Anatomical Terminology

Anatomical Position and Body Regions

The anatomical position is a standardized stance used as a reference in anatomy. The body stands upright, facing forward, with feet parallel and arms at the sides, palms facing forward.

• Axial Portion: Includes the head, neck, and trunk.

• Appendicular Portion: Includes the limbs (arms and legs).

• Body Regions: Specific areas such as cephalic (head), thoracic (chest), abdominal (abdomen), pelvic (pelvis), brachial (arm), femoral (thigh), etc.

Example: The antecubital region refers to the front of the elbow, while the popliteal region is the back of the knee.

Directional Terms and Body Planes

Directional terms describe the locations of structures relative to other structures or locations in the body.

• Superior (cranial): Toward the head

• Inferior (caudal): Toward the feet

• Anterior (ventral): Toward the front

• Posterior (dorsal): Toward the back

• Medial: Toward the midline

• Lateral: Away from the midline

• Proximal: Closer to the point of attachment

• Distal: Farther from the point of attachment

• Superficial (external): Toward the surface

• Deep (internal): Away from the surface

Body Planes:

• Sagittal Plane: Divides body into right and left parts

• Midsagittal (Median): Divides body into equal right and left halves

• Parasagittal: Divides body into unequal right and left parts

• Frontal (Coronal) Plane: Divides body into anterior and posterior parts

• Transverse Plane: Divides body into superior and inferior parts

Body Cavities and Abdominopelvic Regions

• Dorsal Cavity: Contains cranial and vertebral cavities

• Ventral Cavity: Contains thoracic and abdominopelvic cavities

• Thoracic Cavity: Includes pleural cavities, mediastinum, and pericardial cavity

• Abdominopelvic Cavity: Includes abdominal and pelvic cavities

Abdominopelvic Quadrants: Right/Left Upper and Lower Quadrants

Abdominopelvic Regions: Right/Left Hypochondriac, Lumbar, Iliac; Epigastric, Umbilical, Hypogastric

Serous Membranes and Fluid

• Serous Fluid: Lubricates organs, reducing friction

• Serous Membranes: Double-layered membranes lining body cavities and covering organs

• Examples: Visceral and parietal pericardium (heart), pleura (lungs), peritoneum (abdominal organs)

Histology: Tissues

Overview of Tissue Types

The human body contains four primary tissue types:

• Epithelial Tissue (ET): Covers surfaces, lines cavities, forms glands

• Connective Tissue (CT): Supports, binds, protects, stores energy, transports

• Muscle Tissue: Contracts to produce movement

• Nervous Tissue: Conducts electrical impulses, processes information

Epithelial Tissue

• Polarity: Apical (free) and basal (attached) surfaces

• Cellularity: Densely packed cells, little extracellular matrix

• Specialized Contacts: Tight junctions, desmosomes

• Supported by CT: Basement membrane (basal lamina + reticular lamina)

• Avascular: No blood vessels; nutrients diffuse from underlying CT

• Regeneration: High mitotic rate

Naming: By layers (simple = 1, stratified = 2+) and cell shape (squamous, cuboidal, columnar)

Connective Tissue

• Origin: Mesenchyme (embryonic tissue)

• Matrix: Ground substance + fibers (collagen, elastic, reticular)

• Cells: -blasts (immature, secrete matrix), -cytes (mature, maintain matrix)

• Vascularity: Varies (bone = highly vascular, cartilage = avascular)

Subtypes: Connective tissue proper, cartilage, bone, blood

Connective Tissue Proper

• Areolar CT: Loose, supports and binds tissues

• Adipose CT: Fat storage, insulation

• Reticular CT: Supportive network for cells

• Dense Regular CT: Parallel collagen fibers, tendons/ligaments

• Dense Irregular CT: Irregular collagen fibers, dermis

• Elastic CT: Elastic fibers, allows stretch

Cartilage

• Cells: Chondroblasts (secrete matrix), chondrocytes (in lacunae)

• Types: Hyaline (most common), elastic, fibrocartilage

• Features: Avascular, surrounded by perichondrium (except fibrocartilage)

Bone (Osseous Tissue)

• Cells: Osteoblasts (build bone), osteocytes (maintain bone), osteoclasts (break down bone)

• Types: Compact (osteons), spongy (trabeculae, marrow spaces)

• Highly vascularized

Blood (Vascular Connective Tissue)

• Plasma: Liquid matrix, transports substances

• Formed Elements: Erythrocytes (RBCs, carry O2), leukocytes (WBCs, immunity), thrombocytes (platelets, clotting)

Muscle Tissue

• Function: Contraction for movement

• Types: Skeletal (voluntary, striated), cardiac (involuntary, striated, intercalated discs), smooth (involuntary, non-striated)

• Highly vascularized, excitable cells (myocytes)

Nervous Tissue

• Location: Brain, spinal cord, nerves

• Cells: Neurons (conduct impulses), neuroglia (support, protect, insulate)

• Neuron Structure: Soma (cell body), dendrites (input), axon (output), axon terminals, myelin sheath (Schwann cells in PNS), nodes of Ranvier

Integumentary System

Skin Structure

• Epidermis: Stratified squamous epithelium; layers (superficial to deep): stratum corneum, lucidum (thick skin only), granulosum, spinosum, basale

