Muscular

THE MUSCULAR SYSTEMBy Elisa Glubok

SUMMARY OF THE MUSCULAR SYSTEM

Skeletal - Striated, Voluntary structurally supported by the skeletal system controlled by the nervous system 1. Muscle Fibers 2. Nuclei

Cardiac-Striated, Involuntary Myocardium: the heart muscle Heart pumps the circulatory system 1. Cardiac Muscle Cell 2. Nuclei 3. Intercalated Disks

Smooth-Non-Striated, Involuntary Digestive tract Urinary tract/bladder Esophagus Uterus Blood vessels Other Internal Organs, Etc.

IMAGES FROM: http://www.uoguelph.ca/zoology/devobio/210labs/muscle1.html

THE STRUCTURAL HIERARCHY OF THE SKELETAL MUSCLE

Image from: http://academic.kellogg.cc.mi.us/herbrandsonc/bio201_McKinley/f10-1a_structural_organ_c.jpg

SLIDING FILAMENT THEORY

Image from: http://www.octc.kctcs.edu/GCaplan/anat/Notes/API%20Notes%20J%20%20Muscle%20Contraction.htm

SLIDING FILAMENT THEORY CNTD.

Images from: http://www.octc.kctcs.edu/GCaplan/anat/Notes/API%20Notes%20J%20%20Muscle%20Contraction.htm, http://commons.wikimedia.org/wiki/Image:Sarcomere.svg

•Troponin complex is attached to strands of Tropomyosin•Tropomyosin surrounds thin actin filament•Troponin complex attaches to Ca 2+ during contraction •Troponin complex unblocks myosin binding site•Myosin head attaches to binding site •Thin and thick filament slide past each other

SDU Sliding Filament Theory

THE NEUROMUSCULAR JUNCTION Neuromuscular Junction Acetylcholine (ACh) is a neurotransmitter used to

communicate with the skeletal muscle fibers ACh is stored in the synaptic vessels at the

neuromuscular junction When the junction receives an impulse, calcium

ions (Ca 2+) are released ACh is released at the membrane through

exocytosis ACh diffuses across myoneural junction The binding of ACh sends an action potential

down through the T-tubules ACh is then broken down by AChE

(acetylcholinesterase) Muscle fiber contracts in response to action

potential

THE NEUROMUSCULAR JUNCTION CNTD.

Image from: http://www.octc.kctcs.edu/GCaplan/anat/Notes/API%20Notes%20J%20%20Muscle%20Contraction.htm

THE INVOLUNTARY MUSCLES

Striated, multinucleate Contraction can occur

without nervous input Pacemaker cells= cells

that produce stimulation for contraction

Intercalated disks allow for communication between cardiac cell muscles for coordinated contractions

Arranged parallel Contracts and relaxes

without conscious thought

Contracts as a single unit

Single innervating nerve sends message to multiple cells to move similarly

“spindle” shaped cells with single central, elongated nucleus

Cardiac Muscle Smooth Muscle

HELPFUL VIDEOS

Muscular Sliding Filament Theory (1)

Muscular Sliding Filament Theory (2)

Muscular Contraction

Neuromuscular Junction

MUSCULAR DYSTROPHY

Group of 30+ diseases caused by genetic inheritance

Cannot be acquired throughout life

Different ages onset, may not be apparent at birth

More common in boys

Generalized weakness of the voluntary muscles

Degeneration of skeletal muscles

Generally symmetrically distributed weakness

No pain Sometimes mental

retardation THERE IS NO CURE FOR

MUSCULAR DYSTROPHY

Causes/Facts Effects

DUCHENNE MUSCULAR DYSTROPHYA.K.A. PSEUDOHYPERTROPHIC DYSTROPHY Most common and severe type of

muscular dystrophy Caused by an absence of

dystrophin (keeps muscles intact)

Shows up in early childhood Results in generalized weakness

and muscle deterioration of the thighs, hips, pelvic area and shoulders

Progresses to affect all voluntary, breathing, and heart muscles

Survival beyond 30’s is rare Primarily affects boys because

the disease is X-linked recessive About 2 in 1,000 of boys (0.2%)

are born with the disease Women can be carriers but

rarely exhibit symptoms

Image from: http://www.humanillnesses.com/original/Men-Os/Muscular-Dystrophy.html

WORKS CITEDCampbell, Neil A. and Reece, Jane B. Biology: AP Edition. San Francisco, CA: Pearson Education, 2005.Christoffersen, Hans. “Muscle Tissue.” Developmental Biology Online. University of Guelph. 8 May 2008.

<http://www.uoguelph.ca/zoology/devobio/210labs/muscle1.html>.Dowshen, Steven. “Your Muscles.” Kids Health for Kids. June 2006. Nemours Foundation. 2 May 2008.

<http://www.kidshealth.org/kid/htbw/muscles.html>.“Duchenne Muscular Dystrophy.” Muscular Dystrophy Association. July 2007. Google. 8 May 2008.

<http://www.mda.org/disease/dmd.html>“Learning the Muscular System.” Kellogg Community College. 19 January 2005. 12 May 2008.

<http://academic.kellogg.cc.mi.us/herbrandsonc/bio201_McKinley/f10-1a_structural_organ_c.jpg>.Liang, Barb. “The Neuromuscular Junction.” Advanced Anatomy and Physiology. 6 May 2008.

<http://www.wisc-online.com/objects/index_tj.asp?objid=AP2804>.“Muscles and Muscle Systems.” Encyclopedia Brittanica. Fifteenth Edition Chicago: Encyclopedia Brittanica.

(24, 452-479)“Muscular Dystrophy.” Human Illnesses and Behavioral Health. 12 May 2008. Google.

<http://www.humanillnesses.com/original/Men-Os/Muscular-Dystrophy.html>“Muscular System, Sliding Filament Theory.” YouTube. 8 December 2007. 7 May 2008.

<http://youtube.com/watch?v=EdHzKYDxrKc>.“Muscular System, Sliding Filament Theory (2).” YouTube. 8 December 2007. 7 May 2008.

<http://youtube.com/watch?v=Vlchs4omFDM&feature=related>.“Neuromuscular Junction.” YouTube. 8 December 2007. 8 May 2008. <http://youtube.com/watch?

v=ZscXOvDgCmQ&feature=related>.“NINDS Muscular Dystrophy Information Page.” National Institute of Neurological Disorders and Stroke. 12

February 2008. National Institutes of Health. 6 May 2008. <http://www.ninds.nih.gov/disorders/md/md.htm>..

“Muscular System.” Human Anatomy Online. Intellimed National Corporation. 5 May 2008. <http://www.innerbody.com/image/musfov.html>

Ritchison, Gary. “BIO 301 Human Physiology.” Eastern Kentucky University. 1 May 2008. <http://people.eku.edu/ritchisong/RITCHISO//301notes3.htm>.

“Stages of a Muscle Contraction.” Anatomy and Physiology I. 12 May 2008. <http://www.octc.kctcs.edu/GCaplan/anat/Notes/API%20Notes%20J%20%20Muscle%20Contraction.htm>