• Movement
• generates heat (maintains body temp)
• maintains posture (stability)
• closes body openings (closing of bladder so it doesn't leak)

• Always associated with bone
• attached to bone, primary job is to move bone

surrounds hollow organs (ie stomach, blood vessels, intestines)

• Striated
• Long stripes running through it, bundles of nuclei, really big cells (many nuclei)
• Typically voluntary and able to be consciously controlled (exceptions: blinking, breathing)

• Thin layer of areolar (connective) tissue surrounding the plasma membrane of each cell (fiber)

• allows room for capillaries and nerve fibers

• Slightly thicker layer of connective tissue
• surrounds a bundle of cells called a fascicle

• Muscle cells are referred to as muscle fibers
• plasma membrane = sarcolemma
• T tubules = holes in the plasma membrane that allows an impulse from a motor neuron to travel through the interior of a muscle cell
• sarcoplasmic reticulum (smooth endoplasmic reticulum): stores calcium (muscle will not contract if calcium is not there)

• Decrease in muscle cell size, always a result of lack of use
• The end result is death of a muscle cell
• It is replaced by connective tissue (scar tissue)

• Eyes, fingers, mouth, tongue
• Fine motor movements
• Controlling smaller items
• Less (fewer) fibers or cells

• Move legs, abs, shoulders
• Larger muscle groups
• Higher # of muscle cells

• Like a synapse, but not in the CNS.
• The connection between the end of the axon and the muscle cell.
• Acetylcholine is the neurotransmitter.

• Not striated
• Long, skinny
• Spindle shaped cells
• involuntary - no conscious control
• Controlled by hormones or autonomic system
• Can be stimulated to contract by the autonomic nervous system or by the endocrine system
• ex) oxytocin & the uterus
• Typically found around hollow organs
• Contraction speed is very slow, but can remain contracted for long periods of time without fatiguing

• Only in the heart
• Involuntary
• Highly branched cells - brain looks at the heart as if it is one cell that is why branching is so important
• Lock together with intercalated discs
• Contraction rates - vary depending on need & activity

• Desmosomes
• Lock the cells in the cardiac muscle together so they can communicate - if they don't, the cells will die (and so will you)

• Nerve signal stimulates the release of acetylcholine.
• Muscle cell will depolarize.
• Binds onto the muscle cell.

• Binding of acetylcholine to the muscle cells open Sodium and Potassium Channels
• ACh makes muscle bend and sends response

• Depolarization occurs - impulse for contraction travels through the cell.
• If no acetylcholine released, no polarization, no muscle contraction.

• The impulse for contraction spreads over plasma membrane and enters T tubules causing Calcium gates to open in SR (sarcoplasmic reticulum)

After the calcium gates open

The myosin head gets ahold of actin, it builds a chemical bond called cross-bridge attachment.

Binds onto an active site on actin.

Power Stroke takes place. The myosin head falls over, still attached to actin (was standing upright), pulls on actin thats what makes muscle cells shorter.

Now ATP must come break the crossbridge attachment.

The myosin head must be reset. Because it had fallen over, it has to stand back up. The energy is required to break the bond and reset itself. If no calcium is available or present, the muscle will not move at all.

When the nerve impulse ends for a contraction, the calcium gets pumped back into the SR.

Forms crossbridges, causes rigormortis

It is a carbohydrate; polysaccharide, use for energy

To burn anything; you need fuel and oxygen

• Too much carbon dioxide and lactic acid
• Not enough oxygen, not enough energy source (glucose, glycogen)

• Replacing oxygen that was used during exercise; recharging blood
• Oxygen helps breakdown lactic acid
• The quicker it is paid back; the better
• Winded, panting - have to payback other body systems for borrowed amounts

• Large amounts of mitochondria, myoglobin and blood
• Slow to contract, but do not fatigue easily

