week 1 Flashcards
(78 cards)
what is difference between isometric and isotonic contractions in skeletal muscle
isometric - length says same and tension changes (supporting object/body posture maintaince)
isotonic - tension stays the same and length changes (moving objects/moving body)
in skeletal muscles is AP longer of shorter than twitch
shorter, so repeat AP’s gives stronger contraction
tetanus causes what in muscles
sustained contraction
when is skeletal muscle at its optimum length for contraction
at rest
what are the three types of skeletal muscle fibres?
I - slow oxidative
IIa - fast oxidative
IIb/x - fast glycolytic.
knee jerk reflex tests what nerve
femoral (L3-L4)
two types of intrinsic muscle diseases
acquired (toxic, endocrine, inflammatory, non-inflammatory) and genetically determined(congenital, chronic degredation, abnormal ion surface membranes.)
symptoms of intrinsic muscle diseases
muscle weakness/tiredness, myalgia, stiffness, delayed relaxation after voluntary contraction
investigations for intrincis muscle diseases
EMG, muscle enzymes (CK), inflammatory markers (ESR/PV). muscle biopsy. nerve conduction studies.
name differences between skeletal and cardiac muscles
SKM - neurogenic, has NMJ, no gap junctions, Ca2+ entitely from S.R
CARDIAC - myogenic, no NMJ, has gap junctions, Ca2+ induced Ca2+ (from ECF to SR).
what is the transmitter at the NMJ (neuromuscular junction) in SKM
acetylecholine.
what is a motor unit
a single alpha neutron and all the skeletal muscle fibres it innervates.
why is there variation in size of motor units
because precision and power needed for different things - power= thigh, fine precision =hands/eye.
what is a sacromere and what is it made up of?
a sarcomere is the functional unit of SKM.
made form myosin (thick and darker) and actin (thin and lighter)
difference between ligaments and tendon
tendon - attach muscle to bone
ligaments attach bone to bone
difference between strain and sprain
sprain - stretching/tearing of ligaments.
strain - stretching/tearing of muscles/tendon
describe type 1 SKM fibres
slow oxidative, abundant myoglobin and mitochondria. resist fatigue (red fibres)
describe type IIa SKM fibres
fast oxidative, intermediate, uncommon, fast contracting and relatively resistant to fatigue.
describe type 11b/x SKM fibres
fast anarobic, great force, tire quick, (white fibres).
SKM description
striated, multinucleate, unbraced, voluntary, 3 types
how does cartilage get its nutrition
through ECM, as is avascular.
what are chondrocytes and what’s their function
cells found in cartilage, live in LACUNA (ECM),
actively secrete and maintain ECM.
describe cartilage
semi-rigid, permable and deformable
what is ECM in hyaline cartilage made up off?
75% water
25% organic