Lab Exam 2

Epidermis

Superficial, avascular layer composed of keratinized stratified squamous epithelium.

Dermis

Deeper, vascular connective tissue layer beneath the epidermis; contains nerve endings, hair follicles, and glands.

Dermal Papilla

Finger-like upward projections of the dermis that interlock with the epidermis to form skin ridges (fingerprints).

Hair Follicle

Tubular invagination of the epidermis surrounding the hair root.

Hair Root

The portion of the hair embedded below the skin surface within the follicle.

Hair Shaft

The visible portion of the hair extending above the skin surface.

Sebaceous Gland

Multi-lobed, oil-producing gland connected directly to hair follicles; secretes sebum.

Eccrine Sweat Gland

Coiled tubular gland located in the dermis with a duct leading directly to a surface pore for thermoregulation.

Pacinian Corpuscle (Lamellar)

Large, onion-like layered sensory receptor located deep in the dermis or hypodermis; detects deep pressure and vibration.

Meissner’s Corpuscle (Tactile)

Small, oval sensory receptor situated high in the dermal papillae; detects light touch.

Arrector Pili Muscle

Smooth muscle band extending from the upper dermis to the hair follicle; contracts to pull hair upright ("goosebumps").

Coronal

Connects frontal bone with parietal bones across the anterior skull.

Sagittal

Connects the right and left parietal bones along the midline top of the skull.

Lambdoidal

Connects parietal bones with the occipital bone along the posterior skull.

Squamosal

Connects parietal bone with temporal bone on the lateral side of the skull.

Parietal Bones

Pair forming superior and lateral walls of the cranium.

Temporal Bones

Pair on inferior sides of cranium.

Zygomatic Process

Posterior projection forming part of the cheekbone.

Zygomatic Arch

Formed by zygomatic process of temporal bone and temporal process of zygomatic bone.

External Acoustic Meatus/Canal

Outer canal opening leading to the eardrum.

Mastoid Process

Rounded projection posterior to the ear for muscle attachment.

Styloid Process

Needle-like downward projection for muscle and ligament attachment.

Carotid Canal

Anteromedial opening on inferior surface for internal carotid artery.

Jugular Foramen

Large posterior opening on inferior surface for internal jugular vein and cranial nerves IX, X, XI.

Frontal Bone

Anterior skull bone forming forehead and upper orbits.

Supraorbital Foramen/Notch

Small opening above orbit for nerves and vessels.

Occipital Bone

Posterior and inferior base of skull.

Foramen Magnum

Large central opening allowing brainstem to connect with spinal cord.

Occipital Condyles

Smooth rounded processes flanking foramen magnum that articulate with atlas (C1).

Sphenoid Bone

Butterfly-shaped bone spanning the floor of the central cranium.

Greater & Lesser Wings

Lateral extensions forming parts of cranial floor and orbits.

Sella Turcica

Saddle-shaped depression holding the pituitary gland.

Optic Canal

Anterior canal for optic nerve (CN II).

Superior Orbital Fissure

Slit-like opening in orbit for CN III, IV, V1, VI.

Foramen Ovale

Oval opening for mandibular nerve (CN V3).

Foramen Spinosum

Small posterolateral opening for middle meningeal artery.

Foramen Lacerum

Irregular jagged opening at junction of sphenoid, temporal, and occipital bones.

Ethmoid Bone

Spongy bone between orbits forming nasal roof and septum.

Perpendicular Plate

Superior vertical plate forming upper nasal septum.

Crista Galli

Superior median ridge anchoring dura mater.

Cribriform Plate

Horizontal perforated plate flanking crista galli for olfactory nerve fibers (CN I).

Maxilla

Upper jawbone forming central face, hard palate, and floor of orbits.

Mandible

Lower jawbone (only movable skull bone).

Mental Foramen

Opening on anterior lateral body for mental nerve and vessels.

Zygomatic Bones

Cheekbones.

Temporal Process

Posterior process joining temporal bone.

