Lab Exam 2

Integumentary System (Skin Model)

Integumentary model key anatomical features, AI generated

  • 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").

Axial Skeletal System

Skull suture anatomical landmarks, AI generated

  • Skull Sutures

    • 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.

  • Cranial Bones & Features

    • 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).

  • Facial Bones & Features

    • 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.

    Anatomy of a representative vertebra, AI generated

  • Vertebrae

    • Universal Structures:

      • 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.

    • Cervical Vertebrae (C1–C7): Smallest vertebrae; feature transverse foramina for vertebral arteries.

      • 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 & Ribs

    • 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.

Appendicular Skeletal System

Appendicular skeleton major divisions, AI generated

  • Pectoral Girdle & Upper Limb

    • 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: Narrowing distal to tubercles (frequent fracture site).

      • 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: Medial bump for biceps insertion; Styloid Process: Distal lateral point at wrist.

    • Carpals (Wrist - 8 bones): Proximal row (lateral to medial): Scaphoid, Lunate, Triquetral, Pisiform. Distal row (lateral to medial): Trapezium, Trapezoid, Capitate, Hamate.

    • Metacarpals: Palm bones numbered I–V starting at thumb.

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

  • Pelvic Girdle & Lower Limb

    • Os Coxae (Hip Bone):

      • 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: Angle connecting head to long body.

      • Linea Aspera: Posterior longitudinal ridge on shaft.

      • Medial & Lateral Condyles: Distal rounded joint surfaces.

      • Intercondylar Fossa: Deep posterior notch between condyles.

      • Patellar Groove/Surface: Smooth anterior distal surface for kneecap.

    • Patella: Sesamoid kneecap bone.

    • Tibia: Medial shin bone.

      • Tibial Tuberosity: Anterior proximal bump for patellar ligament insertion.

      • Anterior Crest: Sharp shin ridge.

      • Medial Malleolus: Distal inner ankle bump.

    • Fibula: Lateral slender leg bone.

      • Head: Proximal enlargement; Lateral Malleolus: Distal outer ankle bump.

    • Tarsals (Ankle - 7 bones): Talus (articulates with tibia), Calcaneus (heel bone), Navicular, Cuboid, and Cuneiforms (1st/Medial, 2nd/Intermediate, 3rd/Lateral).

    • Metatarsals: Sole bones numbered I–V starting at big toe.

    • Phalanges (Foot): Toe bones (Proximal, Middle, Distal); Hallux (big toe) has only proximal and distal.