AN ORIENTATION TO THE
HUMAN BODY
Human Biology
• It is the structural, functional, behavioral
basis of the human organisms’ ability to
adapt to and survive in its environment.
NECESSARY LIFE
FUNCTIONS
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Maintain boundaries –
Movement
Process of metabolism
Maintain homeostasis
Reproduction
Responsiveness/irritability
Growth
TRUE FOR:
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Unicellular
Made up of one cell
Example – ameba,
Maintain boundaries –
cell membrane
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Multicellular
Made up of many cells
Example – humans
Maintain boundaries –
skin
• Must maintain
homeostasis for single
cell as well as for
organism
Survival Needs
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Nutrients
Oxygen
water
body temperature
Appropriate atmospheric pressure
ORGANIZATION OF HUMAN
BODY
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Cell
Tissues
Organ
Organ system
Organism
Population
Community
Ecosystem/biome
biosphere
FEEDBACK SYSTEM
• Feedback system is a cycle of events in
which the status of a body condition is
continually monitored, evaluated, changed,
remonitored, reevaluated continuously.
HOMEOSTATIC CONTROL
MECHANISMS
• Receptor
• Control center
• Effector
MAINTAINING
HOMEOSTASIS
• Negative feedback system
• Positive feedback system
HOMEOSTATIC IMBALANCE
• Most diseases are a result of disturbances in
the body’s homeostasis
• Efficiency decreases with age
LANGUAGE OF ANATOMY
Provides ways to accurately describe
the body
ANATOMY
• Study of structure and shape of the body
and body parts and their relationship to each
other
• Gross anatomy – study of large observable
structures
• Microscopic anatomy – study of structures
that require a microscope to been seen
PHYSIOLOGY
• Study of how the body and its parts
function.
Structure determines function.
Governing rule in anatomy
Terms
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Disorder
Disease
Symptom
Signs
Pathology
Epidemiology
Pharmacology
diagnosis
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Infectious disease
Pathogens
Local disease
Systemic disease
ANATOMICAL POSITION
• Standard position
• Basis for directional terms
DIRECTIONAL TERMS
• Explain exact location of 1 body structure in
relation to another.
REGIONAL TERMS
• Anterior body landmarks – toward / at front
of body
• Posterior body landmarks – toward / at back
of body
BODY PLANES AND
SECTIONS
• Imaginary line through the body wall or
organ
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Three sections
• Sagittal section
• Frontal (coronal) plane
• Transverse sections (cross-section)
BODY CAVITIES
TWO MAIN CAVITIES
1. Dorsal Cavity
2. Ventral Cavity
Dorsal cavity
2 divisions that are continuous with each other
1. Cranial – space for brain
2. Spinal cavity – space for spinal cord
Foramen magnum – opening at base of brain
allows for spinal cord to
connect with brain
Ventral cavity
• 1. Thoracic cavity – separated from rest of ventral
cavity by diaphragm
surrounded by ribs
houses heart, lungs
2. Abdominopelvic
a. abdominal – superior cavity
houses stomach, liver, intestines
b. Pelvic – inferior cavity
houses reproductive organs, bladder,
rectum
9 regions of abdominopelvic
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Right hypochondriac region
Left hypochondriac region
Right lumbar region
Left lumbar region
Right iliac region
Left iliac region
Epigastric region
Umbilical region
Hypogastric region
CRANIAL CAVITIES
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Sphenodial sinus
Frontal sinus
Orbital cavity
Nasal cavity
Oral cavity
Middle ear cavity
Cranial cavity
Medical imaging
• Bombards the body with energy to reveal
structures of internal organs, and chemical
processes of body
X-RAY
• Oldest
• Visualize hard bony structures
• Locate abnormally dense structures such as
tumors and TB nodules
ULTRASOUND
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Sonography
Equipment is inexpensive
Uses high frequency sound waves
So far, no harmful effects on living tissue
Determines fetal age, position: locating
placenta.
CT SCAN
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Computer tomography
Confines its beam to a thin slice of tissue
Like a refined version of X-ray
Eliminated exploratory surgery
Patient is moved through a doughnut shaped
CT machine – tube rotates around bed
PET
• Positron-emission tomography
• it sends images about metabolic processes
• Insights into brain activity (mental illness,
Alzheimer’s disease, epilepsy)
• Uses radioisotopes
MRI
• Magnetic resonance imaging
• Uses magnetic fields 3,000 to 60,000 times
stronger than the earth’s
• Bones do not show up thus they do not interfere
with viewing soft tissue behind bone
• Good at picking up degenerative diseases – ex MS
• Very expensive