Physio & Biochem Flashcards
What are the main components of bone matrix?
Type 1 (&5) collagen and Ca10(PO4)6(OH)2 (Hydroxyapatite)
What is the normal yearly rate of remodeling?
5-10%
What is the scientific name of vitamin D3?
Cholecalciferol
What is the inheritance pattern of ehlers-danlos syndrome?
Autosomal dominant
What is the activated form of vitamin D3 called?
Calcitriol
What is the function if Subunits 1-6 in voltage gated channels?
S1-S4 sense the voltage
S5 & S6 are the pore
Resting membrane potential of muscles and neurons
-90 & -70 respectively
Length of action potential in muscles
2-5ms
What are the small clefts found in the muscular side of the motor end plate called?
Sub-neural cleft
What is the socket for the neural terminal in the muscle called?
Synaptic gutter/trough
How many ACh are needed to activate thr ACh receptors in the muscle?
2; on the a-subunits
How much is MEPP?
0.4 mv (100 released causes action potential)
What is quantal theory?
Small quantas of Ach are released randomly at rest producing a MEPP
What does the triad of reticulum former by?
A T-tubule with 2 terminal cisternae of ssrcoplasmic reticulum
What is the function of tropomodulin?
Modulates the size of actin at the exposed end (-/pointed)
What is the function of CapZ
Caps the barbed end of actin at the Z band
List the names of the 3 troponin proteins and their functions
Troponin I : attach to actin
Troponin T : attach to tropomyosin
Troponin C : attach to calcium
What is the function of Titin?
Acts as a base for myosin to wrap around and also has an elastic part attaching myosin to the Z-disk
What is the function of Nebulin?
Sets up the length of actin and gives it a ground to wrap around
What is the function of a-actinin?
Attaches actin to z-disk
What is Fenn effect?
More contractile force needs more ATP
What causes rigor mortis?
Lack of ATP keeping cross bridges stuck on actin
What is the difference between isometric and isotonic contraction?
Isometric= constant length with increasing tension
Isotonic= Change in length but constant tension
What is G-actin?
The monomer of F-actin
Give an example of a type 2 muscle fiber with small motor units
Eye, face and hand
Give an example of a type 1 muscle fiber with big motor units
Posture muscles
What causes muscles to have passive tension?
Connective tissue (fascia)
What is the difference in EMG between curare and botulinum toxin?
Botulinum causes less depolarization
What are dense bodies?
Proteins stimulating calcium channels that stimulate ACh production
What 4 steps of muscle contraction require ATP?
Na/K pump (Rest)
Ach production (end plate)
SERCA depolarization (of RyR)
Power stroke (of myosin)
