Hair, Glands, Nails, Bone (Osteology) and Joints - Vocabulary Flashcards

A comprehensive set of vocabulary flashcards covering hair structure, skin glands, nails, bone anatomy and physiology, and joint types from the lecture notes.

Hair shaft

Part of the hair that extends beyond the skin (epidermis).

Hair root

Part of the hair that penetrates through the epidermis and dermis down to the subcutaneous layer.

Hair follicle

Layer surrounding the hair root; site of mitosis that produces hair cells.

Sebaceous gland

Oil gland that lubricates hair and skin by producing sebum.

Arrector pili muscle

Smooth muscle that contracts to move the hair and create goosebumps, helping generate heat.

Goosebumps

Hair standing on end caused by contraction of the arrector pili muscles.

Apocrine sweat gland

Sweat gland attached to hair follicles; associated with body odor when mixed with bacteria.

Eccrine sweat gland

Sweat gland not attached to a hair follicle; opens directly to the skin surface; found all over the body.

Ceruminous gland

Gland that secretes cerumen (earwax) in the external ear canal.

Cerumen

Earwax produced by ceruminous glands; protects and lubricates the ear.

Nail body

Visible part of the nail on the surface of the finger or toe.

Free edge (nail)

Part of the nail that extends beyond the distal tip of the finger or toe.

Nail root

Portion of the nail embedded in the skin fold; site of nail growth.

Lunula

Half-moon white area at the proximal nail; a region of thicker epidermis indicating growth.

Eponychium

Cuticle; band of skin that adheres the skin to the nail body.

Nail matrix

Cells surrounding the nail root that undergo mitosis to form the nail.

Osteoprogenitor cells

Stem/osteogenic cells that differentiate into osteoblasts.

Osteoblasts

Bone-forming cells that create new bone matrix.

Osteocytes

Mature bone cells that maintain bone tissue.

Osteoclasts

Bone-resorbing cells that break down bone tissue.

Compact bone

Dense bone tissue composed of osteons; provides rigidity and strength.

Spongy bone

Lattice-like, porous bone with trabeculae; houses red bone marrow.

Osteon (Haversian system)

Structural unit of compact bone; also called the Haversian system.

Central (Haversian) canal

Blood vessel-containing channel at the center of an osteon.

Lamellae

Concentric mineralized rings around the central canal in an osteon.

Lacunae

Small spaces in bone housing osteocytes.

Canaliculi

Tiny channels connecting lacunae, enabling intercellular communication and nutrient flow.

Periosteum

Outer membrane that covers bone except where articular cartilage is present.

Endosteum

Membrane lining the inner surface of the medullary cavity.

Medullary (marrow) cavity

Hollow center of the diaphysis; contains yellow bone marrow in adults.

Red bone marrow

Marrow in which blood cells are produced (hematopoiesis).

Yellow bone marrow

Fat-storing marrow within the medullary cavity.

Epiphyseal plate

Cartilaginous growth plate in growing individuals that allows bone lengthening.

Epiphyseal line

Fusion line that forms after growth stops; epiphyseal plate becomes bone.

Diaphysis

Shaft of a long bone.

Epiphysis

Ends of a long bone that participate in joints.

Metaphysis

Region between the diaphysis and epiphysis; contains the growth plate in kids.

Frontal bone

Forehead bone of the skull.

Supraorbital foramen

Hole above the orbit that transmits the supraorbital nerve and vessels.

Frontal sinus

Air-filled cavity within the frontal bone.

Parietal bones

Pair of bones forming the superior sides and roof of the skull.

Temporal bones

Bones located at the sides of the skull near the ears; contain mastoid and styloid processes and the external auditory meatus.

Mastoid process

Bony projection behind the ear; attachment for neck muscles.

Styloid process

Spike-like projection near the ear.

External auditory meatus

Ear canal; opening that conducts sound to the eardrum.

Occipital bone

Posterior/base of the skull; contains the foramen magnum.

Foramen magnum

Large opening in the occipital bone through which the spinal cord passes.

Occipital condyles

Rounded knobs on either side of the foramen magnum that articulate with the first cervical vertebra.

External occipital protuberance

Prominent bump at the back of the skull.

Hypoglossal canal

Small openings that transmit the hypoglossal nerve.

Sphenoid bone

Bat-shaped bone at the base of the skull; forms part of the orbits and skull base.

Sphenoid sinus

Air-filled cavity within the sphenoid bone.

Sella turcica

Depression in the sphenoid bone that houses the pituitary gland.

Foramen rotundum

Round hole in the sphenoid; transmits the maxillary nerve (V2).

Foramen ovale

Oval opening in the sphenoid; transmits the mandibular nerve (V3).

Foramen spinosum

Small opening in the sphenoid; transmits the middle meningeal vessels.

Foramen lacerum

Irregular opening at the base of the skull near the sphenoid; in life mostly cartilage.

Paranasal sinuses

Air-filled spaces within skull bones (frontal, maxillary, sphenoid, ethmoid) that lighten the skull and humidify air.

Ethmoid bone

Bone between the nasal cavity and orbits; contains the cribriform plates, olfactory foramina, perpendicular plate, and conchae.

Cribriform plate

Part of the ethmoid with tiny holes (olfactory foramina) for smell nerves.

Olfactory foramina

Small holes in the cribriform plate allowing olfactory nerves to pass.

Perpendicular plate (nasal septum)

Part of the ethmoid forming the nasal septum.

Superior/middle/inferior nasal conchae

Ethmoid structures that form bony scrolls inside the nasal cavity to increase surface area.

Hyoid bone

U-shaped bone in the throat that is not directly attached to other bones; attaches to muscles.

Fontanels

Connective tissue gaps between newborn cranial bones (e.g., anterior and posterior fontanels) that allow skull growth.

Suture bones

Bones defined by location in the skull sutures; fuse as the skull develops.

Sesamoid bones

Bones embedded within tendons (e.g., patella) to protect tendons and alter pressure.

Sutures

Immovable fibrous joints between skull bones that fuse as the skull matures.

Gomphosis

Fibrous joint that anchors a tooth in its socket.

Syndesmosis

Fibrous joint where two bones are joined by a ligament (e.g., radius/ulna, tibia/fibula) with limited movement.

Synovial joint

Freely movable joint with a synovial cavity, synovial fluid, and articular cartilage.

Planar (gliding) joints

Synovial joints where bones slide past each other (e.g., intercarpal joints, ribs with vertebrae).

Hinge joint

Synovial joint allowing flexion and extension (e.g., elbow, knee).

Pivot (rotational) joint

Synovial joint permitting rotation around a single axis (e.g., atlas–axis, radius–ulna).

Condyloid joint

Synovial joint permitting circular movement (e.g., radius with carpal bones).

Saddle joint

Specialized synovial joint in the thumb allowing some circumduction but not a full circle.

Ball-and-socket joint

Synovial joint allowing flexion, extension, abduction, adduction, and rotation (e.g., shoulder, hip).

Frontal bone landmarks

Frontal bone with supraorbital foramen and frontal sinus.

Temporal bone landmarks

Temporal bone with mastoid process, styloid process, and external auditory meatus.

Occipital landmarks

Occipital bone with foramen magnum, occipital condyles, and external occipital protuberance.