1. THE HUMAN BODY: An Orientation
CHAPTER ONE:
THE HUMAN BODY:
An Orientation

2. I. WHAT IS ANATOMY?
Anatomy = study of the structure and shape of body parts and how they relate to each other
Ana = apart
Tomy = to cut
What does anatomy literally mean?
To cut apart

3. THREE MAIN TYPES OF ANATOMY
Gross
Microscopic
Developmental

4. GROSS ANATOMY
1. Gross anatomy (macroscopic) = the study of large body structures visible to the naked eye, such as the:
- heart
- kidney
- lung
A. Regional Anatomy = All of the structures in one particular region of the body, such as the abdomen or leg.
B. Systemic Anatomy = the gross anatomy of the body is studied system by system.
C. Surface Anatomy = the study of body structures as they relate to the overlying skin

5. MICROSCOPIC ANATOMY
2. Microscopic Anatomy = Concerns structures too small to be seen with the naked eye.
Cytology = the study of cells
cyto = cell
Histology = the study of tissues
histo = tissue

6. DEVELOPMENTAL ANATOMY
3. Developmental anatomy = traces structural changes that occur in the body throughout the life span A. Embryology = concerns environmental changes in the embryo prior to birth

7. SPECIALIZED BRANCHES OF ANATOMY
Used primarily for medical diagnosis and scientific research.
Anatomic Pathology = the study of structural changes caused by disease
Radiographic Anatomy = studies internal structures through x-ray
Molecular Biology = the structure of biological molecules is investigated.

8. TOOLS FOR STUDYING ANATOMY
Anatomic terminology
Observation
Manipulation
Palpation = feeling organs with your hands
Auscultation = listening to organ sounds with a stethoscope

9. II. WHAT IS PHYSIOLOGY?
Physiology = study of how the body and its part work or function
Physio = nature
Ology = the study of
What does physiology literally mean?
The study of nature

10. TYPES OF PHYSIOLOGY
Renal Physiology = considers kidney function and urine production
Neurophysiology = Explains the functioning of the nervous system
Cardiovascular Physiology = Studies the functioning of the heart and blood vessels

11. III. ANATOMY AND PHYSIOLOGY
Anatomy and physiology are always related
Each part of your body has a job (function)
Structure determines the function
Principle of complementarity of structure and function: what a structure can do depends on its specific form
Examples??
Bones
Heart

12. IV. LEVELS OF STRUCTURAL ORGANIZATION
Chemical
Cellular
Tissue
Organ
Organ system
Organism

14. Organ Systems Integumentary Skeletal Muscular Nervous Endocrine
Cardiovascular
Lymphatic/Immunity
Respiratory
Digestive
10. Urinary
11. Reproductive

15. V. MAINTAINING LIFE Necessary Life Functions
1. Maintaining boundaries – separating internal vs. external environments
2. Movement
3. Responsiveness – reaction to stimuli
4. Digestion – breaking down food/chemicals
5. Metabolism – all chemical reactions in a body
6. Excretion – getting rid of wastes
7. Reproduction – producing new cells for growth
8. Growth – occurs when building activities are faster than destroying activities

16. V. MAINTAINING LIFE Survival Needs
1. Nutrients – carbohydrates, proteins, fats, and minerals
2. Oxygen – necessary for cellular respiration
3. Water – basis of body fluids, 60% of body weight
4. Normal body temperature
5. Atmospheric pressure – needed for proper breathing
Just having these needs are not enough
You need to have them at the correct amounts

17. VI. HOMEOSTASIS
Homeostasis = ability of the body to maintain relatively stable internal conditions even though the outside world changes continuously

18. NEGATIVE FEEDBACK
Negative feedback mechanisms = causes the variable to change in the opposite direction, returning to its ideal level.
Examples:
1. Regulation of body temperature
2. Blood Sugar
3. Heart Rate
Others??

19. EXAMPLES OF HOMEOSTASIS CONTROLLED BY NEGATIVE FEEDBACK

20. POSITIVE FEEDBACK Positive feedback mechanisms:
the response enhances the original stimulus so the original activity is accelerated
Less common than negative feedback
Examples
1. Blood Clotting
2. Enhancement of labor contractions during childbirth

21. EXAMPLE OF POSITIVE FEEDBACK

22. