The Human Body
Chapter 1
Human Anatomy and Physiology
Anatomy: The study of body structures and their
relationships
Static within a species
Physiology: The study of the functions of body
structures
Dynamic within a species
Subdivision Examples
Anatomy Physiology
• Gross anatomy • Neurophysiology
– Regional • Pathophysiology
– Systemic
– Surface • Cardiovascular physiology
• Microscopic anatomy • Renal Physiology
– Cytology • Others
– Histology
• Embryology
• Developmental anatomy
• Others
Life is an Emergent Property
• Atoms
• Molecules
• Organelles
• Cells
• Tissues
• Organs
• Organ systems
– Listed in fig 1.3
• Organismal level
Organ Systems
ORGAN SYSTEM COMPONENTS FUNCTIONS
Integumentary Skin, hair, nails Protection
Skeletal Bones Support/movement
Nervous Brain, spinal cord, nerves, sense Control and
organs communication
Muscular Muscles Movement
Endocrine Hormones and associated glands Homeostasis
Cardiovascular Heart, blood vessels, blood Transport of substances
Lymphatic Lymph vessels and lymph nodes Transport, immunity
Respiratory Nose, trachea, lungs Transport of gases
Digestive Mouth, esophagus, stomach, Energy acquisition and
intestines food processing
Urinary Kidneys, ureters, bladder, urethra Water balance
Reproduction Gonads Propagation
Life’s Essentials
• Maintain boundaries
• Move
• Respond to
environment
• Digestion
• Excretion
• Metabolism
• Reproduce
• Grow
Survival Essentials
• Nutrients
– Fuel for the cells
– Building materials
• Oxygen
– Release energy from nutrients
• Water
– Facilitates reactions and excretions/secretions
• Normal body temperature
– Regulate metabolic reactions
• Atmospheric pressure
– Corresponds with gas exchange w/i cells
• Adequate amounts, not just presence maintains a healthy state
Homeostasis
• Dynamic state of equilibrium
• 3 components
– Receptor (afferent)
– Control center (set point)
– Effector (efferent)
• Imbalance causes illness & disease
– Increase with age
– Disruptions in feedback
Feedback
• Negative
– Most homeostatic mechanisms
• Turn off or slow original stimuli
• Stabilizes
– Body temperature, heart and breathing
rate, & blood glucose
• Positive
– Increases the original stimuli
– Oxytocin (labor) and blood clotting
ANATOMICAL LANGUAGE
Anatomical Position
• Standing tall with upper limbs at sides
and face, palms and toes forward
• Reference position when describing
body part locations
– Left and right is specimen’s
– Variations for bipeds and quadrupeds
Anatomical Regions to Know
Anatomical Directions to Know
Superior/ inferior
Cranial/caudal
Ventral/ dorsal
Anterior/ posterior
Medial/ lateral
Intermediate/ proximal/
distal
Superficial/ deep
External/ internal
Supine/ prone
Ipsilateral/ contralateral
Study tip: pick two structures on self and describe as many ways as possible
Body Planes are Like Breads
• Frontal (coronal) section:
• Sagittal section: divides divides anterior and posterior
the body longitudinally – e.g.: loaf of bread
into left and right
– Midsagittal: equal
parts • Transverse (cross) section:
– Parasagittal: off divides superior and inferior
– e.g.: hamburger bun or bagel
midline
– e.g.: hotdog bun – Oblique section: diagonal
cuts
Body Cavities
• Dorsal
– Cranial: brain
– Vertebral: spinal cord
• Ventral
– Thoracic
• Left & right pleura
• Mediastinum (pericardial)
– Abdominopelvic
• No real separation
• Protection differences
• Diaphragm divides
Serous Membranes
• Double-layer membrane
separated by serous fluid
– Reduces friction; lubricates
• Line walls and organs of ventral
body cavities
– Parietal serosa lines walls
– Visceral serosa lines organs
(viscera)
– Named for associated organs
• Never exposed to external
environment
Other Body Cavities
• Open to environment (generally)
Abdominopelvic Subdivisions
Epigastric
Regions (9) Quadrants (4)
Umbilical
Hypogastric
Hypochondriac
Lumbar
Inguinal
• Anatomists use; references • Clinicians use; references to
location and orientation of describe pain, tenderness,
internal organs and injuries