1) Smaller than skeletal muscles

2)Their fibers don't extend the full length of the muscle

Where are skeletal receptors located:

Where are smooth muscle receptors located:

Neuromuscular Junction

Across entire length of the muscle fiber

In Skeletal Muscle Ca+ is stored:

In Smooth Muscle Ca+ is stored:

Sacroplasmic Reticulum

Extracelllar Fluid

Streched smooth muscle can still develop:

Can relax when..

Tension (urinary bladder)

Streched

1) Doesn't use as much ATP per unit/time

2)Crossbridges are latched together longer (Actin and Myosin)

Smooth Muscle Contrations

Slow Waves

1) Spontaneous waves of electrical activity

2)Determines frequence, direction and velocity of rhythmic contrations

1) Spontaneously depolarize over time

2) Don't need to be innervated, nerve and hormanal activity can change the rate

1) Channels that link cytoplasm of one cell to another

2)Low resistance for electrical Activity

3)Propogate Depolarizations betwn smooth muscle cells

Slow waves don't always reach:

Added wave will reach threshold =

multiple Action Potentionals=

Threshold

Action Potentional

Stronger Contractions

Parasympathetic N.S:

Increases?

Blocked by?

Main Neurotransmitter?

Gut motility(amount and strength of contraction)

Atrophine

Acetylcholine

Sympathetic

What is main neurotransmitter?

Decreases?

Epinephrine

In strength and amount of contraction

Single Unite Smooth Muscle

Can contract without:

Examples:

Exhibit:

Have?

Input, nervous involved activity

Blood Vessels around Intestines

Slow Waves

Have gap junctions

Multi Unit Smooth Muscle

Nearly always..

Examples: Sphincter in urinary iris of th eye

No...

Under nervous control

Gap junctions