HLSC 1200U Lecture Notes - Lecture 17: Intercalated Disc, Endoplasmic Reticulum, Cardiac Muscle
Document Summary
Thread like cells with many cross striations and many nuclei per cell. Elongated narrow cells, no cross striations, one nucleus per cell. Branching cells with intercalated disks (formed by abutment of plasma membranes of two cells) Similarities to skeletal muscle: contain parallel myofibrils, t-tubules (part of pm), and sr. Can lead to fatigue due to depleted atp muscle gets tired. Contracts rhythmically and continuously to maintain constant and blood flow. Similarities to skeletal muscles: contain thin and thick filaments. Excitability (irritability: are able to stimulated and respond to regulatory signals (neve) Contractility: able to contract (shortening), produces body movement. Extensibility: able to extend (stretch), allow muscle to return to normal resting relaxed length. Function: pulls on bones and muscles to move the body and its parts. Anatomy midterm review #2: maintain homeostasis, heat is part of waste products when energy is produced. Posture: continue partial contraction of some skeletal muscles when sit, stand, or stay still.
