Laboratory

ANATOMY & PHYSIOLOGY REVIEWER

CHAPTER 1 — INTRODUCTION TO ANATOMY AND PHYSIOLOGY

I. Definition and Interrelationship of Anatomy and Physiology

ANATOMY

— Study of the structure and shape of the body and its parts.

• Focuses on what body parts look like, where they are located, and how they are organized.

• Anatomy = Structure

GROSS ANATOMY

— Study of large body structures visible to the naked eye.

MICROSCOPIC ANATOMY

— Study of structures too small to be seen without a microscope.

REGIONAL ANATOMY

— Study of all structures in a particular body region, such as the cervical, abdominal, or cephalic)

SYSTEMIC ANATOMY

— Study of the structures of a specific organ system, such as the skeletal or muscular system.

PHYSIOLOGY

— Study of how the body and its parts function.

• Focuses on how organs, tissues, cells, and systems work.

• Physiology = Function

Relationship Between Anatomy & Physiology

— Structure and function are closely related. The structure of a body part determines or influences how it performs its function.

🧠 Remember:
Anatomy = Structure
Physiology = Function

II. Chemistry of Life

MATTER

— Anything that occupies space and has mass.

States of Matter

Solid
— Has a definite shape and definite volume.
Example: bones, teeth

Liquid
— Has a definite volume but takes the shape of its container.
Example: blood plasma

Gas
— Has no definite shape or volume.
Example: oxygen, air

Physical Change

— A change that does not alter the basic chemical composition of a substance.

Examples:

• Melting ice

• Cutting food

• Crushing a substance

Chemical Change

— A change that alters the chemical composition of a substance and produces new substances.

Examples:

• Digestion

• Cellular respiration

• Fermentation

ENERGY

— The ability to do work or cause matter to move.

Kinetic Energy

— Energy of motion.

Potential Energy

— Stored energy that has the potential to do work.

Four Major Forms of Energy

Chemical Energy
— Energy stored in chemical bonds.
Example: energy in food and ATP

Electrical Energy
— Energy produced by the movement of charged particles.
Example: nerve impulses

Mechanical Energy
— Energy involved in the movement of matter.
Example: muscle contraction

Radiant Energy
— Energy that travels as electromagnetic waves.
Example: sunlight/UV radiation

Energy conversion in the body:
Food → Chemical Energy → ATP → Mechanical/Electrical Energy

Energy conversions also produce heat.

ELEMENTS & ATOMS

ELEMENT

— A substance that cannot be broken down into simpler substances by ordinary chemical methods.

There are 118 known elements, including naturally occurring and synthetic elements.

ATOM

— The smallest unit of an element that retains the properties of that element.

An atom consists of:

• Protons

• Neutrons

• Electrons

NUCLEUS

— The central part of an atom containing protons and neutrons.

• Positively charged because of its protons.

• Contains most of the atom’s mass.

ISOTOPES

— Atoms of the same element that have the same number of protons but different numbers of neutrons.

Example:

• Carbon-12

• Carbon-13

• Carbon-14

They are all carbon because they have 6 protons, but they have different numbers of neutrons.

4 Elements That Make Up About 96% of the Human Body

🧠 CHON

• C — Carbon

• H — Hydrogen

• O — Oxygen

• N — Nitrogen

SUBATOMIC PARTICLES

🧠 Remember:
P = Positive
N = Neutral
E = Negative

Electrical Charges

• Same charges → repel

• Opposite charges → attract

Neutral Atom

— Has an equal number of protons and electrons.

Ion

— An atom that has gained or lost electrons, giving it a charge.

Cation
— Positively charged ion formed when an atom loses electrons.

Anion
— Negatively charged ion formed when an atom gains electrons.

🧠 CATion = +
🧠 ANion = −

MOLECULES & COMPOUNDS

MOLECULE

— Two or more atoms chemically bonded together.

Example: H₂

COMPOUND

— A substance made of two or more different elements chemically combined.

Example: CH₄

🧠 Important:

• H₂ = molecule but not a compound

• CH₄ = molecule and compound

CHEMICAL BONDS

Ionic Bond

— Chemical bond formed by the transfer of electrons from one atom to another.

Example:
Na → Na⁺ + electron
Cl + electron → Cl⁻
Na⁺ + Cl⁻ → NaCl

Covalent Bond

— Chemical bond formed when atoms share electrons.

