BIOL 2001 Lecture Notes - Lecture 4: Autonomic Nervous System, Stay Apparatus, Somatic Nervous System
Document Summary
Skeletal muscles: movement, ta(cid:374)di(cid:374)g (cid:862)stay apparatus(cid:863) i(cid:374) horses, heat generation. Smooth: involuntary, controlled by the autonomic nervous system, cells have no striations; 1 nucleus per cell, spindle shaped cells. Cardiac: involuntary, controlled by the autonomic nervous system, each muscle cell constantly contracts & relaxes (beats, cells have striations; 1 nucleus per cell, cells split and branch. Skeletal: voluntary, controlled by somatic nervous system, cells have striations; multiple nuclei, cells appear more dense than cardiac. Myocyte/myofiber each muscle cell or muscle fibre. Each myocyte is made up of tiny, thread-like myofibrils. Fascia thin sheets of connective tissue separating each muscle. Tendons dense connective tissue attaching muscle to bone. Muscle can only do two things: contract or relax, contracting muscles often cause joints to flex. Muscles contract in response to a nerve impulse and shorten to produce a muscle action. Nerve impulse contract shorten muscle action (flex a joint or extend a joint) Without nervous stimulation muscles will atrophy (waste away)
