ILA Flashcards
What is osteomalacia?
defective mineralisation of bone matrix in an adult
what is osteoporosis?
reduced bone density (reduced bone matrix)
what is the function of macrophages?
- type of WBC
- in bone marrow
- attacks bacteria and tumour cells
what is the role of UV light in vitamin D metabolism?
converts 7-dehydrocholestrol -> cholecaliferol
where is 1-25-dihydroxyvitamin D formed?
kidney
what is hydroxyapatite made of?
calcium and phosphate
what is sickle cell anaemia caused by?
- autosomal recessive
- inherited
- substituting AA in beta globin chain
which enzyme unwinds supercoiled DNA?
topoisomerase
in sickle cell disease, an acute pain crisis is typically caused by capillary occlusion in the…
bone
what do specific amino acids bind to?
tRNA
what type of structure does a protein with a number of sub-units held together by cross links have?
quaternary structure
what is transcription?
DNA copied into mRNA that leaves the nucleus
what is translocation?
genetic material exchanged between chromosomes
what is translation?
mRNA used to specific AAs required to make proteins
what is transamination?
reaction where amino group is removed from an AA in metabolism
what enzyme causes the double helix to unzip?
helicase
where are ribosomes assembled?
inside the nucleus
- translocate to cytoplasm through nuclear pores
where is aldosterone synthesised?
adrenal cortex
what type of hormone is aldosterone?
steroid
what is aldosterone released in response to?
angiotensin II
what is the function of aldosterone?
promotes Na+ reabsorption and K+ secretion in DCTs
where is ADH synthesised?
hypothalamus
how is total body water distributed by volume?
assume healthy 70kg male
intracellular: 28L
interstitial: 11L
intravascular: 3L
what is the function of renin?
angiotensinogen -> angiotensin I
which substances are taken into account when calculating plasma osmolarity?
Na+
glucose
urea
what is the principal site of renin production?
juxtaglomerular cells
occlusion in which artery is most likely to result in a fatal heart attack and why?
left main coronary artery
- supplies largest area of hear muscle
what is a raised central venous pressure a sign of?
right sided heart failure
why can left-sided heart failure lead to a pulmonary oedema?
causes an increase in pulmonary pressure
which artery supplies the SA and AC nodes? (most of the time)
right coronary artery
which artery supplies the His-Purkinje system?
LAD
what is stroke volume in the average person?
70 mls
what is the function of the ductus arteriosus in the foetal CVR system?
allows blood to bypass foetal lungs by shunting it from pulmonary artery -> aorta
what is the relationship between SVR & BP with the sympathetic nervous system?
- SNs cause vasoconstriction
- increases systemic vascular resistance
- increases BP
what is the relationship between BP & SVR with the parasympathetic nervous system?
PNs do not have major influence on peripheral blood vessel diameter as they do not have parasympathetic innervation
what nerve innervates the pericardium?
phrenic (C3-5)
what stimulates carotid chemoreceptors?
changes in:
- O2
- CO2
- H+
give an example of a condition that would normally lead to type 2 respiratory failure
COPD
give an example of a condition that would lead to type 1 respiratory failure
pulmonary embolism
how would you calculate vital capacity?
TV + IRV + ERV
what is the function of histamine 1?
mediate increase in vascular permeability at sites of inflammation
what is the function of histamine 2?
increases release of gastric acid
how many layers of muscle are present in the stomach wall and what are they?
3
- longitudinal
- circular
- oblique
what is the action of the proton pump in the parietal cells of the stomach
K+ in
H+ out
what substance is secreted by enterochromaffin cells?
histamine
what is the effect of the vagus nerve on parietal cells?
releases ACh onto them
where does the common bile duct drain into?
duodenum
what is secreted by chief cells?
pepsinogen
what is the function of intrinsic factor produced in the stomach?
allows absorption of vitamin B12 in terminal ileum
what artery supplies the jejunum?
superior mesenteric artery
what is the change in cell-type seen in the lower oesophagus after prolonged acid reflux?
stratified squamous -> columnar
where is fat first acted upon by lipase enzymes?
oral cavity