Example: H₂

Hydrogen Bond

— A weak attraction involving a hydrogen atom and an electronegative atom, usually oxygen or nitrogen.

Important in:

• Water

• Protein structure

• DNA structure

🧠 Ionic = Transfer
🧠 Covalent = Share
🧠 Hydrogen = Attraction

CHEMICAL REACTIONS

Synthesis Reaction

— Two or more substances combine to form a larger or more complex substance.

A + B → AB

🧠 Synthesis = Build

Decomposition Reaction

— A larger substance breaks down into smaller substances.

AB → A + B

🧠 Decomposition = Break

Exchange Reaction

— Parts of two compounds are swapped or exchanged.

AB + CD → AD + CB

🧠 Exchange = Swap

ENDERGONIC REACTION

— A reaction that requires or absorbs energy.

Example: building larger molecules from smaller molecules.

EXERGONIC REACTION

— A reaction that releases energy.

Example: cellular reactions that release usable energy from nutrients.

WATER

— The most abundant inorganic compound in the body, making up roughly two-thirds of body weight.

Major Properties/Functions

• High heat capacity → helps regulate body temperature

• Excellent solvent → dissolves many substances

• Participates in chemical reactions

• Provides cushioning and lubrication

• Helps transport substances

SALTS

— Ionic compounds made of cations and anions.

Important ions include:

• Na⁺

• K⁺

• Ca²⁺

• Phosphate

• Fe

Importance

• Nerve impulses

• Muscle contraction

• Fluid/electrolyte balance

• Bone structure

• Oxygen transport

Iron (Fe) → important component of hemoglobin.

ACIDS & BASES

Acid

— A substance that releases hydrogen ions (H⁺) or acts as a proton donor.

• pH below 7

• Example: HCl

Base

— A substance that accepts H⁺ or commonly releases OH⁻ in water.

• pH above 7

• Example: NaOH

Strong Acid/Base

— Completely ionizes in water.

Example: HCl

Weak Acid/Base

— Partially ionizes in water.

Examples:

• Carbonic acid

• Acetic acid

NEUTRALIZATION

— A reaction between an acid and a base that produces a salt and water.

Acid + Base → Salt + Water

Example:

HCl + NaOH → H₂O + NaCl

pH

— A measure of the hydrogen ion concentration of a solution.

• pH < 7 → Acidic

• pH = 7 → Neutral

• pH > 7 → Basic/Alkaline

At pH 7:

H⁺ = OH⁻

Acid-Base Balance

Cells are sensitive to pH changes. The body maintains acid-base balance through:

• Chemical buffers

• Lungs

• Kidneys

III. Levels of Organization in the Human Body

From simplest → most complex:

1. Chemical Level — atoms and molecules

2. Cellular Level — cells

3. Tissue Level — groups of similar cells

4. Organ Level — two or more tissues working together

5. Organ System Level — organs working together

6. Organismal Level — the entire human body

🧠 Mnemonic:
C C T O O O

Chemical → Cellular → Tissue → Organ → Organ System → Organism

IV. Homeostasis and Feedback Mechanisms

HOMEOSTASIS

— The process by which the body maintains a relatively stable internal environment despite external changes.

Dynamic Balance

— Homeostasis does not mean that conditions remain completely unchanged. Instead, body conditions fluctuate within a normal range.

FEEDBACK MECHANISMS

— Processes that regulate body functions by responding to changes in the internal environment.

Negative Feedback

— Reverses or reduces the original stimulus to return a condition toward its normal range.

Example:

• Body temperature rises → sweating → heat is lost → temperature decreases

🧠 Negative = Reduces

Positive Feedback

— Amplifies or increases the original stimulus until a specific event is completed.

Examples:

• Blood clotting

• Labor contractions

🧠 Positive = Reinforces

V. Anatomical Terminologies

ANATOMICAL POSITION

— The standard reference position used to describe the location of body structures.

The body is:

• Standing upright

• Facing forward

• Arms at the sides

• Palms facing forward

• Feet directed forward

DIRECTIONAL TERMS

Superior

— Toward the head or upper part.

Example: Forehead is superior to the nose.

Inferior

— Toward the lower part or away from the head.

Example: Navel is inferior to the breastbone.

Anterior / Ventral

— Toward the front of the body.

Example: Breastbone is anterior to the spine.

Posterior / Dorsal

— Toward the back of the body.

