Anatomy & Physiology I: Cytology, Histology, and Anatomical Terminology

Course and Exam Information

• Course: Anatomy & Physiology I Lab (Fall 2026)

• Midterm Exam Window: Week of October 5, 2026 – October 10, 2026

• Exam Duration: Approximately $50$ minutes

• Exam Logistics & Mandatory Rules:

  • Every student MUST bring a SCANTRON.

  • Exams start strictly ON TIME.

  • NO SMART DEVICES allowed in the exam room.

  • Last Day to Study in Lab: Friday, October 2, 2026.

  • Lab Access Restriction: Starting Saturday, October 3, 2026, the lab room is OFF ACCESS.

• Upcoming Due Dates & Quizzes:

  • Histology & Cytology "Check your Recalls" assignments are due next week.

  • Quiz scheduled for next week covering the Integumentary System (Skin Section).

Anatomical Orientation and Directional Terminology

• Anatomy & Physiology Definition: Anatomy and Physiology (A&P) is the study and science of the structure and function of the human body. Mastery requires continuous repetition and practical application of specialized medical terminology.

• Standard Anatomical Position:

  • Definition: A standardized, universal position of reference used by healthcare professionals and scientists to describe body parts and positions unambiguously.

  • Position Criteria:

  • Body standing upright, facing forward.

  • Toes pointing forward.

  • Feet spaced shoulder-width apart.

  • Upper limbs at the sides with palms facing forward.

• Major Body Divisions:

  • Axial Region: Consists of the head, neck, and trunk. This region houses the central nervous system structures associated with the mind (brain and spinal cord).

  • Appendicular Region: Consists of the upper and lower limbs attached to the axial body.

• Directional Term Pairs:

  • Anterior (Ventral) vs. Posterior (Dorsal):

  • Anterior / Ventral: Refers to the front of the body or a structure, or structures traveling toward the front (e.g., the nose is on the anterior side of the body; anterior rami [RAY-mee] of spinal nerves travel toward the front).

  • Posterior / Dorsal: Refers to the back side of the body or a structure, or structures traveling toward the back (e.g., posterior rami).

  • Superior vs. Inferior:

  • Superior: Toward or closer to the head (e.g., superior vena cava is closer to the head; head is superior to the neck).

  • Inferior: Away from the head or toward the tail/feet (e.g., inferior vena cava is located farther away from the head; abdomen is inferior to the chest).

  • Scope Limitation & Rule: Used ONLY on structures located in the axial region (head, neck, and trunk). With very few exceptions, superior and inferior are never used on upper and lower limbs.

  • Mnemonic: "Use your superior mind to remember when to use superior and inferior" — reminds you to use these terms strictly where structures associated with your mind (brain and spinal cord) are housed.

  • Proximal vs. Distal:

  • Scope Limitation & Rule: Used ONLY on the appendicular region (upper and lower limbs) to replace superior and inferior. Limb positional terms must account for mobility; for example, raising an arm above the head changes the relative vertical orientation of the hand to the shoulder, rendering superior/inferior ambiguous.

  • Proximal: Refers to closeness or proximity of a structure to its point of origin (the shoulder for upper limbs, the hip for lower limbs). Root word proxim- means "near" (e.g., proximity, approximate).

    • Mnemonic: The more proximal structure is in the closest proximity to the hip or shoulder (e.g., the proximal end of the femur is closest to the hip; the knee is proximal to the ankle).

  • Distal: Refers to farness or distance of a structure from its point of origin (shoulder or hip). Root word dist- means "far" (e.g., distance, distant, distinct, distend).

    • Mnemonic: The more distal structure is the most distant from the hip or shoulder (e.g., the distal end of the femur is farthest from the hip; fingers are distal to the wrist).

  • Medial vs. Lateral:

  • Midline: An imaginary vertical line running down the exact center of the body.

  • Medial: Closer to the midline of the body (e.g., the ulna is the inner forearm bone, making it medial to the radius; eyes are medial to the ears; nose is medial to the cheek).

  • Lateral: Farther away from the midline of the body (e.g., the radius is the outer forearm bone, making it lateral to the ulna; ears are lateral to the eyes; arm is lateral to the torso).

  • Superficial vs. Deep:

  • Superficial: Closer to the surface of the body or skin (e.g., skin is superficial to muscle).

  • Deep: Farther away from the surface of the body or deeper internal (e.g., muscle and bone are deep to skin; lungs are deep to the chest wall).

• Clinical Application & Precision Comparisons:

  • Imprecise Description: "The wound is near the middle and top of the chest."

  • Precise Description: "The wound is on the right anterior thoracic region, $4\,\text{cm}$ lateral to the sternum, and $3\,\text{cm}$ inferior to the acromial region."

