smooth and cardiac muscle Flashcards
what is the main function of smooth muscle?
mechanical control of organ systems
describe the shape and structure of a smooth muscle fibre
spindle shaped
single central nucleus
is smooth muscle voluntary or involuntary?
involuntary
is smooth muscle striated or non-striated?
non-striated
what is the function of cardiac muscle?
intrinsic myogenic activity that’s responsible for heart beat
how are cardiac myocytes organised?
in a branched network that runs in different directions
is skeletal muscle voluntary or involuntary?
voluntary
what kind of movements is skeletal muscle responsible for?
locomotion
maintenance of posture
breathing via contraction of the diaphragm
is skeletal muscle striated or not?
striated
how many nuclei are found in skeletal muscle cells and how are they arranged?
multiple
peripherally-located
what cellular junctions are found in cardiac muscle?
intercalated discs
gap junctions
what cellular junctions are found in smooth muscle?
gap junctions
what calcium binding mechanisms do skeletal, smooth and cardiac muscle have?
skeletal - troponin
cardiac - troponin
smooth - calmodulin
what are A bands in cardiac muscle fibres?
thick bands
dark bands
what are I bands in cardiac muscle fibres?
thin bands
light bands
what is the sarcolemma?
the plasma membrane of the muscle
what are intercalated discs?
sites of thickening of the sarcolemma
what are intercalated discs made up of and what are their functions?
gap junctions - allow ions to pass from cell to cell so the AP can move between cells in a coordinated fashion
desmosomes - anchor ends of the cells together
define automaticity
the ability to spontaneously depolarise
define rhythmicity
the ability to depolarise in a regular and repetitive way