Example: Spine is posterior to the breastbone.

Medial

— Toward the body’s midline.

Example: Heart is medial to the arms.

Lateral

— Away from the body’s midline.

Example: Arms are lateral to the chest.

Intermediate

— Between a more medial and a more lateral structure.

Proximal

— Closer to the point of attachment or origin of a body part.

Example: Elbow is proximal to the wrist.

Distal

— Farther from the point of attachment or origin.

Example: Wrist is distal to the elbow.

Superficial

— Toward or closer to the body surface.

Example: Skin is superficial to the skeleton.

Deep

— Away from the body surface or more internal.

Example: Lungs are deep to the rib cage.

CHAPTER 2 — THE CELL

I. Cell Theory

CELL THEORY

The three major principles are:

1. All living organisms are made of one or more cells.

2. The cell is the basic structural and functional unit of life.

3. All cells come from pre-existing cells.

Early Scientists

Robert Hooke
— First used the term “cell” after observing cork under a microscope.

Antonie van Leeuwenhoek
— First to observe and describe living cells and microorganisms.

Matthias Schleiden
— Proposed that plants are made of cells.

Theodor Schwann
— Proposed that animals are made of cells.

Rudolf Virchow
— Stated that all cells arise from pre-existing cells.

II. Protoplasm

PROTOPLASM

— The living material of a cell, consisting of the cytoplasm and nucleus.

It includes:

• Cytoplasm

• Nucleoplasm

🧠 Protoplasm = Cytoplasm + Nucleus/Nucleoplasm

CYTOPLASM

— Everything outside the nucleus but inside the plasma membrane.

Cytoplasm vs Protoplasm

III. Major Cell Organelles and Their Functions

Three Major Regions of a Cell

Plasma Membrane

— Outer boundary of the cell that protects the cell and controls what enters and leaves.

Cytoplasm

— Gel-like region containing organelles and where many cellular activities occur.

Nucleus

— Control center containing DNA and directing cellular activities.

Plasma Membrane

Fluid Mosaic Model

— Describes the membrane as a flexible phospholipid bilayer containing proteins, cholesterol, and carbohydrates that can move within the membrane.

Phospholipid Bilayer

Hydrophilic Heads

• “Water-loving”

• Polar

• Face watery environments

Hydrophobic Tails

• “Water-fearing”

• Nonpolar

• Face inward away from water

Membrane Proteins

Enzymes
— Catalyze chemical reactions.

Receptors
— Receive hormones or other chemical messages.

Anchoring Proteins
— Attach cells to structural fibers or neighboring structures.

Channels
— Allow specific ions and small molecules to pass through.

Carriers
— Bind substances and transport them across the membrane.

Glycocalyx

— A sugar-rich layer on the outer surface of the plasma membrane.

Functions:

• Cell recognition

• Cell identity

• Determines blood types

• Cell-to-cell interactions

• Can serve as binding sites for some pathogens

Cell Junctions

Tight Junction

— Seals neighboring cells together and prevents substances from leaking between cells.

🧠 Tight = Stop leaking

Desmosomes

— Strong cell-to-cell attachments that prevent cells from being pulled apart.

🧠 Desmosome = Strong attachment

Gap Junctions

— Channels that allow ions and small molecules to pass directly between neighboring cells.

🧠 Gap = Communication

NUCLEUS

Functions

• Control center of the cell

• Contains DNA

• Directs cellular activities

Nuclear Envelope

— A double membrane surrounding the nucleus with pores that allow materials to move between the nucleus and cytoplasm.

Nucleoli

— Dark-staining regions where ribosomal components are produced and assembled.

Chromatin

— Loose, uncondensed DNA associated with proteins in the nucleus.

Chromosomes

— Condensed structures made of DNA and proteins, especially visible during cell division.

CYTOPLASM

Cytosol

— Semitransparent fluid portion of the cytoplasm containing water, dissolved nutrients, ions, and other substances.

Inclusions

— Stored substances within the cytoplasm.

Examples:

• Lipid droplets

• Glycogen granules

• Melanin

Organelles

— Specialized cellular structures that perform specific functions.

MITOCHONDRIA

— “Powerhouse of the cell.”

Functions:

• Produces ATP

• Site of aerobic cellular respiration

• Contains a double membrane

• Inner membrane forms cristae

• Contains its own DNA

• Can divide

🧠 Mitochondria = ATP/Energy

RIBOSOMES

— Structures responsible for protein synthesis.

Free Ribosomes

— Produce proteins used mainly inside the cell.

Bound Ribosomes

— Attached to rough ER and produce proteins destined for secretion, membranes, or certain organelles.

ENDOPLASMIC RETICULUM (ER)

— A network of membranes involved in the production, processing, and transport of substances.

Rough ER

— ER with ribosomes attached.

Functions:

• Protein synthesis

• Protein processing/folding

• Transports proteins through vesicles

🧠 Rough = Ribosomes = Protein

Smooth ER

— ER without ribosomes.

Functions:

• Lipid metabolism

• Cholesterol/phospholipid synthesis

• Detoxification

• Important in liver cells

🧠 Smooth = Lipids + Detox

GOLGI APPARATUS

— “Packaging and shipping center” of the cell.

Functions:

• Modifies proteins

• Sorts proteins

• Packages proteins

• Ships proteins to their destinations

Three Major Destinations

1. Outside the cell

2. Plasma membrane

3. Lysosomes

Exocytosis

— Process by which materials are released outside the cell through vesicles fusing with the plasma membrane.

Endocytosis

— Process by which the cell takes materials into the cell by forming a vesicle from the plasma membrane.

🧠 Exo = Exit
🧠 Endo = Enter

LYSOSOMES

— “Cellular stomach.”

Contain digestive enzymes that break down:

• Worn-out cell parts

• Foreign substances

• Cellular debris

• Certain ingested materials

Especially abundant in phagocytic cells, such as some white blood cells.

PEROXISOMES

— Small membrane-bound organelles containing enzymes that break down fatty acids and detoxify harmful substances.

Functions:

• Fatty acid breakdown

• Detoxification

• Break down hydrogen peroxide into safer substances

🧠 Peroxisome = Detox + Fat breakdown

CYTOSKELETON

— A network of protein fibers that supports cell shape, organizes organelles, and assists in movement and transport.

Three Main Fibers

Microfilaments
— Thinnest fibers; help with cell shape and movement.

Intermediate Filaments
— Provide strength and help stabilize cell structures.

Microtubules
— Thickest fibers; help with intracellular transport, cell movement, and chromosome movement during cell division.

🧠 Microfilaments → Intermediate → Microtubules

CENTRIOLES

— Cylindrical structures made of microtubules that help organize the spindle fibers during cell division.

Usually found in pairs within the centrosome of animal cells.

VACUOLES

— Membrane-bound sacs that store water, nutrients, ions, and waste materials.

In animal cells, they are generally smaller than the large central vacuole found in plant cells.

IV. Transport Mechanisms

Passive Transport

— Movement of substances without using cellular energy (ATP).

Diffusion

— Movement of substances from an area of higher concentration to lower concentration.

Osmosis

— Diffusion of water across a selectively permeable membrane.

Facilitated Diffusion

— Movement of substances from high to low concentration through membrane proteins, without ATP.

🧠 Passive = No ATP

Active Transport

— Movement of substances from lower to higher concentration, requiring cellular energy (ATP).

🧠 Active = ATP

V. Cell Cycle and Division

CELL CYCLE

— The sequence of events through which a cell grows, prepares for division, and divides.

Interphase

— Period when the cell grows and prepares for division.

Includes:

G₁ Phase
— Cell grows and performs normal functions.

S Phase
— DNA is replicated.

G₂ Phase
— Cell continues growing and prepares for division.

🧠 G₁ → S → G₂

Mitotic Phase

— Includes:

• Mitosis

• Cytokinesis

MITOSIS

— Division of the nucleus that produces two genetically similar daughter cells.

Stages:

P — Prophase
M — Metaphase
A — Anaphase
T — Telophase

🧠 PMAT

Cytokinesis

— Division of the cytoplasm to form separate daughter cells.

MEIOSIS

— Specialized cell division that produces haploid sex cells (gametes).

Produces:

• Four genetically different daughter cells

• Cells with half the chromosome number of the original cell

Mitosis vs Meiosis

CHAPTER 3 — TISSUES AND HISTOLOGY

I. Introduction to Histology and Tissue Classification

HISTOLOGY

— The study of tissues and their microscopic structure.

TISSUE

— A group of similar cells that work together to perform a specific function.

