Chapter 10🧬🔬🫀

Exercise helps with…..

maintaining muscle mass and function.

What are the neuromuscular junctions….

• Synaptic Knob

• Synaptic Vesicles

• Motor End Plate

• Synaptic Cleft

• ACh receptors

• AChE

ACh stands for….

Acetylcholine

AChE stands for….

Acetylcholinesterase

Synaptic Knob is thr….

expanded end and surface area of the neuron

Synaptic Vesicles is the…..

Membrane-bound sacs filled with ACh = neurotransmitters

Motor End Plate is the….

Region on the Sarcolemma to increase surface area.

Synaptic Cleft is the…..

Narrow space separating the Synaptic Knob from the Motor End Cleft.

ACh receptors….

are in the Motor End Plate that bind ACh

AChE is….

an enzyme in the Synaptic Cleft, and decomposes ACh

what is the Cross Bridge Cycle???

it is the theory of muscle contraction based on muscle proteins that slide past each other to generate movement

ACh causes the release of….

Calcium from the T Tubules

Calcium is sent to Actin and….

binds with Troponin

Troponin causes the Tropomyosin to….

move off the Actin binding sites

Myosin head attaches to…

Actin active site forms a Cross Bridge

Cross-Bridge pulls the….

Thin Filament towards center of the Sarcomere

ADP and Phosphate are….

released from Myosin

Creatine Phosphate a high energy molecule coverts….

ADP to ATP

ATP then binds to….

Myosin

Muscle contractions involves….

• Sliding movement of Thin Filaments past the Thick Filaments

•Thin filaments slides towards the center of the Sarcomere

Sliding continues until the overlapping of the….

Thin and Thick filaments is complete.

Motor nerve impulse causes….

ACh to be released into the Synaptic Cleft

When ACh binds to receptors in the Motor End Plate….

initiate a muscle impuse along the Sarcolemma and T-tubule Membrane

When Calcium is then released into the Sarcoplam….

Calcium ions bind to Troponin, which causes Tropomyosin to uncover active binding sites.

Mysosin heads bind to Actin and form Cross Bridges…..

Myosin heads detach

What is necessary for detachment???

ATP

Without Motor Units….

nothing happens, muscle doesn’t contract.

what is Muscle Tissue comprised of???

Motor Units that are used for Comtraction.

Motor units are comprised of….

Single Motor Neurons

Neuromuscular junction

Muscle Fibers

When motor unit is stimulated…

All Muscle Fibers under its control contract.

Recruitment is…

the process by which different Motor Units are activated to produce Muscle Contraction.

What is needed for muscle relaxation???

ATP

What is Skeletal Muscle Fatigue???

inability to contract a muscle.

what does it cause???

• Decreased blood flow

• ion imbalances across sarcolemma

• Accumulation of lactic acid

What is

sustained contraction and involuntary contraction

Muscle tone is….

Continuous state of a partial muscle contraction.

Sustained Contractions are….

smaller motor units that are recruited first

larger units recruit later

produce smooth movements

Muscle Hypertrophy is….

increase in Muscle Fiber Size

Muscle Atrophy….

wasting of muscle tissue

Skeletal Muscles generate a….

variety of body movements

Skeletal Muscle and bones function as….

mechanical devices = Levers

The action of each muscle mostly depends upon….

• The kind of joint it is associated with

•The way the muscle is attached on either side of the bone

The four types of Muscle movement…

• Agonist/Prime mover

• Antagonist

• Synergist

• Fixator

Agonist/ Prime mover

Produces specific movement when contracted

Antagonist

Resists the Prime Mover’s action and causes movement in the opposite direction

Synergist

A muscle that assists the Agonist or Prime Mover

Fixator

Contracts Isometrically to stabilize the Origin of the Prime Mover

What are the 2 types of muscle contraction

Isotonic and Isometric

Isotonic

Muscle tension equals or is great than resistance

Muscle shortens

Isometric

Muscle tension is less than the resistance

Muscle does not shorten = no movement