2. TOB Flashcards
What is an ectopic pregnancy?
Implantation of the embryo in Fallopian tube or another site not the posterior uterine wall.
What are the complications of ectopic pregnancies?
Rupturing can lead to miscarriage and haemorrhage.
What is placenta praevia?
Implantation of the embryo in lower segment of uterine wall, blocking the cervix.
How are placenta praevia pregnancies dealt with?
Perform C-section to avoid haemorrhage.
What causes Marfan’s syndrome?
Autosomal dominant causes misfolding of fibrillin so there is more elastic connective tissue.
What is the presentation of Marfan’s syndrome?
Very tall, long digits, high arched palate.
What is the risk of Marfan’s syndrome?
Often die from aortic rupture around 40 years old.
What is Ehlers-Danlos syndrome?
Type III collagen deficiency leading to a loss of structure.
What is the presentation of Ehlers-Danlos syndrome?
Stretchy skin, unstable joints, etc.
What is vitiligo?
An autoimmune condition that attacks melanocytes causing loss of pigmentation in the skin.
In what population does vitiligo have a more obvious effect?
Dark skinned.
What is alopecia?
Autoimmune destruction of hair follicles causing hair loss.
What is alopecia worsened by?
Stress.
What is psoriasis?
Extreme overproduction of skin cells causing too much corneum and scaling.
What is the presentation of psoriasis?
Scaling on skin.
How is psoriasis managed?
Give steroids.
What causes malignant melanoma?
Excessive UV radiation causing melanocyte mutation.
What is malignant melanoma?
An aggressive skin cancer.
What affects the prognosis of malignant melanoma?
If it has penetrated through the basement membrane, then it’s a poorer prognosis. Also metastases give a poor prognosis.
What is osteogenesis imperfecta?
An autosomal dominant condition where type I collagen is deformed or deficient.
What is the most severe presentation of osteogenesis imperfecta?
No conversion of foetal skeleton to solid bone.
What is the normal presentation of osteogenesis imperfecta?
Lots of fractures, bowed long bones, blue sclerae.
What can vitamin D deficiency lead to?
Less Ca2+ absorbed so less rigid bones -> rickets of osteomalacia.
What is Rickets?
Vitamin D deficiency in children when they are still growing leads to bowed bones.
What is osteomalacia?
Vitamin D deficiency in adults that causes bone and back ache.
What is osteoporosis?
Where osteoclast activity is greater than osteoblast activity.
What is type I osteoporosis?
Menopausal, oestrogen no longer mediates osteoclast function.
Which fractures are common in type I osteoporosis?
Hip and vertebrae fractures.
What is type II osteoporosis?
Old age, osteoblast action is less so no bone remodelling.
What is acromegaly and gigantism caused by?
Excess growth hormone causing increased bone deposits.
What causes acromegaly?
Excess growth hormone if epiphyseal growth plates are closed (in adults) then there is more intramembranous ossification so larger flat bones.
What causes gigantism?
Excess growth hormone if epiphyseal growth plates are open (in growing children) so there is more intramembranous and endochondral ossification causing long bones to get longer and tall stature.
What is a complication of neonatal hypothyroidism?
Cretinism - retardation and short stature.
How is cretinism avoided in neonates with hypothyroidism?
Thyroxine is given before aged 3 weeks to prevent irreversible change.
What causes achondroplasia?
An autosomal dominant defect causing deformed fibroblast growth factor receptor and so less endochondral ossification.
What are the features of achondroplasia?
Short limbs, enlarged forehead, normal trunk, 4ft tall.
What is myasthenia gravis?
An autoimmune condition with destruction of end plate ACh receptors.
What is the presentation of myasthenia gravis?
Droopy eyelids, fatigue, sudden collapse.
How is myasthenia gravis managed?
With immunosuppression and AChesterase inhibitors so ACh stays in the synapse for longer.
What is muscular dystrophy?
X linked recessive disorders with absent or truncated dystrophin causing muscle fibres to tear on contraction.
What is the difference between Duchenne’s and Becker’s muscular dystrophy?
Duchenne’s has absent dystrophin, Becker’s has truncated dystrophin.
What is a sequelae of muscle fibres tear in muscular dystrophy?
Ca2+ induced necrosis.
What are the clinical features of muscular dystrophy?
Fat and connective tissue laid down, Gower’s sign (brace thighs with arms), chest muscles destroyed.
How can muscular dystrophy lead to death?
The chest muscles can be destroyed leading to respiratory collapse and death.
What is the effect of botulinum toxins?
They block ACh release so there is no muscle contraction.
How is botulism used clinically?
In botox to stop facial muscles contraction and therefore to prevent wrinkles.
What is thyrotoxicosis?
Increased BMR leads to protein catabolism and atrophy.
What is hypoparathyroidism?
Lack of parathyroid hormone causes lack of Ca2+ absorption and tetany.
What is malignant hyperthermia?
An autosomal dominant life threatening reaction to general anaesthesia.
How is malignant hyperthermia life threatening?
It releases Ca2+ from al SR stores in response to general anaesthesia, which causes a huge spike in oxphor in skeletal muscle, causing a huge temperature spike and death.
How is malignant hyperthermia dealt with?
Manage symptoms with paracetamol. Dantrolene to prevent Ca2+ release.
What is multiple sclerosis?
Autoimmune destruction of myelin sheath and Schwann cells causing reduced conduction and loss of function.
How is multiple sclerosis managed?
B interferon or steroids to mediate immune function.