Four Primary Tissue Types

1. Epithelial Tissue — covers and lines surfaces

2. Connective Tissue — supports and connects

3. Muscle Tissue — produces movement

4. Nervous Tissue — communicates and controls

II. Epithelial Tissue

EPITHELIAL TISSUE

— Tissue that covers body surfaces, lines cavities and organs, and forms glands.

Major Functions

• Protection — protects underlying tissues

• Absorption — takes in substances

• Secretion — releases substances

• Filtration — allows certain substances to pass

• Sensation — detects stimuli

General Features / Appearance

• Cells are tightly packed with very little space between them.

• Has a free/apical surface facing the outside or a body cavity.

• Has a basal surface attached to a basement membrane.

• Usually avascular — contains no blood vessels.

• Cells are arranged in layers.

Classification by Number of Layers

SIMPLE EPITHELIUM

— Consists of one layer of cells.

Location:

• Areas where absorption, secretion, filtration, or diffusion occur.

Purpose:

• Allows substances to pass through easily.

• Also performs absorption and secretion.

Features/Appearance:

• Only one cell layer thick.

• All cells contact the basement membrane.

🧠 Simple = 1 layer

STRATIFIED EPITHELIUM

— Consists of two or more layers of cells.

Location:

• Areas exposed to friction or physical stress.

• Example: skin and lining of the mouth.

Purpose:

• Mainly provides protection against physical damage, pathogens, and chemical stress.

Features/Appearance:

• Multiple layers of cells.

• Only the deepest layer contacts the basement membrane.

• Usually thicker than simple epithelium.

🧠 Stratified = Several layers

PSEUDOSTRATIFIED EPITHELIUM

— Appears to have multiple layers, but all cells contact the basement membrane.

Location:

• Commonly found lining the respiratory tract, such as the trachea.

Purpose:

• Secretes and moves mucus.

• Helps trap and remove particles from inhaled air.

Features/Appearance:

• Appears multilayered because nuclei are at different heights.

• Actually one layer.

• Often contains cilia and goblet cells.

🧠 Pseudo = Looks stratified, but isn’t

Classification by Cell Shape

SQUAMOUS

— Cells are flat and thin.

Location:

• Found where rapid diffusion or filtration occurs.

• Example: alveoli and blood vessel lining.

Purpose:

• Allows rapid diffusion and filtration.

• Provides a smooth surface for movement of substances.

Features/Appearance:

• Very thin, flat cells.

• Nucleus is usually flattened.

🧠 Squamous = Flat

CUBOIDAL

— Cells are approximately cube-shaped.

Location:

• Kidney tubules

• Some glands

• Ovarian surface

Purpose:

• Absorption and secretion.

Features/Appearance:

• Cells are about as tall as they are wide.

• Usually have a round, centrally located nucleus.

🧠 Cuboidal = Cube

COLUMNAR

— Cells are tall and column-shaped.

Location:

• Digestive tract

• Gallbladder

• Some respiratory passages

Purpose:

• Absorption and secretion.

• Some types help move mucus.

Features/Appearance:

• Tall, rectangular cells.

• Nuclei are usually oval and located toward the base.

• May have microvilli or cilia.

🧠 Columnar = Tall

III. Connective Tissue

CONNECTIVE TISSUE

— Tissue that supports, connects, protects, and binds other tissues and organs.

General Features / Appearance

• Cells are more widely separated than epithelial cells.

• Has abundant extracellular matrix.

• Matrix consists of ground substance + protein fibers.

• Usually has a good blood supply, although some types have limited blood supply.

Location

Found throughout the body, including:

• Under the skin

• Around organs

• Tendons and ligaments

• Bones

• Cartilage

• Blood

• Adipose tissue

Purpose / Functions

• Support

• Binding

• Protection

• Storage

• Insulation

• Transport

• Immune defense

Three Main Components

1. CELLS

— Living components of connective tissue.

Examples:

Fibroblasts
— Produce fibers and ground substance.

Location: Throughout connective tissue
Purpose: Produce and maintain the extracellular matrix
Appearance: Usually spindle-shaped or branching cells

Adipocytes
— Fat-storing cells.

Location: Adipose tissue
Purpose: Store energy, insulate the body, and cushion organs
Appearance: Large, round cells with a large lipid droplet that pushes the nucleus to the side

Macrophages
— Cells that engulf and destroy foreign materials and cellular debris.

