Foundations 1 Medicine University of Birmingham
What is the mechanism for smooth muscle contraction
- A stimuli opens the calcium channel - Calcium binds to a regulatory protein called calmodulin which is very similar to troponin. - This activates myosin light-chain kinase through phosphorylation - The cross bridge cycle starts.
What roles do insulin undertake?
- Activates glycogen synthase - Deactivates glucose synthase
What three components are a local anaesthetic composed of?
- Aromatic ring - Linkage - Amine group
Describe the erythropoetin cycle
- Blood loss leads to lower oxygen levels in the proximal tubule - The kidney releases Epo which travels to where the haematopoietic stem cells are up regulating the pathway to produce RBCs - The Epo binds to the Epo receptor which generates a signal on the inside of the cell leading to transcription factors binding genes. - This may lead to a cascade.
What happens after severing of a neurone?
- The two ends swell and fluid leaks out leading to loss of synaptic transmission between the two neurones -Astroglia then start surround the synaptic terminal -The cell body will then undergo chromatolysis (dissolution of the nil bodies in the cell body) - The distal stump of the axon (the end of the injured neurone which is attached to the end of the axon) undergoes wallerian degeneration.
What are the different routes of administration of local anaesthetic
- Topical - Nerve block - Epidural - Infiltration - Spinal
What are the symptoms of Cushing's
- hyperglycemia - CNS irritability - NA & fluid retention (edema) - thin extremities - GI distress (increase acid) - females: amenorrhea, hirsutism - thin skin - purple striae - bruises & petechiae - personality changes - moon face - increase susceptibility to infection - males: gynecomastia - fat deposits on face and back of shoulders - osteoporosis
What are the symptoms of acromegaly
- long bones can no longer grow - enlarged bones of hands, feet, MX and MD cause separation of teeth and malocclusion - Soft tissue grown in size (lips, nose, skin and tongue thicken) -Curving of the spine causing hunchback appearance - Thick and greasy skin - Gigantism - Fatigue and muscle weakness
What is FGF23?
Fibroblast Growth Factor 23. it is produced by bone cells and is released when there is high serum phosphate.
Where is the myenteric plexus located?
Found in the full length of the GI tract between two smooth muscles
What part of the cell cycle is the restriction point?
G1
What does the endoderm become?
GI and respiratory tracts
When does the PNS and CNS work together?
PNS = Erection (Point) SNS = Ejaculation ( Shoot)
What are the two phases of metabolism
Phase 1 - Oxidation Phase 2 - Conjugation
What enzyme is involved in glycolysis
Phosphofructokinase
What do CDKs do?
Phosphorylate sets of cellular proteins that are important to enter a certain phase of the cell cycle
What are the three vesicles on the neural tube called
Prosencephalon, Mesencephalon, Rhombencephalon
What are the four plates which the neural tube differentiates into?
Roof, Alar, Basal, Floor
Which cells myelinate axons in the PNS
Schwann cells
What causes the swelling of the eyes in graves disease?
When antibodies attach to the soft tissues around the eyes leading to swelling.
What part of the cortex are mineralocorticoids produced
Zona glumerulosa
What is the basal lamina?
a layer of extracellular matrix secreted by the epithelial cells, on which the epithelium sits
What does ADME mean?
absorption, distribution, metabolism, excretion
Which part of the pancreas secretes glucagon
alpha cells
which type of neurones innervate skeletal muscle
alpha-motoneurones
Which part of the pancreas produces glucose
beta cells
What do C cells produce?
calcitonin
What are the three germ layers
ectoderm, mesoderm, endoderm
What are the routes of administration?
enteral, parenteral, topical
What causes Cushing's syndrome?
excess cortisol
What causes acromegaly?
excessive production of somatropin (growth hormone) after closing of the epiphyses
What causes Grave's disease?
hyperthyroidism. Antibodies bind to the TSH receptor which leads to overstimulation of the TSH receptor.
