MUSCLES!

After this powerpoint… You can: Define what muscle is made of Explain where they are found Classify the three types of muscle After this powerpoint…

Vocabulary: Contractile – To become reduced in size by or as if by being drawn together Fascia – connective tissues that surrounds muscles, groups of muscles, blood vessels, and nerves, like cling-wrap to a bunch of sandwiches Tendon – A tough band of fibrous connective tissue that usually connects muscle to bone.

Vocabulary Epi- (prefix): on top of Peri- (prefix): about or around Endo- (Prefix): within or inside Myo- (Prefix): muscle Sarco- (Prefix): flesh

Muscle is a contractile tissue of animals (including humans)

Why are muscles important? (remember MPH!)

Movement is the contractile ability of muscle tissues. Example One bone stays stationary while the other is drawn closer It also allows for movement of tissues for important functions like: Blood flow Swallowing food Breathing Digestion & excretion Function 1: Movement

Function 2: Posture Poor posture may lead to: Limited breathing Stress/pain in back, knees, hips, shoulders Stress on internal organs such as Heart Intestines Liver lungs Function 2: Posture

Muscle provides a layer of insulation, helping the body to regulate temperature Also, when the core body temperature drops, muscles ‘shiver’ to make heat for the body. Function 3: Heat

Muscle What is it made of?

Muscle Fibers Muscles are made of muscle cells called muscle fibers. Muscle fibers are Long Cylindrical Have more than one nucleus Have striations (stripes) Muscle Fibers

Muscle fibers contain myofibrils, which contain either actin or myosin. These two act as the ‘motor’ of a muscle’s contraction Muscle Fibers

A layered section of these actins and myosins is called a sarcomere Myosin is thick and actin is thin, so these appear striped, or striated (sarco = muscle) In the presence of calcium, actin slides past myosin, causing the muscle fiber to contract Muscle Fibers

Muscle Fibers A group of muscle fibers is called a fascicle A group of fascicles is called a muscle Every layer is individually wrapped in perimysium Muscle Fibers

Types of muscle There are three types of muscle in the body SKELETAL SMOOTH CARDIAC Types of muscle

Skeletal Skeletal muscle is also called voluntary muscle It is attached to bones for movement These are muscles you can control! Skeletal

Smooth Smooth muscle is also called involuntary muscle It is found at or in soft tissues and organs to provide movement Peristalsis in esophagus Diaphragm for breathing Smooth

Cardiac Muscle Cardiac Muscle is different because: The cells have one nucleus It is resistant to fatigue Its both striated and involuntary The cells in cardiac muscle are interconnected, allowing for better transfer of signals Cardiac Muscle

Muscle Naming Muscles can be named based on 4 categories Location (Tibialis anterior) Function (Levator scapulae) Appearance (trapezius, rhomboids) Attachment Sites (Sternocleidomastoid) Muscle Naming