Chapter10Outline

.docx

School

Guilford Technical Community College *

*We aren’t endorsed by this school

Course

MISC

Subject

Anatomy

Date

Oct 30, 2023

Type

docx

Pages

Uploaded by MinisterTurtleMaster400

Chapter 10: Muscle Tissue I. Skeletal Muscle A. Functions - skeletal movement, posture, support B. Anatomy Figure 10-1 1. Connective Tissue a. Epimysium - connective tissue surrounds muscle b. Perimysium - innervated/ vascularized connective tissue divides muscle into fascicles (bundles) c. Endomysium -connective tissue surrounds individual skeletal muscle cells (fibers) 2. Skeletal Muscle Fiber Figure 10-2, 10-3 - large, multinucleated, striated cell with sarcolemma (membrane) and sarcoplasm (cytoplasm) - transverse tubules perpendicular to membrane extend into cytoplasm -cylindrical myofibrils contain thin (actin) and thick (myosin) filaments -sarcoplasmic reticulum with stored Ca2+ 3. Sarcomere Figure 10-4 - smallest repeating functional unit of a myofibril a. A Band -contains overlapping thick and thin filaments i. M Line - darker region where adjacent thick filaments are bound/stabilized ii. H Band - lighter region on each side of M line with only thick filaments iii. Zones of Overlap -thin/thick filaments overlap b. I Band - contains thin filaments (no thick) i . Z Line -boundary between two sarcomeres -titin binds thick filaments 4. Thin Filaments filamentous actin (detail) Figure 10-7 a. Actin (F actin) -twisted strand of globular proteins (G actin) with active sites for myosin b. Nebulin

- thin long strand holds actin stable c. Tropomyosin -double stranded protein wraps actin and covers myosin blinding sites d. Troponin - globular protein with Ca2, tropomyosin, and actin binding sites 5. Thick Filaments (detail) Figure 10-7 a. Myosin - proteins twist around one another -creates tail bound to other myosin proteins and head which binds actin b. Titin -bind thick filaments to z line to prevent overstretching C. Skeletal Muscle Contraction 1. Sliding Filament Theory Figure 10-8 - during contraction, thin filaments slide along thick filaments so each sarcomere shortens (myofibrils shorten) 2. Neuromuscular Junction Figure 10-10 -axon branch connects/communicates with skeletal muscle fiber a. Axon Terminal -axon end that releases neurotransmitter (acetylcholine) into synaptic cleft ( space) b. Motor End Plate - sarcolemma with receptors that bind ACh (signals Na + uptake) and acetylcholinesterase (protein) (digest ACh) D. Contraction Cycle Figures 10-9, 10-10, 10-11, 10-12 1. Rest -myosin head energized (ATP binds/splits) and cocked 2. Ca 2+ Release -Na+ uptake following neural signal causes release of Ca2 from SR -CA2 binds troponin, exposes active sites on thin filaments 3. Contraction - cross bridges form between cocked myosin head and active sites on actin -power stroke occurs as myosin head pivots -cross bridge detaches, myosin head recocks (after ATP binds/splits) and new power stroke accrues 4. Relaxation Figures 10-10, 10-13 - acetylcholinesterase digests ACh

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version