Muscular Ana Cendejas Period:7 (Body Movement (Dorsiflexion- lifting the…
Ana Cendejas Period:7
Major Functions of Muscular System
Change in body position. Also movement of substances within the body.
- Maintains body position. Stabilizing joints, body posture, regulate organ volume.
- Heat production. Contraction produces heat
Names of Muscles
: Rectus femoris, vastus lateralis, and vastus medialis
: Gastrocnemius, soleus, fibularis longus, extensor digitorum longus, and tibialis anterior
: lliopsoas and pectineus
Tensor fascia lata, sartorius, adductor longus and gacilis
: Rectus adominis, external oblique, transversus abdominis and internal oblique
: Pronator teres, brachioradialis, flexor carpi radialis, and palmaris longus
: Triceps, biceps brachii
Trapezius and deltoid
: Platysma, sternohyoid, sternocleidomastoid
: Epicranius, frontal, orbicularis oculi, zygomaticus, and orbicularis oris
: Temporalis and masseter
Types of Muscle Tissue
- Cells are long, cylindrical, branched and has single central nucleus. It is striated and it forms the heart wall.
- Cells are spindle which means they are shaped with single central nucleus and has no striation,appears smooth. It controls movement inside internal organs. They are found mainly in hollow walls of organs like the digestive tract, blood vessels, urinary, and reproductive organs.
- Cell are long, cylindrical, parallel, and multi nucleated. It is striated which means they are visible banding stripes. It makes up about 40-50 % of the body weight "red meat".
-movement that decreases angle of joint
-movement that increases angel of joint
- extension beyond 180 degree
- movement of a bone around a longitudinal axis
- movement of limb away from midline
- movement of limb towards the midline
- proximal end of a limb is stationary and the distal end moves in circle
- lifting the superior surface of foot towards shin
flexion- pointing toe
- turn sole of foot medially
- turn sole of foot laterally
- forearm rotates laterally so palm faces anteriorly
- forearm rotates medially so palm faces posteriorly
- movement of thumb to touch tips of other fingers
Muscle Contraction (the sliding filament theory)
1.Nerve impulse or action potential travels down sarcolemma and into T-tubules causing sarcoplasmic reticulum to release ca++ into sarcoplasm
Ca++ binds to actin myofilament, exposing the myosin binding site
Myosin head attaches to actin, forming actin/myosin cross bridges
Myosin head moves toward M line of sarcomere pulling actin filament past myosin
5.The actions are repeated many times powered by ATP (ATP needed to release myosin heads from actin)
Two lines get closer together as actin and myosin filaments slide past each other and sarcomeres shortening the entire myofibril
Structure of the Skeletal Muscle
1.Each muscle fiber is a single,long, and cylindrical muscle cell
Under the Sarcolemma is the sarcoplasm with many mitochondria and nuclei
Sarcoplasm contains glycogen for energy and myoglobulin for oxygen storage
3.The sarcoplasm contains parallel myofibrils.
Myofibrils are made up of myofilaments
Thick filaments of myofibrils are made up of the protein myosin
Thin filaments of myofibrils are mainly composed of the protein actin,along with troponin and tropomyosin
Myofibrils are made up of many sarcomeres, joined end to end
A sarcomere extends from one z line to the next
Under the sarcolemma of a muscle fiber is the sarcoplasmic reticulum that works with the transverse T-tubules
Sarcoplasmic reticulum: specialized smooth endoplasmic reticulum functions to store and release calcium when muscle contracts fuse to form cisternae
Transverse Tubules: Infoldings of sarcolemma that penetrate into muscle fiber filled with extracellular fluid;open to cell surface and extends into muscle cell.