Location: Many connective tissues
Purpose: Immune defense and removal of debris
Appearance: Irregular/amoeba-like cells

2. FIBERS

— Protein structures that provide strength, support, and elasticity.

Collagen Fibers

— Strong fibers that resist stretching and pulling.

Appearance: Thick, strong, flexible bundles.

Location: Tendons, ligaments, skin, and many connective tissues.

Purpose: Provide strength and structural support.

🧠 Collagen = Strength

Elastic Fibers

— Fibers that can stretch and return to their original shape.

Appearance: Thin, branching fibers.

Location: Skin, walls of large arteries, lungs.

Purpose: Provide elasticity and flexibility.

🧠 Elastic = Stretch + Return

Reticular Fibers

— Thin, branching fibers that form a supportive network.

Appearance: Fine, branching mesh.

Location: Lymph nodes, spleen, bone marrow.

Purpose: Provide a supporting framework for cells and organs.

🧠 Reticular = Network

3. GROUND SUBSTANCE

— Noncellular material located between cells and fibers.

Location:

• Surrounds connective tissue cells and fibers.

Purpose:

• Supports and binds cells.

• Helps with nutrient and waste exchange.

Appearance:

• May be fluid, gel-like, or solid depending on the type of connective tissue.

🧠 Connective Tissue = Cells + Fibers + Ground Substance

IV. Muscle Tissue

MUSCLE TISSUE

— Specialized tissue capable of contraction, producing movement.

General Features

• Made of elongated cells called muscle fibers.

• Contains proteins that allow contraction.

• Responsible for movement of the body and substances inside the body.

SKELETAL MUSCLE

Location:

• Attached primarily to bones.

Purpose:

• Produces voluntary body movement.

• Maintains posture.

• Generates body heat.

Features/Appearance:

• Long, cylindrical fibers

• Striated — visible light and dark bands

• Multiple nuclei, usually located at the edges of the cells

• Voluntary

🧠 Skeletal = Bones + Voluntary + Striated

CARDIAC MUSCLE

Location:

• Found only in the heart wall.

Purpose:

• Contracts rhythmically to pump blood throughout the body.

Features/Appearance:

• Striated

• Short, branching cells

• Usually one central nucleus

• Has intercalated discs connecting cells

• Involuntary

🧠 Cardiac = Heart + Involuntary + Striated

SMOOTH MUSCLE

Location:

• Walls of hollow organs, such as:

  • Stomach

  • Intestines

  • Blood vessels

  • Urinary bladder

  • Uterus

Purpose:

• Moves substances through organs.

• Controls the diameter of blood vessels and other passages.

Features/Appearance:

• Spindle-shaped cells

• One central nucleus

• No visible striations

• Involuntary

🧠 Smooth = Hollow organs + Involuntary + Non-striated

V. Nervous Tissue

— Tissue specialized for communication and rapid transmission of electrical signals.

Main Cells

Neurons
— Receive and transmit electrical signals.

Neuroglia
— Support, protect, nourish, and maintain neurons.

CHAPTER 4 — THE INTEGUMENTARY SYSTEM

I. The Layers of the Skin

SKIN

— The body’s largest organ and its primary external protective barrier.

Two major layers:

1. Epidermis

2. Dermis

EPIDERMIS

— The outermost layer of the skin.

Characteristics:

• Stratified squamous keratinized epithelium

• Avascular

• Produces new skin cells

• Contains melanin-producing cells

• Provides a protective and waterproof barrier

Five Epidermal Layers

Deepest → Superficial:

1. Stratum Basale

2. Stratum Spinosum

3. Stratum Granulosum

4. Stratum Lucidum

5. Stratum Corneum

🧠 B → S → G → L → C

Stratum Basale

— Deepest layer.

• Single layer of cells

• Contains dividing stem cells

• Produces new keratinocytes

• Contains melanocytes

• Contains Merkel cells

Stratum Spinosum

— “Spiny layer.”

• Contains many desmosomes

• Provides strength

• Contains immune Langerhans/dendritic cells

Stratum Granulosum

— “Granular layer.”

• Contains keratohyalin granules

• Cells begin keratinization

• Helps form a water-resistant barrier

Stratum Lucidum

— “Clear layer.”

• Found ONLY in thick skin

• Palms of hands

• Soles of feet

• Provides additional protection from friction

🧠 EXAM TRAP: Lucidum = Thick skin only

Stratum Corneum

— Outermost layer.

