascade?
Ca+
what is the likely blood volume of a 60kg woman?
4.2 litres
What is the width of a red blood cell?
7.5um
