`Example: The femur is part of the appendicular skeleton, while the sternum is part of the axial skeleton.

| Term | Definition | Example |

| ---------------------- | ------------------------------------------------------- | --------------------------------------- |

| Superior (cranial) | Toward the head or upper part of the body | The head is superior to the chest. |

| Inferior (caudal) | Away from the head or toward the lower part of the body | The stomach is inferior to the heart. |

| Anterior (ventral) | Toward the front of the body | The sternum is anterior to the spine. |

| Posterior (dorsal) | Toward the back of the body | The heart is posterior to the sternum. |

| Medial | Toward the midline | The nose is medial to the eyes. |

| Lateral | Away from the midline | The arms are lateral to the chest. |

| Proximal | Closer to the point of attachment (used for limbs) | The elbow is proximal to the wrist. |

| Distal | Farther from the point of attachment | The fingers are distal to the elbow. |

| Superficial | Toward or at the surface | The skin is superficial to the muscles. |

| Deep | Away from the body surface | The bones are deep to the skin. |

| Region | Common Name | Location |

| ---------------- | ----------- | ---------------------------- |

| Cephalic | Head | Entire head region |

| Cervical | Neck | Area between head and thorax |

| Thoracic | Chest | Between neck and abdomen |

| Abdominal | Abdomen | Below the thorax |

| Pelvic | Pelvis | Lower trunk area |

| Brachial | Arm | Upper arm |

| Antebrachial | Forearm | Between elbow and wrist |

| Carpal | Wrist | Base of hand |

| Femoral | Thigh | Upper leg |

| Crural | Leg | Lower leg (shin area) |

| Plantar | Sole | Bottom of foot |

| Plane | Description | Example |

| --------------------------- | ---------------------------------------------- | ------------------------------------------ |

| Sagittal | Divides body into right and left parts | Midsagittal divides exactly in the middle. |

| Frontal (coronal) | Divides body into anterior and posterior parts | Heart and lungs seen from front. |

| Transverse (horizontal) | Divides body into superior and inferior parts | Used for CT or MRI scans. |

| Oblique | Divides body at an angle | Rarely used; diagonal cut. |

| System | Major Organs | Main Function |

| ------------------ | ------------------------------------ | ------------------------------------------------------- |

| Integumentary | Skin, hair, nails | Protection, vitamin D synthesis, temperature regulation |

| Skeletal | Bones, joints | Support, movement, protection, stores minerals |

| Muscular | Muscles | Movement, posture, heat production |

| Nervous | Brain, spinal cord, nerves | Control and communication |

| Endocrine | Glands (pituitary, thyroid, adrenal) | Hormone production and regulation |

| Cardiovascular | Heart, blood vessels | Transport of nutrients, gases, waste |

| Lymphatic | Lymph nodes, spleen | Immunity and fluid balance |

| Respiratory | Lungs, trachea | Gas exchange (O₂ in, CO₂ out) |

| Digestive | Stomach, intestines, liver | Breaks down and absorbs nutrients |

| Urinary | Kidneys, bladder | Removes waste, regulates water balance |

| Reproductive | Ovaries, testes | Produces gametes and hormones |

| Microscope Part | Function |

| ---------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |

| Ocular lenses (eyepieces) | The lenses you look through; usually magnify 10×. |

| Objective lenses | Found on the rotating nosepiece; provide additional magnification. Common powers: 4× (scanning), 10× (low power), 40× (high power), and sometimes 100× (oil immersion). |

| Stage | The flat platform where the slide is placed. |

| Stage clips / mechanical stage | Hold the slide in place and allow movement. |

| Condenser | Focuses light onto the specimen. |

| Iris diaphragm | Adjusts the amount of light reaching the specimen. |

| Coarse adjustment knob | Moves the stage up and down quickly for general focusing (use only with low power). |

