Ch 8 Intro To A&p

Front 1

musculoskeletal system

Back 1

The bones, muscles, and joints together form an integrated system called the musculoskeletal system.

Front 2

myology

Back 2

The scientific study of muscles is known as myology

Front 3

orthopedics

Back 3

The branch of medical science concerned with the prevention or correction of disorders of the musculoskeletal system is called orthopedics

Front 4

Three muscle types

Back 4

Skeletal
Cardiac
Smooth

Front 5

Skeletal Muscle

Back 5

muscle tissue is attached to bones and moves parts of the skeleton.

Striated
Voluntary
Many nuclei
Nerve control
No discs or gap junctions

Front 6

Cardiac Muscle

Back 6

Cardiac muscle tissue, found only in the heart, forms the bulk of the heart wall

Striated
Intermediate speed
Involuntary
Single nuclei
spontaneously beat by nerve control
intercalated discs & gap junctions

Front 7

Smooth Muscle

Back 7

located in the walls of hollow internal structures

such as blood vessels, airways, the stomach, and the intestines

Nonstriated
Slow
Involuntary
Single nuclei
nerve and hormone control
intercalated discs & gap junctions

Front 8

4 basic muscle functions

Back 8

Producing body movements

Stabilizing body posture

Stabilizes Joints

Producing heat

Front 9

Muscle connective tissue types

Back 9

Epimysium - covering entire muscle

perimysium - covering fascicles

endomysium covering individual muscles

Front 10

skeletal muscle overview

Back 10

Tendon - T for "Tissue" to "Tissue"
attached to bone by Aponeurosis
(ligament attaches bone to bone)

-fascia (bundle of muscle fibers-10 to 100)
skeletal muscle
-epimysium binds many fascicles together
-perimysium - surrounds a bundle of muscle fibers
-endomysium - surrounds each individual muscle fiber
muscle fiber

Front 11

Sarcomere

Sarcolemma

Sarcoplasmic reticulum

Back 11

THE BASIC (OR FUNCTIONAL) UNIT OF MUSCLE CONTRACTION.

A sarcomere is the repeating unit of filaments inside a muscle cell (myofibril)

Sarcolemma -plasma membrane of a muscle cell

Sarcoplasmic reticulum - SER that stores calcium in muscle

Front 12

What proteins are present in the A band and in the I band?

Back 12

A band:
MYOSIN

I band:
actin
troponin
tropomyosin.

Front 13

Myofibrils

Back 13

Bundles of tubelike proteins that make up a muscle fiber.

The myofibril is the cytoskeleton of the muscle cell

Myofibrils are composed of myofilaments

Front 14

myofilaments

Back 14

ACTIN - thin myofilament of a sarcomere

1) Tropomyosin covers the binding sites on Actin
2) Troponin bound with calcium causes sliding of tropomyosin

MYOSIN - thick myofilament of a sarcomere (Paddle like heads)

bind with ACTIN during muscle contractions

Front 15

Muscle contraction

Sliding filament theory

Back 15

sliding actin and myosin filaments

1.Upon neural stimulation, Calcium is released from the Sarcoplasmic reticulum.

2. Calcium binds with troponin - tropomyosin strand shifts, exposing binding sites on actin.

3.Myosin binds to actin.

4.ATP provides the energy - myosin heads to pivot
(causes the actin filament to slide and the muscle to “shorten”)

5. ATP energy releases actin from myosin and reestablish the “cocked-and-ready position

Front 16

Neuromuscular junction

Back 16

A synapse between the axon terminals of a somatic motor neuron and the sarcolemma of a muscle fiber (cell).

Front 17

ATP in muscle contractions

Back 17

Splitting phosphate off ATP to make diphosphate releases energy for contraction

(1) for the sliding of filaments - a bending movement (or cocking of the myosin heads.)

(2) for the separation of actin and myosin which relaxes the muscle

(3) ATP runs down after death - muscle goes into rigor mortis

Front 18

Motor unit

Back 18

A motor neuron and all of the muscle fibers it stimulates form a motor unit.

single motor unit may
include as few as 10 or as many as 2000 muscle fibers

Front 19

Motor neuron sequence

Back 19

motor neuron excites a skeletal muscle fiber in the following way

Nerve impulse at the synaptic end bulbs triggers

Release of acetylcholine ACh (neurotransmitter)

Activation of ACh receptors

Generation of muscle action potential

Breakdown of ACh. Effect of ACh lasts only briefly because of breakdown by enzyme acetylcholinesterase

Front 20

Calcium in the muscle contraction

Back 20

release of calcium from the sarcoplasmic reticulum allows actin to bind with myosin by moving troponin and tropomyosin

Front 21

contraction cycle

Back 21

Splitting ATP

Forming crossbridges

Power stroke

Binding ATP and detaching

Front 22

What causes crossbridges to detach from actin?

