Anatomy & Physiology: Core Concepts and Systems Study Guide

Chapter 1: Introduction to Anatomy and Physiology

Definition and Relationship

Anatomy is the study of the structure of body parts and their relationships, while physiology focuses on the function of those parts. Understanding both is essential for comprehending how the human body operates.

• Anatomy: Examines the physical structure, such as organs and tissues.

• Physiology: Studies the processes and functions of anatomical structures.

• Relationship: Structure determines function; changes in anatomy can affect physiology.

Levels of Organization in the Human Body

The human body is organized into hierarchical levels, each with increasing complexity.

• Chemical level: Atoms and molecules

• Cellular level: Cells, the basic unit of life

• Tissue level: Groups of similar cells performing a common function

• Organ level: Structures composed of two or more tissue types

• Organ system level: Groups of organs working together

• Organism level: The complete living being

Homeostasis

Homeostasis is the maintenance of a stable internal environment despite external changes. It is vital for survival and proper function.

• Components: Receptor (detects change), Control center (processes information), Effector (responds to change)

• Negative feedback: Reduces the effect of the stimulus (e.g., temperature regulation)

• Positive feedback: Enhances the effect of the stimulus (e.g., blood clotting)

Chapter 2: Chemical Basis of Life

Atomic Structure

Atoms are the basic units of matter, composed of protons, neutrons, and electrons.

• Proton: Positive charge, found in nucleus

• Neutron: No charge, found in nucleus

• Electron: Negative charge, orbits nucleus

• Atomic number: Number of protons in an atom

• Isotope: Atoms of the same element with different numbers of neutrons

Chemical Bonds

Chemical bonds hold atoms together in molecules and compounds.

• Ionic bonds: Transfer of electrons between atoms, forming cations and anions

• Covalent bonds: Sharing of electrons between atoms; can be polar or nonpolar

• Hydrogen bonds: Weak attractions between polar molecules, important in water and biological macromolecules

Water and Solutions

Water is essential for life due to its unique properties.

• Solvent: Dissolves substances

• Solution, colloid, suspension: Types of mixtures based on particle size and distribution

• Hydrophilic: Water-attracting molecules

• Hydrophobic: Water-repelling molecules

pH and Buffers

pH measures the concentration of hydrogen ions in a solution.

• pH scale: Ranges from 0 (acidic) to 14 (basic); 7 is neutral

• Buffer: Substance that stabilizes pH by absorbing or releasing H+ ions

Formula:

$\text{pH} = -\log_{10}[\text{H}^+]$

Organic Molecules

Organic molecules are carbon-based and include carbohydrates, lipids, proteins, and nucleic acids.

• Macromolecule: Large molecule made of smaller subunits

• Monomer: Single subunit

• Polymer: Chain of monomers

Carbohydrates

Carbohydrates provide energy and structural support.

• Monosaccharide: Simple sugar (e.g., glucose)

• Disaccharide: Two monosaccharides (e.g., sucrose)

• Polysaccharide: Many monosaccharides (e.g., starch, glycogen)

• General formula: (CH2O)n

Lipids

Lipids are hydrophobic molecules used for energy storage and membrane structure.

• Types: Fatty acids, triglycerides, phospholipids, steroids

• Saturated fatty acids: No double bonds

• Unsaturated fatty acids: One or more double bonds

Proteins

Proteins are polymers of amino acids and perform various functions.

• Amino acid: Contains amino group and carboxyl group

• Peptide bond: Covalent bond between amino acids

• Levels of structure: Primary, secondary, tertiary, quaternary

Nucleic Acids

Nucleic acids store and transmit genetic information.

• DNA: Double-stranded, stores genetic code

• RNA: Single-stranded, involved in protein synthesis

Enzymes

Enzymes are proteins that catalyze chemical reactions, lowering activation energy.

• Specificity: Each enzyme acts on a specific substrate

• Reusable: Not consumed in reactions

• Activation energy: Minimum energy required for a reaction

Comparison Table: DNA vs RNA

Feature	DNA	RNA
Strands	Double	Single
Sugar	Deoxyribose	Ribose
Bases	A, T, C, G	A, U, C, G
Function	Genetic storage	Protein synthesis

ATP Function

ATP (adenosine triphosphate) is the energy currency of the cell.

• ATP & ADP: ATP releases energy when converted to ADP

Formula:

$\text{ATP} \rightarrow \text{ADP} + \text{P}_i + \text{Energy}$

Chapter 3: Cell Structure and Function

Plasma Membrane

The plasma membrane controls entry and exit of substances, maintaining homeostasis.