| Fine adjustment knob | Allows precise focusing under higher magnifications. |

| Arm | Supports the upper parts of the microscope; used for carrying. |

| Base | Supports the microscope and contains the light source. |

| Light source / illuminator | Provides the light that passes through the specimen. |

| Nosepiece (revolving turret) | Holds the objective lenses and allows switching between them. |

| Objective Lens | Power | Ocular (10×) | Total Magnification |

| ---------------------------- | --------- | ---------------- | ----------------------- |

| Scanning | 4× | 10× | 40× |

| Low Power | 10× | 10× | 100× |

| High Power | 40× | 10× | 400× |

| Oil Immersion (if available) | 100× | 10× | 1000× |

| Structure | Function | Visual Tip (Model / Microscope) |

| -------------------------------------- | ------------------------------------------------------------------ | --------------------------------------- |

| Plasma membrane | Selectively permeable barrier; controls what enters/exits the cell | Thin outer boundary |

| Cytoplasm | Gel-like material that contains organelles | Background of cell interior |

| Nucleus | Control center; stores DNA | Large round structure, often in center |

| Nuclear envelope | Double membrane around nucleus | Has visible pores |

| Nucleolus | Site of ribosome production | Dark spot inside nucleus |

| Ribosomes | Site of protein synthesis | Small dots—free or on ER |

| Rough endoplasmic reticulum (RER) | Has ribosomes; modifies and transports proteins | Folded membranes near nucleus |

| Smooth endoplasmic reticulum (SER) | Lipid synthesis and detoxification | Tubular, no ribosomes |

| Golgi apparatus | Packages, modifies, and ships proteins | Stack of flattened sacs (like pancakes) |

| Mitochondria | Produce ATP (energy) | Bean-shaped with inner folds (cristae) |

| Lysosomes | Contain digestive enzymes; break down waste | Small spheres in cytoplasm |

| Centrioles | Form spindle fibers during mitosis | Cylindrical pairs near nucleus |

| Cytoskeleton | Provides structure and movement | Network of fibers in cytoplasm |

| Stage | Description | What You’ll See |

| --------------- | ------------------------------------------------------------------------------------------------------- | ------------------------------------------------------- |

| Interphase | Cell grows, performs normal functions, and replicates DNA before division. (Includes G₁, S, G₂ phases.) | Nucleus and nucleolus visible; chromatin not condensed. |

| Prophase | Chromatin condenses into chromosomes; nuclear envelope breaks down; spindle forms. | Thick chromosomes appear; no visible nucleus. |

| Metaphase | Chromosomes line up along the middle (equator). | Chromosomes in a straight line across center. |

| Anaphase | Sister chromatids separate and move toward opposite poles. | “V-shaped” chromosomes moving apart. |

| Telophase | Nuclear envelopes reform; chromosomes uncoil. | Two nuclei forming at opposite ends. |

| Cytokinesis | Division of cytoplasm into two cells. | Cell pinches in half (cleavage furrow). |

| Phase | Key Features Under Microscope |

| -------------- | ------------------------------------------------- |

| Interphase | Normal nucleus visible; DNA uncoiled |

| Prophase | Chromosomes appear thick; nuclear envelope fading |

| Metaphase | Chromosomes aligned in middle |

| Anaphase | Chromatids pulled apart to opposite ends |

| Telophase | Two nuclei forming; cell beginning to split |

| Type | Structure / Description | Function | Location |

| ---------------------------------------- | ----------------------------------------------------------- | ------------------------- | ------------------------------------------ |

| Simple squamous | Single layer of flat cells | Diffusion, filtration | Lungs (alveoli), lining of blood vessels |

| Simple cuboidal | Single layer of cube-shaped cells | Secretion, absorption | Kidney tubules, glands |

| Simple columnar | Tall cells, may have goblet cells or cilia | Absorption, secretion | Lining of small intestine, stomach |

| Pseudostratified columnar | Appears layered; nuclei at different levels; often ciliated | Moves mucus | Lining of trachea, upper respiratory tract |

