Human Anatomy And Physiology

Front 1

What is the root word that means muscle?

Back 1

Myo

Front 2

What are the 3 types of muscles?

Back 2

Skeletal
Cardiac
Smooth

Front 3

Skeletal

Back 3

~attach to & cover the bony skeleton.
~Striated
~Voluntary
~Responsible for overall body mobility

Front 4

Cardiac

Back 4

~only in the heart
~Striated
~Involuntary
~Pumps blood in the body

Front 5

Smooth

Back 5

~found in the walls of hollow visceral organs, such as the stomach, urinary bladder, & respiratory passages.
~Not striated
~Involuntary
~Forces fluids & other substances through internal body channels

Front 6

Special Characteristics of Muscle Tissue

Back 6

~Excitability
ability to receive & respond to a stimulus
~Contractility
ability to shorten forcibly when adequately stimulated
~Extenibility
ability to extend or stretch
~Elasticity
ability to recoil & resume its resting length after stretching

Front 7

Muscle Functions

Back 7

~Producing movement
~Maintaining posture & body positioin
~Stabilizing joints
~Generating heat

Front 8

Is muscle an organ?

Back 8

Yes

Front 9

Epimysium

Back 9

......

Front 10

Perimysium

Back 10

~ Around the muscle
~ Fascicles
~ Perimysium surrounds each fascicle

Front 11

Endomysium

Back 11

~ Within the muscle
~ Wispy sheath of connective tissue that surrounds each individual muscle fiber
~ Consists of fine areolar tissue

Front 12

A muscle fiber is another name for myofibril.

Back 12

........

Front 13

What are muscle attachments?

Back 13

~ Direct (fleshy attachment)
the epimysium of the muscle is fused to the periosteum of a bone or perichondrium of a cartilage
~ Indirect
the muscle's connective tissue wrapping extend beyond the muscle either as a ropelike tendon or as a sheetlike aponeurosis.

Front 14

What is the difference between origin and insertion?

Back 14

Origin is the attachment point that doesn't move

Insertion is the attachment point that does move

Front 15

What is the difference between a direct or indirect attachment?

Back 15

In direct (fleshy) attachment the epimysium of the muscle is fused to the periosteum of a bone or perichondrium of a cartilage.

Indirect attachments the muscle's connective tissue wrappings extend beyond the muscle either as a ropelike tendon or as a sheetlike aponeurosis.

Front 16

Indirect attachments are much more common because of their durability and small size.

Back 16

...................

Front 17

What is fascia and aponeurosis?

Back 17

Aponeurosis: fibrous or membranous sheet connecting a muscle and the part it moves

Fascia: layers of fibrous tissue covering and seperating muscle

Front 18

Cross Bridge Cycle

Back 18

1. Cross Bridge Formation
~ Energized myosin head attaches to an actin myofilament, forming a cross bridge.
2. The power (working) stroke.
~ ADP and Pi are released and the myosin head pivots and bends, changing to its bent low-energy state. As a result it pulls the actin lament
toward the M line.
3.Cross bridge detachment.
~ After ATP attaches to myosin, the link between myosin and actin weakens, and the myosin head detaches (the cross bridge “breaks”).
4. Cocking of the myosin head
~ As ATP is hydrolyzed to ADP and Pi , the myosin head returns to its prestroke high-energy, or “cocked,” position. *

Front 19

Events at the Neuromuscular Junction

Back 19

1. Action potential arrives at axon terminal of motor neuron
2. Voltage-gated calcium channels open. Calcium enters the axon terminal moving down its electochemical gradient.
3. Ca2+ entry causes ACh (aneurotransmitter) to be released by exocytosis.
4. ACh diffuses across the synaptic cleft and binds to its receptors on the sarcolemma.
5. ACh binding opens ion channels in the receptors that allow simultaneous passage of Na+ into the muscle fiber and K+ out of the muscle fiber. More Na+ ions enter than K+ ions exit, which produces a local change in the membrane potential called the end plate potential.
6.ACh effects are terminated by its breakdown in the synaptic cleft by acetylcholinesterase and diffusion away from the junction.

Front 20

Excitation-Contraction Coupling

Back 20

1. The action potential propogates along the sarcolemma and down the T tubules.
2. Calcium ions are released. Transmission of the AP along the T tubules of the triads causes the voltage-sensitive tubule proteins to change shape. This shape change opens the Ca2+ release channels in the terminal cisterns of the sarcoplasmic reticulum (SR), allowing Ca2+ to flow into the cytosol.
3. Calcium binds to troponin and removes the blocking action of tropomyosin. When Ca2+ binds, troponin changes shape, exposing binding sites for myosin (active sites) on the thin laments.
4. Contraction begins Myosin binding to actin forms cross bridges and contraction (cross bridge cycling) begins. At this point, E-C coupling is over.

Front 21

What are the parts of the muscle cell?

Back 21

Fascicle
muscle fiber
sarcolemma
nucleus
sarcoplasm
myofibril
filaments

Front 22

glycosome

Back 22

granules of stored glycogen that provide glucose during muscle cell activity

Front 23

myoglobin

Back 23

a red pigment that stores oxygen

Front 24

Myofibrils

Back 24

rodlike bundle of contractile filaments found in muscle fibers

they appear striated because of the alternating dark and light bands

Front 25

Sarcomere

Back 25