• Made mainly of dead, flattened keratinized cells

• Main physical barrier

• Continuously sheds

• Helps prevent water loss and microbial entry

DERMIS

— Deeper, thicker layer of skin made mainly of connective tissue.

Contains:

• Blood vessels

• Nerves

• Hair follicles

• Sweat glands

• Sebaceous glands

• Sensory receptors

• Collagen and elastic fibers

Papillary Layer

— Superficial layer of the dermis.

• Thin areolar connective tissue

• Contains dermal papillae

• Contains capillaries

• Contains touch receptors

• Helps form fingerprints

Reticular Layer

— Deeper and thicker dermal layer.

• Dense irregular connective tissue

• Contains blood vessels

• Hair follicles

• Sweat glands

• Sebaceous glands

• Nerves

• Deep pressure receptors

II. The Hair

HAIR

— A keratinized structure that grows from hair follicles in the skin.

Functions

• Protects the scalp

• Eyelashes protect the eyes

• Nose hairs help filter particles

• Provides some insulation

• Contributes to sensation

Hair Structure

Root
— Portion of the hair below the skin.

Shaft
— Portion extending above the skin surface.

Three Layers of the Hair Shaft

1. Medulla — central core

2. Cortex — provides strength and contains pigment

3. Cuticle — outer protective layer

🧠 Medulla → Cortex → Cuticle

Hair Color

— Determined mainly by melanin produced by melanocytes in the hair bulb.

Hair Texture

• Flat/ribbon-like shaft → curly hair

• Oval shaft → wavy hair

• Round shaft → straight hair

Hair Follicle

— A tubular structure in the skin from which hair grows.

Hair Papilla

— Structure containing blood vessels that supplies nutrients to the hair matrix.

Matrix

— Region of actively dividing cells responsible for hair growth.

Arrector Pili

— Small bands of smooth muscle attached to hair follicles.

When contracted:

• Hair stands upright

• Skin dimples

• Produces goose bumps

Triggered by:

• Cold

• Fear/emotional stress

III. The Nails

NAIL

— A scalelike modification of the epidermis made primarily of hard keratin.

Main Parts

Free Edge
— Portion of the nail that extends beyond the fingertip/toe.

Body
— Visible portion of the nail.

Root
— Portion embedded in the skin.

Nail Folds
— Skin folds surrounding the nail.

Cuticle
— Thin layer of skin that overlaps the nail plate near its base.

Nail Bed

— Skin underneath the nail plate.

Nail Matrix

— Thickened region responsible for nail growth.

Nail Plate

— Hard, visible part of the nail made of heavily keratinized dead cells.

Nail Color

— Normally pink because of blood vessels beneath the nail.

IV. The Glands

Cutaneous Glands

— Exocrine glands that release secretions through ducts onto the skin surface or into hair follicles.

Two major types:

1. Sebaceous glands

2. Sweat glands

SEBACEOUS GLANDS

— Oil glands that produce sebum.

Functions of Sebum

• Lubricates skin

• Lubricates hair

• Helps prevent drying

• Helps keep hair from becoming brittle

• Has some antibacterial properties

Location

• Found throughout most of the body

• Absent from palms and soles

• Usually empty into hair follicles

Adolescence

Sebaceous glands become more active because of androgens, contributing to oily skin and acne.

🧠 Sebaceous = Sebum/Oil

SWEAT GLANDS

— Also called sudoriferous glands.

Functions:

• Temperature regulation

• Sweat production

• Excretion of small amounts of metabolic waste

Two main types:

1. Eccrine

2. Apocrine

ECCRINE GLANDS

— Numerous sweat glands distributed widely throughout the body.

• Secrete sweat directly onto the skin surface

• Important in thermoregulation

• Especially abundant on palms, soles, and forehead

Sweat Contains

• Water

• Salts

• Small amounts of metabolic wastes

• Other dissolved substances

Thermoregulation

High temperature → sweat production → evaporation → heat loss

🧠 Eccrine = Everywhere + Cooling

APOCRINE GLANDS

— Larger sweat glands that are mainly found in specific areas.

Common locations:

• Axillary/armpit areas

• Genital areas

They usually empty into hair follicles.

Secretion

• Thicker/milky

• Contains proteins and lipids

• Initially odorless

• Bacteria break down its components → body odor

Become active at puberty.

