Presentation on theme: "Muscular System Unit F. Describe the structure of the muscles."— Presentation transcript:
Muscular System Unit F
Describe the structure of the muscles.
Nearly half our weight comes from muscle tissue. There are 650 different muscles in the human body. Muscles give us shape, posture, movement and form. Muscles produce most of our body heat.
Skeletal muscle Attached to bone. Striated (striped) appearance. Voluntary. Multinucleated muscle cell bundles (muscle cells = muscle fibers). Sarcolemma = cell membrane. Contract quickly, fatigue easily, can’t maintain contraction or long period of time.
Smooth muscle. Visceral (organ) muscle. Found in walls of digestive system, uterus and blood vessels. Cells small and spindle- shaped. Involuntary. Controlled by autonomic nervous system. Act slowly, do not tire easily, can remain contracted for long time.
Cardiac muscle. Found only in the heart. Striated and branched. Involuntary. Cells are fused- when one contracts, they all contract.
Analyze the function of the muscular system
When a muscle becomes shorter, thicker & causes movement, it is said to have? CONTRACTIBILITY
Excitability (irritability)- the ability to respond to certain stimuli by producing impulses.
Extensibility- the ability to be stretched. Elasticity- ability of muscle to return to its original length when relaxing.
As a muscle contracts, it pulls the insertion bone closer to the origin bone. Movement occurs at the joint between the origin and the insertion. Rule: A muscle’s insertion bone moves toward its origin bone. 1.Muscles move bones by pulling on them. 2. Groups of muscles usually contract to produce a single movement.
Motor unit- a motor neuron plus all the muscle fibers it stimulates.
Muscle fatigue- caused by the accumulation of lactic acid in the muscles.
Neuromuscular junction- the junction between the motor neuron’s fiber which transmits the impulse- and the muscle cell membrane.
Is a chemical neurotransmitter, diffuses across the synaptic cleft (carries impulse across synaptic cleft).
Identify characteristics & treatment of common muscle disorders.
Atrophy- wasting away of muscles. Massaging the muscle helps atrophy. Failing to exercise can make muscles weak, flaccid & cause them to atrophy.
Myalgia- muscle pain.
Tendonitis- inflammation of a tendon.
Strain- tear in the muscle resulting from excessive use. Bleeding inside the muscle can result in considerable amount of pain & swelling. Ice packs will help stop the bleeding and reduce swelling.
Sprain- stretched ligament
Hypertrophy- an increase in the size of the muscle cell. A person who lifts weights & overuses his muscles will enlarge their size.
Muscle spasm (cramp)- sustained contraction of the muscle, usually because of overuse. Severe calf pain at night is caused by muscle spasms.
Special circular muscles in openings of esophagus and stomach, stomach and small intestine, anus, urethra and mouth.
Major muscle that lies over the upper ribs?
Muscle that abducts the upper arm at the shoulder joint?
Medical name for the calf muscle?
Circular muscles in the openings between the esophagus & stomach are?
The main muscle in the lower back is the?
The main muscle of the upper back is the?
What muscle is found in the arm?
What muscle is considered VOLUNTARY?
Which kind of muscle forms the walls of the heart?
Joanie is experiencing oxygen dept. What has he been doing? Oxygen debt- after exercise, the amount of oxygen needed by the muscle to change lactic acid back to glucose.
If you want to improve your extensibility you should do what every morning?