Muscular System Principles of Health Science Dr. Wood
Characteristics of muscles Excitability: : irritability or ability to respond to stimulus Contractibility: : ability to contract (become short and thick) Extensibility: : ability to be stretched Elasticity: : allows muscle to return to its original shape after being contracted or stretched
Three main kind of muscles Cardiac Visceral or smooth Skeletal
Cardiac muscle Forms the walls of the heart and contraction causes blood to circulate Involuntary: : functions without conscious thought
Visceral or smooth muscle Found in internal organs of the body such as digestive system, eye, blood vessels Also involuntary
Skeletal muscle Attached to bones and causes body movement Voluntary: : have control over its action
Functions of skeletal muscle Movement Produce heat and energy Posture Protection of internal organs
Muscle attachment Tendons: : strong connective tissue cords that attach muscle to bone Fascia: : tough sheet like membrane that covers and protects tissue
Muscle attachment to bone Origin: : the end that does not move Insertion: : the end that does move when the muscle contracts
Muscle tone: : state of partial contracture of a muscle Atrophy: : muscles shrink in size and lose strength when not used for a long period Contracture: : severe tightening of a flexor muscle resulting in bending of a joint also from lack of use
Abduction Moving a body part away from the midline
Muscle movements Adduction: : moving toward the body
Flexion Decreasing the angle between two bones or bending
Extension Increasing the angle between two bones or straightening
Pronation vs. Supination Supination: rotation of the forearm so that the palm is forward Pronation: : rotation of the forearm so that the palm faces backward
Ankle movement Dorsiflexion: movement of the top of the foot upward toward the lower leg Plantarflexion: downward movement of the top of the foot
More muscle movements Rotation: : turning a body part around its own axis, turning the head from side to side Circumduction: : moving in a circle at a joint, swinging the arm in a circle
Gastrocnemius Back of the lower leg Flexes the sole of the foot
Quadriceps femoris Front of the thigh Extends the leg
Gluteus maximus Buttocks Extends the thigh Injection site
Latissimus dorsi Spine around to the chest Extends and adducts the upper arm
Rectus abdominus Ribs to the pubis Compresses the abdomen
Intercostals Between the ribs Moves ribs for breathing
Triceps brachii Upper arm Extends the lower arm
Biceps brachii Upper arm Flexes the lower arm
Trapezius Upper back and neck Extends head and moves shoulder
Shoulder Abducts the arm Injection site Deltoid
Pectoralis major Upper chest Adducts and flexes the upper arm
Sternocleidomastoid Side of neck Turns & flexes head
Sartorius Front of thigh Abducts thigh, flexes leg
Tibialis anterior Front of lower leg Flexes and inverts foot
Muscle diseases Fibromyalgia: : Chronic pain in muscles Muscular dystrophy: inherited, progressive muscle atrophy Myasthenia gravis: impulses are not transmitted to the muscles leading to weakness and paralysis
More muscle diseases Spasms: cramps, sudden painful involuntary muscle contraction Strain: overstretching of muscle or tendon
Image Citations Slide 10: Achilles tendon-1/16/06 http://ergonext.com/aa- science-msd/image/ach msd/image/ach-tendon.gif Slide 11: 1/16/06 http://www.gla.ac.uk/ibls/fab/images/anatomy/gastro2a.gif Slide 12: 1/16/06 http://www.cannock.ac.uk/sports/images/muscle_actions/adducti on.jpg Slide 12: 1/16/06 http://biking.taiiku.tsukuba.ac.jp/~takai/anatomy/e- anatomy/gr/adduction.gif Slide 13: 1/16/06 http://www.lighthousept.com/webimages/abduction_hip.gif Slide 14: 1/16/06 http://www.e-prolab.com/comlab/sttop/sttop prolab.com/comlab/sttop/sttop- bm/pictures/flexion.gif Slide 15: 1/16/06 http://weboflife.ksc.nasa.gov/exerciseandaging/images/exercises/ knee_extension.gif Slide 17: Delmar Learning s Medical Terminology Image Library, Second Edition. Version 1.0. ISBN: 1-40181 4018-1009-8 Slide 18: 1/16/06 http://www.spectroscopynow.com/ftp_images/2x6-hand.jpg hand.jpg
Image Citations Slide 19: 1/16/06 http://www.exrx.net/graphics/gastrocnemiuslateral.gif Slide 20: 1/16/06 http://www.gomotion.dk/billeder/ovelser/muskel_forside_laar.gif Slide 21: Gluteus maximus 1/16/06 http://sv.wikipedia.org/wiki/gluteus_maximus Slide 22: 1/16/06 http://www.exrx.net/graphics/latissimusdorsiside.gif Slide 23: 1/16/06 http://www.sportfit.com/sportfitglossary/images/rectus.gif Slide 24: 1/16/06 http://www1.tpg.com.au/users/sfrancis/med/intercostals.jpg Slide 25: Anterior arm muscles 1/16/06 http://owensboro.kctcs.edu/gcaplan/anat/study%20guide/image 870.gif Slide 26: 1/16/06 http://www.easygym.com/muscles/coude- biceps-brachial.jpg brachial.jpg Slide 27: 1/16/06 Trapezius http://sv.wikipedia.org/wiki/trapezius
Image Citations Slide 28: 1/16/06 http://www.douglas.bc.ca/muscles/files/images/deltoid.jpg Slide 29: 1/16/06 Pectoralis major http://pl.wikipedia.org/wiki/grafika:pectoralis_major.png Slide 30: 2/17/07 Sternocleidomastoid, http://www.exrx.net/muscles/sternocleidomastoid.html Slide 31: 2/17/07 Sartorius, http://www.exrx.net/muscles/sartorius.html Slide 32: 2/17/07 Tibialis anterior, http://www.exrx.net/muscles/tibialisanterior.html