Chapter 7: Muscular System
Muscle spasm
A involuntary contraction of the muscle
Muscle strain
A tear in the muscle
Muscle fatigue
Caused by an accumulation of lactic acid, waste product of muscle metabolism
Sphincter muscle
Circular open and close allow the passage of substance
Rectus abdominus
Compresses the abdominal cavity
Dystonia
Condition characterized by involuntary muscle contraction that causes repetitive movement or abnormal posture
Cardiac muscle
Contains membranes fused at places called intercalated disks
Characteristics of muscles are
Contractility- ability of the muscle to shorten, which reduces distance b/t parts of its content Excitability- characteristic shared w/ nerve cells; ability to respond to stimuli Extensibility- ability of muscles to be stretched Elasticity- ability of a muscle to return to its original length after stretching
Frontalis
Controls facial expressions
Masseter
Controls mastication (chewing and eating)
Prime mover
Creates movement in a single direction
What Sources of energy are needed for muscle contraction?
Glucose, oxygen, ATP (adenosine triphosphate)
Cardiac muscle cells located
Heart
Diaphrgragm
Helps in breathing
Exercise
Improves muscle strength and efficiency and circulation Injury- extensive you'll build scar tissue
Tetanus (lockjaw)
Infectious disease characterized by continuous spams of voluntary muscles
Shin splints
Injury to the muscle tendon in front of tibia
Motor unit
Is a motor neuron (nerve cell) plus all of the muscle fibers it stimulates
Effects Aging has on the muscle
Loss of strength, energy, or fatigue
ATP
Major source of energy and breaks down lactic acid
Massage
Massage therapy provides relaxation of the muscles
Intramuscular injections
May be given in deltoid, dorsal gluteal, vastus lateralis
Tibialis anterior
Moves the ankle
Peroneus longus
Moves the ankle, foot, and toes
Biceps
Moves the arm
Sternocleidomastoid
Moves the head
Sartorius
Moves the lower leg
Deltoid
Moves the shoulder
Gluteus maximus
Moves the upper leg
Flexor capri
Moves the wrist, hand, and fingers
Muscle tone
Muscle are always in a state of slight contraction and ready to pull
Skeletal muscle cells located
Muscle fibers
Hypertrophy
Muscle fibers increase in size from overuse
Smooth muscle
Muscle has ability to cause the diameter of blood vessels to decrease on contraction
Myalgia
Muscle pain. Fibromyalgia is collection of symptoms
Antagonist
Muscle pulls from opposite direction (triceps and biceps)
Atrophy
Muscles shrink from disuse
Muscle atrophy
Muscles shrink in size due to insufficient usage
Smooth (visceral) muscle
No striated, has one nucleus, and is involuntary (cannot move it)
Your two unpaired muscles are
Orbicularis Oris and diaphragm
Hernia
Organ protrusion comes through the muscle Abdominal, hiatal, inguinal
Origin
Part of the muscle attached to a fixed point on the bones; the least movable during a contraction
Insertion
Part of the muscle attached to the movable part of the bone; it's most movable during a contraction
Electrical stimulation
Passes electrical currents through the body
Gastrocnemius
Points toes and flexes the lower leg
Lactic acid
Product of muscle contraction that is changed back to glucose
Functions of the muscular system
Responsible for all body movement Giving the body form and shape Producing most of the bodys heat
Synergist
Steady movement
Cardiac muscle
Striated and branched, found only in the heart
Skeletal muscle
Striped or striated, attached to the bones of the skeleton, and voluntary (you can move it)
Muscles only pull; never push
True
The diaphragm is a dome-shaped muscle that separates the thoracic and abdominal cavities
True
The external oblique flexes the spinal column and compresses the abdominal cavity
True
The intercostals are found b/t ribs and help us breathe
True
There are 327 muscles that are antagonist
True
There are 656 muscles in your body
True
To much lactic acid in the blood will cause the muscles to cramp and fatigue
True
Involuntary or smooth muscle cells located
Walls of the internal organs