  • Complex Clinical Case Example: "The bullet entered the right posterior scapular region, $3\,\text{cm}$ lateral to the vertebral region, $4\,\text{cm}$ inferior to the cervical region, and penetrated deep to the muscle and bone, but superficial to the lung and parietal pleura…"

• Directional Terms Practice Solutions:

  • The elbow is proximal to the wrist.

  • The chin is inferior to the nose.

  • The shoulder is lateral to the clavicle (collarbone).

  • The forehead is superior to the mouth.

  • The skin is superficial to the muscle.

  • The esophagus is deep (or posterior) to the sternum (breastbone).

  • The nose is medial to the cheek.

  • The spine is on the posterior (or dorsal) side of the body.

  • The arm is lateral to the torso.

  • The knee is distal to the hip.

Microscopy and Magnification

• Compound Light Microscope Lenses:

  • Objective Lenses:

  • $4\text{X}$ Scanning Objective

  • $10\text{X}$ Low Power Objective

  • $40\text{X}$ High Power Objective

  • Ocular Lens (Eyepiece): Typically $10\text{X}$ magnification.

• Total Magnification Formula:   $\text{Total Magnification} = \text{Objective Lens Magnification} \times \text{Ocular Lens Magnification}$

• Magnification Calculations:

  • Scanning Power ($4\text{X}$ Objective):     $4\text{X} \times 10\text{X} = 40\text{X}$

  • Low Power ($10\text{X}$ Objective):     $10\text{X} \times 10\text{X} = 100\text{X}$

  • High Power ($40\text{X}$ Objective):     $40\text{X} \times 10\text{X} = 400\text{X}$

• Field of View Relationship: Higher magnification brings structures closer into view but reduces the overall field area covered.

Cytology: Cell Structure and Biology

• Etymology & Definition: Cytology is derived from cyt- (cells) and -ology (study of) — the scientific study of cells. Cells are the fundamental living units of organisms and exist in unicellular or multicellular forms.

• Three Primary Components of Cells:

  1. Plasma Membrane

  2. Cytoplasm

  3. Nucleus

• 1. Plasma Membrane:

  • Structure: Outer cellular boundary formed by a phospholipid bilayer.

  • Polar Heads: Hydrophilic (water-loving) heads facing outward.

  • Non-Polar Tails: Hydrophobic (water-fearing) tails facing inward.

  • Properties: Semipermeable barrier governing transport.

  • Embedded Molecular Components: Contains embedded proteins and steroids essential for structural stabilization, cellular communication, and molecular transport.

• 2. Cytoplasm:

  • Definition: Jellylike aqueous gel filling the interior of the cell.

  • Constituents:

  • Cytosol: Water, dissolved solutes, RNA, metabolic enzymes, and structural proteins.

  • Cytoskeleton: Network of protein filaments and microtubules providing mechanical support, shape, and internal movement pathways.

  • Organelles: Specialized internal cellular sub-structures executing distinct biological functions.

• 3. Organelle Functions:

  • Ribosomes: Unbound/free floating in cytosol or bound to the endoplasmic reticulum; primary machinery for protein synthesis.

  • Peroxisomes: Membrane-enclosed sacs containing specialized enzymes that detoxify metabolic waste and harmful substances.

  • Mitochondria: Bean-shaped organelles responsible for cellular respiration and generating cellular energy (ATP).

  • Endoplasmic Reticulum (ER):

  • Rough ER: Studded with membrane-bound ribosomes; modifies and folds synthesized proteins.

  • Smooth ER: Lacks ribosomes; synthesizes lipids, phospholipids, and steroids.

  • Golgi Apparatus: Flattened membrane stacks that modify, package, and sort cellular products within vesicles for intracellular delivery or exocytosis.

  • Lysosomes: Membrane-bound vesicles filled with hydrolytic enzymes that digest cellular debris, engulfed foreign materials, and worn-out organelles.

• Comparison of Plant Cells vs. Animal Cells:

  • Plant Cells:

  • Possess a large central vacuole for fluid and nutrient storage.

  • Enclosed by a rigid, thick cell wall outside the membrane.

  • Large, rigid, fixed geometric shape.

  • Contain chloroplasts for photosynthesis (autotrophic; produce their own food).

  • Animal Cells:

  • Lack a large central storage vacuole.

  • Bounded exclusively by a flexible plasma membrane (no cell wall).

  • Small, rounded, or irregular/variable shape.

  • Lack chloroplasts (heterotrophic; cannot synthesize food).

Histology: Tissue Classification and Types

• Etymology & Definition: Histology is derived from hist- (tissue) and -ology (study of) — the microscopic study of tissue structures.

• Four Fundamental Human Tissue Types:

  1. Muscle Tissue: Specialized to contract and generate force (e.g., skeletal muscle, cardiac muscle, smooth muscle).

  2. Nervous Tissue: Specialized to receive environmental stimuli, transmit electrical impulses, and process signals (e.g., neurons, neuroglial cells).

  3. Connective Tissue: Specialized to connect, bind, support, protect, and transport materials (e.g., bone, adipose tissue, ligaments, blood, white fibrous tissue, cartilage).

