ToB Diseases/Syndromes Flashcards
What are some signs of rickets?
Calcium deficiency in children: Long bones that are soft and malformed, bossing, bow legs, enlargement of costochondral junction
What are some symptoms of osteomalacia?
Bone pain, backache, muscle weakness and increased risk of fracture
What happens in osteogenesis imperfecta?
An autosomal dominant mutation in Type 1 collagen;
Type 1: COL1A1 allele loss leads to frequent fractures after walking (bones are thin, curved and shorter), blue sclera and progressive hearing loss
Type 2: lethal perinatal disease
What is characterisic of Osteoporosis? What are the 2 types?
What are the common fracture sites, how can it be detected and treated?
Loss of spongy bone leads to reduced mechanical strength and increased fractures in wrist, spine and hips
Detected with DEXA (measures bone mineral density) and treated with bisphosphonates (binds to calcium hydroxyapatite crystals to suppress osteoclast activity)
Type 1: Postmenopausal women, increased osteoclast activity due to loss of estrogen
Type 2: elderly, reduced osteoblast activity with age
What are 4 modifiable and 5 non-modifiable risk factors for osteoporosis?
Modifiable: Ca2+ intake, exercise, smoking alcohol
Non-modifiable: age, gender, previous fractures, limb build and other disorders like rheumatoid
What happens in actinic solar keratosis?
Chronic sun exposure - epidermal dysplasia with 8-20% progressing into squamous cell carcinoma
List the 2 types of non-melanoma skin cancers
- Basal cell carcinomas originate from follicular keratinocytes
- Squamous cell carcinomas originate from basal keratinocytes
What is psoriasis? How would you treat it and what are 2 possible causes?
The extreme proliferation of the basal layer in response to inflammatory cytokines reduces the epithelial turnover to 3-7 days, causes a reduced granular layer and malformed corneum layer
Treat with Vit D which helps cell differentiation and topical steroids. 2 possible causes are genetic and external environment trigger
What happens in vitiligo?
Autoimmune destruction of melanocytes produces patchy depigmentation
What happens in solar/actinic lentigines?
Increased melanocytes in response to sun exposure leads to liver spots and can progress to lentigo maligna melanoma
What is malignant melanoma?
Benign growth of melanocytes and can be difficult to differentiate from a mole
What is alopecia and what are the 2 main types? What can scarring alopecia cause?
Hair loss
1. Androgenic alopecia: hair follicle miniaturisation in response to dihydrotestosterone exposure
- Autoimmune alopecia: areata (patches), totalis (whole head), Universalis (all over the body)
Scarring alopecia can cause irreversible follicular stem cell damage
What’s the difference between intrinsic and extrinsic skin ageing?
Intrinsic: chronological wrinkles
Extrinsic: UV induced injury to the dermal collagen and elastin, e.g; solar elastosis
What are the components of the dermis!
Dense and loose irregular CT, ECM, cells (immune, adipocytes and fibroblasts), sweat glands and mechanoreceptors
Lymphatics, vessels and nerves
What causes Marfan’s syndrome? What are 4 symptoms?
An autosomal dominant mutation in fibrillin 1, abnormally tall, arachnodactyly, frequent dislocations and risk of aortic rupture
What causes William’s syndrome? What are 3 symptoms
Spontaneous deletion in chromosome 7 that codes for elastin, symptoms include learning and CVS problems and a big mouth
Name 2 diseases that occur as a result of elastic fibre disorders?
William’s syndrome and Marfan’s syndrome
What causes elhers danlos? Name one possible consequence and 2 symptoms
An autosomal dominant mutation causing failure to produce type 2 collagen and can cause an aortic rupture.
Symptoms: weak CT around joints causing joint hypermobility and easily bruisable skin
What causes scurvy? Name 3 symptoms
Lack of Vit. C reduces the ability for prolyl hydroxylase to cleave preprocollagen to procollagen
Symptoms: weak periodontal ligaments can lead to gum ulceration, weak collagen can lead to hemorrhage and re-opening of old wounds
What causes osteoarthritis? What are 2 risk factors?
What are 4 symptoms?
Wear and tear of articulate cartilage (specifically hyaline), a lack of stem cells means the cartilage doesn’t heal after damage
Risks: age and weight gain
Symptoms: pain, stiffness, tenderness, swelling
What is achondroplasia and what causes it? What is one sign?
Short limbed dwarfism caused by an autosomal dominant point mutation in fibroblast growth factor FGFR3 which promotes early growth plate closure. This means there are reduced chondrocytes and less matrix production
Symptom: disproportionate limbs
What is the difference between multiple sclerosis and Guilliam barre?
MS: Autoimmune destruction of myelination in the CNS
Guilliam barre: autoimmune destruction of myelination in the PNS
What are 3 symptoms of horner’s syndrome?
- droopy eyelids
- papillary constriction
- absence of sweating on half the face
What is Hirschsprung’s disease?
A rare congenital disease where ineffective peristalsis means stools back up in the intestines leading to constipation and bowel obstruction - can lead to a serious intestinal infarction
What is Raynaud’s phenomenon? What are some symptoms and what precipitates it? What can it lead to chronically?
Spasming of the digital arteries, usually precipitated by cold and stress and causes pallor, cyanosis, redness, pain and paraesthesia. Chronically it can cause tissue infarction
What is Duchenne’s Muscular Dystrophy?
What are two early signs?
X linked recessive, early-onset 2-7 years. Impaired calcium homeostasis damages contractile fibres and absence of dystrophin (a protein that keeps muscles intact) means the sarcolemma is fragile and tears at contractions
Cells may die and undergo pseudohypertrophy (enlargement at the site of an organ) which can be an early sign (they are replaced with CT and fat). Another early sign is gower’s sign
What happens in organophosphate poisoning?
Irreversibly inhibits Ach esterase which leads to excessive Ach and overstimulation at the junction
What happens in Botulinism? Which toxin causes this?
Clostridium botulinum blocks Ach release which causes paralysis
What happens in myasthenia gravis? What could you give for treatment?
What are 4 symptoms?
Autoimmune destruction of endplate Ach receptors, give Ach esterase inhibitors like neostigmine
Symptoms: fragility, sudden falling, droopy eyelids, double vision
What is the consequence of rhabdomyolysis?
Death of muscle fibres causes them to release their contents into the bloodstream which can present as coca-cola urine and progress to renal failure
What is one consequence of thyrotoxicosis?
Excessive thyroid hormones leads to an increase in metabolism and excessive protein catabolism
What happens during channelopathies? What are 2 things you could give for relief?
Anesthetics stimulate the release of stored Calcium which causes muscle contractions and excessive heat, give dantrolene and cooling