Back 22

Binding of ATP to the myosin heads detaches them from actin.

Front 23

Muscle tone

Back 23

Continual involuntary activation of a small number of motor units produces muscle tone, which is
essential for maintaining posture.

Front 24

Properties of Muscle Tissue

Back 24

Contractility - shorten

Extensibility - stretch

Elasticity - return to original shape

Excitability respond to nerve stimilus

Front 25

Synaptic end bulb

Back 25

the terminal end of an axon that divides into bulb shaped structures at a junction.

Front 26

Synaptic cleft

Back 26

Space in between the synaptic end bulb and the muscle fiber

Front 27

Motor end plate

Back 27

Part of the muscle cell that receives and recognizes a nerve impulse.

Front 28

Acetylcholine

Back 28

Neurotransmitter that is released from a synaptic end bulb during nerve stimulation. It forms a bridge at the synaptic cleft that allows the nerve impulse to jump across the cleft to the muscle fiber.

Front 29

Acetylcholinesterase

Back 29

Enzyme (produced at the NMJ) that breaks down acetylcholine, allows for the reabsorption of calcium ions, and terminates the muscle contraction

Front 30

Direct Phosphorylation

Back 30

Supplies the energy for the first several seconds of physical activity (Ex: Lifting a heavy weight or object)

cleaving of a phosphate off of adenosine triphosphate (ATP), leaving adenosine diphosphate (ADP)

ADP + CP => ATP + C

Front 31

Anaerobic glycolysis

Back 31

Oxygen intake is insufficient to meet the demands of the working skeletal muscles (such as in exhaustive exercise)

Glucose is broken down to pyruvic acid, then converted to lactic acid, which decreases blood pH and leads to muscle fatigue

Anaerobic glycolysis yields only 2 ATP per molecule of glucose

Front 32

Aerobic Respiration

Back 32

Aerobic respiration is the most efficient method of energy production, yielding 36 ATP per molecule of glucose

during low-to-moderate physical activity where oxygen intake is sufficient to meet the demands of the working muscles

It involves a series of metabolic pathways within the mitochondria.

Front 33

Myoglobin

Back 33

– Protein that stores oxygen within the muscle fiber

Front 34

Glycogen

Back 34

-- stored form of glucose within the muscles

Front 35

Oxygen debt

Back 35

-- refers to the elevated amount of oxygen that is required by the body following exercise or exertion to restore the body to its preexercise conditon

Front 36

Lactic acid

Back 36

-- is produced when a person is unable to take in enough oxygen to meet the demands of the body's working tissues

When this occurs exercise is referred to as anaerobic.

Lactic acid is produced which slows the production of ATP. As a result and muscle fatigue occurs

Front 37

Agonist

versus

Antagonist

Back 37

Agonist -- prime mover. Muscle that is directly responsible for effecting a movement.


Antagonist -- Muscle that is on the opposite side of the joint from the prime mover. Must relax in order for the agonist to contract

Front 38

Origin and Insertion

Back 38

Origin -- refers to the more fixed and less movable attachment of a muscle

Insertion -- refers to the less fixed and more moveable attachment of a muscle

Front 39

Atrophy

Back 39

Refers to the reduction in size of an organ or cell due to disuse or disease.

Front 40

Hypertrophy

Back 40

-- refers to an increase in size of an organ or cell. May be normal (as in growth in size of muscle cells due to exercise) or abnormal (as in enlargement of the heart due to being overworked

Front 41

Flexion

Extension

Hyperextension

Abduction

Adduction

Back 41

Flexion – Refers to the decreasing angle of a joint (as in bending the elbow)

Extension—refers to the increasing angle of a joint (as in straightening the elbow)

Hyperextension – refers to the extreme extension of a joint

Abduction – movement of a limb away from the midline.

Adduction – movement of a limb towards the midline.

Front 42

Rotation

Circumduction

Dorsiflexion

Plantar Flexion

Back 42

Rotation—Circular movement of a joint around its axis.

Circumduction – circular movement of a limb at its far (distal) end.

Dorsiflexion – Flexing the foot. Bringing the toe up higher than the heel.

Plantar Flexion – Pointing the toes. Toes are lower than the heels

Front 43

Inversion

Eversion

Supination

Pronation

Back 43

Inversion – turning the sole of the foot inward (medially)

Eversion – turning the sole of the foot outward (laterally)

Supination – Act of rotating the arm so that the palm is turned upward or forward.

Pronation – Act of rotating the arm so that the palm is facing downward