Ch 10, Smooth muscle Slides & Pictures (copy)

Do smooth muscle cells have sarcomeres?

No

What is the arrangement of thick and thin filaments in smooth muscle?

They overlap, like skeletal muscle

What are dense bodies in smooth muscle?

Where the thin filaments connect to

What connects the dense bodies in smooth muscle?

Intermediate filaments

Where are dense bodies attached?

To the sarcolemma (cell membrane)

What part of the nervous system controls smooth muscle?

The autonomic nervous system (involuntary)

What are varicosities in smooth muscle innervation?

Where neurotransmitters are released in smooth muscle

Where do varicosities form in smooth muscle?

In diffuse junctions

How are smooth muscle cells usually arranged?

Connected to each other in sheets

What allows signals to move between cells quickly?

Gap junctions

How do smooth muscle cells typically contract?

As a single unit

Smooth muscle contractions are _______ to start, but last longer than skeletal muscle contractions:

Slower

Chemicals released from nerve signals such as _________ and ________ can stimulate smooth muscle:

ACh and Norepinephrine

Some _______ can signal smooth muscles to tighten (like during childbirth):

hormones

_________, a chemical released during allergies or inflammation can cause smooth muscle contractions:

Histamine

What is the most common type of smooth muscle?

Single-unit smooth muscle (visceral muscle)

In what places can single-unit smooth muscle be found?

The digestive tract, uterus, bladder

Single-unit smooth muscle works together as a unit, which means…

When one contracts, the others follow

Because of _______ cells, single-unit smooth muscle can often contract rhythmically on their own, even without nerves:

Pacemaker cells

What kind of smooth muscle is found in large airways of lungs, large arteries, and internal iris muscles (muscles controlling the iris)?

Multi-unit smooth muscle

How do the cells work structurally in Multi-unit smooth muscle?

Independently

How is single-cell smooth muscle similar to multi-cell smooth muscle?

They both are involuntary

What hormone helps build muscle?

Testosterone

Why do men generally have more muscle mass than women?

Because testosterone increases muscle growth.

What percentage of a man’s body weight is typically muscle?

About 42%

What percentage of a woman’s body weight is typically muscle?

About 36%

What is sarcopenia?

The gradual loss of muscle mass due to aging

At what age does sarcopenia usually begin?

Around age 30

What can minimize sarcopenia?

Exercise

Most muscles attach to how many bones?

Two, one at each end

What is the relatively stationary end of a muscle that doesn’t move much during contraction called?

The origin

What is the thick, fleshy midregion of a muscle called?

The belly

What is the more mobile end of a muscle that moves during contraction called?

Insertion

What determines the strength and direction of a muscle's pull?

Fascicle arrangement

Which fascicle arrangement is thick in the middle and tapered at both ends?

Fusiform

Name this fascicle arrangement:

Fusiform

What are fusiform arrangements designed for?

Strength

Which fascicle type has uniform width and straight, parallel fibers?

Parallel

Name this fascicle arrangement:

Parallel

Which fascicle arrangements have parallel fascicles?

Fusiform and parallel

Which fascicle arrangement is fan-shaped with a broad origin and narrow insertion?

Convergent

Name this fascicle arrangement:

Convergent

What does it mean for a muscle to have parallel fascicles?

The individual muscle fibers run in the same direction

In which type of pennate muscle do all fascicles insert from one side?

Unipennate

Which pennate type has fascicles inserting from two sides of the tendon?

Bipennate

Which type of pennate muscle has multiple feather-like fascicle arrangements?

Multipennate

Name this fascicle arrangement:

Unipennate

Name this fascicle arrangement:

Bipennate

Name this fascicle arrangement:

Multipennate

What kind of fascicle arrangement forms a ring around an opening?

Circular muscles (sphincters)

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Hinge Joint

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Plane Joint

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Saddle Joint

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Pivot Joint

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Condyloid Joint

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Ball and Socket Joint

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Abduction

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Adduction

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Circumduction

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Medial Internal Rotation

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Medial External Rotation

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Elevation

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Depression

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Protraction

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Retraction

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Supination

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Pronation

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Radial Flexion

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Ulnar Flexion

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Abduction of fingers

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Abduction of thumb

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Opposition of thumb

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Inversion

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Eversion

What type of tissue is affected in a sprain?

Ligaments are stretched or torn in a sprain.

Why do partial ligament tears heal slowly?

Because ligaments have poor blood supply.

What is usually required for a full ligament tear to heal properly?

Prompt surgery is usually required for the best outcome.

Can cartilage damage typically heal on its own?

No, cartilage damage is usually not self-repairing.

What might be necessary when cartilage is damaged and does not heal?

The damaged cartilage may need to be surgically removed.

What is a dislocation (luxation)?

A condition where bones are forced out of alignment.

What is a subluxation?

A partial dislocation.

What is the treatment for a dislocated joint?

It needs to be reduced—bone ends must be returned to their proper position.

What tissue is often stretched during a dislocation?

Ligaments are often stretched during a dislocation.

What are bursitis and tendonitis?

They are inflammatory conditions affecting bursae and tendons.

What is arthritis?

Arthritis refers to over 100 types of inflammatory or degenerative joint diseases.

What are four common symptoms of arthritis?

Pain, stiffness, swelling, and loss of range of motion or mobility.

What is the most common chronic form of arthritis?

Osteoarthritis

What is osteoarthritis also called?

"Wear-and-tear" arthritis.

What causes osteoarthritis?

Joint overuse leads to cartilage breakdown.

What type of disorder is rheumatoid arthritis?

A chronic inflammatory autoimmune disorder.

What happens to the joints in rheumatoid arthritis?

The body's immune cells attack joint components.

How does rheumatoid arthritis compare to osteoarthritis in severity?

It is usually more severe.

What causes joint inflammation in gouty arthritis?

Uric acid crystals in the joint tissue.

What leads to uric acid buildup in gout?

Either too much uric acid production or too little excretion.

Who is more commonly affected by gout?

Men.

What can happen if gout is not treated?

Bone ends can fuse, causing joint immobilization.

What are common treatments or lifestyle changes for gout?

Medications, drinking water, avoiding alcohol and purine-rich foods.