| Stratified squamous (keratinized) | Many layers; surface cells dead and filled with keratin | Protection | Epidermis of skin |

| Stratified squamous (nonkeratinized) | Many layers; surface cells alive | Protection, moist surface | Mouth, esophagus, vagina |

| Transitional epithelium | Changes shape; rounded to flat when stretched | Stretching | Urinary bladder, ureters |

| Stratified cuboidal/columnar (rare) | Two or more layers of cube or column cells | Protection, secretion | Some glands (salivary, mammary) |

| Type | Description | Function | Location |

| ---------------------- | ------------------------------------------- | ------------------------------------ | ------------------------------------- |

| Areolar (loose) | All 3 fiber types, lots of ground substance | Cushions organs, binds tissues | Under epithelium, around capillaries |

| Adipose | Fat cells with nucleus pushed aside | Stores energy, insulation | Under skin, around organs |

| Reticular | Network of reticular fibers | Supports soft organs | Spleen, lymph nodes |

| Dense regular | Collagen fibers parallel | Strong attachment, resists tension | Tendons, ligaments |

| Dense irregular | Collagen fibers irregularly arranged | Strength in many directions | Dermis of skin |

| Elastic connective | Many elastic fibers | Stretch and recoil | Walls of arteries, lungs |

| Hyaline cartilage | Firm matrix, chondrocytes in lacunae | Smooth surface, supports | Ends of long bones, trachea, nose |

| Elastic cartilage | More elastic fibers | Flexibility | Ear, epiglottis |

| Fibrocartilage | Thick collagen fibers | Shock absorption | Intervertebral discs, pubic symphysis |

| Bone (osseous) | Hard matrix with osteocytes in lacunae | Support, protection, calcium storage | Skeleton |

| Blood | Fluid matrix (plasma) with cells | Transport gases, nutrients, waste | Blood vessels |

| Type | Description | Control | Location | Function |

| ------------ | ------------------------------------------ | ----------- | ----------------------------------------------------- | ------------------------------- |

| Skeletal | Long, cylindrical, multinucleate, striated | Voluntary | Attached to bones | Movement of skeleton |

| Cardiac | Branched, striated, intercalated discs | Involuntary | Heart | Pumps blood |

| Smooth | Spindle-shaped, no striations | Involuntary | Walls of hollow organs (stomach, intestines, vessels) | Moves substances through organs |

| Function | Description |

| -------------------------- | --------------------------------------------------------------- |

| Protection | Barrier against injury, pathogens, and UV light |

| Temperature regulation | Sweat glands and blood vessels help control heat loss |

| Sensation | Sensory receptors detect touch, pressure, pain, and temperature |

| Excretion | Small amounts of wastes removed in sweat |

| Vitamin D synthesis | Skin cells use sunlight to make vitamin D |

| Water retention | Prevents dehydration by limiting water loss |

| Layer | Tissue Type | Key Features / Function |

| ----------------------------------- | ---------------------------------------------- | ----------------------------------------------------- |

| Epidermis | Stratified squamous keratinized epithelium | Outer layer; protection and water resistance |

| Dermis | Dense irregular & areolar connective tissue | Contains blood vessels, glands, and sensory receptors |

| Hypodermis (subcutaneous layer) | Loose connective (areolar & adipose) | Anchors skin to underlying structures and insulates |

| Layer | Tissue Type | Contents / Function |

| ------------------- | --------------------------------- | ------------------------------------------------------------------ |

| Papillary layer | Loose (areolar) connective tissue | Dermal papillae (fingerprints), capillaries, sensory neurons |

| Reticular layer | Dense irregular connective tissue | Collagen and elastic fibers, glands, hair follicles, blood vessels |

| Structure | Description / Function | Location / Appearance |

| ------------------------------- | ----------------------------------------------- | ------------------------------- |

