Chp. 7 - Muscular System

What are the three types of muscles?

Skeletal, cardial, smooth

Muscles make up what percent of total body weight?

40%

What is the end of a motor neuron that attaches to a muscle fiber called?

Synaptic knob

What is the difference between synaptic cleft and neuromuscular cleft?

Synaptic cleft is between two neurons, neuromuscular cleft is between a neuron and muscle fiber

What is the group of neurons that a motor neuron stimulates called?

Motor unit

What is the name of the space between a motor neuron and muscle fiber?

Neuromuscular cleft

What is the name of the structure in a motor neuron that store and releases neurotransmitters?

Neuromuscular vessels

Explain the process of a mudcle contraction in 4-5 steps.

1. Neurotransmitters release, opening sodium ions, causing an action potential in the sarcolemma.

2. The AP travels to the sarcoplasmic reticulum causing it to release calcium.

3. The AP carried by motor neuron reaches neuromuscular junction.

4. Actin slides over myosin

5. Muscle shortens.

Highlighted diagram photos

Define contractility

Ability to shorten

Define elasticity

Ability to stretch

Define excitability

Ability to respond to stimuli

What are the two types of muscle that are striated?

Skeletal and cardiac

What are the two types of muscles that contain one nucleus per cell?

Smooth and cardiac

What are 5 functions for the skeletal system?

Movement, stability, heart beat, heat generation, glycemic control

What is the epimysium?

Connective tissue around the entire muscle

What is the perimysium?

The connective tissue around fascicles

What is a fascicle?

A bundle of muscle fibers

What is a muscle fiber also known as?

Muscle cell

What is the endomysium?

The connective tissue that surrounds each individual muscle fiber

What is a myofibril?

A unit of protein in muscle fibers

Order these from biggest to smallest: myofilament, muscle fiber, myofibril

Muscle fiber, myofibril, myofilament

What is the sarcolemma?

The cell membrane of a muscle fiber

What is a sarcomere?

Contractile unit

What is the function of rhe sarcoplasmic reticulum?

To store and release calcium

What does a z disc do?

Separate sarcomeres

What is a thick myofilament called?

Myosin

What is a thin myofilament called?

Actin

Which type of myofilament is shaped like a golf club?

Myosin

What are acting filaments shaped like?

Beaded necklaces

Skeletal muscle is striated. (T or F)

True

Smooth muscle is striated. (T or F)

False

What are the three types of muscles?

Skeletal, cardiac, smooth

Which muscle type is the only voluntary one?

Skeletal

Which type of muscle has branching or Y-like appearance?

Cardiac

Which muscle type has a spindle-like or tappered appearance on the ends?

Smooth

Where is smooth muscle located?

Around organs