Chapter 6 anatomy and physiology for massage therapy

A muscle contraction occurs when _____________, allowing myosin to pull itself along, increasing the overlap of the two myofilaments, and shortening the sarcomere

A chemical bond is formed between the actin and myosin myofilaments that pull them together and increases the overlap between them

Explain the length-strength ratio

A muscle that is already shortened will also be weak, because sarcomere is already shortened and overlap is maximized, leaving little room for sliding

A motor unit is made of

A single nerve cell called a motor neuron and multiple muscle fibers it innervates

Fascia is the tough yet pliable sheet of _________________ that covers, divides and supports all the structures of the body

Connective tissue

When threshold stimulus is reached ____ the muscle fibers in that motor unit fully contract.

All

ATP provides energy for the cells of the body to do their work by:

Breaking the bond of the third phosphate and using energy of the bond to do work/which creates ADP

Only a small amount of ATP is floating around inside muscles cells at any given time, so if activity persists for more than a few seconds the cell must use one of three methods to get more

Creatine phosphate, anaerobic cellular metabolism, and aerobic cellular metabolism.

Anaerobic cellular metabolism

Glucose obtained from blood or the breaking down of glucose stored within muscle

Muscle fatigue

Is the inability of muscle to contract forcefully after prolonged activity even when stimulated to do so.

Some reasons for muscle fatigue are

Lack of oxygen, depletion of glycogen, decreased in calcium supply needed for myofilament bonding.

The primary functions of the muscular system are

Movement of body parts, posture, stabilization of joints, and production of heat

Creatine phosphate

Muscle activity increases, phosphate ions are broken off of ATP molecules to release energy, leaving two phosphate ions behind and creates ADP

The central portion of every muscle is the ____________

Muscle belly

If less than the threshold is transmitted, ____ of the fibers contract. This applies to to the individual motor unit, not the whole muscle.

None

Skeletal muscle fibers have more than one _______ and two or three times as many ____________

Nucleus; mitochondria

Aerobic cellular metabolism

Oxygen is made available to muscles from oxygen-binding proteins either in blood or stored in muscle fibers.

Muscle tissue is "excitable" meaning it is designed to:

Respond quickly to simulation from the nervous system

Because the muscles of the body make up the majority of our "flesh" the prefix ______ is used to name cell features as a way of saying you are specifically talking about muscle

Sarco

The cytoplasm is called __________

Sarcoplasm

When a muscle or tendon is injured, we call that a ______

Strain

Muscle attaches to bone via cord-like ______ or a broad flat sheet called ___________

Tendon; Aponeurosis

The place where tendon becomes bone is called _______________________, and the place where muscle becomes tendon is called _________________________.

Tenoperiosteal junctio; musculotendinous junction

The spot where the motor neuron interfaces with a muscle fiber is called

The neuromuscular junction

The physiology of muscle contraction is explained by a model called

The sliding filament mechanism

Retinacula

Thickened superficial bands- holds tendons in place

The minimum amount of stimulation required to produce contraction from the motor unit is called

Threshold stimulus