ToB Flashcards
What causes Marphans Syndrome? How does it present?
Its a deffect in the chromosome that codes for fibrillin which effects elastic fibers
Large elastic arteries rupture due to bulging under pressure
What causes Ethlers-Danlos Disease? How does it present?
Deficiency in type III Collagen
Causes ruptures in tissues with high reticulin content
What causes Psoriasis? How does it present?
Disorder of epidermal growth + differentiation
Causes extreme proliferation of basal layer, leads to thickening of prickle cell layer + production of excessive stratum corneum
What is Alopecia Areata?
Autoimmune attack of hair follicles
What is Vitiligo?
Autoimmune attack against Melanocytes, usually in symmetrical areas of skin
What are the 3 types of cartilage?
Hyaline - Nose, Trachea, Articulating bone surfaces
Elastic - Epiglotis, External ear
Fibrocartilage - Intravertibral disks
What is the structure of compact bone? How do different parts of the bone communicate?
Concentric Lamellae with central neurovascular cannal, these communicate via Volkmanns cannals
What stimulates + Inhibits Osteoclasts?
Stimulated by PTH
Inhibited by Calcitoxin
What causes Osteogenesis Imperfecta? What does it lead to?
Caused by a mutation to the type I Collagen gene
Leads to abnormal collagen synthesis by osteoblasts + fibroblasts, Leads to bone fragility
Why is Vitamin D needed? What does a deficiency in Vitamin D lead to?
Needed in the absorbtion of Calcium + Phosphate in the small intestine
Deficiency leads to poorly mineralised + pliable matrix, causes effected bones to bend
What happens in Rickets?
Bones fail to calcify normally. Bones grow slowly + become deformed, growth plates are distorted by body weight + muscle activity
What happens in Osteomalacia and what causes it?
Bones soften due to calcium deficiency
What happens to the bones in Osteoporosis?
Bone density is reduced as there is more activity of Osteoclasts than Osteoblasts, Medullary cannals become enlarged + gaps appear in lamellae
What are the two different causes of Osteoporosis?
Type I - Occurs in post menopausal women, reduced oestrogen leads to increased number of osteoclasts
Type II - Occurs in both sexes due to reduced Osteoblast function
How does the sliding filament theory work?
Calcium binds to Troponin, moves tropomyosin away from the actin binding sites
What is Myasthesia Gravis?
Autoimmune destruction of the end plate Ach receptors, loss of junctional folds at the end plate
What is Duchenns Muscular Dystrophy? What does it cause?
Genetic fault causing reduced synthesis of proteins that anchor actin filaments to the cell wall
Causes muscle fibers to tear themselves apart
What is Malignant Hyperthermia? How does it cause this?
Life threatening reaction to some drugs used for anaesthetics
Causes an increase in Ca2+ release, this causes an increase in skeletal muscle metabolism. This overwhelms the bodies ability to supply O2 and remove CO2
What is Multiple Sclerosis?
The removal of the Myelin sheath from around an axon + replaced with scar tissue