• Dermis: Papillary layer (areolar CT, dermal papillae, tactile corpuscles), reticular layer (dense irregular CT, lamellar corpuscles, glands, hair follicles)

• Hypodermis: Subcutaneous layer, mostly adipose tissue

Accessory Structures: Hair (follicle, papilla, medulla, cortex, cuticle), glands (eccrine, apocrine, sebaceous), arrector pili muscle, nerve endings

Skeletal System Overview

Bone Structure and Classification

• Long Bones: Longer than wide (e.g., femur)

• Short Bones: Cube-shaped (e.g., carpals)

• Flat Bones: Thin, flat (e.g., sternum)

• Irregular Bones: Complex shapes (e.g., vertebrae)

• Sesamoid Bones: Embedded in tendons (e.g., patella)

Bone Anatomy: Periosteum (outer membrane), compact bone (osteons, lamellae), spongy bone (trabeculae, marrow), epiphysis (ends), diaphysis (shaft), medullary cavity (yellow marrow), endosteum (lining cavity), articular cartilage (joint surface), epiphyseal plate/line (growth region)

Axial and Appendicular Skeleton

Axial Skeleton

• Skull: Cranial and facial bones, sutures, fontanels (in fetus), paranasal sinuses

• Vertebral Column: Cervical (C1–C7), thoracic (T1–T12), lumbar (L1–L5), sacrum, coccyx; intervertebral discs and foramina

• Thoracic Cage: Sternum (manubrium, body, xiphoid), ribs (true, false, floating), costal cartilage

• Hyoid Bone: Supports tongue, not attached to other bones

Appendicular Skeleton

• Pectoral Girdle: Clavicle, scapula

• Upper Limb: Humerus, radius, ulna, carpals, metacarpals, phalanges

• Pelvic Girdle: Os coxa (ilium, ischium, pubis), acetabulum, obturator foramen

• Lower Limb: Femur, patella, tibia, fibula, tarsals, metatarsals, phalanges

Joints (Articulations)

Major Joint Structures

• Shoulder: Ligaments (coracoacromial, coracohumeral, etc.)

• Elbow: Radial/ulnar collateral, annular ligaments

• Hip: Iliofemoral, ischiofemoral, pubofemoral ligaments

• Knee: Patellar ligament, collateral ligaments, cruciate ligaments, menisci

Muscular System

Muscle Identification

• Head/Neck: Frontalis, temporalis, masseter, sternocleidomastoid, etc.

• Torso: Pectoralis major/minor, intercostals, rectus abdominis, trapezius, latissimus dorsi

• Arm: Biceps brachii, triceps brachii, deltoid, rotator cuff muscles

• Leg: Quadriceps, hamstrings, gluteals, gastrocnemius, tibialis anterior, etc.

Muscle Groupings: By location and function (e.g., flexors/extensors, abductors/adductors)

Nervous System

Brain Anatomy

• Cerebrum: Lobes, gyri, sulci, corpus callosum, basal nuclei

• Diencephalon: Thalamus, hypothalamus, epithalamus

• Brainstem: Midbrain, pons, medulla oblongata

• Cerebellum: Lobes, vermis, arbor vitae

• Ventricles and CSF: Lateral, third, fourth ventricles; choroid plexus; flow of CSF

• Meninges: Dura mater, arachnoid mater, pia mater

Spinal Cord and ANS

• Spinal Cord: Enlargements, conus medullaris, cauda equina, filum terminale

• Cross-section: White matter (funiculi), gray matter (horns), central canal, roots, rami

• ANS Structures: Sympathetic trunk, ganglia, rami communicantes

Cranial and Spinal Nerves

• Cranial Nerves (I–XII): Names, foramina, branches

• Spinal Nerves: Cervical, thoracic, lumbar, sacral

• Plexuses: Cervical (phrenic), brachial (axillary, musculocutaneous, radial, median, ulnar), lumbar (femoral), sacral (sciatic, tibial, common fibular)

Special Senses

Eye Anatomy

• External Structures: Eyelids, conjunctiva, lacrimal apparatus

• Muscles: Rectus and oblique muscles, innervation

• Layers: Fibrous (sclera, cornea), vascular (choroid, ciliary body, iris), retina (photoreceptors, bipolar, ganglion cells)

• Chambers: Anterior (aqueous humor), posterior (vitreous humor)

Ear Anatomy

• External Ear: Auricle, external acoustic meatus, tympanic membrane

• Middle Ear: Tympanic cavity, ossicles (malleus, incus, stapes), oval/round windows, pharyngotympanic tube

• Inner Ear: Bony and membranous labyrinths, cochlea (scalae, organ of Corti), vestibule (utricle, saccule), semicircular canals/ducts, hair cells, nerves

Sample Table: Types of Epithelial Tissue

Additional info:

• For each tissue, students should be able to identify key features under the microscope, such as cell shape, arrangement, and presence of structures like cilia or goblet cells.

• For bones and muscles, students should be able to identify structures on models and real specimens, and know their anatomical relationships.

• For nervous and special senses, students should understand both gross and microscopic anatomy, as well as functional significance.