Muscle Anatomy and Pathology: Connective Tissue Changes, Naming, and Function

What are the pathological changes that can occur in connective tissue over time?

Connective tissue can thicken, shorten, calcify, and erode.

What are the learning objectives related to muscles?

Describe how muscles are named, palpate individual muscles, identify attachments, actions, synergists, antagonists, and common muscle pathologies.

How are individual muscles arranged in the body?

Muscles are arranged in layers, typically three to five layers in most areas of the body.

What is the difference between deep and superficial muscles?

Deep muscles are closest to the bone, while superficial muscles are closest to the skin.

What is concentric muscle action?

Concentric action occurs when muscle fibers shorten.

What is eccentric muscle action?

Eccentric action restrains or controls movement produced by the agonist by lengthening while maintaining muscle fiber shortening.

What is isometric muscle action?

Isometric action occurs when muscle fibers shorten and attempt to pull on a bone, but actual movement is prevented at the joint.

What features are used to name muscles?

Muscles can be named based on location, function, shape, direction of fibers, number of heads or divisions, points of attachment, and size.

What are direct muscle attachments?

Direct attachments are rare and occur when muscles attach directly to bone or cartilage.

What are indirect muscle attachments?

Indirect attachments are more common and occur when muscle fascia extends beyond the muscle and attaches to other connective tissue.

What is the process for palpating muscles?

To palpate muscles, identify bony landmarks, trace the muscle between attachments, follow fiber direction, locate the belly of the muscle, and have the client contract the muscle.

What is the primary function of the muscles of the face and head?

They produce movement for facial expressions and are vital for nonverbal communication.

What are the four main pairs of muscles involved in mastication?

The masseter, temporalis, medial pterygoid, and lateral pterygoid muscles.

What are the functions of the muscles of the neck?

They move the neck at cervical spinal joints, assist in swallowing, and provide neck extension.

What role do deep muscles of the back and posterior neck play?

They are responsible for neck and head extension, lateral flexion, rotation, and maintaining proper spinal curve.

What is the primary function of the deep muscles of the thorax?

Their primary function is to create movements necessary for breathing.

What is the most important muscle of inspiration?

The diaphragm.

What do the abdominal muscles and fascia form?

They form the anterior and anterolateral abdominal wall.

What actions do the abdominal muscles perform?

They compress abdominal contents during expiration, urination, and defecation.

What muscles form the pelvic floor?

The levator ani and coccygeus muscles.

What is the function of the muscles of scapular stabilization?

They hold the scapula to the rib cage and move the scapula during muscle actions.

What accompanies scapular movements?

Clavicular movements accompany scapular movements.