Muscle system

Three primary functions of muscle

provide motion, maintain posture, generate heat

Is muscle one of the four basic tissues of the body?

Yes

Various types of muscle

Skeletal, Smooth, Cardiac

Type of muscle that is skeletal muscle

Voluntary striated muscle

What surrounds skeletal muscle cells?

Fibrous connective sheath = epimysium

How do tendons attach to bones?

Fibrous tissue bands (attach muscles to bones or other structure)

Example of aponeuroses

Linea alba-- that runs lengthwise between the muscles on an animal's ventral midline

What does the linea alba connect?

Connects the abdominal muscles from each side together and is a common site for surgical entry into the abdomen

More stable muscle attachment site

Origin

Prime mover in skeletal muscle action

Agonist

Muscle that directly opposes the action of an agonist

Antagonist

Skeletal muscle actor responsible for stabilizing the joint

Fixator

Skeletal muscle actor that assists the agonist

Synergist

Ways to name muscles - Action

A portion of a muscle's name is often related to its function, such as flexor muscles.

Ways to name muscles - Shape

A muscle's name can reflect its distinctive shape, such as the deltoid muscle.

Ways to name muscles - Location

A muscle's name can indicate its physical location in the body.

Ways to name muscles - Direction of fibers

The term rectus means 'straight.'

Ways to name muscles - Number of heads or divisions

The number of heads refers to the number of attachment sites that a muscle has to its origin.

What does the term cephal mean?

It means 'head.'

Example of a muscle with two heads

Biceps brachii muscle

Where can you find cutaneous muscles in the body?

Connective tissue (fascia) just beneath the skin.

What are cutaneous muscles called?

Cutaneous trunci due to location on the thorax and abdomen.

Masseter muscle

Muscle responsible for closing the jaw.

Sternocephalicus

Muscle that flexes the head and neck.

Brachiocephalicus

Muscle that extends the head and neck and pulls the front leg forward.

Deltoideus

Muscle that abducts the arm.

Lateral head of triceps brachii

Muscle that extends the elbow joint.

Biceps brachii

Muscle that flexes the elbow joint and extends the shoulder.

Brachialis

Muscle that flexes the elbow joint.

Extensor carpi radialis

Muscle that extends the wrist.

Superficial digital flexor

Muscle that flexes the digits.

Deep Pectoral

Muscle that adducts the forelimb.

External abdominal oblique

Muscle that supports abdominal organs and helps flex the back.

Gastrocnemius

Muscle that flexes the knee and extends the ankle.

Semimembranosus

Muscle that extends the hip joint.

Semitendinous

Muscle that extends the hip joint and flexes the knee.

Biceps femoris

Muscle that extends the hip joint and flexes the knee.

Gluteus medius (Middle gluteal)

Muscle that abducts the thigh.

Tensor fasciae latae

Muscle that flexes and abducts the thigh.

Sartorius

Muscle that flexes the hip and knee.

Trapezius

Muscle that moves the head laterally and supports the shoulder.

Functions of the abdominal skeletal muscles

Support abdominal organs, help flex the back, participate in defecation, urination, parturition, vomiting, and regurgitation, and have a role in respiration.

Linea alba

The point where the left and right parts of the abdominal skeletal muscles come together.

Main function of the thoracic and pelvic limb skeletal muscles

Locomotion.

Skeletal muscles used for respiration

Inspiratory muscles, diaphragm, external intercostal muscles, expiratory muscles, internal intercostal muscles, abdominal muscles.

Muscle fiber

Another term for the skeletal muscle cell.

Primary protein filaments of a sarcomere

Actin and myosin.

Neuromuscular junction

Site where ends of motor nerve fibers connect to muscle fibers, containing neurotransmitter acetylcholine.

Anaerobic metabolism

Non-oxygen-dependent metabolism where the need for oxygen exceeds the available supply, resulting in lactic acid formation.