| Hair shaft | Visible part of hair above skin | Extends from follicle |

| Hair root | Part below surface | Anchors hair into follicle |

| Hair follicle | Tube-like structure around root | Surrounded by dermal tissue |

| Arrector pili muscle | Smooth muscle that causes “goosebumps” | Attached to hair follicle |

| Sebaceous gland | Secretes sebum (oil) to lubricate hair/skin | Usually near hair follicle |

| Sweat (sudoriferous) glands | Produce sweat for cooling | Coiled tubular glands in dermis |

| Eccrine glands | Watery sweat; temperature regulation | Found all over body |

| Apocrine glands | Thicker sweat (with scent) | Armpits, groin |

| Sensory receptors | Detect touch, pressure, pain, temperature | Throughout dermis |

| Blood vessels | Nourish skin, regulate temp | In dermis and hypodermis |

| Nails | Modified epidermis for protection | Fingertips and toes |

| Division | Includes | Function |

| ------------------------- | -------------------------------------- | ------------------------------------------------ |

| Axial Skeleton | Skull, vertebral column, ribs, sternum | Protects brain, spinal cord, and thoracic organs |

| Appendicular Skeleton | Limbs and girdles (shoulder, pelvic) | Movement and support |

| Bone Type | Description / Example |

| ------------------- | -------------------------------------------- |

| Long bones | Longer than wide (femur, humerus) |

| Short bones | Cube-shaped (carpals, tarsals) |

| Flat bones | Thin and often curved (skull, ribs, sternum) |

| Irregular bones | Complex shapes (vertebrae, pelvis) |

| Sesamoid bones | Form within tendons (patella) |

| Bone / Structure | Location / Description |

| ----------------------- | --------------------------------------------------------------------------------------------------------------------- |

| Frontal bone | Forehead |

| Parietal bones (2) | Top and sides of skull |

| Temporal bones (2) | Sides near ears |

| Occipital bone | Back of skull; contains foramen magnum |

| Sphenoid bone | Butterfly-shaped; forms base of skull |

| Ethmoid bone | Between eyes; forms part of nasal cavity |

| Maxilla | Upper jaw |

| Mandible | Lower jaw; only movable facial bone |

| Zygomatic bones (2) | Cheekbones |

| Nasal bones (2) | Bridge of nose |

| Lacrimal bones (2) | Small bones at inner corner of eye socket |

| Palatine bones (2) | Posterior part of hard palate |

| Vomer | Forms lower portion of nasal septum |

| Sutures | Coronal (frontal-parietal), Sagittal (between parietals), Lambdoid (parietal-occipital), Squamous (parietal-temporal) |

| Region | # of Vertebrae | Key Features |

| --------------------- | ------------------ | ----------------------------------------------------------------- |

| Cervical (C1–C7) | 7 | Small, has transverse foramina; C1 = atlas, C2 = axis |

| Thoracic (T1–T12) | 12 | Articulate with ribs; long spinous processes |

| Lumbar (L1–L5) | 5 | Largest, weight-bearing |

| Sacrum | 5 fused | Connects spine to pelvis |

| Coccyx | 3–5 fused | Tailbone |

| Bone / Structure | Description |

| ---------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |

| Sternum | Breastbone; consists of: manubrium, body, xiphoid process |

| Ribs (24 total) | 12 pairs: <br>• True ribs (1–7) attach directly to sternum <br>• False ribs (8–10) attach indirectly via cartilage <br>• Floating ribs (11–12) do not attach to sternum |

| Costal cartilage | Connects ribs to sternum |

| Thoracic vertebrae | Posterior anchors of ribs |

| Region | Major Bones |

| ------------------- | ------------------------------------------------------ |

| Pectoral girdle | Clavicle, scapula |

| Upper limb | Humerus, radius, ulna, carpals, metacarpals, phalanges |

| Pelvic girdle | Coxal bones (ilium, ischium, pubis) |

| Lower limb | Femur, tibia, fibula, tarsals, metatarsals, phalanges |