The Muscular System 7.5

Functions of the muscular system

• Hold the body erect and make movement possible

• Generates nearly 85% of the heat that keeps the body warm

• Move food through the digestive system

The muscular system

• The body has more than 600 muscles

• Muscle make up about 40%-45% of the body’s weight

Excitability (characteristics of the muscles)

ability to respond to a stimulus such as a nerve impulse.

Contractibility (characteristics of the muscles)

fibers that are stimulated by nerves contract, or become short and thick, which causes movement

Extensibility (characteristics of the muscles)

the ability to be stretched

Elasticity (characteristics of the muscles)

allow the muscle to return to its original shape after it has contracted or stretched.

Muscle fibers (Structures of the muscles)

long slender cells that make up muscles

Fascia (Structures of the muscles)

connective tissue that is flexible to allow muscle movements

Tendons (Structures of the muscles)

non-elastic tissue that attaches a muscle to a bone

Skeletal Muscles (Types of muscle issues)

attached to the bones of the skeleton and make body motions possible. This is voluntary muscles that you can control

Antagonistic muscle pairs

• Antagonistic – refers to working in opposition to each

other

• 1. Contraction – the tightening of a muscle

• 2. Relaxation – occurs when a muscle returns to its

original form

Abduction (Muscle motion)

away from the midline

Adduction (Muscle motion)

toward the midline

Flexion (Muscle motion)

bending the limbs at the joint

Extension (Muscle motion)

straightening out of a limb

Elevation (Muscle motion)

Smile

Depression (Muscle motion)

Frown

Rotation (Muscle motion)

movement around an axis such as the shoulder joint

Circumduction (Muscle motion)

circular movement at the far end of a limb

Supination (Muscle motion)

palm of hand up or sole of the foot is turned upward

Pronation (Muscle motion)

palm of hand or sole of the foot is turned downward

Dorsiflexion (Muscle motion)

bends the foot upward at the ankle

Plantar flexion (Muscle motion)

bends the foot downward at the ankle

ATROPHY

Weakness or wearing away of body tissue and structures

CACHEXIA

Condition of physically wasting away due to the loss of weight and muscle mass that occurs in patients with diseases

HERNIA

Tissue of an internal organ protrudes through a weak area in the muscle normally containing it

CONTRACTURE

Permanent tightening of muscles, tendons, ligaments, or skin

SPASM

Sudden, involuntary contraction of one or more muscles

MYOCLONUS

Quick, involuntary jerking of a muscle or group of muscles. May occur normally as a person is falling asleep

SINGULTUS

Hiccups

TORTICOLLIS

Wryneck. A stiff neck due to spasmodic contraction of the neck muscles that pull the head toward the affected side

DYSKINESIA

Distortion or impairment of voluntary movement resulting in fragmented or jerky motions

MYASTHENIA GRAVIS

Chronic autoimmune disease that affects the neuromuscular junction and produces weakness and rapid fatigue of voluntary muscles, especially in the eye, MUSCULAR DYSTROPHYface, and throat

MUSCULAR DYSTROPHY

Describes a group of more than 30 genetic diseases that are characterized by progressive weakness and degeneration of the skeletal muscles that control movement, without affecting the nervous system

OVERUSE TENDINITIS

Inflammation of tendons caused by excessive or unusual use of a joint

ROTATOR CUFF TEAR

Occurs as an irritated tendon weakens or as the result of a fall or injury

CARPAL TUNNEL RELEASE

Surgical enlargement of the carpal tunnel or cutting of the carpal ligament to reduce the pressure on the median nerve

A GANGLION CYST

A benign fluid-filled lump that usually occurs on the outer surface of the wrist or hand

A HEEL SPUR

A calcium deposit in the plantar fascia near its attachment to the calcaneus

FIBROMYALGIA

Chronic widespread musculoskeletal pain

• Symptoms include:

-Muscle stiffness

-Fatigue

-Headaches

-Depression

SPRAIN

Injury to a joint, such as an ankle, knee, or wrist. Usually occurs when a ligament is wrenched or torn

RICE

• THE MOST COMMON FIRSTAID TREATMENT FOR SOFT TISSUE INJURIES

• R - REST

• I - ICE

• C - COMPRESSION

• E - ELEVATION

STRAIN

Injury to the body of a muscle or to the attachment of a tendon. Overuse injuries that involves a stretched or torn muscle or tendon attachment

HAMSTRING INJURY

A strain or tear on any of the three hamstring muscles that straighten the hip and bend the knee

ACHILLES TENDINITIS

Painful inflammation of the Achilles tendon caused by excessive stress being placed on that tendon

Hemiparesis (types of paralysis)

weakness affecting one side of the body

Hemiplegia (types of paralysis)

total paralysis affecting only one side of the body

Paraplegia (types of paralysis)

paralysis of both legs and the lower part of the body. An individual affected with paraplegia is known as paraplegic

Quadriplegia (types of paralysis)

paralysis of all four extremities. An individual affected with quadriplegia is known as a quadriplegic.