MedSoc SAQ Flashcards

1
Q

Explain the process of alcohol metabolism in the liver

A
  1. Alcohol is metabolised to acetaldehyde by alcohol dehydrogenase
  2. Acetaldehyde is metabolised to acetate by acetaldehyde dehydrogenase
  3. Acetate is broken down into CO2 and water
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe the steps of bilirubin metabolism

A
  1. Unconjugated bilirubin binds to albumin to be transported to the liver
  2. UDP glucoronyl transferase catalyses the addition of glucoronic acid, forming conjugated bilirubin
  3. Conjugated bilirubin dissolves into bile, and is reduced to urobilinogen in the small intestine
  4. Urobilinogen can be reabsorbed into the blood and oxidised to urobilin
  5. Urobilin can be recycled into bile or excreted in urine
  6. Urobilinogen can also be oxidised into stercobilin by intestinal bacteria and excreted in faeces
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Why would an unhealthy liver lead to bruising?

A

The liver produces bile salts that are essential for vitamin K absorption. Clotting factors 10, 9, 7 and 2 rely on vitamin K for their synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Explain the effects of low albumin in the blood

A

Albumin is a plasma protein that maintains oncotic pressure. A decrease in albumin causes a decrease in oncotic pressure, resulting in net movement of water out of the blood into the interstitial fluid. Oedema.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How are changes in osmolality of extracellular fluid detected?

A

Osmoreceptors in the hypothalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe how antibodies are specific to one antigen?

A

Antibodies bind to antigens via the variable region, which determines the specificity of the antibody.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe ketogenesis

A
  1. High rates of fatty acid oxidation create overwhelming amounts of acetyl-CoA for the Kreb’s cycle
  2. Two molecules of acetyl-CoA are converted into acetoacetyl-CoA by thiolase
  3. Acetoacetyl-CoA is converted into acetoacetate
  4. Acetoacetate is converted into acetone and betahydroxybutyrate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Give some examples of multifactorial diseases

A

Type 2 diabetes, spina bifida, schizophrenia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Explain how a girl can be a carrier of an X linked recessive disorder

A

The mutated gene is located on the X chromosome. A female can be a carrier as they have two X chromosomes, so one can be affected but it is not enough to produce the affected phenotype

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What shape are red blood cells, and why are they this shape?

A

Biconcave disc, to increase the surface area to volume ratio. This makes oxygen exchange more efficient.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is a single nucleotide polymorphism?

A

A DNA sequence variation occurring when a single nucleotide in the genome sequence is altered, with the alteration present in at least 1% of the population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is preload?

A

The initial stretching of the cardiac myocytes prior to contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is afterload?

A

The pressure the left ventricle must overcome to eject blood in systole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Name some risk factors for coronary artery disease

A

Smoking, obesity, male sex, age, family history

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe oesophageal innervation

A

The oesophagus is innervated by the vagus nerve. The upper portion of the oesophagus has voluntary (striated) fibres. The lower portion of the oesophagus has involuntary (smooth) fibres. The middle third has a mix of the two.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the mechanism of action of NSAIDs?

A

NSAIDs are COX (1 and 2) inhibitors. This prevents prostaglandin synthesis, which decreases gastric mucosal protection.

17
Q

What are the differences between thoracic and cervical vertebrae?

A
  1. Cervical vertebrae have transverse foramina but thoracic vertebrae do not
  2. Thoracic vertebrae have longer spinous processes than cervical vertebrae
  3. Thoracic vertebrae have costal facets and cervical vertebrae do not
18
Q

Where does the spinothalamic tract decussate?

A

1-2 vertebral levels above level of entry into the spinal cord

19
Q

What cells produce CSF and where are they located?

A

Ependymal cells in the choroid plexus of the ventricles

20
Q

What is lipofuscin?

A

A pigment formed from peroxidation of lipids in older cells

21
Q

What colour is lipofuscin, and what 2 organs is it most abundant in?

A

It is orange/brown, and most abundant in the heart and liver

22
Q

Explain how micturition occurs

A
  1. Stretch receptors in the bladder wall are stimulated by an increase in pressure
  2. This stimulates the parasympathetic pelvic splanchnic nerve, causing the detrusor muscle to contract, and the relaxation of the internal urethral sphincter
  3. Conscious relaxation of the external urethral sphincter allows urination
23
Q

How can cysts in the renal medulla affect urinary output?

A

The loop of Henle extends deep into the renal medulla. Cysts in the renal medulla can cause large volumes of dilute urine as the loop of Henle is unable to reabsorb water sufficiently.

24
Q

Define glomerular filtration rate and give the equation

A

The volume of fluid filtered from the glomerulus into Bowman’s capsule per minute

GFR = Filtration coefficient x Net filtration pressure

25
Q

What is the equation for net filtration pressure?

A

Hydrostatic pressure of the glomerulus - Hydrostatic pressure of the Bowman’s space - Oncotic pressure in glomerulus

26
Q

Explain the process of exhalation during exercise

A
  1. The diaphragm and external intercostals relax
  2. The internal intercostals and abdominal muscles contract
  3. This causes the ribs and sternum to move down and in, and the diaphragm further into the thoracic cavity, decreasing thoracic volume and increasing intrathoracic pressure
  4. This causes a greater volume to be expired than normal
27
Q

Explain how the blood carries oxygen

A
  1. Haemoglobin binds to oxygen to form oxyhaemoglobin
  2. Oxygen cooperatively binds to haemoglobin, meaning haemoglobin has a greater ability to bind to oxygen after 1 subunit is already bound
  3. This means that the oxygen dissociation curve is sigmoid shape
28
Q

How is mucus moved through the airways?

A
  1. Mucus is transported by the muco-ciliary escalator
  2. The cilia beat in directional waves to transport mucus from the lower respiratory tract to the pharynx
  3. Mucus can be swallowed or coughed out
29
Q

What is the most common type of pulmonary macrophage and how does it fight infections?

A

Alveolar macrophages destroy bacteria through phagocytosis.

The membrane fuses with a lysosome forming the phagolysosome, and the lysosome enzymes destroy the bacteria.

30
Q

What is the name of the area where dopamine neurons are found?

A

Substantia nigra pars compacta

31
Q

What is the Brodmann area for Broca’s area?

A

44/45

32
Q

What is the Brodmann area for Wernicke’s area?

A

22

33
Q

A patient presents with a foot drop. State what nerve is affected, and its root.

A

Common peroneal nerve

L5