A&P Chapter 8 Muscles

What is a motor unit?

A single motor neuron with the muscle fibers it innervates

The molecule _____ supplies energy for muscle contraction.

ATP

______________ is a term describing the movement of a body part away from the midline of the body.

Abduction

Is the proteins that makes up the thin myofilaments

Actin

What is a tendon?

Attaches muscle to bone

Why is the triceps brachii muscle sometimes called the "boxer's muscle"?

Because it is the muscle responsible for delivering blows in a fight.

When a person flexes the knee what movement is this?

Bending it

The muscle that flexes the elbow is the:

Biceps Brachii

How would you define the term: posture?

Body parts are held in the position, balancing the distribution of weight.

What is oxygen debt?

Continued increased metabolism that must occur in a cell to remove excess lactic acid that accumulates during prolonged exercise. Labored breathing after the cessation of exercise is required to "pay the debt" of oxygen required for the metabolic effort.

_________ is a term used to describe the movement that is the opposite of flexion.

Extension

Masseter

Head or Neck

Sternocleidomastoid

Head or Neck

Temporal Muscle

Head or neck

Cardiac Muscle makes up the bulk of the tissue of the

Heart

How does muscle function affect body temperature?

The contraction of muscle fibers produces most of the heat required to maintain body temperature.

What action do the hamstring muscles perform?

The hamstring muscles flex the leg

How does a muscle produce different levels of strength?

The muscle fibers have a threshold stimulus, and each one is different, therefore providing the body with the ability to exert different levels of strength.

What are the functions of the muscles of mastication?

The muscles of mastication close the mouth and produce chewing movements. As a group they are among the strongest muscles in the body.

What roles do the respiratory, circulatory, nervous and skeletal systems play in producing normal movements?

The respiratory, circulatory, nervous, and skeletal systems all play essential roles in producing normal movements. The respiratory and circulatory systems provide oxygen and nutrients and eliminate waste; the nervous system provides the electrical stimuli and interpretation; and the skeletal system provides the framework, support, anchor, and movement. The normal function of the muscular system depends on the normal function of many other systems as well.

How is dorsiflexion of the foot performed?

The toe is pointed upward and toward the head

What are the two primary respiratory muscles?

The two primary respiratory muscles are the intercostals and the diaphragm

When a prime mover muscle contacts, what does its antagonist do?

They produce a movement in opposition to the prime movers.

How do a muscles myofilaments provide the mechanism for movement?

Thick and thin myofilaments in a muscle fiber first attach to one another by forming "bridges" that then act as levers to ratchet or pull the myofilaments past each other

_____________ is the mimimal level of stimulation required to cause a muscle fiber to contract

Threshold Stimulus

The following are types of contractions

Titanic

This muscle is also called the boxers muscle:

Triceps Brachii

External Oblique

Trunk

Rectus Abdominis

Trunk

Pectoralis Major

Trunk/moves upper extremity

Skeletal Muscles can also be called

Voluntary Muscles

Smooth Muscles can also be called

visceral muscles involuntary muscles nonstriated muscles

That happens when a person abducts his or her arm?

you are moving the part away from the midline of the body

Is the protein that makes up the thick myofilaments

Myosin

Each skeletal muscle is filled with two types of myofilaments called

Myosin and Actin

What is the difference between isotonic and isometric muscle contractions?

In an isotonic contraction, the muscle changes length, producing movement. In an isometric contraction, the muscle pulls forcefully against a load (changes tension) but does not change length.

The muscle attachment to the more movable bone is called the

Insertion

_____________ is a type of muscle contraction that does not produce movement and does not allow the muscle to shorten but does increase muscle tension

Isometric

A contraction in which muscle length remains the same but muscle tension increases is called an

Isometric Contraction

_______________ is a type of muscle contraction that produces movement in a joint and allows the muscle to shorten.

Isotonic

How does strength training affect a person's muscles?

It increases the number of myofilaments in each muscle fiber.

_______________ is the waste product produced when the muscle must switch to an energy supplying process that does not require oxygen.

Lactic Acid

A single motor neuron with all the muscle fibers it innervates is called a

Motor Unit

Rectus Femoris

Move Lower Extremity

Gastrocnemius

Move lower extremity

Sartorius

Move lower extremity

Biceps Brachii

Move upper extremity

What are the three primary functions of the muscular system?

Movement, posture or muscle tone, and heat production

The three functions of the muscular system are

Movement, posture, heat production

Triceps Brachii

Moves Upper extremity

Gluteus maximus

Moves lower extremity

What is another name for muscle cell?

Muscle Fiber

The muscle attachment to the more stationary bone is called the

Origin

What is the origin and insertion of a muscle?

Origin- where muscle starts (non-moveable side), Insertion- tendinous (tendious) side, where muscle ends (moveable-side)

Movement around a longitudinal axis is:

Rotation

The ____________ is the basic functional unit of contraction in a skeletal muscle

Sarcomere

The contractile unit of the muscle is:

Sarcomere

What role does acetycholine play in muscle contraction?

Signal chemicals called neurotransmitters are released by motor neurons in response to a nervous impulse. Acetylcholine (Ach) is the type of neurotransmitter operating in each neuromuscular junction. Acetylcholine moves across the neuromuscular junction and triggers events within the muscle fiber that result in contraction or shortening of the muscle fiber.

How do the types of muscle differ?

Skeletal muscles are also striated muscle. They are voluntary. Smooth muscles are not striated and are involuntary. Cardiac muscles are not striated and are around the heart.

Hypertrophy can be enhanced by

Strength Training

__________ describes the hand position when the body is in anatomical position

Supination

What are the three main types of muscle tissue?

skeletal, cardiac, smooth