Muscle Quick Facts Courage is very important Like

Muscle Quick Facts “Courage is very important. Like a muscle, it is strengthened by use. ” -Ruth Gordon

What causes muscle cramps? • A muscle contracts with great intensity and stays contracted, refusing to stretch or lengthen again. • This is a change in the nervous impulse. • Minerals such as _______________________________play a key role in the transmission of these signals. • Imbalances of these minerals, as well as certain hormones, fluids and chemicals can cause muscle cramps. • ______________________________________________

Muscle Spasm • A ___________________ __ _____________contraction. • Feels like a tight knot. • Occur in muscles that are overworked or injured. • Rest and time resolve most muscle spasms.

How many muscles does it take to smile and frown? • _____ to smile • _____ to frown

What is the longest muscle in the body? • __________

How many muscles are involved in chewing food? • Four pairs of muscles in the face are involved in chewing (mastication). • They are some of the strongest muscles of the body.

How many muscles are in the fingers and thumbs? • ______________________________________ • The _______ that control these_______ are located in the hand forearm.

Which are the fastest muscles? • _______________ • Allow your eyes to move.

Smallest Muscles? • • ______________ Found in the middle ear. Thinner than a thread (0. 05 inches) in length. It activates the stirrup that sends vibrations from the eardrum to the inner ear.

Largest Muscle?

The Muscular System “Muscles come and go; flab lasts. ” -Bill Vaughan

Intro • There are more than _____muscles in the human body • Muscles are responsible for our breathing and eating • The beating of our hearts involved muscle activity

Muscle tissue What is tissue? ◦ _______________________________________ Muscle Tissue: ◦ Group of cells that ______ during contraction which creates tension and results in movement. muscle tissue can shorten by about ____ its resting length in response to nerve, nerve-like or hormonal stimulation.

Types of Muscles • There are three types of muscle in the human body:

Types of Muscles

Types of Muscles • Skeletal Muscle – _______________ – Attach ________, via Ligaments. – Voluntary • We have conscious control over these muscles • The brain tells them what to do – “________” or Striped Appearance • Series of light and dark • I bands = Light (Actin), A bands = Dark (Myosin)

Cardiac Muscles (only in the heart) • responsible for creating the action that pumps blood from the heart to the rest of the body • forms the heart’s thick wall (layers of interlacing cardiac muscle fibres) • _____________–they are not controlled consciously • are directed to act by the autonomic nervous system –contract spontaneously in association with special impulse-conducting muscle cells _______________________________________________ • cardiac muscle is also ________________ • definitive junctions between cells (intercalated discs) • a centrally located nuclei

Smooth Muscles • ____________________________________________________________ • centrally positioned nucleus, no cross striations • found in walls of organs with hollow cavities (viscera) and serve to propel material along the length of those cavities – Including blood vessels, hair follicles, intestines • contract more slowly than skeletal muscle tissue (sustained, rhythmic contractions –menstrual contractions and stomach cramps) • can remain contracted for longer periods of time • _____________– their spindle-shaped fibres are usually arranged in dense sheets.

Tendons vs. Ligaments Tendon: (skeletal movement) • tough bands of connective tissue that join -____________. • Ligament: – Attach ___________

Properties of Muscle Fibres • Irritability • Contractibility • Elasticity • Extensibility • Conductivity