1. Anatomical Regions, Directions, and Body Cavities
The Human Body
Anatomical Regions, Directions, and Body Cavities

2. . Describes the structures of the body
Overview of Anatomy
Anatomy – the study of the structure of body parts and their relationships to one another
. Describes the structures of the body
What they are made of
Where they are located
Associated structures

3. Anatomy
Gross or macroscopic
Microscopic
Developmental

4. examines large, visible structures
Gross or macroscopic anatomy,
examines large, visible structures
Regional – all structures in one part of the body (body areas ).
Systemic – gross anatomy of the body studied by system ( organ system)
Surface – study of internal structures as they relate to the overlying skin (exterior features )

5. Cytology – study of the cell structure
Microscopic Anatomy
examine cells and molecules
Cytology – study of the cell structure
Histology – study of tissues structure

6. Developmental Anatomy
Traces structural changes throughout life
Embryology – study of developmental changes of the body before birth

7. Levels of Organization
The Chemical (or Molecular) Level
Atoms are the smallest chemical units
Molecules are a group of atoms working together
The Cellular Level
Cells are a group of atoms, molecules, and organelles working together
The Tissue Level
A tissue is a group of similar cells working together
The Organ Level
An organ is a group of different tissues working together

8. Levels of Organization
The Organ Level
An organ is a group of different tissues working together
The Organ System Level
An organ system is a group of organs working together
Humans have 11 organ systems
The Organism Level
A human is an organism

9. Homeostasis
Homeostasis
All body systems working together to maintain a stable internal environment Systems respond to external and internal changes to function within a normal range (body temperature, fluid balance)

10. Body Planes
Anatomic reference systems describe the location and functions of body parts. The basic reference systems are: body planes, body directions, body cavities, and structural units
Body planes are imaginary horizontal and vertical lines used to divide the body into sections
The use of these planes makes it easier to describe the location of an organ or problem.

11. Body Planes Sagittal – divides the body into right and left parts
Midsagittal or medial – sagittal plane that lies on the midline
Frontal or coronal – divides the body into anterior and posterior parts
Transverse or horizontal (cross section) – divides the body into superior and inferior parts
Oblique section – cuts made diagonally

13. Anatomical Regions Abdominopelvic quadrants Abdominopelvic regions
Abdominopelvic quadrants. The four abdominopelvic quadrants are formedb
by two perpendicular lines that intersect at the the navel.
1. Right upper quadrant (RUQ)
2. Left upper quadrant (LUQ)
3. Right lower quadrant (RLQ)
4. Left lower quadrant (LLQ)

14. Abdominopelvic regions
Abdominopelvic regions The nine abdominopelvic regions provide more precise regional descriptions.
1. Epigastric – above the stomach
2. Umbilical – near the umbilicus or belly
button
3. Hypogastric / pelvic – below the stomach
4. Hypochondriac – below the ribs
5. Lumbar/Lateral – near the large bones of the
spinal cord
6. Iliac / inguinal – near the groin

16. The Directional Terms
Superior and inferior – toward and away from the head,
respectively
Anterior and posterior – toward the front and back of the
body
Medial, lateral, and intermediate – toward the midline,away
from the midline, and between
more medial and lateral structure
. Proximal and distal – closer to and farther from the
origin of the body
Superficial and deep – toward and away from the
body surface

18. Body Cavities Internal chambers that suspend vital organs Functions:
1. Protect delicate organs from shock and cushions them.
2. Allow Internal organs to change size and shape without distorting other organs.

19. Body Cavities
Dorsal Body
Cavity
Ventral Body
Cavity

20. I. Doral Body Cavity Subdivided into:
1. Cranial Cavity- contains the brain .
2. Spinal Cavity- contains the spinal
cord.

21. extends from the cranial cavity to the end of the vertebral column.
A. Cranial Cavity
Within the bony skull.
Protects the brain
B. Spinal Cavity . .
extends from the cranial cavity to the end of the vertebral column.
protects the spinal cord.

22. Ventral Body Cavity
The diaphragm divides this cavity into:
Thoracic Cavity-
A superior cavity in the chest.
B. Abdominopelvic Cavity-
An inferior cavity containing the organs of the abdomen and the pelvis.

23. How do the body cavities protect organs?
Serous membranes line the walls of the cavities and cover the surface of the organs. Membranes secrete a fluid (serous fluid) that reduces friction within the cavity.

24. Naming the Two Layers
Visceral- the layer of membrane that covers the organ.
Parietal - the layer of membrane that lines the cavity.
Both layers secrete a fluid that fills the space between.

25. surrounds and protects the heart. 2. Two Pleural Cavities-
A. Thoracic Cavity
Contains three internal chambers:
Pericardial Cavity-
surrounds and protects the heart.
2. Two Pleural Cavities-
surround the left and right lung .

26. 1. Pericardium Made of two layers: a. Visceral pericardium-
membrane covering the heart.
b. Parietal pericardium
membrane on the outside.
c. Pericardial Cavity- is the fluid-filled space between Made of two la

27. Mediastinum
The region within the thoracic cavity between the pleural cavities.
Contains the pericardium + esophagus + trachea.
It is only a region and not a cavity.

28. 2. Pleural Cavity Cavity around each lung. Made by the
a. visceral pleura
b. parietal pleura.

29. Abdominopelvic Cavity
Abdominal
Cavity (Superior)
Pelvic Cavity
(Inferior)

30. B. Abdominopelvic Cavity
Divided into:
1. Abdominal Cavity- superior; from diaphragm to lowest vertebra.
2. Pelvic Cavity- inferior to the above; pelvic bones form wall and muscles form its floor.

31. Abdominal Cavity
Lined by a serous membrane- peritoneum which protects the liver, stomach, spleen, small intestine and most of the large intestine.
Kidneys are retroperitoneal- behind the peritoneum.

32. Peritoneum Two membranes: 1. Visceral Peritoneum- covers the organs.
2. Parietal Peritoneum- lines the abdominopelvic cavity.
3. Peritoneal Cavity- is the fluid-filled space between.

33. Pelvic Cavity Inferior portion of the abdominopelvic cavity.
Contains the last segments of large intestine, urinary bladder, and reproductive organs.
Only the most superior organs in the pelvic cavity are covered in peritoneum (uterus, uterine tubes, ovaries, and bladder.