muscles Flashcards
Three types of muscle
Skeletal
cardiac
smooth
Two types of striated muscle
Skeletal
cardiac
Type of non-striated muscle
Smooth
Sarcolemma
Outer membrane of muscle
Sarcoplasm
Cytoplasm of a muscle cell
sarcomere
The contraction unit of striated muscle
Skeletal muscle T tubules
T tubules- invagination is of the Sacrolemma which the sodium ions can travel and are sandwiched between the terminal cisterna of the sarcoplasmic reticulum
this forms a triad
t tubels are found at the AI junction - a band Myosin I band actin
Where are skeletal T tubels found
AI junction
a - thick Myerson
I-actin
As skeletal muscle t tubules found in diet or triad
Triad
terminal cisterna of the sarcoplasmic reticulum, T tubules, terminal cisterna of the sacroplasmic reticulum
T tubules what are they made fun and function
Invagination of the sarcolemma down which sodium ions can travel
Role of terminal cisterna of the scaroplasmic reticulum
Stores calcium irons for release upon depolarisation by T tubules
What causes depolarisation of the sacroplasmic reticulum
t tubules
Where are cardiac T tubules found
Z band
What is the z band
The line in which actin filaments and adjacent sarcomas are anchored
What the cardiac T tubule dyad made of
sarcoplasmic reticulum terminal cisterna connecting to t trivial
Skeletal muscles have layers
Endomysium - inner
perimysium-middle
epimysium-outer
endomysium
Inner layer
loose connective tissue
surrounds each individual muscle fibre
the muscle fibres called Myofibrils and the contraction unit as a sacrament
perimysium
Middle layer
dense connective tissue which surrounds fasicle
contains nerves and blood vessels
epimysium
Outer layer
that connect tissue
What types of fibres can striated muscle have
Three types
slow twitch Ia
fast twitch 2a
fast twitch 2 B
Each fascicle has at least one of each
Type 1 and type II muscle fibres can be described as oxidative or glycolytic
type 1-slow oxidative
type 2a- fast oxidative and glycolytic
type 2b- first glycolytic
Describe the blood flow in the three types of fibres
Type I- rich blood supply
type 2a - rich blood supply
type 2b- poor blood supply
Describe whether the muscle fibres are anaerobic or aerobic
Type I aerobic
type IIa aerobic
type IIB anaerobic
Compare the myoglobin levels in the different type of muscle fibres
Type I hi myoglobin levels
type II a hi myoglobin levels
type IIB low myoglobin levels
Describe the number of cytochrome is in the different types of muscle fibres
Type I many cytochrome’s
type II a many cytochrome’s
type IIB few cytochrome’s
Compare the colour of the different muscle fibres
Type I red
type II a red/pink
type IIB White
Compare their resistance to fatigue of the 3 muscle types
Type I fatigue resistant
type IIa moderate fatigue resistant
type IIb rapidly fatigue
Describe the type of activities each muscle fibre specialise for
Type I endurance type activities- long distance run
type II a- assist type I and 2b activities
type iib strength/anaerobic type activities
Cardiac muscle has what which striated muscles don’t have
Intacolating disc
Compare the position of the nucleus in cardiac and skeletal muscle
Cardiac nucleus is central one or two of them per cell
skeletal nucleus and edge multi-nucleated
What is the contract of cell in cardiac muscle called
Not Sarcomere, cardio my site
Cardiac muscle can act as an endocrine tissue secreting
ANP - atrial natriurectic peptide
BNP-grain type natriuretic peptide
Continued muscle contraction depends upon
Calcium ions
ATP
Hypertrophy
Enlargement of individual cells
Hyperplasia
Mitosis of cells
Atrophy
Cells get smaller
Purkinje fibres are differ to cardiac myocytes because
Abundant glycogen
sparse myofibrils
extensive gap junction sites
Role of purkinje fibres
Conduct action potentials rapidly
Heart contractions initiated in
Siniatrial atrial node
The conduction travels from the SA to wear in the heart
Atrioventricular node
What to smooth muscle not have that striated muscle has
Not striated
no sarcomere
no t tubules
Compare the force of contraction of smooth muscle and striated muscles
Contraction a slower more sustained and requires less ATP
Smooth muscle has the ability to do what which striated muscle cant
Stretch
Mature muscle repair skeletal muscles
Skeletal muscle cannot divide
but can regenerate by mitotic activities of satellite cells
hyperplasia following muscle injury
satellite cells can also fuse with existing muscle cells to increase mass hypertrophy
Mature muscle repair in cardiac muscle
Adult cardiac muscle is incapable of regeneration
following damage fibroblasts invade divide and laydown scar tissue
Children’s muscle can regenerate
