ToB Diseases/Syndromes

Question 1

What are some signs of rickets?

Answer 1

Calcium deficiency in children: Long bones that are soft and malformed, bossing, bow legs, enlargement of costochondral junction

Question 2

What are some symptoms of osteomalacia?

Answer 2

Bone pain, backache, muscle weakness and increased risk of fracture

Question 3

What happens in osteogenesis imperfecta?

Answer 3

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

Question 4

What is characterisic of Osteoporosis? What are the 2 types?

What are the common fracture sites, how can it be detected and treated?

Answer 4

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

Question 5

What are 4 modifiable and 5 non-modifiable risk factors for osteoporosis?

Answer 5

Modifiable: Ca2+ intake, exercise, smoking alcohol

Non-modifiable: age, gender, previous fractures, limb build and other disorders like rheumatoid

Question 6

What happens in actinic solar keratosis?

Answer 6

Chronic sun exposure - epidermal dysplasia with 8-20% progressing into squamous cell carcinoma

Question 7

List the 2 types of non-melanoma skin cancers

Answer 7

1. Basal cell carcinomas originate from follicular keratinocytes
2. Squamous cell carcinomas originate from basal keratinocytes

Question 8

What is psoriasis? How would you treat it and what are 2 possible causes?

Answer 8

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

Question 9

What happens in vitiligo?

Answer 9

Autoimmune destruction of melanocytes produces patchy depigmentation

Question 10

What happens in solar/actinic lentigines?

Answer 10

Increased melanocytes in response to sun exposure leads to liver spots and can progress to lentigo maligna melanoma

Question 11

What is malignant melanoma?

Answer 11

Benign growth of melanocytes and can be difficult to differentiate from a mole

Question 12

What is alopecia and what are the 2 main types? What can scarring alopecia cause?

Answer 12

Hair loss
1. Androgenic alopecia: hair follicle miniaturisation in response to dihydrotestosterone exposure

2. Autoimmune alopecia: areata (patches), totalis (whole head), Universalis (all over the body)

Scarring alopecia can cause irreversible follicular stem cell damage

Question 13

What’s the difference between intrinsic and extrinsic skin ageing?

Answer 13

Intrinsic: chronological wrinkles
Extrinsic: UV induced injury to the dermal collagen and elastin, e.g; solar elastosis

Question 14

What are the components of the dermis!

Answer 14

Dense and loose irregular CT, ECM, cells (immune, adipocytes and fibroblasts), sweat glands and mechanoreceptors

Lymphatics, vessels and nerves

Question 15

What causes Marfan’s syndrome? What are 4 symptoms?

Answer 15

An autosomal dominant mutation in fibrillin 1, abnormally tall, arachnodactyly, frequent dislocations and risk of aortic rupture

Question 16

What causes William’s syndrome? What are 3 symptoms

Answer 16

Spontaneous deletion in chromosome 7 that codes for elastin, symptoms include learning and CVS problems and a big mouth

Question 17

Name 2 diseases that occur as a result of elastic fibre disorders?

Answer 17

William’s syndrome and Marfan’s syndrome

Question 18

What causes elhers danlos? Name one possible consequence and 2 symptoms

Answer 18

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

Question 19

What causes scurvy? Name 3 symptoms

Answer 19

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

Question 20

What causes osteoarthritis? What are 2 risk factors?

What are 4 symptoms?

Answer 20

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

Question 21

What is achondroplasia and what causes it? What is one sign?

Answer 21

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

Question 22

What is the difference between multiple sclerosis and Guilliam barre?

Answer 22

MS: Autoimmune destruction of myelination in the CNS

Guilliam barre: autoimmune destruction of myelination in the PNS

Question 23

What are 3 symptoms of horner’s syndrome?

Answer 23

1. droopy eyelids
2. papillary constriction
3. absence of sweating on half the face

Question 24

What is Hirschsprung’s disease?

Answer 24

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

Question 25

What is Raynaud’s phenomenon? What are some symptoms and what precipitates it? What can it lead to chronically?

Answer 25

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

Question 26

What is Duchenne’s Muscular Dystrophy?

What are two early signs?

Answer 26

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

Question 27

What happens in organophosphate poisoning?

Answer 27

Irreversibly inhibits Ach esterase which leads to excessive Ach and overstimulation at the junction

Question 28

What happens in Botulinism? Which toxin causes this?

Answer 28

Clostridium botulinum blocks Ach release which causes paralysis

Question 29

What happens in myasthenia gravis? What could you give for treatment?

What are 4 symptoms?

Answer 29

Autoimmune destruction of endplate Ach receptors, give Ach esterase inhibitors like neostigmine

Symptoms: fragility, sudden falling, droopy eyelids, double vision

Question 30

What is the consequence of rhabdomyolysis?

Answer 30

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

Question 31

What is one consequence of thyrotoxicosis?

Answer 31

Excessive thyroid hormones leads to an increase in metabolism and excessive protein catabolism

Question 32

What happens during channelopathies? What are 2 things you could give for relief?

Answer 32

Anesthetics stimulate the release of stored Calcium which causes muscle contractions and excessive heat, give dantrolene and cooling