Muscular SystemMuscular System

Tracie Haan

M.E. Meyerhofer

Chelsea Friesen

Muscular System Physiology 4 main functions of the muscles:

Produces movement

Maintain posture

Reinforces and stabilizes joints

Generates heat

Muscle Types

There are three main

muscle types: Skeletal Cardiac Smooth

Skeletal Muscles The four primary functions of skeletal muscles:

Movement Posture Support Heat regulation

Controlled under somatic nervous system Voluntarily Controlled Striated Most skeletal muscles are attached to bones

by bundles of collagen fibers known as tendons.

Skeletal Muscle Structure Skeletal Muscle Cells (myocytes)

myoblasts○ Myofibrils

Skeletal MusclesBelly

○ Fascia: Epimysium Perimysium Endomysium

○ Muscle Fiber (Cell)Tendon

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Skeletal MusclesMajor Muscles:

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Mechanics Of Mechanics Of Movements DemoMovements Demo

Cardiac Muscles Two types of cardiac cells:

Electrical and myocardial Heats contracts rhythmically the whole life of an organism. Autonomically controlled, involuntary muscle, polarized Striated

Cardiac muscles are auto-rhythmic Muscles contract even in the absence of neuronal innervation (pacemaker

cells)

Smooth Muscles All involuntary actions within body with exception to the heart 2 types:

Visceral smooth muscle

Multiunit smooth muscle

No striations due to the absence of sarcomeres

Some smooth muscle areas include: the walls of the viscera, iris of the eye, urinary tract and blood vessels.

Stimulate movement such as peristalsis

Common Muscular Diseases

Muscular Dystrophy- Group of genetic disorders Muscle weakness and loss of muscle tissue Gets worse over time No cure

Sprains and Strains-Sprain-

○ Stretched or torn ligament○ Ligaments connect bones at the joints

Strain-○ Stretched or torn tendon or muscle○ Tendons connect the muscle to the bone

Common Muscular Diseases

Myositis- Inflammation of muscle fibers Swelling of skeletal muscles Group of diseases Causes muscle weakness and degeneration

Contraction and Contraction and Relaxation LabRelaxation Lab

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Sources http://www.livestrong.com/article/261129-smooth-muscle-structure/ http://www.andrews.edu/~schriste/Course_Notes/

Anatomy__Physiology__and_Elect/anatomy__physiology__and_elect.html

http://nursingcrib.com/anatomy-and-physiology/anatomy-and-physiology-muscular-system/

http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002172/ http://www.livestrong.com/article/83692-common-muscular-diseases/ http://healthmad.com/medicine/human-muscular-system/