ch5 Muscle (10), smooth, Nervous Tissue (12)

Muscle Tissue function

body/organ movement, posture, comms, heat product

Muscle Tissue characteristics

Contractility (shorten to produce movement)

Excitability: Respond electrical signals

Elasticity & Extensibility: Can stretch beyond resting length, snap back into shape

Conductivity: transmit an electrical signal (an action potential) along the cell membrane

skeletal muscle fiber nucleus

nucleus cardiac muscle fiber

intercalated disc (cardiac muscle)

contain numerous desmosomes and gap junctions

• Between cardiac muscle fibers

• Mechanical connection b/w adjacent cardiac muscle cells

• Electrical connection b/w adjacent cardiac muscle cells, providing for spread of polarization impulses throughout myocardium

branched cardiac muscle fiber

Involuntary contraction of myocardium

Contraction maybe modulated by autonomic nervous system

smooth muscle fiber

walls hollow internal organs and tubes (stomach, intestines, urinary bladder, uterus, respiratory airways, blood vessels)

Spindle-shaped muscle cells with tapered ends

• Each fiber has single, centrally-placed nucleus

• Fibers tightly packed and arranged in staggered arrays
  

neuron nucleus

soma

glial cell neuron

neuron

• Generate, conduct, receive nerve (electrical) impulses

• Axons direct information AWAY from soma

• Dendrites direct information TOWARD soma

dendrite

direct info TOWARD soma

Axon

direct info AWAY from soma