Triggered by:

• Stress

• Pain

• Sexual arousal

Have little role in normal temperature regulation.

🧠 Apocrine = Axilla + Genital + Adolescence

V. Functions: Protection, Thermoregulation, Sensation

1. Protection

The skin protects deeper tissues from:

• Physical injury

• Chemicals

• Microorganisms

• Excessive water loss

• UV radiation

2. Thermoregulation

The skin helps regulate body temperature through:

• Sweating

• Blood vessel dilation/constriction

• Radiation of heat

Hot → Blood vessels dilate + sweating → Heat loss

Cold → Blood vessels constrict → Heat conserved

3. Sensation

Sensory receptors in the skin detect:

• Touch

• Pressure

• Pain

• Temperature

• Other environmental stimuli

4. Synthesis

The skin contributes to the production of:

• Vitamin D

• Certain defensive proteins

🧠 P-R-S-S

Protection → Regulation → Synthesis → Sensation

⭐ SUPER HIGH-YIELD MEMORIZATION

CHAPTER 1

Anatomy → Structure
Physiology → Function

Regional anatomy → Specific body region
Systemic anatomy → Specific organ system

Levels:
Chemical → Cellular → Tissue → Organ → Organ System → Organism

CHON:
Carbon → Hydrogen → Oxygen → Nitrogen

Ion:
Cation = +
Anion = −

Bonds:
Ionic = Transfer
Covalent = Share
Hydrogen = Attraction

Reactions:
Synthesis = Build
Decomposition = Break
Exchange = Swap

Homeostasis:
Negative feedback = Reduces/reverses
Positive feedback = Amplifies/reinforces

Directional terms:
Superior ↔ Inferior
Anterior ↔ Posterior
Medial ↔ Lateral
Proximal ↔ Distal
Superficial ↔ Deep

CHAPTER 2

Cell Theory:
All living things are made of cells → Cell is basic unit → Cells come from pre-existing cells

Protoplasm:
Cytoplasm + Nucleus

Plasma membrane:
Hydrophilic = Water-loving
Hydrophobic = Water-fearing

Junctions:
Tight = Stop leaking
Desmosome = Strong attachment
Gap = Communication

Organelles:
Mitochondria → ATP
Ribosomes → Protein
Rough ER → Protein
Smooth ER → Lipids + Detox
Golgi → Modify + Package + Ship
Lysosome → Digest
Peroxisome → Detox + Fat breakdown
Cytoskeleton → Support + Movement

Transport:
Diffusion → High → Low
Osmosis → Water
Facilitated diffusion → High → Low + Protein
Active transport → Low → High + ATP

Cell cycle:
G₁ → S → G₂ → M

Mitosis:
PMAT

CHAPTER 3

4 Tissue Types:
Epithelial → Cover/line
Connective → Support/bind
Muscle → Movement
Nervous → Communication

Epithelial classification:
Layers → Simple / Stratified
Shape → Squamous / Cuboidal / Columnar

Connective tissue:
Cells + Fibers + Ground Substance

Muscle:
Skeletal → Voluntary
Cardiac → Heart
Smooth → Involuntary organs

Nervous:
Neurons → Signals
Neuroglia → Support

CHAPTER 4

Skin layers:
Epidermis → Dermis

Epidermis:
Basale → Spinosum → Granulosum → Lucidum → Corneum

Special epidermal cells:
Melanocyte → Melanin
Langerhans/Dendritic → Immune defense
Merkel → Touch

Dermis:
Papillary → Superficial + fingerprints + capillaries
Reticular → Deep + glands + follicles + pressure receptors

Hair:
Medulla → Cortex → Cuticle

Glands:
Sebaceous → Sebum/oil
Eccrine → Cooling
Apocrine → Axillary/genital + puberty

Skin functions:
Protection → Regulation → Synthesis → Sensation

Topics I removed based on your Table of Contents

I did not include the following from your original notes because they are not listed under the TOC sections shown in your photo:

• Organ systems

• Eight essential life processes

• Five survival needs

• Body cavities

• Pericardial/pleural/mediastinum details

• ATP as a separate chemistry topic

• Burns

• Rule of Nines

• Critical burns

• Skin cancer

• ABCDE rule

• Lanugo and vernix

• Aging skin

• Aging hair

• Most developmental aspects

• Detailed body membranes