HUMAN ANATOMY & PHYSIOLOGY
QUICK REVISION NOTES
Chapter 1 — The Human Body:
Organization, Anatomy & Homeostasis
1.1 Anatomy & Physiology
Anatomy: Study of body structure.
Physiology: Study of body function.
Key principle: Structure determines function.
1.2 Levels of Organization
Chemical → Cellular → Tissue → Organ → Organ system → Organism
● Chemical: Atoms + molecules
● Cellular: Basic living unit
● Tissue: Similar cells performing a function
● Organ: 2+ tissue types working together
● Organ system: Organs working together
● Organism: Complete living individual
1.3 Anatomical Position
Anatomical position: Standing upright, face forward, arms at sides, palms forward.
Directional Terms
Term Meaning
Superior Above
Inferior Below
Anterior Front
Posterior Back
Medial Toward midline
Lateral Away from midline
Proximal Near point of attachment
Distal Far from point of attachment
Superficial Near surface
, Deep Away from surface
1.4 Body Planes
Sagittal: Divides left/right.
Midsagittal: Equal left/right halves.
Frontal (coronal): Divides anterior/posterior.
Transverse: Divides superior/inferior.
1.5 Major Body Cavities
Dorsal Cavity
● Cranial: Brain
● Vertebral: Spinal cord
Ventral Cavity
● Thoracic: Heart + lungs
● Abdominal: Most digestive organs
● Pelvic: Urinary/reproductive organs + rectum
Diaphragm: Separates thoracic and abdominal cavities.
1.6 Major Organ Systems
System Main Function
Integumentary Protection + temperature regulation
Skeletal Support + protection + mineral storage
Muscular Movement + heat
Nervous Rapid control + communication
Endocrine Hormonal regulation
Cardiovascular Blood transport
Lymphatic/Immune Fluid balance + defense
Respiratory O₂/CO₂ exchange
Digestive Digestion + nutrient absorption
Urinary Waste removal + fluid balance
Reproductive Reproduction
1.7 Homeostasis
Homeostasis: Maintenance of a relatively stable internal environment.
, Homeostatic Control
Stimulus → Receptor → Control center → Effector → Response
● Stimulus: Change in internal/external condition
● Receptor: Detects change
● Control center: Processes information
● Effector: Produces response
Negative Feedback
Reverses the original change.
Examples:
● Body temperature regulation
● Blood glucose regulation
● Blood pressure regulation
Most common homeostatic mechanism.
Positive Feedback
Amplifies the original change.
Examples:
● Labor contractions
● Blood clotting
1.8 Homeostasis & Disease
Homeostatic imbalance → Dysfunction → Disease
The body continuously adjusts variables such as:
● Temperature
● Blood glucose
● Blood pressure
● pH
● Water balance
● Electrolytes
● Oxygen/CO₂ levels
1.9 Key Connections
Cells → tissues → organs → organ systems → organism
Nervous + endocrine systems: Coordinate body functions.
All organ systems: Work together to maintain homeostasis.
Core Idea
, Anatomy = structure
Physiology = function
Homeostasis = internal stability
Chapter 2 — Chemistry of Life
2.1 Matter & Atoms
Matter: Has mass and occupies space.
Atom: Smallest unit of an element.
Subatomic Particles
● Proton: + charge; nucleus
● Neutron: No charge; nucleus
● Electron: − charge; outside nucleus
Atomic number = Number of protons
Mass number = Protons + neutrons
Element: Substance made of one type of atom.
2.2 Ions & Isotopes
Ion: Charged atom due to electron gain/loss.
● Cation: Positive; loses electrons
● Anion: Negative; gains electrons
Isotopes: Same element; different numbers of neutrons.
2.3 Chemical Bonds
Ionic Bond
Electron transfer → attraction between opposite ions.
Covalent Bond
Electron sharing between atoms.
● Nonpolar: Unequal? No; electrons shared relatively equally.
