respiratory 5-8 Flashcards
What is blood?
liquid CT which supports, connects, separates different tissues
What is the ECM of blood?
- plasma (clotting fibres)
State the 3 functions of blood.
- transports: dissolved gasses, hormones, nutrients
- regulation: pH- buffers, temperature
- protection: clot, WBC’s, antibodies
Name the 3 formed elements of blood.
- RBC’s
- platelets
- WBC’s (granular and agranular leukocytes)
Name the granular and agranular leukocytes.
Hint - BEN
- granular - eosinophils, basophils and neutrophils
- agranular - small lymohocytes (T and B-cells) and monocytes
What is haematocrit?
volume taken up by RBC’s (clinically-relevant feature)
What is the haematocrit in males compared to females and why?
- females 38-46%
- males 40-54%- (more testosterone causes erythropoietin to produce RBC’s)
How does haematocrit affect anaemia?
- low haematocrit
- reduced ability of blood to carry O₂ as less RBC’s
What is polycytheamia?
- haematocrit raised to 65%
- leading to increased viscosity of blood, resistance in vessels, BP and stroke risk (so heart must work harder)
What are the causes of polycytheamia?
- improper RBC production
- tissue hypoxia
- dehydration
- blood doping
What controls RBCs and platelet number?
-VE feedback controls in RBM
What is haemopoiesis?
formation of blood cells in red bone marrow
What is found in RBM and which two subtypes does it give rise to?
- pluripotent stem cells
- subtypes:
1. myeloid cells
2. lymphoid cells
Where do myeloid cells develop and give rise to?
- in RBM
- platelets, RBC’s + all WBC’s but lymphocytes
Where do lymphoid cells develop and give rise to?
- in RBM
- B + T lymphocytes
How can bone marrow be examined?
by bone marrow exam (pelvic girdle) producing histological images
What do some myeloid cells differentiate into?
- progenitor cells
- which cannot reproduce, so form CFU (colon-forming unit of myeloid cells)
What do some lymphoid cells differentiate into?
precursor cells
What do precursor cells develop into?
actual formed elements
What is hormone erythropoietin regulated by and used for?
- testosterone levels
- kidney
What is hormone thrombopoietin used for and where is it found?
- platelet formation
- liver
What is carboamino haemoglobin?
CO₂ bound to the AAs of a globulin molecule
Why do RBC’s bind and carry NO?
- vasodilation
- thrombotic control
What is the equation for buffer control and which enzyme is involved?
- CO₂ + H₂O → H₂CO₃
- carbonic anhydrase
What happens to the oxygen-dissociation curve, when:
a) blood in the lungs becomes more alkaline due to a loss in carbonic acid?
b) carbon dioxide diffuses in from the tissue to blood in the capillaries?
a) shifts to LHS
b) shifts to RHS
What does it mean for temperature if the curve shifts:
a) left?
b) right?
a) decreased temperature, decreased [H+]
b) increased temperature, increased [H+]
Is oxygen water-soluble?
no
What shape is the oxygen dissociation curve?
sigmoidal
What does exercise create in oxygen dissociation and which effect does this lead to?
- acidic conditions (lactic acid)
- the Bohr Effect
What does the oxygen dissociation curve shifting curve RHS/LHS require?
a higher/lower pO₂ to get same saturation of oxygen
Describe the activity of RBC’s.
- rapidly damaged in transit
- no nucleus/organelles so cannot synthesise repair proteins
- as PMs become fragile, may burst
What are ruptured RBCs removed by and what happens to their contents?
- macrophages
- contents recycled
Describe the process of recycling RBCs using the following diagram in 14 stages.
- RBC death and phagocytosis in spleen
- heme and globin split
- globin converted to AAs to be for protein synthesis
- Fe3+ ion is removed from heme group
- enzyme transferrin converts Fe3+ into for liver storage
- bound transferrin and Fe3+ remain
- transferrin and Fe3+ used in endocytosis
- Fe3+ + globin + VitB12 + erythropoietin (hormone-driven) so erythropoiesis occurs in BM; to recycle heme, Fe3+ and transferrin transported to red bone marrow (where RBCs are made) and they return to circulation
- biliverdin from heme is converted to bilirubin (for bodily disposal)
- some bilirubin stored in liver
- other bilirubin transported to small intestine via bile duct (all else by bloodstream)
- bilirubin to urobilinogen converted by bacteria
- urobilinogen → urobilin → urine in kidney (yellow colour) - excreted
- in large intestine, urobilinogen → stercobilin → faeces (broken down bilirubin - brown) - excreted
What can iron overload cause?
- toxic Fe build-up across the body
- can cause serious damage to vital organs (i.e. heart/liver)
- or can result in infection (iron-dependent microbes which flourish in excess Fe)
What is erythropoiesis?
RBC production
Describe the stages of erythropoiesis.
pro-erythroblast (RBM) → cells which make haemoglobin → reticulocytes → eject their nuclei
What is hypoxia?
lack of oxygen in tissues
What is blood doping?
- injection of epoetin (epo) alfa (anemia treatment)
can be dangerous, hard to measure, done in Kenya
What do mast cells do and where are they found?
Hint - like a flag/mast as they do all of the main roles
- vasodilation, inflammation, recruitment of phagocytes, allergic reactions
- CT, mucous membranes
What do macrophages do and where are they found?
- phagocytes which stimulate other WBC’s
- tissues
What do monocytes do and where are they found?
- differentiate into macrophages + dendritic cells → respond to inflammation
- infected tissues, stored in spleen
What do neutrophils do and where are they found?
- first responders to infection, abundant phagocyte, release toxins, inhibit microbes and recruitement
- tissues
What do basophils do and where are they found?
- defence from parasites, release histamines for inflammation, allergic reactions
- circulate in blood and tissues