UNC-Chapel Hill EXSS 276 - EXAM 4 STUDY GUIDE (15 pages)

Unformatted text preview:

EXAM 4 STUDY GUIDE Chapter 10 Muscle Tissue Skeletal Muscle Muscle Facts 40 50 of body weight is muscle muscle gain is 2 times faster than muscle loss smallest muscles are in ear holding it ear drum together largest muscle gluteus maximus keeps us upright strongest muscles glutes massester tongue muscles can only pull no pushing it contracts shortens born with all muscle fibres you will ever have skeletal muscle contractions are voluntary except when cold somatic skeletal voluntary heart muscle never gets tired 3billion beats in lifetime Somatic Motor Neuron Includes both sensory to CNS and motor neuron to skeletal muscle Neurons that stimulate skeletal muscle fibers Produce both reflexive and voluntary movements ACh Only one pathway Effect of motor neuron is always excitation Communication between motor neuron and a muscle fiber occurs at synapse If motor neurons cease to stimulate a muscle paralyzed limp muscle that has no muscle tone Types of Muscles Skeletal muscle tissue Striated Multinucleated Voluntary Because it can be made to contract or relax by conscious control Cardiac Striated Uninucleated Involuntary Heart wall pumps blood to all parts of body Natural pacemaker that initiates each contraction authorhythmicity Smooth Nonstriated Uninucleated Involuntary Located in the walls of hollow internal structures Blood vessels airways and most organs in abdominopelvic cavity Function motion Muscle Function 1 Produce body movements 2 Stabilizing body positions 3 Storing and moving substances within the body a Sphincters smooth muscle help prevent the outflow of the contents of a hollow organ ex temporary storage of food in the stomach or urine in the urinary bladder b Cardiac muscle contractions of the heart pump blood through blood vessels of the body c Smooth muscle contractions also move food and substances i Bile and enzymes through the GI tract push gametes sperm and oocytes through the passageways of the reproductive system and propel urine through the