1 / 9

____ Chapter 49 ~ Sensory and Motor Mechanisms

____ Chapter 49 ~ Sensory and Motor Mechanisms. ( Just focusing on motor mechanisms ) Motor Mechanisms. Vertebrate Skeletal Muscle. Contract/relax: antagonistic pairs w/skeleton Muscles: bundle of…. Muscle fibers: single cell w/ many nuclei consisting of….

luisbarnes
Télécharger la présentation

____ Chapter 49 ~ Sensory and Motor Mechanisms

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ____ Chapter 49 ~ Sensory and Motor Mechanisms • (Just focusing on motor mechanisms) • Motor Mechanisms

  2. Vertebrate Skeletal Muscle • Contract/relax: antagonistic pairs w/skeleton • Muscles: bundle of…. • Muscle fibers: single cell w/ many nuclei consisting of…. • Myofibrils: longitudinal bundles composed of…. • Myofilaments: • Thin~ 2 strands of actin protein and one strand of a regulatory protein • Thick~ staggerd arrays of myosin protein http://entochem.tamu.edu/MuscleStrucContractswf/index.html

  3. Vertebrate Skeletal Muscle • Sarcomere: repeating unit of muscle tissue, composed of…. • Z lines~sarcomere border • I band~only actin protein • A band~actin & myosin protein overlap • H zone~central sarcomere; only myosin http://www.sumanasinc.com/webcontent/animations/content/muscle.html

  4. Sliding-filament model • Theory of muscle contraction • Sarcomere length reduced • Z line length becomes shorter • Actin and myosin slide past each other (overlap increases) http://www.blackwellpublishing.com/matthews/myosin.html

  5. Actin-myosin interaction • 1- Myosin head hydrolyzes ATP to ADP and inorganic phosphate (Pi); termed the “high energy configuration” • 2- Myosin head binds to actin; termed a “cross bridge” • 3- Releasing ADP and (Pi), myosin relaxes sliding actin; “low energy configuration” • 4- Binding of new ATP releases myosin head • Creatine phosphate~ supplier of phosphate to ADP

  6. Muscle contraction regulation, I • Relaxation: tropomyosin blocks myosin binding sites on actin • Contraction: calcium binds to toponin complex; tropomyosin changes shape, exposing myosin binding sites http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter10/animation__action_potentials_and_muscle_contraction.html

  7. Muscle contraction regulation, II • Calcium (Ca+)~ concentration regulated by the…. • Sarcoplasmic reticulum~ a specialized endoplasmic reticulum • Stimulated by action potential in a motor neuron • T (transverse) tubules~ travel channels in plasma membrane for action potential • Ca+ then binds to troponin

  8. Materials Muscle model/chicken wing • The following is needed for each student: 4 red/black licorice strands (the thick twisted type) • 10 red licorice strands (the thin type) • a paper towel; toothpicks • one raw chicken wing • one dissection tray; dissection tools, gloves.

  9. Muscle cell simulation: contraction/relaxation • Procedure: • Two thin pieces of licorice intertwined to represent thin actin filaments • Thick licorice to represent thick myosin fibers • Toothpicks represent the Z lines where thin filaments attach

More Related