Your SlideShare is downloading. ×
0
The Muscular System
The Muscular System
The Muscular System
The Muscular System
The Muscular System
The Muscular System
The Muscular System
The Muscular System
The Muscular System
The Muscular System
The Muscular System
The Muscular System
The Muscular System
The Muscular System
The Muscular System
The Muscular System
The Muscular System
The Muscular System
The Muscular System
The Muscular System
The Muscular System
The Muscular System
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×
Saving this for later? Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime – even offline.
Text the download link to your phone
Standard text messaging rates apply

The Muscular System

485

Published on

0 Comments
1 Like
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total Views
485
On Slideshare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
0
Comments
0
Likes
1
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide

Transcript

  • 1. T- 1-855-694-8886Email- info@iTutor.comBy iTutor.com
  • 2.  The muscular system is a complexcollection of tissues, each with a differentpurpose. Understanding the components of themuscular system, including the varioustypes of connective tissues, is a good wayto understand how bodies and physicalmovement work.© iTutor. 2000-2013. All Rights Reserved
  • 3.  Body movement (Locomotion) Maintenance of posture Respiration– Diaphragm and intercostal contractions Communication (Verbal and Facial) Constriction of organs and vessels– Peristalsis of intestinal tract– Vasoconstriction of b.v. and other structures (pupils) Heart beat Production of body heat (Thermogenesis)© iTutor. 2000-2013. All Rights Reserved
  • 4.  Excitability: capacity of muscle to respond to astimulus. Contractility: ability of a muscle to shorten andgenerate pulling force. Extensibility: muscle can be stretched back to itsoriginal length. Elasticity: ability of muscle to recoil to original restinglength after stretched.© iTutor. 2000-2013. All Rights Reserved
  • 5. © iTutor. 2000-2013. All Rights Reserved
  • 6.  Skeletal– Attached to bones– Makes up 40% of body weight– Responsible for locomotion, facial expressions, posture, respiratorymovements, other types of body movement– Voluntary in action; controlled by somatic motor neurons Smooth– In the walls of hollow organs, blood vessels, eye, glands, uterus, skin– Some functions: propel urine, mix food in digestive tract,dilating/constricting pupils, regulating blood flow,– In some locations, auto rhythmic– Controlled involuntarily by endocrine and autonomic nervous systems Cardiac– Heart: major source of movement of blood– Auto rhythmic– Controlled involuntarily by endocrine and autonomic nervous systems© iTutor. 2000-2013. All Rights Reserved
  • 7. © iTutor. 2000-2013. All Rights Reserved
  • 8. Muscle attachments– Most skeletal muscles run fromone bone to another.– One bone will move – otherbone remains fixed.Origin – less movableattachment.Insertion – more movableattachment.© iTutor. 2000-2013. All Rights Reserved
  • 9. Muscle attachments (continued)– Muscles attach to origins and insertions byconnective tissueFleshy attachments – connective tissue fibers areshort.Indirect attachments – connective tissue forms atendon or aponeurosis.– Bone markings present where tendons meetbonesTubercles, trochanters, and crests.© iTutor. 2000-2013. All Rights Reserved
  • 10.  Composed of muscle cells (fibers), connective tissue, bloodvessels, nerves. Fibers are long, cylindrical, and multinucleated. Tend to be smaller diameter in small muscles and larger inlarge muscles. 1 mm- 4 cm in length. Develop from myoblasts; numbers remain constant. Striated appearance. Nuclei are peripherally located.© iTutor. 2000-2013. All Rights Reserved
  • 11. © iTutor. 2000-2013. All Rights Reserved
  • 12.  SR is an elaborate, smooth endoplasmic reticulum– runs longitudinally and surrounds each myofibril– Form chambers called terminal cisternae on either side of the T-tubules A single T-tubule and the 2 terminal cisternae form a triad SR stores Ca++ when muscle not contracting– When stimulated, calcium released into sarcoplasm– SR membrane has Ca++ pumps that function to pump Ca++ out ofthe sarcoplasm back into the SR after contraction© iTutor. 2000-2013. All Rights Reserved
  • 13. © iTutor. 2000-2013. All Rights Reserved
  • 14.  Many elongated myosin molecules shaped like golf clubs. Single filament contains roughly 300 myosin molecules. Molecule consists of two heavy myosin molecules wound togetherto form a rod portion lying parallel to the myosin myofilament andtwo heads that extend laterally. Myosin heads1. Can bind to active sites on the actins molecules to form cross-bridges.(Actin binding site)2. Attached to the rod portion by a hinge region that can bend andstraighten during contraction.3. Have ATPase activity: activity that breaks down adenosinetriphosphate (ATP), releasing energy. Part of the energy is used tobend the hinge region of the myosin molecule during contraction© iTutor. 2000-2013. All Rights Reserved
  • 15. Tropomyosin Tropoin ActinMyosin© iTutor. 2000-2013. All Rights Reserved
  • 16.  Thin Filament: composed of 3 major proteins1. F (fibrous) actin2. Tropomyosin3. Troponin Two strands of fibrous (F) actin form a double helix extending thelength of the myofilament; attached at either end at sarcomere.– Composed of G actin monomers each of which has a myosin-binding site (see yellow dot)– Actin site can bind myosin during muscle contraction. Tropomyosin: an elongated protein winds along the groove of the Factin double helix. Troponin is composed of three subunits:– Tn-A : binds to actin– Tn-T :binds to tropomyosin,– Tn-C :binds to calcium ions.© iTutor. 2000-2013. All Rights Reserved
  • 17.  Cells are not striated Fibers smaller than those in skeletal muscle Spindle-shaped; single, central nucleus More actin than myosin No sarcomeres– Not arranged as symmetrically as in skeletal muscle,thus NO striations. Caveolae: indentations in sarcolemma;– May act like T tubules Dense bodies instead of Z disks– Have noncontractile intermediate filaments© iTutor. 2000-2013. All Rights Reserved
  • 18. © iTutor. 2000-2013. All Rights Reserved
  • 19. Grouped into sheets in walls of hollow organs. Longitudinal layer – muscle fibers run parallel to organ’slong axis. Circular layer – muscle fibers run around circumference ofthe organ. Both layers participate in peristalsis.© iTutor. 2000-2013. All Rights Reserved
  • 20.  Found only in heart where it forms a thick layer calledthe myocardium. Striated fibers that branch Each cell usually has one centrally-located nucleus Fibers joined by intercalated disks– IDs are composites of desmosomes and gap junctions– Allow excitation in one fiber to spread quickly to adjoiningfibers Under control of the ANS (involuntary) and endocrinesystem (hormones) Some cells are autorhythmic– Fibers spontaneously contract (aka Pacemaker cells)© iTutor. 2000-2013. All Rights Reserved
  • 21. © iTutor. 2000-2013. All Rights Reserved
  • 22. The endCall us for moreInformation:www.iTutor.com1-855-694-8886Visit

×