● Polar: Unequal electron sharing.
QUICK REVISION NOTES
Chapter 1 — The Human Body:
Organization, Anatomy & Homeostasis
1.1 Anatomy & Physiology
Anatomy: Study of body structure.
Physiology: Study of body function.
Key principle: Structure determines function.
1.2 Levels of Organization
Chemical → Cellular → Tissue → Organ → Organ system → Organism
● Chemical: Atoms + molecules
● Cellular: Basic living unit
● Tissue: Similar cells performing a function
● Organ: 2+ tissue types working together
● Organ system: Organs working together
● Organism: Complete living individual
1.3 Anatomical Position
Anatomical position: Standing upright, face forward, arms at sides, palms forward.
Directional Terms
Term Meaning
Superior Above
Inferior Below
Anterior Front
Posterior Back
Medial Toward midline
Lateral Away from midline
Proximal Near point of attachment
Distal Far from point of attachment
Superficial Near surface
, Deep Away from surface
1.4 Body Planes
Sagittal: Divides left/right.
Midsagittal: Equal left/right halves.
Frontal (coronal): Divides anterior/posterior.
Transverse: Divides superior/inferior.
1.5 Major Body Cavities
Dorsal Cavity
● Cranial: Brain
● Vertebral: Spinal cord
Ventral Cavity
● Thoracic: Heart + lungs
● Abdominal: Most digestive organs
● Pelvic: Urinary/reproductive organs + rectum
Diaphragm: Separates thoracic and abdominal cavities.
1.6 Major Organ Systems
System Main Function
Integumentary Protection + temperature regulation
Skeletal Support + protection + mineral storage
Muscular Movement + heat
Nervous Rapid control + communication
Endocrine Hormonal regulation
Cardiovascular Blood transport
Lymphatic/Immune Fluid balance + defense
Respiratory O₂/CO₂ exchange
Digestive Digestion + nutrient absorption
Urinary Waste removal + fluid balance
Reproductive Reproduction
1.7 Homeostasis
Homeostasis: Maintenance of a relatively stable internal environment.
, Homeostatic Control
Stimulus → Receptor → Control center → Effector → Response
● Stimulus: Change in internal/external condition
● Receptor: Detects change
● Control center: Processes information
● Effector: Produces response
Negative Feedback
Reverses the original change.
Examples:
● Body temperature regulation
● Blood glucose regulation
● Blood pressure regulation
Most common homeostatic mechanism.
Positive Feedback
Amplifies the original change.
Examples:
● Labor contractions
● Blood clotting
1.8 Homeostasis & Disease
Homeostatic imbalance → Dysfunction → Disease
The body continuously adjusts variables such as:
● Temperature
● Blood glucose
● Blood pressure
● pH
● Water balance
● Electrolytes
● Oxygen/CO₂ levels
1.9 Key Connections
Cells → tissues → organs → organ systems → organism
Nervous + endocrine systems: Coordinate body functions.
All organ systems: Work together to maintain homeostasis.
Core Idea
, Anatomy = structure
Physiology = function
Homeostasis = internal stability
Chapter 2 — Chemistry of Life
2.1 Matter & Atoms
Matter: Has mass and occupies space.
Atom: Smallest unit of an element.
Subatomic Particles
● Proton: + charge; nucleus
● Neutron: No charge; nucleus
● Electron: − charge; outside nucleus
Atomic number = Number of protons
Mass number = Protons + neutrons
Element: Substance made of one type of atom.
2.2 Ions & Isotopes
Ion: Charged atom due to electron gain/loss.
● Cation: Positive; loses electrons
● Anion: Negative; gains electrons
Isotopes: Same element; different numbers of neutrons.
2.3 Chemical Bonds
Ionic Bond
Electron transfer → attraction between opposite ions.
Covalent Bond
Electron sharing between atoms.
● Nonpolar: Unequal? No; electrons shared relatively equally.
● Polar: Unequal electron sharing.