• Smaller amounts of mitochondria, myoglobin, and blood
• Contract quickly, but fatigue quickly.
• Ex) short distance runner, sprinter, eyes (skeletal muscles)

bend arm at the elbow

origin: scapula

insertion: radius

straighten arm

antagonist of biceps; posterior side

origin: humerus, scapula

inserts: olecranon of ulna (elbow)

bend the wrist, pulling hand toward elbow

ventral surface of forearm and hand muscles for flexing

(inside of hand and arm)

straighten the wrist

antagonist of flexors, dorsal surface of forearm and hand muscles

(outside of arm) used for extending

raise arm to horizontal position or higher

triangular shape

origin: scapula, clavicle

inserts: humerus

pull arm forward

origin: clavicle, sternum, ribs

inserts: humerus

synergist with latissimus dorsi to work together to pull arm down

antagonists to latissimus dorsi by itself

muscle that moves humerus

pull arm backward

origin: starts on thoracic vertebrae continues down to ilium

inserts: humerus

synergist with pectoralis major to work together to pull arm down

also antagonizes deltoid

muscle that moves humerus

pulls scapulas together, shoulders back

origin: occipital bone continuing down to the thoracic vertebrae

inserts: scapula

scapula movement

pull scapulas laterally and forward

origin: ribs

inserts: scapula

scapula movement

strong muscle to keep scapula in place

raise scapula, pull head back (raise up)

deeper muscle

origin: cervical vertebrae

inserts: scapula

pull head forward

origin: sternum & clavicle

inserts: mastoid process (bump behind the ear)

close jaw

origin: zygomatic

inserts: mandible

works with temporalis to chew (synergist)

close jaw

origin: temporal bone

inserts: mandible

works with masseter to chew (synergist)

open jaw, pull lip down

mouth down to chest

open mouth, pout

very thin, not strong

antagonist of temporalis and masseter

round of mouth

purse lips

assists with eating

movement of skin

close eyelids

squint

round of eye

movement of skin

drink through straw

cheek muscle

important for eating, tightening skin, create vacuum

keeps food from squirting out of mouth

bend forward

flex @ hip

covered with other muscle and connective tissue

origin: pubic bone

inserts: sternum @ xiphoid process (distal end of sternum) and small amt of ribs

stand erect

extend spine

pull on spine to straighten us up

long thin strap-like muscles going up spine

inhale

separates chest cavity from abdomen

breathing muscles, does not have antagonist

exhale passively

raise/lower chest wall

external: pull ribs up and out as we take a breath

internal: pull ribs back down and in during forceful exhale - in between ribs

external obliques

bend forward, twist torso

run at an angle until they catch iliac crest

origin: lateral side of ribs

inserts: low/medial iliac crest, top of rectus abdominus

bend forward, twist torso

origin: iliac crest

inserts: ribs, connective tissue

these muscles are responsible for rotation

pull abdominal wall in

run horizontal

deepest of 3 abdominal muscles

important for birth, bladder, and bowels

compresses abdomen

"picture taking muscle"

pull leg back

origin: ilium, sacrum, coccyx

inserts: femur

raise thigh or pull it forward

origin: lumbar vertebrae, ilium

inserts: femur

antagonist to rectus abdominus

comprised of 2 muscles; iliacus, psoas major

located right under sartorius

pull thigh laterally

origin: ilium

inserts: femur - connective tissue (IT band) on top of femur

pull thigh medially

functional group

antagonize tensor fasciae muscle

inside groin muscle

origin: pubis

inserts: femur

bend knee

flex from back side

origin: several muscles

inserts: tibia

straighten knee

antagonist to hamstrings

origin: bit of ilium, femur

insert: tibia (tibial tuberosity)

raise leg, pulling knee medially

rolls thigh out so medial surface comes up

very skinny muscle

origin: lateral side of ilium

inserts: medial side of tibia (inside)

stand on tiptoe; raises heel up

calf muscle

origin: distal end of femur

inserts: calcaneus (heel bone); long strap of connective tissue, calcaneal tendon

raise toes

point toes up

origin: on tibia

inserts: metatarsals

part of normal walking motion