The Human Body: An Orientation
Learning About Your Body Is Fascinating
How do we:
• Move with speed and accuracy?
• Perceive visual stimuli, feel hunger or
temperature?
• How do our physical brains correspond to
our immaterial minds?
• How can we heal from a wide variety of
injuries?
Learning About Your Body Is Important
A&P students will:
• Advance medical
breakthroughs
• Serve in important
healthcare capacities
• Be able to correctly interpret
medical news and advice to
care for yourself and your
family
Introduction to Human
Anatomy and
Physiology
Gross Anatomy
Anatomy:
• The structure of body parts
Gross Anatomy:
• The study of body parts
visible by eye
Subdivisions:
• Regional anatomy
• Systemic anatomy
• Surface anatomy
Regional Anatomy:
The study of all structures within a region
• Includes all structures
such as muscles, bones,
blood vessels, nerves,
etc.
Systemic Anatomy:
The study of all structures within a system
Surface Anatomy:
The study of internal structures as they relate to the overlying skin surface
Microscopic Anatomy
Cytology
• The study of cellular
structure
Histology
• The study of tissues
Levels of structural organization
Cell:
– The most basic unit of life
Tissue:
– Groups of similar cells that have a
common function
Organ:
– Discrete structure composed of at
least two tissue types that
performs a specific function
Organ system:
– Organs that work together to
accomplish a common purpose
Physiology
Physiology:
• The function of body
parts
Subdivisions:
• Cellular physiology
• Exercise physiology
• Systemic physiology
• Pathophysiology
Overview of the 11 organ systems
Overview of the 11 organ systems
Overview of the 11 organ systems_
_Overview of the 11 organ systems
Homeostasis and
Directional Terms
Homeostasis
•
Homeostasis is the tendency towards a
stable internal environment despite
continuous perturbations
– From Greek “staying the same”
• Physiological parameters are kept within
certain limits
– Dynamic equilibrium
• Necessary for health and survival
– Maintained by contributions of all
organ systems
Homeostatic Control Mechanisms
• Monitors the internal environment
and makes corrections as needed
• Three parts:
1. Receptor – receives stimuli,
transmits to control center
2. Control center – processes
information and generates a
response command
3. Effector – Carries out the
command to elicit change
Negative and Positive Feedback
Negative (-) feedback:
• Reduces effect of stimulus
• I.E., body temp, breathing rate,
blood sugar levels
Positive (+) feedback:
• Increases response
• I.E., labor contractions, blood
clotting
Diseases:
• Homeostatic imbalance
Negative Feedback Example:
Body Temperature
Positive Feedback Example:
Blood Clotting
Anatomical position
• The language of anatomy keeps
reference points and directional
terms accurate
• Anatomical position is the
universal reference point
– Body erect
– Feet slightly apart
– Upper limbs at sides
– Palms and head face forward
– Thumbs pointing out
Supine and Prone Position
Facing up
Supine
Facing down
Prone
11 Directional Terms
• Used to describe the position
of one body part relative to
another.
• Many are grouped in pairs:
– Opposite meanings (i.e., anteriorposterior)
– Combined meanings (i.e.,
anterosuperior)
Anterior and Posterior
Front
Anterior
Back
Posterior
Midline, Medial, and Lateral
Terms of Laterality
Inferior and Superior
Inferior:
Situated nearer
to the feet than
the head; the
lower part of a
structure
Superior: Situated
towards the head
and further away
from the feet; the
upper part of a
structure.
Deep, Superficial, Distal, Proximal
Ventral, Dorsal, Caudal, and Cephalic/Rostral
Embryonic Terms
• Ventral = Anterior
• Dorsal = Posterior
• Caudal = Inferior
• Cephalic/Rostral = Superior
Ventral, Dorsal, Caudal, and Cephalic
As the brain develops, the
embryonic terms take on new
meaning
Anatomical Planes
• Body parts are relative to
planes
• Planes are imaginary flat
surfaces that passthrough parts of the body
• Body sections are divided
by planes
Frontal (coronal) and transverse planes
Frontal plane divides the body into
front and back portions
Transverse divides the body into
superior and inferior portions
Sagittal and Oblique Planes
Sagittal plane divides the body
vertically into right and left portions
Oblique plane divides the body at an
angle
Review of planes and positions
Magnetic Resonance Imaging (MRI)
Abdominopelvic 4 Quadrants, 9 Regions
Used to establish differential diagnosis
Quadrants are more commonly used in the clinic
Two body cavities and their subdivisions help
offer organ protection and organization
Ventral Cavity Serosa Membranes
(also called serous membranes)
Thin, double-layered
membranes
• Parietal serosa lines cavity wall
• Visceral serosa lines internal
organs
Layers are separated by a slitlike cavity
• Filled with serous fluid
• Secreted by both layers
Serous fluid reduce friction when organs
move against each other and the cavity wall
Three types of serous membranes
Pericardium
• Heart
Pleurae
• Lungs
Peritoneum
• Abdominopelvic
cavity
Jokes
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