Class Notes (839,081)
Canada (511,183)
BIOL 1410 (94)
Lecture

Muscular System

4 Pages
101 Views

Department
Biological Sciences
Course Code
BIOL 1410
Professor
Jennifer Mcleese

This preview shows page 1. Sign up to view the full 4 pages of the document.
Description
Muscular System  Skeletal muscle system  Primarily attached to bone  Movement by contracting giving off heat Skeletal Muscle  Cells called fibers Fascicle: Groups of fibers Muscle: Group of fascicles Fascia = CT Epimysium: Surrounds entire muscle Perimysium: Surrounds fascicles Endomysium: Surrounds each muscle fiber Tendons + Aponeurosis  Extensions of epi, peri and Endomysium  Anchors to bone (periosteum) cartilage, skin or fascia of other muscles Tendon: Rope like (Achilles) Aponeurosis: Sheet like (Galea aponeurotica) Skeletal Muscle Fiber Structure  Large multinucleate cells Sarcolemma: Cell membrane Sarcoplasm: Cytoplasm Myofibrils (intracellular structures): Hundreds-thousands, composed of sarcomeres Sarcomere  2 types of myofilaments/proteins Thin filaments: Made of actin (contraction) Tropomysin + Troponin regulate contraction Thick Filaments  Myosin for contraction  Attached to Z discs by titin (protein)  Has tail with 2 globular heads (head extends toward actin and forms crossbridge)  Myofilaments create dark and light bands/striations of the sarcomere  Banding pattern: A Band: Length of thick filaments - myosin + actin (with troponin and tropomyosin) H Zone: Lighter band at center of A Band myosin only I Band: Light=actin (with troponin and tropomyosin) and titin Z Disc: Proteins in center of I Band, actin and titin attach, connect sarcomeres M Line: Myosin tail connect to each other (center of sarcomere)  Sarcomeres join end to end at Z discs to form myofibrils Dark: A band where myofilaments overlap Light: No overlap, H zone myosin only, I band actin only T-tubules  Parts of sarcolemma that extend deep into fiber/cell  Directly encircle myofilaments of myofibrils t junction of A and I bands (2/sarc) Sarcoplasmic Reticulum (SR)  Smooth ER Triad: 2 enlarged areas of SR (terminal cisternae) and T-tubule
More Less
Unlock Document

Only page 1 are available for preview. Some parts have been intentionally blurred.

Unlock Document
You're Reading a Preview

Unlock to view full version

Unlock Document

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit