Past papers physiology Flashcards
Name the pancreatic exocrine hormone responsible for breakdown of
Proteins
Peptides
Carbohydrates
Neutral fat
Cholesterol esters
Phospholipids
q1
Trypsinogen
trypsin
pancreatic a amylase
pancreatic lipase
pancreatic lipase
pancreatic phospholipase A
Why do the pancreatic hormones not digest the pancreas itself?
q2
Enzymes are produced as pro-enzymes (zymogens) inactive form
Zymogens are stored in vesicles (zymogen granules)
Stored with protease inhibitors
Name two other constituents of pancreatic juice
q1c
Water
HCO3
Sodium, potassoin, chloride
Define neonatal hypoglycaemia.
q2
A plasma glucose level of less than 30 mg/dL (1.65 mmol/L) in the first 24 hours of life
and less than 45 mg/dL (2.6 mmol/L) thereafter.
Why is this value of neonatal hypoglycaemia different compared to a 1-year-old?
At birth, there is an immediate increase in metabolic requirements, and oxygen consumption rises
Glycogen stores are exhausted by 3–4 hours in response to catecholamine secretion
after which the fat stores are mobilized with an increase in plasma FFA and glycerol concentrations
As premature babies have inadequate stores of glycogen, hypoglycaemia frequently occurs
List the two major endogenous sources of energy in the neonate
Glycogen
Fat (adipose tissue)
List two non-pathological causes of neonatal jaundice.
Physiological jaundice (increased RBC load and immature liver function)
breastmilk
List four pathological mechanisms of neonatal jaundice.
Increased production of bilirubin
Decreased conjugation of bilirubin
Impaired excretion of bilirubin
Biliary obstruction
criggler najja vs dubin Johnson vs Gilbert
Gilbert Mildlylow UGTactivity;autosomalrecessive ↑UCB
Naja Absence of UGT highmortality ↑UCB
dubin Deficiencyofbilirubincanaliculartransportprotein;autosomalrecessive ↑CB
List 10 normal respiratory changes in the elderly.
Airway: no teeth, increased use of dentures and poor seal on bag mask
Pharnyx: Decreased pharyngeal tone, especially at night (asleep)
Thoracic cage: decreased compliance
Ossification of costal cartilage, kyphosis
Increaesed lung compliance
Degeneration of elastic fibres of the alveolar septae
Increased closing capacity
Increased FRC, RV
Flattening of hemidiaphragm
Hypoxic Pulmonary Vasoconstriction reflex being less active
Reduced diffusion capacity of alveoli
Reduced alveolar surface area
Increased alveolar-capillary membrane thickness
Diaphragm and intercostal muscle atrophy
What are the 3 chemical components making up a DNA nucleotide?
Nitrogenous base
Pentose sugar
Phosphate
Briefly describe the cellular control of protein formation
RNA is produced as a copy of the DNA genetic code in the nucleus and exported to the cytoplasm
Messenger RNA (mRNA)
mRNA then leaves the nucleus and travels to the ribosomes of the rough ER, the protein-producing factory of the cell.
In the nucleus, mRNA is synthesized as a copy of a specific section of DNA (transcription)
Transfer RNA (tRNA).
In the cytoplasm, the 20 different types of tRNA gather the 20 different amino acids and ‘transfer’ them to the ribosome, ready for protein synthesis.
Ribosomal RNA (rRNA).
Within the ribosome, rRNA aligns tRNA units (with the respective amino acids attached) in their correct positions along the mRNA sequence.
The amino acids are joined together, and a complete protein is released.
How does apoptosis differ from necrosis?
NECROSIS: Cell death by injury/disease
▫ External triggers (e.g. infection, temperature)
▫ Internal triggers (e.g. ischemia)
APOPTOSIS
▪ Programmed cell death
▪ Based on caspase cascade
Describe the role of lung macrophages in bacterial pneumonia in
Margination
rolling
adhesion
trnasmigrationandchemotaxis
phagocystosis
killing phagocytosed cells
Mechanisms in killing of bacteria
refer figure on question 5b
In the space below draw and label a diagrammatic representation of 2 adjacent liver (hepatic)
lobules.
Also Indicate and label, on your diagram the area most at risk of
i) Ischaemic injury. (1)
ii) Toxic injury.
Define and briefly explain the anaerobic threshold in terms of exercise physiology.
Lactate threshold/Metabolic threshold also called
At the Anaeroic Threshold, the rate at which lactate appears in the blood will be equal to the rate of its disappearance
Lactate levels will also begin to rise at this time as liver and other alternative lactate consumption sites become overwhelmed
The exercise intensity at which lactic acid starts to suddenly accumulate in the plasma.
This happens when lactate is produced faster than it can be metabolized
The lactate threshold occurs at about 50-70% of VO2 max.
Which factors are involved in initiating a clot following vessel injury?
pages9 10 11 12 skipped
Tissue factor
Factor VIIa
Factor Va
Factor Xa
Factor IIa (thrombin)
Which factors are involved in the ‘amplification phase’ to increase thrombin production?
Va
VIIIa
IXa
Briefly describe the mechanism of clot stabilisation.
Thrombin converts fibrinogen to fibrin monomer. Hydrogen bonds link fibrin monomers to form a
loose, insoluble fibrin polymer.
Factor XIII activated by thrombin and calcium stabilize the fibrin polymers via covalent bond
cross links
In the table below show the normal response for each of the following to mild hypothermia (36o C)
and severe hypothermia (30o
C).
refer toquestion 12