Zygomatic Arch

Arch formed with temporal bone.

Lacrimal Bones

Small bones in medial orbital wall.

Nasolacrimal Canal

Groove housing tear duct into nasal cavity.

Nasal Bones

Small paired bones forming bridge of nose.

Vomer

Inferior plow-shaped bone forming lower nasal septum.

Hyoid Bone

U-shaped floating bone in anterior neck; anchors tongue muscles.

Body

Anterior solid weight-bearing block.

Vertebral Foramen

Central canal housing spinal cord.

Spinous Process

Posterior projection felt along spine.

Transverse Process

Lateral projections for muscle attachment.

Pedicle

Bony bridge connecting body to transverse process.

Lamina

Bony roof connecting transverse process to spinous process.

Atlas (C1)

Ring-like bone without body or spinous process; has superior facets articulating with occipital condyles and facet for dens anteriorly.

Axis (C2)

Has vertical peg (dens/odontoid process) acting as pivot for atlas.

Thoracic Vertebrae (T1–T12)

Heart-shaped bodies with costal facets for rib articulation; long downward-sloping spinous processes.

Lumbar Vertebrae (L1–L5)

Massive blocky bodies; short, hatchet-shaped spinous processes.

Sacrum

Triangular bone formed by 5 fused vertebrae.

Coccyx

Tailbone formed by 3–5 fused vestigial vertebrae.

Sternum

Breastbone consisting of superior Manubrium, middle Body (gladiolus), and inferior Xiphoid Process.

True Ribs (1–7)

Direct cartilage attachment to sternum.

False Ribs (8–12)

Indirect cartilage attachment (8–10) or no anterior attachment (11–12).

Floating Ribs (11–12)

Subgroup of false ribs with unattached anterior ends

Clavicle

S-shaped collarbone.

Scapula

Shoulder blade.

Spine

Posterior prominent ridge.

Supraspinous Fossa

Depression superior to spine.

Infraspinous Fossa

Depression inferior to spine.

Acromion Process

Lateral apex of spine articulating with clavicle.

Glenoid Cavity

Lateral socket articulating with humerus head.

Coracoid Process

Anterior hook-like projection for muscle attachments.

Subscapular Fossa

Smooth anterior concave surface facing ribs.

Humerus

Arm bone.

Anatomical Neck

Smooth groove surrounding head; Surgical Neck

Deltoid Tuberosity

Lateral mid-shaft roughened ridge for deltoid attachment.

Trochlea

Medial spool-shaped distal condyle for ulna.

Capitulum

Lateral rounded distal condyle for radius.

Olecranon Fossa

Deep posterior distal depression for ulnar olecranon process.

Ulna

Medial forearm bone.

Trochlear (Semilunar) Notch

C-shaped wrench-like groove grasping humerus trochlea.

Coronoid Process

Anterior lip of trochlear notch.

Olecranon Process

Posterior prominent elbow tip.

Styloid Process

Distal medial point at wrist.

Radius

Lateral forearm bone.

Head

Disc-shaped proximal end; Radial Tuberosity

Carpals (Wrist - 8 bones)

Proximal row (lateral to medial)

Metacarpals

Palm bones numbered I–V starting at thumb.

Phalanges (Hand)

Finger bones (Proximal, Middle, Distal); Pollex (thumb) has only proximal and distal.

Ilium

Superior region featuring Iliac Crest (upper rim) and Greater Sciatic Notch (posterior cutout for sciatic nerve).

Ischium

Inferior posterior region featuring Lesser Sciatic Notch, Ischial Tuberosity (sit-bone weight bearer), Acetabulum (deep socket for femur head), and Obturator Foramen (large hole between ischium and pubis).

Pubis

Inferior anterior region joining at Pubic Symphysis (cartilage pad).

Femur

Thigh bone.

Head

Proximal sphere articulating with acetabulum; Neck & Shaft

Linea Aspera

Posterior longitudinal ridge on shaft.