Introduction to Anatomy and Physiology Concepts

Anatomy

Study of a body part's structure & its relationships to other parts

Physiology

Study of how body parts work; functional processes

Pathophysiology

Explores altered functions caused by disease; links clinical signs with underlying structural/functional change

Gross (Macroscopic) Anatomy

Large structures visible to naked eye

Regional approach

Examine all structures in one body region (e.g., thorax)

Systemic approach

Examine one system throughout the body (e.g., cardiovascular)

Surface Anatomy

Study of internal structures as related to overlying skin (e.g., locating blood vessels for venipuncture)

Microscopic Anatomy

Structures too small for naked eye

Cytology

Study of cells

Histology

Study of tissues

Developmental Anatomy

Structural changes across lifespan

Embryology

Changes prior to birth

Anatomical Position

Standard reference: Body erect, feet together, eyes forward; palms face anteriorly; thumbs point laterally

Prone

Same position but face-down

Supine

Same position but face-up

Ventral

Inferior; contrast with humans where ventral = anterior

Dorsal

Superior; contrast with humans where dorsal = posterior

Superior

Toward head/upper part; above

Inferior

Away from head/lower part; below

Anterior

Front of body

Posterior

Back of body

Medial

Toward midline

Lateral

Away from midline

Proximal

Nearer point of limb attachment/origin

Distal

Farther from origin

Superficial

Toward surface

Deep

Internal/away from surface

Ipsilateral

Same side

Contralateral

Opposite side

Sagittal Plane

Divides body into right & left portions

Frontal (Coronal) Plane

Anterior vs posterior portions

Transverse (Horizontal/Cross) Plane

Superior vs inferior portions; also called axial

Pelvic

Bladder, reproductive organs, rectum

Serous Membranes (Serosae)

Double-layered; secrete slippery serous fluid to reduce friction

Parietal serosa

Lines cavity wall

Visceral serosa

Covers organs

Serous cavity

Potential space with fluid

Heart example

Parietal pericardium → pericardial space → visceral pericardium

Balloon analogy

Fist pushes into balloon (inner wall = visceral, outer = parietal, air = cavity)

Homeostatic Imbalance of Serosa (Serositis)

Inflammation of serous membranes

Pericarditis

Inflamed pericardium → chest pain, fluid accumulation

Pleuritis/Pleurisy

Inflamed pleura → painful breathing

Peritonitis

Inflamed peritoneum → rigid abdomen, possible sepsis

Abdominopelvic Subdivisions

Quadrants (used clinically)

Quadrants

Right Upper (RUQ), Right Lower (RLQ), Left Upper (LUQ), Left Lower (LLQ)

Nine-Region Method

More precise abdominopelvic subdivision

Key superficial organs

e.g., liver RUQ & epigastric; spleen LUQ & left hypochondriac; appendix RLQ/right iliac

Other Small Cavities

Oral & Digestive, Nasal, Orbital, Middle-ear, Synovial (in joints)

Levels of Structural Organization

Chemical level - atoms → molecules; Cellular level - ≈ 10^{13} cells; Tissue level - groups of similar cells; Organ level - two or more tissue types form organs; Organ system level - organs cooperate; Organismal level - total of all systems creating a living human

Integumentary System

Skin, hair, nails; barrier, vitamin D synthesis, excretion, temperature regulation

Skeletal System

bones, cartilage, ligaments, tendons; support, protection, hematopoiesis, mineral storage, levers for muscles

Muscular System

skeletal muscles; movement, posture, heat

Nervous System

brain, spinal cord, nerves; fast control, responsiveness, short-term homeostasis via electrical signals

Endocrine System

glands (pituitary, thyroid, adrenals, pancreas, gonads, etc.); hormones for growth, reproduction, nutrient use, long-term homeostasis

Cardiovascular System

heart & blood vessels; pump & transport blood carrying O2, CO2, nutrients, wastes

Lymphatic/Immune System

lymphatic vessels, nodes, spleen, thymus, tonsils; return fluid, cleanse blood, immune surveillance

Respiratory System

nasal cavity, pharynx, larynx, trachea, bronchi, lungs; gas exchange, acid-base balance

Digestive System

oral cavity → anus; breaks down food, absorbs nutrients, expels feces

Urinary System

kidneys, ureters, bladder, urethra; eliminate nitrogenous wastes, regulate water, electrolytes, acid-base

Male Reproductive System

testes, vas deferens, prostate, penis → sperm & hormones

Female Reproductive System

ovaries, uterine tubes, uterus, vagina, mammary glands → eggs, hormones, support fetus

Interstitial Fluid

mediates exchange between blood & cells

Maintain Boundaries

separation of internal/external environments (skin, plasma membrane)

Movement

whole-body & internal (blood, food)

Responsiveness (Excitability)

sense & respond to stimuli (nervous system key)

Digestion

break down food for absorption

Metabolism

all chemical reactions; Catabolism (breakdown) & Anabolism (synthesis)

Excretion

removal of wastes (urine, feces, CO₂)

Reproduction

cellular (mitosis) & organismal (offspring)

Growth

increase cell size &/or number

Nutrients

carbs, proteins, lipids, vitamins, minerals supply energy & building blocks

Oxygen

final electron acceptor for aerobic respiration

Water

60-80% of body mass; solvent & chemical reactant

Normal Body Temperature

37°C (98°F); governs metabolic rate

Appropriate Atmospheric Pressure

required for adequate gas exchange in lungs

Homeostasis

dynamic equilibrium of internal environment within narrow limits

Negative Feedback

Response reduces/negates original stimulus; Examples: body temperature control, blood glucose regulation, blood pressure

Positive Feedback

Response amplifies stimulus; ends only when event completes; Limited normal examples: blood clotting cascade, uterine contractions during childbirth