• Fluid mosaic model: Describes membrane as a dynamic structure of lipids and proteins

• Functions: Protection, communication, transport

Cell Organelles

• Ribosomes: Protein synthesis

• Endoplasmic reticulum (ER): Protein and lipid synthesis

• Golgi apparatus: Modifies, sorts, and packages proteins

• Lysosomes: Digestion of cellular waste

• Peroxisomes: Breakdown of fatty acids and toxins

• Mitochondria: ATP production

Nucleus and Chromosomes

The nucleus contains genetic material and controls cell activities.

• Chromatin: DNA and associated proteins

• Chromosomes: Condensed chromatin during cell division

• Centromere: Region joining sister chromatids

• Homologous chromosomes: Chromosome pairs with similar genes

• Haploid cells: One set of chromosomes (gametes)

• Diploid cells: Two sets of chromosomes (somatic cells)

Protein Synthesis

Protein synthesis involves transcription and translation.

• Transcription: DNA to RNA

• Translation: RNA to protein

• Codon: Three-base sequence on mRNA

• tRNA: Transfers amino acids to ribosome

Cell Cycle and Mitosis

The cell cycle includes growth and division phases.

• Mitosis: Produces two identical daughter cells

• Meiosis: Produces four genetically unique gametes

Membrane Transport

Cells exchange substances through various transport mechanisms.

• Passive transport: Diffusion, osmosis, facilitated diffusion (no energy required)

• Active transport: Requires energy (ATP)

• Endocytosis: Cell takes in substances

• Exocytosis: Cell expels substances

Osmosis and Tonicity

Osmosis is the movement of water across a selectively permeable membrane.

• Isotonic: Equal solute concentration

• Hypertonic: Higher solute concentration outside cell

• Hypotonic: Lower solute concentration outside cell

Chapter 4: Tissues

Types of Tissues

The human body has four basic tissue types: epithelial, connective, muscle, and nervous tissue.

• Epithelial tissue: Covers surfaces, lines cavities, forms glands

• Connective tissue: Supports, protects, binds other tissues

• Muscle tissue: Produces movement

• Nervous tissue: Transmits electrical signals

Characteristics of Epithelial Tissue

• Cells closely packed

• Free (apical) surface

• Attached to basement membrane

• Avascular (no blood vessels)

• Regenerative

Glandular Epithelium

• Endocrine glands: Secrete hormones into blood

• Exocrine glands: Secrete products into ducts

Connective Tissue

• Cells: Fibroblasts, adipocytes, macrophages

• Extracellular matrix: Fibers (collagen, elastic, reticular), ground substance

• Types: Loose (areolar, adipose), dense (regular, irregular), cartilage, bone, blood

Supporting Connective Tissue

• Cartilage: Hyaline (joints), elastic (ear), fibrocartilage (intervertebral discs)

• Bone: Rigid support

Chapter 5: Integumentary System

Functions

The integumentary system protects the body, regulates temperature, and synthesizes vitamin D.

• Protection from hazards

• Excretion of salts and wastes

• Temperature regulation

• Vitamin D synthesis

• Immune response

Structure of Skin

• Epidermis: Stratified squamous epithelium

• Dermis: Connective tissue (papillary and reticular layers)

• Accessory structures: Hair follicles, glands, nails

Layers of Epidermis

• Stratum basale: Deepest, mitotic cells

• Stratum spinosum: Keratinocytes

• Stratum granulosum: Keratin granules

• Stratum lucidum: Only in thick skin

• Stratum corneum: Superficial, dead keratinized cells

Skin Color

• Melanin: Pigment produced by melanocytes, protects from UV

• Carotene: Yellow-orange pigment from diet

• Blood flow: Influences skin color

Dermis Structure

• Papillary layer: Areolar tissue, touch receptors

• Reticular layer: Dense irregular connective tissue

Hair and Glands

• Hair follicle: Shaft (above skin), root (anchored)

• Arrector pili: Muscle causing hair to stand

• Sebaceous glands: Secrete oil for lubrication and antimicrobial protection

• Sudoriferous glands: Merocrine (sweat for cooling), apocrine (scent glands)

Body Heat Loss

• Insulation by adipose tissue

• Vasoconstriction/vasodilation of capillaries

• Evaporative cooling by sweat

Additional info: Some explanations and examples have been expanded for clarity and completeness.