1. Introduction to the Human Body
Chapter one

2. Understanding the Human Body
Curiosity
Illnesses, injuries, death
Obtained knowledge regarding the human body as science and medicine advanced

3. Anatomy: examines the structures, or morphology, or body parts – their forms, organization
-tomy: (Greek) cutting up
Anatomists rely on examination
Physiology: considers the functions of body parts – what they do and how they do it
Also Greek origin; relationship to nature
Physiologists rely on experimentation

4. A few definitions…
Regional anatomy: study of anatomy based on regions or divisions of the body; emphasis on relations between the structures of that region
Systemic anatomy: study of anatomy based on body systems and their functioning throughout the body
Gross anatomy: study of anatomy that is visible to the naked eye; macroscopic
Microscopic anatomy: study of anatomy at the microscopic level; cells

5. Levels of Organization
The human body is composed of parts within parts, which vary in complexity

6. Maintenance of Life Requirements of Organisms
Water  metabolic processes; transport of substances
Food/Nutrients  energy
Oxygen  release energy from food substances
Heat  regulation of metabolic reaction rates
Pressure  breathing (atmospheric); blood circulation (hydrostatic)
Although we require the aforementioned, these factors alone are not enough to ensure survival; quality and quantity matter.

7. Homeostasis
Equilibrium of the body’s internal environment produced by the interaction of organ systems and regulatory processes (feedback systems).
Homeostasis is a dynamic condition in response to changing conditions.
So important that it requires most of our metabolic energy

8. Continued…
Body maintains homeostasis through a number of self-regulating control systems – homoeostatic mechanisms
Receptors: provide information about the stimuli in the internal environment
Control center: includes a set point, tells what a particular value should be (body temperature)
Effectors: elicit responses that alter conditions in the internal environment ; muscles or glands

9. Feedback Mechanisms
Negative feedback: almost all homeostatic control mechanisms are negative feedback mechanisms. These mechanisms reduce the variable back to its original state or “ideal value”.
Blood sugar  receptors sense the change  pancreas (control center) secretes insulin  blood sugar levels reduce
Positive feedback:  the output enhances the original stimulus.
Child birth: oxytocin is released that intensifies and speeds up contractions.
Blood clotting: vessel is damaged, platelets start to cling to the injured site and release chemicals that attract more platelets. The platelets continue to pile up and release chemicals until a clot is formed.
Just remember that positive feedback mechanisms enhance the original stimulus and negative feedback mechanisms inhibit it.

10. Body Cavities and Terminology
Day two – chapter one

11. Anatomical Position Standing straight, body erect Feet slightly apart
Palms facing forward
Thumbs point away from body
Mrs. Schwab is my favorite science teacher ever

12. Body Planes Sagittal: divides the body into right and left parts
Frontal/coronal: divides the body into anterior and posterior parts
Transverse: divides the body into superior and inferior parts
Deep breaths Schwab Deep Breaths

13. Superior
Inferior

14. Any fluid filled space in a multicellular organism
Body Cavities
Dorsal cavity: protects the nervous system, and is divided into two subdivisions
Cranial cavity: within the skull; encases the brain
Vertebral cavity: runs within the vertebral column; encases the spinal cord
Ventral cavity: houses the internal organs (viscera), and is divided into two subdivisions
Thoracic
Abdominopelvic
Any fluid filled space in a multicellular organism
From Jacob Abbott

15. Thoracic cavity (contains heart
Cranial cavity
(contains brain)
Dorsal
body
cavity
Thoracic cavity (contains heart
and lungs)
Ventral
body cavity
(thoracic and
abdominopelvic
cavities)
Vertebral cavity
(contains spinal
cord)
Diaphragm
Abdominal cavity
(contains digestive
viscera)
Pelvic cavity
(contains bladder,
reproductive organs,
and rectum)
Key:
Dorsal body cavity
Ventral body cavity
(a) Lateral view

16. Thoracic Cavity
Thoracic cavity is subdivided into two pleural cavities, the mediastinum, and the pericardial cavity
Right & Left Pleural cavities: each houses a lung
Mediastinum: contains the pericardial cavity; surrounds the remaining thoracic organs
Pericardial cavity: encloses the heart

17. (b) Anterior view Cranial Vertebral Superior mediastinum Thoracic
Pleural
cavity
Cranial
Vertebral
Pericardial
Thoracic
(contains
heart
and lungs)
Key:
Dorsal body cavity
Ventral body cavity
(b) Anterior view
Figure 1.9b

18. Abdominopelvic cavity
The abdominopelvic cavity is separated from the superior thoracic cavity by the dome-shaped diaphragm
Composed of two subdivisions
Abdominal cavity– contains the stomach, intestines, spleen, liver, gall bladder
Pelvic cavity– lies within the pelvis and contains the bladder, reproductive organs, and rectum

19. Body Cavities Diaphragm Abdominal cavity (contains digestive viscera)
Abdomino-
pelvic
cavity
Key:
Dorsal body cavity
Pelvic cavity
(contains bladder,
reproductive organs,
and rectum)
Ventral body cavity
Figure 1.9b

20. Facial/Head Cavities
Oral and digestive – 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

21. Abdominopelvic Regions

22. Abdominopelvic Quadrants
Right upper
Left upper
Right lower
Left lower
Figure 1.12