Anatomy and Physiology: Axial Skeleton, Appendicular Skeleton, Joints, and Muscle Tissue Review

Vocabulary key terms covering the human axial skeleton, appendicular skeleton, joints, muscle physiology, and muscle tissue disorders.

Axial skeleton

The division of the skeleton that forms the central axis of the body.

Appendicular skeleton

The division of the skeleton that includes the arms and legs.

Paranasal sinuses

Air-filled cavities connecting to the nasal cavity that help filter incoming air and provide resonance to the voice.

Sella turcica

A structure on the sphenoid bone that surrounds and holds the pituitary gland.

Anosmia

The loss of the sensation of smell.

Fontanelles

The soft spots of an infant skull.

Vomer

An unpaired facial bone that forms part of the nasal septum.

Hyoid

The only bone in the human body that does not articulate with another bone.

Nucleus pulposus

The inner gelatinous layer of an intervertebral disc.

Annulus fibrosus

The outer strong layer of an intervertebral disc.

Atlas

The first cervical vertebra (C1), which lacks a spinous process and articulates with the occipital condyles.

Axis

The second cervical vertebra (C2), which features a dens/odontoid process acting as a pivot point for skull rotation.

Scoliosis

Lateral bending of the vertebral column.

Kyphosis

An exaggerated thoracic curve of the vertebral column, often referred to as 'round shoulders.'

Lordosis

An exaggerated lumbar curve of the vertebral column.

Spina bifida

A congenital disorder occurring when the vertebral laminae fail to unite at the midline.

Laminectomy

Surgical removal of a vertebral lamina to relieve symptoms of a ruptured disc.

Glenoid cavity

The fossa of the scapula where the humerus attaches to form the shoulder joint.

Pes planus

The medical condition of flat feet occurring when the arches fall or are absent.

Plantar fasciitis

Inflammation of the plantar fascia that causes pain on the underside of the calcaneus.

Synostosis

An immovable bony joint formed when the gap between two bones ossifies into a single bone.

Synarthroses

Fibrous joints composed of connective tissue that lack a synovial cavity.

Synchondrosis

A cartilaginous joint using hyaline cartilage as connecting tissue, such as the epiphyseal plate.

Symphysis

A cartilaginous joint joined by a fibrocartilage pad, such as the pubic symphysis or intervertebral discs.

Articular cartilage

Hyaline cartilage covering the ends of articulating bones to reduce friction.

Bursa

A fluid-filled pad that reduces friction and stress in a joint.

Arthroscopy

A surgical procedure used to examine the interior of a joint using an arthroscope.

Arthroplasty

The surgical replacement of a joint.

Osteoarthritis

Joint degeneration characterized by the deterioration of articular cartilage.

Gouty arthritis

Joint damage resulting from the deposition of sodium urate crystals within joints.

Rheumatoid arthritis

An autoimmune disease in which antibodies attack joint tissues.

Sprain

Forcible wrenching or twisting of a joint with partial rupture of attachments without dislocation.

Strain

Overstretching of a muscle.

Dislocation

Displacement of a bone from a joint accompanied by tearing of ligaments, tendons, and articular capsules.

Arthralgia

Pain in a joint.

Myology

The scientific study of muscle tissue.

Excitability

The ability of muscle tissue to respond to a stimulus by producing electrical signals.

Contractility

The ability of muscle tissue to shorten and thicken while generating force.

Extensibility

The ability of muscle tissue to stretch without sustaining damage.

Elasticity

The ability of muscle tissue to return to its original shape after stretching or contracting.

Thermogenesis

The production of heat by muscle contractions.

Epimysium

The outer layer of connective tissue surrounding an entire muscle.

Perimysium

The connective tissue layer surrounding bundles of muscle fibers called fascicles.

Endomysium

The inner connective tissue layer surrounding individual muscle fibers.

Motor unit

A functional unit consisting of one motor neuron and all the skeletal muscle fibers it stimulates.

Sarcolemma

The plasma membrane of a skeletal muscle fiber.

Sarcoplasm

The cytoplasm of a muscle fiber.

Sarcomere

The basic functional contractile unit of a striated muscle fiber.

Treppe

The staircase effect in which repeated stimulation of a relaxed muscle leads to progressively stronger early contractions.

Gangrene

Death of soft tissue caused by an interruption of blood supply.

Myalgia

Pain in a muscle.

Myoma

A tumor consisting of muscle tissue.

Myomalacia

Softening of muscle tissue.

Myopathy

Any disease of muscle tissue.

Myositis

Inflammation of muscle fibers.

Origin

The less movable attachment of a muscle to a bone, usually located closer to the axial skeleton.

Insertion

The more movable attachment of a muscle to a bone, usually located near the appendicular skeleton.

Prime mover

The primary muscle that contracts to produce a desired action.

Antagonist

A muscle that relaxes while a prime mover contracts to perform an action.

Synergists

Muscles that steady the movements of a prime mover.