Muscular System Chapter 6

explain 4 different forms of ATP production.

1. Stored ATP 2. Direct phosphorylation of ADP by creatine phosphate. 3. Aerobic Respiration 4. Anaerobic glycolysis and lactic acid formation.

a graded contraction can be produced in what two ways?

1. by changing the frequency of muscle stimulation. 2. by changing the number of muscle cells being stimulated at one time.

each muscle fiber is enclosed in a connective tissue sheath called _______ and several sheathed muscle fibers are wrapped by a fibrous membrane called _______ which form a __________

1. endomysium 2. perimysium 3. fascicle

what are the 4 functional properties of muscle cells?

1. excitability - ability to receive and respond a stimuli. 2. contractility - to shorten/contract. 3. extensibility - muscle cell to strengthen 4. elasticity - resting length after being rested.

what are the factors that contribute to muscle fatigue?

1. imbalances in ions (calcium and potassium). 2. oxygen deficit.

5 functions of the muscular system?

1. producing movement - skeletal muscles are responsible for mobility of the body as a whole, all locomotion. smooth and cardiac muscles work to circulate blood, maintain blood pressure. work to express emotions. 2. maintaining posture and body position - maintaining body posture. 3. stabilizing joints - muscles are found stabilizing joints. 4. generating heat - most responsible for generating heat. uses ATP. maintaining normal body temperature. 5. additional functions - skeletal muscles protect fragile internal organs by enclosure. smooth muscles form valves to regulate the passage of substances through the internal body opening, dialite and constrict the pupils of our eyes, and activate the arrector pili.

what are 3 ways all muscle cells are the same?

1. skeletal and smooth muscle cells are elongated. 2. the ability of muscle to shorten/contract. 3. has to do with terminology.

5 golden rules of skeletal muscle activity

1. with a few exceptions, all skeletal muscles cross at least one joint. 2. typically, the bulk of a skeletal muscle lies proximal to the joint cross. 3. all skeletal muscles have at least two attachments; the origin and insertion. 4. all skeletal muscles can only pull; they never push. 5. during contraction, a skeletal muscle insertion moves toward the origin.

how many layers does smooth muscle have and in which direction do they run?

2 layers. 1. running circularly. 2. longitudinally.

how many muscles are typically involved in body movements?

2 or more muscles acting together or against each other.

Cardiac, Smooth, and Skeletal:

Cardiac: Striated, involuntary. Smooth: No striations, involuntary. Skeletal: Striations, voluntary.

the most common and serious form of muscular dystrophy is?

Duchenne's Muscular Dystrophy.

oppostion

Using the saddle joint allows opposition of the thumb. fingers are touching each other.

how many muscle cells does one motor neuron stimulate?

a few to a hundred, depending on the muscle.

how does an individual acquire muscular dystrophy and what happens to the muscles?

a group of inherited muscle-destroying diseases that affect specific muscle-groups. The muscles enlarge because of fat and connective tissue deposit, and the muscles degenerate and atrophy.

what is oxygen deficit and what specifically is not being supplied with enough oxygen?

a person is not able to take in oxygen fast enough to keep the muscles supplied with all the oxygen they need when they are working vigorously.

the specific neurotransmitter that stimulated skeletal muscle cells is called?

acetycholin.

muscles that oppose or revers a movement is called?

antagonists.

what is the name for "sheetlike"

aponeuroses

what are fixators and ex:

are specialized synergists; they hold a bone still/stabilize the origin of a prime mover so all the tension can be used to move their insertion bone. ex: postural muscles tantalize vertebral column, muscles that anchor the scapulae to the thorax.

why would it be problematic if we did have conscious control of our smooth muscle?

be consistently thinking and would have no time to think.

what element is released into the axon terminal for action potential to take place?

calcium.

what do physicians say how anabolic steroids effect the body?

cause bloated faces; shriveled testes and infertility; liver damage and liver cancer; and changes in blood cholesterol; depression, delusions, and manic behavior involving jekyll-and-hyde personality swings and extreme violence (the so called roid rage).

neurotransmitter

chemical released by neurons that are used to move on a nerve impulse.

what type of tissue provides strength and support so muscles do not tear?

connective tissue.

how does aerobic exercises effect the whole body?

enhances neuromuscular coordination, makes the skeletal stronger, hyertophies of the heat.

what is the name for "overcoat"

epimysium

where are cardiac muscles found, are they striated, and are they under conscious control?

found in the heart; striated; involuntary.

what is the difference between a muscle that is fused and a muscle that is unfused?

fused - completely contracted unfused - what muscle is before is used.

what determines how forcefully a muscle contracts?

how many motor units are stimulated.

what shape do skeleton muscles resemble and how are they nucleated?

huge,cigar shaped; multinucleate; nucleus contains DNA-protein.

how can smooth and skeletal muscles be compared in an analogy?

if skeletal muscle is like a speedy wind up car that quickly runs down, then smooth muscle is like a steady,heavy-duty engine that lumbers along tirelessly.

who are typically diagnosed with Duchenne's muscular dystrophy and how are they visible affect?

in boys between the ages 2-7. active, normal children become clumsy and fall frequently as their muscles weaken.

what do athletes claim anabolic steroids do for them?

increase muscle mass and strength, oxygen-carrying capacity, of the blood, and aggressive behavior.

how is oxygen paid back when an individual is in oxygen deficit?

individuals breathe rapidly and deeply. continues until the muscles have received the amount of oxygen needed to get rid of accumulated latic acid and make ATP and creatine phosphate reserves.

