Chapter 7: Muscles

Muscle

All contractive tissue

Three types of muscles

Skeletal, Smooth, and Cardiac

Striated muscle

The muscle fibers appear to be striped

Skeletal muscles

voluntary muscles, attached to the skeleton, striated, perform external movement

Peristalsis

The internal movement of food

Smooth muscle (visceral muscle)

involuntary, not striated, found in certain organs, blood vessels, and airways; internal movement of food, movement of blood, changes diameter of airways.

Cardiac muscle

Striated muscle, only in the heart, causes heart to contract, internal movement of blood, involuntary.

Tendons

attach skeletal muscle to bone

Ligaments

attach bone to bone

Aponeuroses

a broad sheet of connective tissue.

Agonist (Primary Mover)

The muscles that cause movement

Point of Origin

The muscle end that is attached to stationary bone

Point of Insertion

The muscle end that is attached to moving bone

Synergistic

Assist the primary mover

Antagonist

Muscles that cause movement in the opposite direction when they contract

Diaphragm

skeletal muscle that controls breathing

Rotation

circular movement about an axis

Abduction

move away from midline of the body

Adduction

moves towards midline of the body

Extension

Increasing the angle between two bones connected at a joint

Flexion

Opposite of extension, decrease the angle between two bones

Kinesiology

The study of muscles and movement

Myofibrils

Functional units of muscle

Sarcomeres

Structural units of a myofibril that contract and enable muscle movement.

Myosin

thick myofilaments that interact with actin during muscle contraction.

Actin

thin myofilaments that interact with myosin to facilitate muscle contraction.

Z-lines

Structures that define the boundaries of a sarcomere and anchor actin filaments.

Adenosine Triphosphate (ATP)

The energy that helps myosin heads form as well as break cross bridges with actin.

Calcium (Ca)

Needed for contraction and relaxation of muscle fibers

Sarcoplasmic reticulum (SR)

A specialized endoplasmic reticulum in muscle cells that stores calcium ions, essential for muscle contraction and relaxation.

Acetylcholine

A Neurotransmitter that opens sodium channels and kick-starts muscle contraction

Rigor Mortis

The stiffening process of the body after death

Glycogen

A carbohydrate that waits in reserve to be converted to a useable energy source

Glucose

releases energy for the muscle to function

Tonus

Partial contraction of a muscle with a resistance to stretching

Hypertrophy

increased growth or development of muscles

Atrophy

When muscles waste away due to lack of use

Vasodilate

The widening of blood vessels (diameter gets larger)

Vasoconstrict

The shrinking in diameter of blood vessels

Sphincter

Composed of smooth muscle, act as doorways to let materials in and out

Intercalated Discs

Connects cardiac muscle fibers to make them all contract together (domino effect)Mya

Myalgia

Pain or tenderness in a muscle

Fibromyalgia

Most common musculoskeletal disorder affecting women under 40, aches, pains, muscle stiffness with specific tender points on the body

Ataxia

Muscles are irregular in their actions or lack of coordination

Paralysis

Partial or total loss of the ability to move voluntary muscles

Spasm/Cramp

When a muscle contracts suddenly and violently for a period of time

Sprain

Tears or breaks in ligaments

Strain

tears or injury in muscles and tendons

Shin splints

common running-related inflammatory condition of the extensor muscles and surrounding tissues of the lower leg

Hernia

Tear in muscle wall and an organ protrudes through that opening

Tendinitis

Tendons become damaged

Muscular Dystrophy

Inherited muscular disease where muscle fibers degenerate combined with progressive muscular weakness

Electromyography (EMG)

Test where muscles or muscle groups are stimulated with an electrical impulse

Botulism

Potentially deadly disease caused by food poisoning but, used in botox

Neuromuscular

Effects both nervous system and muscular system

Myasthenia Gravis

neuromuscular disease, patient exhibits gradually increasing profound muscle weakness, Symptoms: drooping of one or both eyelids, progressive paralysis.

Guillain-Barré syndrome

disorder of peripheral nervous system causes flaccid paralysis and loss of reflexes. Ascending paralysis peaks within 10-14 days

Flaccid Paralysis

limp muscles

Tetanus

Rigid paralysis, minor stimulus can cause muscles to go into major spasm, result of toxins produced by bacteria found in the ground, spread by any skin puncture