B1
Describe the structure of heterochromatin compared to euchromatin?
Packed into thicker chromatin fibres compared to euchromatin.
What is the formula for cardiac output (CO)
CO= HR X SV
What are the five anterolateral muscles of the abdominal wall?
External oblique, internal oblique, transversus abdominis, rectus abdominis and pyramidalis.
What are the 2 modes of ossification?
Intramembranous; Bone formed directly from osteoblasts with no template (within the periosteum) e.g. flat bones
Endochondral; Cartilage template formed which is then replaced by bone e.g. long bones
Is bradycardia a common feature of hyperthyroidism or hypothyroidism?
Hypothyroidism
Describe what happens in the G1 phase of the cell cycle?
The cells start making more protein and growing larger, so the new cells will be of normal size.
What is stroke volume influenced by and how?
- Preload (increased preload = increased SV)
- Afterload (increased afterload = decreased SV)
- Inotropy (increased inotropy = increased SV)
What is the general and special sensory nerve supply of the tongue?
General supplied by glossopharyngeal in posterior 1/3 and anterior 2/3 by lingual nerve.
Special sensory glossopharyngeal in posterior 1/3 and facial nerve in the anterior 2/3 via the chorda tympani.
What are the Negative symptoms of Schizophrenia?
The 7 "A"s:
- Apathy; Lack of feeling, emotion, interest or concern
- Avolition; Lack of interest in goal directed behaviour
- Anergia; Persistent lack of energy
- Alogia; Poverty of speech
- Anhedonia; Inability to feel joy or pleasure in things you once enjoyed
- Asociality; Preference for solitary activities
- Affective flattening; Lack of emotional expressions
- Impaired Attention; Inability to concentrate
What's the most common cause of hyperthyroidism in the UK?
Graves disease
What are the 4 factors that can cause oedema?
Low plasma protein concentration, obstruction of lymphatic vessels, increased venous pressure, inflammation.
Describe the phases of action potential in SAN?
phase 4: pacemaker sodium ion influx, calcium ion channels recover from inactivation and pump restores ion gradient.
Phase 0: there is calcium influx into the cell and the cell depolarises.
Phase 3: the calcium ion channel inactivates, there is a delay in the potassium ion efflux from cardiomyocyte and this causes hyperpolarised state.
What is vascular spasm?
Damaged blood vessels constrict, reducing blood flow in the damaged area.
What is the definition of Disability under the Equality Act 2010?
- Anyone who has a physical or mental impairment that has a 'substantial' and 'long-term' negative effect on their ability to do normal daily activities
- 'Substantial' means more than minor or trivial e.g. it takes much longer than usual to complete a daily task like getting dressed
- 'Long-term' means over 12 months
The thyroid gland is responsible for producing which hormones? (Name 3)
T3, T4, Calcitonin
Describe the differences between metacentric, submetacentric and acrocentric chromosomes?
Metacentric the centromere is central and p and q arms are equal length, submetacentric centromere is slightly offset from the centre and acrocentric centromere is severely offset.
What component in the complement system allows opsonisation?
C3b
What are the four most common signs and symptoms of anaemia?
Pallor of conjunctiva
Glossitis
Koilonychia( iron deficiency anaemia)
Dark urine
Explain the following effect of cerebellar damage; Dysmetria?
- Inability to judge distance
- Tend to overshoot/ undershoot movements
What are the 3 types of hypothyroidism based on which organ is affected to cause it?
Describe what happens in the Cori cycle?
The Cori cycle (also known as the Lactic acid cycle), refers to the metabolic pathway in which lactate produced by anaerobic glycolysis in the muscles moves to the liver and is converted to glucose, which then returns to the muscles and is metabolized back to lactate.
What are the roles of the different troponin complex components?
Troponin C (calcium ion binding site)
Troponin I (inhibition of ATP hydrolysis)
Troponin T (structural connection to tropomyosin)
What are the effects of damage to the posterior cerebral artery (PCA)?
- PCA supplies the occipital lobe in which the visual area is located.
- Therefore ischaemic damage to PCA can cause contralateral visual damage/loss.
What is the mechanism of action for Sinemet?
- Sinemet is a combination of Levodopa (dopamine precursor) and Carbidopa (decarboxylase inhibitor).
- They are administered together to prevent excessive dopamine in the body but to increase the dopamine in the brain to replace loss of dopamine due to e.g. Parkinson's disease.
- This works due to Carbidopa inhibiting AAAD (Aromatic L-Amino Acid Decarboxylase) in the periphery so prevents carboxylation of Levodopa into dopamine.
- However, as Levodopa can cross the BBB but Carbidopa cannot, in the brain dopamine is produced, causing increased movement decreasing symptoms of rigidity and hypokinesia.
What drug is given in patients with Thyrotoxicosis?
- Lithium
- Carbamazepine
- Carbimazole
- Levothyroxine
Carbimazole
This interferes with thyroid hormone production, so is used for patients with hyperthyroidism (thyrotoxicosis).