muscle tissue 2
Terms
undefined, object
copy deck
- Excitability
- Especially notable response to stimuli
- Contractility
- Shortens
- Extensibility
- Can stretch
- Elasticity
- Returns to original shape
- Motion
-
total body movement
walking
running
localized movement (grasping pencil or nodding head)
relys on bones, joints, and muscles - Heat Production
- muscle tissue produces heat; heat released by muscle is to maintain body temp.; involuntary muscle contraction of the skeletal increases body temp.
- Maintain posture
- postural muscles contract continuously when a person stabilized joints and maintain body position
- Skeletal, straited, or voluntary
- moves bones of skeleton; alternating can be continuously controlled
- Cardiac or heart
-
found in heart
form wall of heart
straited
involuntary - Smooth, non-straited, or involuntary or viseral
- associated with visceral organs
- Fascia
- Flat or membranous sheet of conn. tissue
- Superficial fascia
-
Also called "hypodermis" or "subcutaneus" tissue
separates muscle from skin - Deep fascia
-
associated with muscles
binds and separates muscles, strengthens them, and allows for movement
gives rise to epimysium, perimysium, tendons, aponeuroses and tendon sheaths associated with skeletal muscles - Epimysium
- Around entire muscle organ
- Fasciculi(fasciles)
- A group or bundle of muscle fibers
- Perimysium
- Surrounds or defines a fascicle
- Endomysium
-
Around each muscle cell
outermost layer - Sarcolemma
- plasma membrane of the muscle fiber
- Muscle cell, muscle fiber or myofiber
- muscle cell
- Tendon
- connects muscle to bone
- Aponeurosis
- A broad flat tendon
- Tendon (synovial) sheath
-
Visceral layer
Parietal layer - Visceral layer
- inner layer of tendon sheath is attached to surface of tendon
- Parietal layer
- outermost layer of tendon sheath, and is attached to the bone
- Typical
-
one artery and one or two veins with a nerve; each muscle cell in close contact with one or more capillaries
each muscle fiber innervated by a nerve process - Muscle cell (fiber) or myofiber
- muscle fiber
- Sarcoplasm
- cytoplasm of the muscle fiber
- Sarcoplasmic reticulum
- Series of membrane enclosed channels; comparable to E.R.
- T-tubule (transverse tubule)
-
At right angles to long axis of cell
opens to outside of sarcolemma - contains extracellular fluid - Triad
- consists of T-tubule and adjacent terminal cisternae
- Myofibrils
- consists of 3 types of myofilaments; thin myofilaments; thick myofilaments; strutural proteins
- Thin myofilaments
-
Actin
Tropomyosin
Troponin
Tropomyosin-Troponin complex - Actin
-
Contractile
have myosin binding sites
bean or pea shaped
twisted together into a helix - Tropomyosin
- cover myosin binding sites on actin in a relaxed muscle fiber
- Troponin
- Holds tropomyosin strands together
- Tropomyosin-Troponin complex
- means that they are hooked together chemically
- Myosin
-
Looks like two golf clubs twisted together
a "motor protein" - uses ATP to push or pull molecules - Thick myofilaments
-
Myosin
Cross bridges (myosin heads) - Cross bridges (myosin heads)
-
the golf clubs heads
have actin binding sites - Structural proteins
- Not as abundant as contractile proteins (actin or myosin) for alignment, stability, elasticity, extensibility etc. of myofibrils
- Titin (connectin)
- One example is titan = gigantic = anchors thick filaments to the Z line (disc); helps in recoil after contraction
- Sarcomere
-
stack or unit of myofilaments
from z line to z line - Z line
-
Define sarcomere
pass through I band
narrow
plate shaped - A (anisotropic) band
- Thick and thin myofilaments that overlap eachother
- I (isotropic) band
- Thin myofilaments only
- H zone
- Thick myofilaments only
- M line
- Middle of H zone
- The sliding filament mechanism
- muscle contraction
- move inwards
- What happens to thin myofilaments during muscle contraction?
- Shorten
- What happens to sarcomeres during muscle contraction?
- stay the same
- What happens to the length of thick and thin myofilaments during muscle contraction?
- Shortens to gone
- What happens to the width of the H zone during muscle contraction?
- Make on/off contact with actin
- What happens to cross bridges (myosin heads) during muscle contraction?
- Motor unit
-
Nerve
Motor Neuron
Axon
Axon terminals
Synaptic end bulbs
Synaptic vescicles
Synapse - Nerve
-
nerve muscle
helps supply motor units
bundle axons traveling together - Motor neuron
- Neurons that stimulate skeletal muscle fibers to contract
- Axon
- threadlike extension from brain or spinal cord to a group of skeletal muscle fibers
- Axon terminals (telodendria)
-
Dendrites
synaptic end bulbs - Synaptic end bulbs (plates, feet, and knobs)
- the motor neuron axon terminal divides into a cluster
- Synaptic vesiscles
-
store and release neurotransmitters
sac like structure
released into synapse - Synapse
- space btwn bulbs and sarcolemma
- Red muscle fibers
-
More myoglobin
More mitochondria
Greater vascular supply
Small fiber diameter - White muscle fibers
-
less myoglobin
less mitochondria
lesser vascular supply
larger fiber diameter