Physiology 2130 Lecture Notes - Lecture 5: T-Tubule, Endoplasmic Reticulum, Sarcolemma
12 Jun 2016
School
Department
Course
Professor
Document Summary
Muscles use chemical energy from the breakdown and metabolism of food to perform work. 3 kinds of muscle cells: skeletal muscles: voluntary motion (what this module focuses on, smooth muscles: walls of blood vessels, airways, various ducts, urinary bladder, uterus, and digestive tract, cardiac muscles: found in heart. Body contains over 600 muscles that have 3 functions: movement (what this module focuses on, heat production, body support and posture. Whole muscles are made up of bundles of fascicule: fasciculi are surrounded by a white connective tissue called perimysium. Each fascicle is made up of groups of muscle cells or fibers: have more than 1 nucleus, surrounded by sarcolemma (muscle cell membrane) over which action potential is transmitted. Sarcolemma has small tube-like projections called transverse (t) tubules. These tubules conduct the action potential deep into the cell where contractile proteins are located. Each muscle cell contains many bundles of myofibrils. Sr tha is close to the t tubule.
