clinical sciences 2 Flashcards
what is the function of leukotrienes?
mediators of inflammation and allergic reactions
causes of bronchoconstriction, mucous production
increases vascular permeability, attracts leukocytes
leukotriene D4 has been identified as the SRS-A (slow reacting substance of anaphylaxis)
where are leukoctrienes secreted from?
secreted by leukocytes
what are leukotrienes formed from?
formed from arachidonic acid by action of lipoxygenase
.
what are examples of mitochondrial disease?
Leber’s optic atrophy
symptoms typically develop at around the age of 30 years
central scotoma → loss of colour vision → rapid onset of significant visual impairment
MELAS syndrome: mitochondrial encephalomyopathy lactic acidosis and stroke-like episodes
MERRF syndrome: myoclonus epilepsy with ragged-red fibres
Kearns-Sayre syndrome: onset in patients < 20 years old, external ophthalmoplegia, retinitis pigmentosa. Ptosis may be seen
sensorineural hearing loss
what would histology of mitochondrial disease show?
muscle biopsy classically shows ‘red, ragged fibres’ due to increased number of mitochondria
how is mitochondria disease inherited?
only via the maternal line
none of the children of an effected male will inherit the disease
all of the children of an affected female will inherit the disease
which immunoglobulin provides immunity to parasites?
IgE
IgE is synthesised to plasma cells
what is suggestive of LBBB?
dominant S wave in V1
QRS > 120ms
what releases interferon gamma?
It is released by natural kill cells and T helper cells (in particular Th1 cells).
what is Achondroplasia?
AD disorder associated with short stature
What is Achondroplasia caused by?
A mutation in the fibroblast growth factor receptor 3 (FGFR-3) gene.
what are the features of achondroplasia ?
short limbs (rhizomelia) with shortened fingers (brachydactyly)
large head with frontal bossing and narrow foramen magnum
midface hypoplasia with a flattened nasal bridge
‘trident’ hands
lumbar lordosis
what is the site of action of ADH?
collecting ducts
what are the boundaries of the popliteal fossa?
Superomedially: Semimembranosus and semitendinosus muscles.
Superolaterally: Biceps femoris muscle.
Inferomedially and Inferolaterally: Medial and lateral heads of the gastrocnemius muscle, respectively.
what are the content of the popliteal fossa?
Popliteal artery
Popliteal vein
Tibial nerve
Common perineal nerve
Popliteal lymph nodes
small saphenous vein
Fat and loose connective tissue
Dermatomes C2 - C8
C2 - posterior half of the skull
C3 - high turtleneck shirt
C4 - low collar shirt
C5 - ventral axial line of upper limb
C6 - thumb and index finger
C7 - middle finger and palm of hand
C8 - ring and little finger
Dermatomes T4 - T10
T4 - nipples
T5 - inframammary fold
T6 - Xiphoid process
T10 - Umbilicus
Dermatomes L1-L5
L1 - inguinal ligament
L4 - knee caps
L5 - big toe, dorm of foot (except lateral aspect)
Dermatomes S1, 2 and 3?
S1 - lateral foot and small toe
S2, S3 - Genitalia
definition of p value?
P value - is the probability of obtaining a result by chance at least as extreme as the one that was actually observed, assuming that the null hypothesis is true
what are microtubules?
Microtubules are components of the cytoskeleton of the cytoplasm. They help guide movement during intracellular transport and also help bind internal organelles. Microtubules are found in all cells except red blood cells.
what is the structure of microtubules?
cylindrical structure composed of alternating α and β tubulin subunits which polymerize to form protofilaments
microtubules are polarized, having a positive and negative end
how do ribosomes help guide intracellular transport?
attachment proteins called dynein and kinesin move up and down the microtubules facilitating the movement of various organelles around the cell
dynein moves in a retrograde fashion, down the microtubule towards the centre of the cell (+ve → -ve)
kinesin moves in an anterograde fashion, up the microtubule away from the centre, towards the periphery (-ve → +ve)
what is fanconi syndrome ?
Fanconi syndrome is a disorder of inadequate reabsorption in the proximal convoluted tubules of the kidneys. This commonly presents with hypophosphataemia as well as hyperchloraemia metabolic acidosis, hypokalaemia, and hypocalcaemia.