what special junctions are cardiac muscle fibers joined with and what is their function?

intercalated discs. the heart activity to be closely coordinated, contracts as a fairly steady rate set by the heart's pacemaker, but can also be stimulated bu the nervous system.

what is specifically causing the generalized muscle weakness and what type of disease is myasthenia gravis consisted?

involves a shortage of acetylcholin receptors at neuromuscular junctions; autoimmune disease.

how can androstenedione effect the body?

men who take: elevated levels of the female estrogen. as well as testosterone (raising risk of feminizing effects, such as enlarged breasts). early puberty. stunted bone growth leading to shorter-than-normal adult height.

neuromusclar junction

motor neuron comes in close contact with skeletal muscle.

one neuron and all skeletal muscle cells it stimulated is called a?

motor unit.

rotation

movement of a bone around its longitudinal axis.

adduction

movement of a limb toward the body mid-line.

extension

movement that increases the angle/distance between 2 bones or parts of the body.

flexion

movement, in sagittal plane, that decreases the angle of the joint and brings 2 bones closer together.

inversion and eversion

movements of the foot inward and out-word. inversion=towards eversion=away.

supination and pronation

movements of the radius around the ulna. supination=turning backwards; pronation=turning forward.

abduction

moving a limb away from the mid-line, medium plane of the body.

in skeletal muscles, the "all-or-none" law of muscle physiology applies to the?

muscle cell, not the whole muscle.

what is the difference between a normal muscle contraction and a muscle twitch?

muscle contraction - muscles can't relax; rapid; constant. muscle twitch - relaxing in between; off and on.

what is muscle tone and what happens to muscle when it is not properly stimulated?

muscles are partially stimulated and ready for action; its the result if different motor units, which are scattered though the muscle, being stimulated by the nervous system in a systematic way.

what rare disease can affect muscles during adulthood and what are the symptoms?

mysathenia gravis; drooping of the upper eyelids, difficulty in swallowing and talking, generalized muscle weakness and fatigability.

to contract, skeletal muscle cells must be stimulated by?

nerve impulses.

do smooth muscles have striations and are they under conscious control and where are they found?

no striations; involuntary; found mainly in the walls of hollow visceral organs such as the stomach, urinary bladder and respiratory passages; are spindled shape, having a single nucleus.

do muscles always shorten when they contract?

no.

is there movement, caused by a contracting muscle, in an isometric contraction and examples?

no. ex: pushing against a wall with bent elbows.

how are muscles arranged?

one muscle (or groups) can do, other muscles can reverse. groups of muscles that produce opposite movements lie on opposite sides of a joint.

what is the essential percent of young men who have tried steroids?

one out of 10 men.

where is the origin and insertion of a muscle?

origin - attached to the immoveable/less moveable bone. insertion - attached to the moveable bone.

a muscle, which has the major responsibility for causing a particular movement, is called?

prime mover.

how does Dechenne's muscular dystrophy progress and what causes individuals with this disorder to die?

progress from the extremities upward, and finally affecting the head and chest muscles.

what is the general function of the smooth muscle?

propels substances along a definite tract/pathway within the body. best described as visceral, nonstriated, and involuntary. "house keeping"

what are the functions of tendons?

providing durability and conserving space. because so small in size, can pass over a joint.

circumduction

proximal ends of limb is stationary and its distal end moves in a circle.

what causes death in individuals with myasthenia gravis?

result of the inability of the respiratory muscles to function (respiratory failure).

what usually comes to mind when someone hears the word muscle? but where else in the body are muscles found?

rippling muscles of professional boxes or weight lifters. muscle is also dominant tissue in the heart and in the walls of other hollow organs of the body.

what are three types of muscle and what do they differ in?

skeletal, smooth, and cardiac. differ in their cell structure, body location, and how they are stimulated to contract.

because skeletal muscles have obvious stripes what are they consisted of?

straited; voluntary. ex: blinking/breathing.

axon

structure of a neuron that carried a nerve impulse away from the cell.

what is the name for "cordlike"

tendon

synaptic cleft

the fluid - filled space as a synapse between neurons.

what unique characteristic do muscles have that sets it apart from any other body tissue? what ability do muscles have because of this characteristic?

the function of muscle is contraction/shortening. muscles are responsible for essentially all body movement and can be viewed as the machines of the body.

what is true muscle fatigue and what type of activity is it common in?

the muscle quits entirely; marathon runners; because we feel fatigued long before it happens and we simply slow down/stop our activity.

how does resistance exercise differ and how does it affect your muscles differently?

the muscles against some immoveable objects. resistance types of weight-lifting muscle cells increase in size, not number.

what are synergists and example?

the prime movers producing the same movement or by reducing undersirabe movements. ex: wrist and finger joints.

what did pharmaceutical companies use anabolic steroids for?

to treat certain muscle - diseases, anemia, and muscle atrophy in patients immobilized after surgery.

dorsiflexion and plantar flexion

up and down movements of the foot and ankle. plantar=point toes' dorsiflextion=lifting foot.

what are anabolic steroids?

variants of testosterons.

what causes muscle fatigue and what is it?

when it is unable to contract even though it is still being stimulated. cause-when strainly working muscle too much.

axon terminal

where axon meets and organ/neuron.

is there movement, caused by a contracting muscles, in an isotonic contraction and examples?

yes. ex: bending of the knee, rotating the arms, and smiling.