Skeletal Pathology, Articulations, and Muscular System Anatomy

Vocabulary practice flashcards covering skeletal pathologies, joints, muscle structure and physiology, as well as axial and appendicular muscle origins, insertions, and actions.

Spina bifida

A condition involving varying degrees of vertebral arch defects, where displacement of the spinal cord leads to a wide range of paralytic states.

Osteopenia

A hormonal decline in osteoblast activity occurring around $30\text{--}40\,\text{yr}$ of age, causing bone to become thin and weak.

Osteoporosis

A bone pathology characterized by a decrease in bone mass to the extent that normal function is compromised.

Scoliosis

An abnormal spinal curvature in the frontal plane, which can be osteopathic (due to bone loss) or myopathic (due to muscle spasm, weakness, or paralysis).

Kyphosis

An abnormal spinal curvature in the sagittal plane.

Brachydactyly

An appendicular skeleton variation characterized by short fingers.

Polydactyly

An appendicular skeleton variation featuring supernumerary digits, occurring more frequently on the radial or fibular side.

Syndactyly

An appendicular skeleton variation involving the fusion or webbing of digits.

Phocomelia

A limb variation characterized by the absence of long bones in the limbs.

Amelia

A severe developmental variation resulting in the complete absence of limbs.

Hydrocephalus

An accumulation of cerebrospinal fluid (CSF) that expands the fetal brain, causing the cranial vault to remain thin, brittle, and deformed because ossification does not keep pace with expansion.

Craniosynostosis

Premature sutural fusion leading to various skull deformities, such as Scaphocephaly, Brachycephaly, and Acrocephaly.

Achondroplasia

A congenital form of dwarfism where cartilages in the braincase and long bones do not grow correctly, leading to premature fusion of epi-/diaphyses and short bones.

Hyperpituitarism

Excessive growth hormone production during puberty that results in proportional Pituitary giants.

Acromegaly

Disproportionate over-growth caused by excessive growth hormone after puberty.

Gout

A metabolic disorder (hyperuricemia) characterized by monosodium urate crystal accumulation and precipitation in the synovial cavity, irritating the synovium and causing joint inflammation.

Diarthrotic joint

A joint that allows free movement, structurally classified as a synovial joint.

Hilton's Law

The anatomical principle stating that the nerve innervating a joint tends to innervate the adjacent muscles and skin.

Osteoarthritis

Degenerative joint disease (DJD) where weight-bearing joints suffer cartilage erosion, osteophyte formation, joint deformity, and limited mobility.

Rheumatoid arthritis

A chronic inflammatory disease characterized by systemic erosion of synovium with a vascularized mass, causing bilateral deforming arthritis typically in small joints.

Ankylosis

The fusion of adjacent bones caused by friction or trauma.

Endomysium

The connective tissue layer surrounding a single muscle fiber (cell membrane).

Perimysium

The connective tissue layer that binds individual muscle fibers together into fasciculi.

Epimysium

The connective tissue layer that binds muscle fasciculi together into a complete muscle.

Pre-synaptic poisons

Toxins that interfere with acetylcholine (ACh) release from the pre-synaptic membrane, such as scorpions, botulism, and tetanus.

Post-synaptic poisons

Toxins that interfere with acetylcholine (ACh) reception at the post-synaptic membrane, such as snake venom and strychnine.

Muscular dystrophy

A congenital clinical condition characterized by a decrease in ACh receptors on muscle end-plates, leading to progressive muscle deterioration and weakness.

Muscle hypertrophy

Enlargement of an exercised or stimulated muscle caused by the addition of muscle fibrils within existing muscle fibers, without changing the total number of muscle cells.

Rigor mortis

A state following death in which muscles remain contracted due to the lack of ATP.

Sternocleidomastoid

An axial neck muscle originating on the sternum and clavicle and inserting on the mastoid process; it rotates the head and flexes the neck.

Rectus abdominis

An abdominal wall muscle originating on the pubic symphysis and inserting on costal cartilage and the xiphoid process; it depresses ribs, flexes the vertebral column, and compresses the abdomen.

Epicranius

A facial muscle structure composed of the occipitalis, epicranial aponeurosis, and frontalis that moves the scalp, raises eyebrows, and wrinkles the forehead.

Agonist

The largest muscle responsible for producing a specific movement at a joint.

Antagonist

A muscle that reverses a joint movement, operating in pairs with agonists.

Synergist

A muscle that adds to joint movement or contributes to stabilization of the joint.

Carpal tunnel syndrome

Painful tendonitis resulting from inflammation of tissue surrounding finger tendons within the restricted space between the flexor retinaculum and carpus.

Biceps brachii

A biarticular forearm flexor with origins on the supraglenoid tubercle (long head) and coracoid process (short head) and insertion on the radial tuberosity.

Sartorius

A biarticular muscle originating at the anterior superior iliac spine and inserting at the pes anserinus of the tibia; it flexes, abducts, and laterally rotates the femur and flexes the leg.

Triceps surae

A posterior leg muscle group composed of the medial and lateral heads of the gastrocnemius together with the soleus.

Tibialis anterior

A muscle originating on the proximal shaft of the tibia and interosseous membrane and inserting on the base of the $1\text{st}$ metatarsal and medial ($1\text{st}$) cuneiform; it dorsi-flexes and inverts the foot.