Posterior belly of digastric
Gluteus maximus and fascia lata
Trapezius and levator scapulae
Diaphragm and external intercostalis
Superior oblique muscle
1. Prime mover- (agonist) leader of that movement. It has major responsibility of making specific movement. Example, biceps
2. Antagonist- opposite of agonist movement muscles. Example triceps
3. Synergist- muscle that adds extra force to help prime movers or reducing unnecessary movement. Example, brachialis
– contraction does not produce movement, contract isometrically. .Example, scapula
Pyramidal cells of motor cortex travel down through cerebral peduncle, pass into the midbrain where they are forming cerebral peduncles. Than they continue to go down passing basal ponds and forming medullary pyramids in medulla oblongata.. Corticospinal tract then cross over at the medulla oblongata forming the lateral corticospinal tract and part of it still travels down at the anterior side of medulla and its called Ventral corticospinal tract. Axons of ventral corticospinal tract leave th tract and enter the spinal cord in the anterior horn grey matter where they stimulate the somatic motor neuron and send signals to biceps brachii.
A motor unit is a motor neuron that acts on skeletal muscle fibers.
1.Action potential arrives at axon terminal
2.Voltage-gated Ca++ channels are open and Ca++ enters the axon terminal
3.Ca++ entering causin the NT being released by exocytosis.
1.NT binds with the receptor on a skeletal muscle cell
2.Sodium Na channel is open (ligand-gated channel)
3.Na influx creating action potential
4.Muscle action potential travels down T-tubules
5.Sarcoplasmic reticulum releases Ca++
6.Calcium binds to troponin
7.Binding Calcium to troponin causing tropomyosin to shift and expose myosin binding sites
8.Myosin binds to actin and myosin head pulls actin filament.
9.ATP binds to myosin head causing myosin to detach from actin
10.Myosin head is cocking back and the cycle is repeated as long as Ca++ is attached to troponin.
SKELETAL MUSCLE RELAXATION
Arch is broken down by AchE or it may diffuse away from synaptic cleft. That will cause Na ligand-gated channels to close. Ca Voltage-gated channels on SR will close. Ca++ pump back into SR from the sarcoplasm. That will cause toomyosin to to return back to block myosin binding sites on actin. Moysin can’t bind to actin and muscle relaxes.The three pathways are anaerobic, aerobic respiration and direct phosphorylation. Anaerobic does not require oxygen, uses glucose as energy source, products 2 ATP per glucose and lactic acid. It lasts approximately 30-40 seconds. Aerobic respiration is the most efficient way, it requires oxygen and the energy sources are glucose, pyruvic acid, free fatty acid from adipose tissue and amino acids from protein catabolism. Aerobic respiration products 32 ATP per glucose and can last for hours. Direct phosphorylation is the quickest way, uses creatine Phosphate as energy source, does not requires oxygen and Products 1 ATP per CT, creatine. Lasts 15 seconds.
Red meat is made up of muscles with slow fibers. Myoglobin is a protein that stores oxygen in muscles and the more myoglobin is in the muscle cells the darker/more red the meat is. Red meat is red because it has a lot of myoglobin filled with oxygen and myoglobin is red color. White meat is made up of muscles with fast fiber..White meat muscles get energy from glycogen. White meat is white because there is a low usage in muscle and the amount of myoglobin is low.
Calcium enters into sarcolemma of smooth muscle through Voltage gated or non voltage gated channels. I can enter from sarcoplasmic reticulum as well. Calcium binds to calmodulin protein. When calcium binds to calmodulin it activates MLCK (myosin light chain kinase) . MLCK activates myosin molecule . Cross bridge occurs with actin of the thin filaments. Contraction begins.
First-class lever, the fulcrum is between effort and load. Example lifting a heavy weight (triceps extension)
Second-class lever, load is between the fulcrum and effort. Example, standing on tip-toe.
Third-class lever, effort is between load and fulcrum. Example, when lying down horizontally and lifting legs up.