  4. Epithelial Tissue: Covers external body surfaces, lines internal organs, lines body cavities, and forms glands (e.g., simple cuboidal, simple columnar, simple squamous, stratified squamous, pseudostratified ciliated columnar epithelium).

• Epithelial Tissue Categorization:

  • Categorization by Layering ($3$ types):

  • Simple Epithelium: Composed of a single layer of cells ($1$ layer thick).

  • Stratified Epithelium: Composed of multiple stacked layers ($2$ or more layers thick).

  • Pseudostratified Epithelium: (Pseudo = false) Appears layered due to nuclei positioned at varying levels, but consists of only a single layer ($1$ layer thick) attached to the basement membrane.

  • Categorization by Cell Shape ($3$ types):

  • Squamous: Thin, flattened, scale-like cells ("squished scales").

  • Cuboidal: Cube-shaped cells with central spherical nuclei.

  • Columnar: Tall, rectangular, column-like cells with elongated nuclei near the basal surface.

Histological Microscopic Slide Identifications

• 1. Human Blood Smear (Blood):

  • Type: Liquid connective tissue.

  • Characteristics: Formed elements including abundant, non-nucleated biconcave red blood cells (erythrocytes), larger nucleated white blood cells (leukocytes), and cell fragments (platelets) suspended in fluid plasma matrix.

• 5. Human Simple Columnar Epithelium:

  • Type: Epithelial tissue.

  • Characteristics: Single layer of tall, column-shaped cells with oval nuclei situated near the basal basement membrane; functions in absorption and secretion; lines stomach, small intestine, and large intestine.

• 7. Stratified Squamous Epithelium:

  • Type: Epithelial tissue.

  • Characteristics: Multiple layers of cells with flat squamous cells at the free apical surface and cuboidal/columnar cells near the basal layer; protects underlying tissues against wear and abrasion; forms skin epidermis, oral lining, and esophagus.

• 8. Simple Cuboidal Epithelium:

  • Type: Epithelial tissue.

  • Characteristics: Single layer of cube-shaped cells with prominent, centrally located spherical nuclei; functions in secretion and absorption; lines renal tubules and small gland ducts.

11. Human Skeletal Muscle:

• Type: Muscle tissue.

• Characteristics: Long, cylindrical, unbranched muscle fibers showing distinct transverse striations and multiple peripherally located nuclei; under voluntary somatic control.

• 14. Giant Multipolar Neuron:

  • Type: Nervous tissue.

  • Characteristics: Large star-shaped neuronal cell bodies (soma) containing central nuclei, displaying multiple branching dendrites and a long axon extension, surrounded by small supporting neurological cells.

• 1. Mammal Smooth Muscle:

  • Type: Muscle tissue.

  • Characteristics: Non-striated, elongated, spindle-shaped cells with a single centrally located oval nucleus; contracts involuntarily; found in the walls of hollow organs (e.g., stomach, intestines, blood vessels).

Reticular connective tissue

Introduction to the Integumentary, Skeletal, and Joint Systems

• Integumentary System Overview:

  • Anatomical Models: Consists of $3$ anatomical skin models examined during lab.

  • Histological Microscope Slides: Nail, hair shaft / hairy skin, skin cross-section.

  • System Functions: Protection against infection and mechanical damage, thermoregulation, cutaneous sensation, vitamin D synthesis, and waste excretion.

• Skeletal System Foundations:

  • Bone Markings: Surface features including projections, ridges, depressions, and openings that serve as joint articulation sites, tendon/ligament attachment points, or passages for blood vessels and nerves.

  • Four Bone Shapes ($4$ Categories):

  1. Long bones (e.g., femur, radius)

  2. Short bones (e.g., carpals, tarsals)

  3. Flat bones (e.g., cranial bones, sternum)

  4. Irregular bones (e.g., vertebrae)

  • Bone Cellular Machinery:

  • Osteoblasts: Bone-forming cells that synthesize, deposit, and secrete organic bone matrix.

  • Osteoclasts: Bone-resorbing cells that break down bone matrix and dissolve minerals.

  • Structural Bone Types:

  • Compact Bone: Dense, hard outer bone layer organized into repeating functional units called osteons.

  • Spongy Bone (Cancellous Bone): Porous inner bone network composed of a lattice of thin trabeculae enclosing red or yellow bone marrow.

• Articulations (Joints):

  • Three Functional Joint Classifications:

  1. Synarthroses: Immovable joints (e.g., cranial sutures).

  2. Amphiarthroses: Slightly movable joints (e.g., pubic symphysis, intervertebral discs).

  3. Diarthroses: Freely movable joints (e.g., shoulder, hip, knee).

  • Structural Classes of Synovial Joints: Freely movable diarthrodial joints characterized by an articular capsule, fluid-filled joint cavity, synovial fluid, and articular hyaline cartilage covering bone ends.