Comprehensive Human Anatomy & Physiology Review: Tissues, Membranes, and Cell Functions

Stratified squamous epithelium

Type of tissue dealing w/ friction (protective, layered).

Stratified squamous (non-keratinized)

Found in the esophagus.

Stratified squamous (keratinized)

Found at the anus.

Variable

Condition being regulated (ex. body temp).

Stimulus

Change in environment.

Receptor

Detects stimulus.

Control Center

Processes info, decides response.

Effector

Carries out response.

Na⁺/K⁺ Pump

Moves 3 Na⁺ out / 2 K⁺ in.

ATP

Required at step where Na⁺ and K⁺ are actively pumped against gradients.

Dense irregular CT

Collagen fibers irregularly arranged, resists tension in many directions, found in dermis.

Ground substance

Produced by fibroblasts; fills space between fibers.

Proximal/Distal

Nearer/further from trunk.

Superior/Inferior

Above/below.

Dorsal/Ventral

Back/front.

Lateral/Medial

Side/midline.

Phospholipid bilayer

With proteins, cholesterol, carbs.

Selectively permeable

Fluid mosaic model.

Simple diffusion

Molecules move high → low concentration until equilibrium.

Primary active transport

Requires ATP (ex. Na⁺/K⁺ pump).

Endocytosis/Exocytosis

Active transport via vesicles.

Simple columnar

Found in GI tract (absorption/secretion).

Simple squamous

Found in lungs, blood vessels (diffusion).

Simple cuboidal

Found in kidneys, glands (secretion/absorption).

Stratified squamous

Found in skin, esophagus, rectum (protection).

Pseudostratified columnar

Found in respiratory tract (secretion, cilia).

Transitional epithelium

Cells change shape (empty → cuboidal, full → squamous).

Visceral pericardium

Attached to heart.

Parietal pericardium

Attached to cavity wall.

Pericardial cavity

Contains lubricating serous fluid.

Cilia

Movement of mucus/particles (respiratory tract).

Microvilli

Absorption (intestines).

Villi

Larger folds in small intestine, increase absorption area.

Flagella

Sperm movement.

Serous membranes

Line cavities, secrete fluid to reduce friction.

Pleura

Lungs.

Pericardium

Heart.

Peritoneum

Abdominal organs.

Epithelial tissue

Covers/lines.

Connective tissue

Support/protection.

Muscle tissue

Movement.

Nervous tissue

Communication.

Complementarity Principle

Structure fits function (ex. simple squamous in alveoli for diffusion).

Negative Feedback Loops

Response reverses stimulus.

Homeostasis

Maintained by negative feedback.

Na⁺ higher outside cell

K⁺ higher inside cell.

Tight junctions

Prevent leakage (intestine).

Desmosomes

Anchor cells (skin).

Gap junctions

Allow communication (cardiac muscle).

Oxygen Diffusion in Stratified Epithelia

Epithelium = avascular → nutrients/oxygen diffuse from underlying connective tissue.

Benign cancer

Non-spreading.

Malignant/Metastatic cancer

Invades, spreads.

Cartilage

Chondrocytes in lacunae, firm but flexible.

Bone

Osteocytes in lacunae, calcified matrix, strong support.

Sagittal plane

Left/right.

Midsagittal plane

Equal halves.

Frontal (coronal) plane

Front/back.

Transverse plane

Top/bottom.

Brachium

Arm.

Cranium

Skull.

Anterior vs Posterior landmarks

Distinguish front from back.

Na⁺/K⁺ Pump - Steps

1. Na⁺ binds inside. 2. ATP phosphorylates pump. 3. Na⁺ released outside. 4. K⁺ binds outside. 5. Phosphate released. 6. K⁺ released inside.

Skin

Largest organ.

Adipose tissue

Stores fat, insulation, protection.

Loose areolar CT

Under epithelia, cushions organs.

Dense regular CT

Tendons/ligaments, resists tension one direction.