muscle tissue Flashcards
which two muscle types are striated and which nervous system do they belong to?
skeletal (somatic) and cardiac (autonomic)
which type of muscle tissue is not straiated?
smooth
what are the functions of skeletal muscle?
voluntary movement of skeleton, movement of eye/tongue, sub-consciuos movement to maintain balance/posture
what is the basic structure of skeletal muscle?
elongated, un-brached cylindrical cells that appear like fibres, multiple peripherally locted nuclei
name the components of macroscopic skeletal muscle tissue in order
muscle fibre, endomysium, fascicle, perimysium (loose connective tissue) and epimysium (dense connective tissue) (bloodvessels inbetween fascicle)
the arrangement of …. within muscle cells gives it its straited appearance?
myofibrils
each myofibril is separated by a small layer of?
sarcoplasm
what is the name of the specialised plasma membrane found in skeletal muscle fibres?
sarcolemma
what are myofilaments?
repeating units of myofibrils
what are the thick dark myofilaments?
myosin
what are the thin light myofilaments?
actin
what are Z lines, and what do they divide each myofibril into?
2 lines that bisect actin, dividing each myofibril into contractile units called sarcomoers
how do sarcomere units contract?
sliding filament mechanism
what is a motor unit within skeletal muscle?
a motor neuron and the skeletal muscle fibers
what is the sarcomplasmic reticulum?
a structure found within striated muscle cells that stores calcium ions
what is the function of the cardiac muscle?
continuous autonomic contractions that pump blood through the cardiovascular system
what is the general strcuture of cardiac muscle?
elongated, branched cylindrical cells, 1 or 2 centrally located nuclei
what are the outermost, middle and inner layer of the macroscopic sctructure of the cardiac muscle?
pericardium, myocardium and endocardium (simple squamous)
describe the histological structure of cardiac muscle
cardiac muscle fibres surrounded by reticular connective tissue, special intercelluar junctions known as intercalated disks amd capilliaries
which muscle type slowly leaks calcium ions?
cardiac muscle
what are modified cardiac muscle cells known as and give examples of the strcutures within the conducting system of the heart
conducting system - sinoatrial node, left/right atria, atrioventricular node, atrioventricular bundle, purkinje fibres, cardiac muscle fibres
what do cardiac muscle fibres have that modified ones do not?
t tubules and intercalated disks
wha is the function of smooth muscle?
lines hollow organs and propells lumen contents by peristalsis
describe the general structure of smooth mucle
small, elongated spindle-shaped cells with tapered ends, single centrally located and no striations
give the outermost, middle and inner layers of the GI tract
outer longitudial layer, inner circular layer and lumen
describe how peristalsis occus in the GI tract?
inner circular layer contricts lumen diameter and outer longitudial layer shortens
what do focal densitiesin smooth muscle do?
anchor cytoplasm to membrane
