1. The Human Body: An Orientation
Chapter 1
Part 2

2. Necessary Life Functions Survival Needs Homeostasis
Maintaining Life
Necessary Life Functions
Survival Needs
Homeostasis

3. Necessary Life Functions
Maintaining Boundaries
Inside must be distinct from outside
Movement
Locomotion
Movement of substances
Responsiveness
AKA “irritability”
Ability to sense changes in environment and respond
Digestion
Breakdown and delivery of nutrients
Metabolism
Chemical reactions within body cells
Excretion
Removes wastes from body and requires many organs
Reproduction
Production of future generation
Growth
Increasing of cell size and number

4. Survival Needs Nutrients Oxygen Taken in via diet
Give energy and maintain cells
Chemicals for energy and cell building
Includes carbohydrates, proteins, lipids, vitamins, and minerals
Oxygen
Required for chemical reactions

5. Survival Needs (con’t)
Water
Obtained through diet
Lose by evaporation from lungs, skin, and excretion
60 – 80% of body weight
Provides for metabolic reactions
Normal (stable) body temperature
Atmospheric pressure – must be appropriate

6. Indicates a dynamic state of equilibrium, or balance.
Homeostasis
Describes the ability to maintain relatively stable internal condition even though the outside world changes continuously.
Indicates a dynamic state of equilibrium, or balance.

7. Homeostatic Control Mechanisms
Communication in the body is accomplished chiefly by the nervous and endocrine systems.
Variable – factor or event being regulated
Receptor – sensor that monitors the environment and respond to changes
Control center – analyzes the input it receives and then determines the appropriate response
Effector – provides a means for response to the stimulus

8. Negative Feedback Mechanism
The output of the system shuts off the original stimulus or reduces its intensity.
This mechanism causes the variable to change in a direction opposite to that of the initial change, returning it to its “ideal” value.
All negative feedback systems have the same goal: to prevent sudden severe changes.

10. Positive Feedback Mechanism
The result of response enhances or exaggerates the original stimulus so that the activity is accelerated.
“Positive” because the change occurs in the same direction as the initial disturbance, causing the variable to deviate further and further from the original value.
Control infrequent events that don’t require continuous adjustments!!

13. The Language of Anatomy
Special terminology is used to prevent misunderstanding
Exact terms are used for:
Position
Direction
Regions
Structures

14. Anatomical Position Anatomical reference point
Body is erect with feet slightly apart
“Standing at attention” pose
Palms face forward and thumbs point away from body

15. Directional Terms
Allow us to explain exactly where one body structure is in relation to another.

16. Orientation and Directional Terms
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

17. Orientation and Directional Terms
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

18. Regional Terms
Used to designate specific areas within the major body divisions.
Two divisions:
Axial part – head, neck, and trunk
Appendicular part – limbs

19. Body
Landmarks
Anterior

20. Body
Landmarks
Posterior

21. Body Planes Plane – flat surface Most frequent body planes:
Sagittal Plane
Vertical plane that divides body into right and left
Midsagittal – exactly on midline
Parasagittal – offset from midline
Frontal Plane
Divides body into anterior and posterior
AKA “coronal” plane
Transverse Plane
Horizontal plane
Divides into superior and inferior parts

22. A section is a cut along a plane.

23. Body Planes
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

24. Body Cavities

25. Axial portion of the body:
Dorsal Body Cavity
Ventral Body Cavity

27. Dorsal Body Cavity Protects nervous system 2 Subdivisions:
Cranial cavity – encases brain
Vertebral cavity – encases spinal cord

28. Ventral Body Cavity 2 Subdivisions:
Thoracic cavity is subdivided into pleural cavities, the mediastinum, and the pericardial cavity
Surrounds ribs and muscles
Pleural cavity – houses lungs
Pericardial cavity – houses hearts, esophagus and trachea
Mediastinum – contains the pericardial cavity, and surrounds the remaining thoracic organs

29. Ventral Body Cavity 2 Subdivisions: (con’t) Abdominopelvic cavity
Separated from thoracic cavity by the dome-shaped diaphragm
It is composed of two subdivisions
Abdominal cavity – contains stomach, intestines, spleen, and liver, and other organs
Pelvic cavity – lies within the pelvis and the contains bladder, reproductive organs, and rectum

30. Membranes in the Ventral Body Cavity
Serosa (serous membrane)
Thin, double-layered membrane
Parietal serosa – membrane lining cavity walls
Visceral serosa – covers organs
Serous fluid
Separates serous membranes
Allows sliding without friction

31. Ventral Body Cavity Membranes
Parietal serosa covering the body walls
Visceral serosa covering the internal organs
Serous fluid separates the serosae

32. Other Body Cavities Oral and digestive Nasal Orbital Middle ear
Mouth and cavities of the digestive organs
Nasal
Located within and posterior to the nose
Orbital
House the eyes
Middle ear
Contains bones (ossicles) that transmit sound vibrations
Synovial
Joint cavities

33. Abdominopelvic Regions
1. Right Hypochondriac: Liver, gall bladder, small intestine, ascending colon, transverse colon, right kidney
2. Epigastric: Esophagus, stomach, liver, pancreas, small intestine, transvers colon, right and left adrenal glands, pancreas, right and left kidneys, right and left ureters, spleen
3. Left Hypochondriac: Stomach, tip of liver, tail of pancreas, small intestines, transverse colon, descending colon, pancreas, left kidney, spleen
4. Right Lumbar: Tip of liver, gall bladder, small intestine, ascending colon, right kidney
5. Umbilical: Stomach, pancreas, small intestine, transverse colon, pancreas, right and left kidneys, right and left ureters

34. Abdominopelvic Regions (con’t)
1. Right Hypochondriac: Liver, gall bladder, small intestine, ascending colon, transverse colon, right kidney
2. Epigastric: Esophagus, stomach, liver, pancreas, small intestine, transvers colon, right and left adrenal glands, pancreas, right and left kidneys, right and left ureters, spleen
3. Left Hypochondriac: Stomach, tip of liver, tail of pancreas, small intestines, transverse colon, descending colon, pancreas, left kidney, spleen
4. Right Lumbar: Tip of liver, gall bladder, small intestine, ascending colon, right kidney
5. Umbilical: Stomach, pancreas, small intestine, transverse colon, pancreas, right and left kidneys, right and left ureters

35. Abdominopelvic Regions

36. Abdominopelvic Quadrants
Quadrants are named according to subject’s pt. of view
Right upper
Left upper
Right lower
Left lower