Where is the submucosal plexus found?
in the stomach and intestine, between one smooth muscle and the submucosa
What is the process of all the synaptic transmissions merging at the interneurone
integration
What do chemoreceptors do?
monitor chemical changes in the blood
Which cells myelinate axons in the CNS?
oligodendrocytes
What are the three types of glial cells?
oligodendrocytes, astrocytes and Schwann cells
What are nociceptors?
pain receptors
What is albumin?
plasma protein
What do mechanoreceptors do?
sense pressure, movement or tension
What does the ectoderm become?
skin and nervous system
How many iodine residues does the most active thyroid hormone have?
three
What is p53?
tumor suppressor gene
Where are glucocorticoids produced?
zona fasciculata
where are adrenal androgens produced
zona reticularis
What are symptoms of diabetes
♦Polyuria ♦Polydyspia ♦Weight loss ♦Sometimes Polyphasia Blurred vision Growth impairment Susceptibility to infection
What enzyme is involved in gluconeogenesis
1,6 bisphosphatase
What is the name for vitamin D
125D3
What are cranial nerves 3, 7, 9 and 10
3 - Occulomotor 7- Facial 9- Glossopharyngeal 10 - Vagus
What is p21?
A CDK inhibitor. (part of that whole CDKN thing) Inhibits ALL CDKs.
What is endothelia-1
A signalling molecule which binds to the ETA receptor which is a Gq-GPCR
What is poliomyelitis?
A viral infection of the nerves controlling skeletal muscles.
What is the agonist for beta adrenoceptors
Adrenaline
What are the five adrenoceptors called
Alpha 1 - Gq Alpha 2 - Gi Beta 1 - Gs Beta 2 - Gs Beta 3 - Gs
What is the cleavage molecule of insulin
C-peptide
What is the first line of treatment for hyperthyroidism
Carbimazole
Where do the cell bodies of the parasympathetic division lie
Cranio-sacral outflow
What do astrocytes do?
Create an environment in which neurones thrive
What enzyme carries out oxidation in metabolism
Cytochrome p450
What causes anencephaly?
Failure of the anterior neuropore to close
What causes spina bifida?
Failure of the superior neuropore to close
What connects the anterior pituitary and the hypothalamus
Hypophyseal portal vein system
What adaptation does the neuromuscular junction have?
Increased cholinergic receptors on the end plate due to folded membrane.
What happens to the distal end of the neurone
It is not viable and dies to a loss of nutritional support from the cell body.
What role does IP3 carry out
It travels to the sarcoplasmic reticulum which causes it to release calcium ions into the cytosol.
What does the mesoderm become?
Musculoskeletal & Circulatory systems
What condition is caused by failure of the neuromuscular junction?
Myasthenia Gravis
Define: Neuropraxia Axontmesis Neurotmesis
Neuropraxia - Dmaage to the myelin sheath of a nerve Axontmesis - damage to the myelin sheath and the axon of a nerve whilst the epineurium, endoneurium and perineurium remain intact.
What is T state and R state
T-state - The inactive form of an enzyme R-state - The active form of an enzyme
Symptoms of hyperthyroidism
Tachycardia; heat intolerance; fatigue; restlessness; tremor; emotional instability; insomnia; warm, moist skin; increased appetite, weight loss; frequent stools; decreased serum lipids; decreased libido; erectile dysfunction
What do microglia do?
These are immune cells of the nervous system.
What are proteoglycans?
They are glycoproteins that are heavily glycosylated
What is prostacyclin?
They are released by the endothelial cells and travel to the smooth muscle cells, binding to the Gs receptor.
What action do anti-thyroid drugs have?
They block thyroperoxidase so iodine residues cannot be put on thyroglobulin.
What are the SGLT2 inhibitors?
They reduce the amount of blood being reabsorbed by the kidney so most of it can pass out of the urine.
Where do the cell bodies of the sympathetic nervous system lie?
Thoraco-lumbar outflow