Welcome to Anatomy & Physiology
Chapter 1 -Human Organization
What do you need to do
to pass this class?
MEMORIZE!
The Scope of Human Anatomy
•
Human anatomy is the study of the structure of
the human body.
•
Provides an essential foundation for the
understanding of physiology, the study of
function.
•
It is not just the structure of organs, but also the
functional reasons behind that structure.
Levels of Structural Organization
•
Chemical Level


•
Cellular Level

•
At least two tissue types that perform a specific function
Organ System

•
Groups of similar cells that have common function
Organ Level

•
Various cell types
Tissue Level

•
Atoms
Molecules
At least two organs that work together to accomplish a common
purpose
Organism

The sum total of all structural levels working together to promote
life
Homeostatic Control Mechanisms


1.
2.
3.
Homeostasis is the relative constancy of the
body’s internal environment.
A homeostatic mechanism as 3 components:
sensor- detects change- nerves
regulatory center-activates the effectorshypothalmus
effector-reverses the change and brings
conditions back to normal.-muscle
contraction

Negative Feedback is the primary mechanism
that keeps a variable close to a particular
value or set point. It prevents change in the
same direction. Example-furnace, body temp.

Positive Feedback is a mechanism that
brings about an ever greater change in the in
the same direction. Can be harmful, examplefever. Childbirth (oxytocin)
sensor
Regulatory
center
effector

Anatomical position – a common visual reference
point
 Person
stands erect with feet together and eyes
forward
 Palms face interiorly with the thumbs pointed away
from the body

Regional terms – names of specific body areas
Axial region – the main axis of the body
 Appendicular region – the limbs


Directional terminology

Refers to the body in anatomical position
 Standardized terms of directions are paired terms
Orientation and Directional
Terms
Orientation and Directional
Terms
Orientation and Directional
Terms
Regional Terms
Regional Terms
Body Planes and Sections
Frontal plane - Lies vertically and divides
body into anterior (front) and posterior
(back) parts
 Sagittal plane – lies vertically and divides
the body into left and right sides.

 Median
(midsagittal) plane - Specific sagittal
plane that lies vertically in the midline

Transverse plane - runs horizontally and
divides body into superior (up) and
inferior (down) parts
Body Planes and Sections
Body Planes and Sections

Oblique section through the trunk
Figure 1.6
Body Cavities and Membranes


Dorsal body cavity
Cavity subdivided
into the cranial
cavity and the
vertebral cavity.
 Cranial
cavity
houses the brain.
 Vertebral cavity
runs through the
vertebral column
and encloses the
spinal cord
Body Cavities and Membranes

Ventral body cavity
– subdivided into:
cavity –
divided into three
parts
 Thoracic
Two lateral parts
each containing a
lung surrounded by
a pleural cavity
 Mediastinum –
contains the heart
surrounded by the
pericardial sac

Body Cavities and Membranes

Ventral body cavity
 Abdominopelvic
cavity – divided
into two parts
Abdominal cavity
– contains the liver,
stomach, kidneys,
and other organs
 Pelvic cavity –
contains the
bladder, some
reproductive
organs, and rectum

Body Cavities and Membranes

Serous cavities – A thin membrane lining a
closed body cavity and moistened with a serous fluid.

Pleura(thoracic), pericardium (heart), and peritoneum
(abdomen)
 Parietal serosa – forms outer wall of the cavity
 Visceral serosa covers the visceral organs (large inner
organs)
Body Cavities and Membranes
Other Body Cavities





Oral cavity
Nasal cavity
Orbital cavities
Middle ear cavities
Synovial cavities
Abdominal Regions and Quadrants

Abdominal regions divide the abdomen into
nine regions
Abdominal Quadrants

Abdominal quadrants divide the abdomen into four
quadrants

Right upper and left upper quadrants
 Right lower and left lower quadrants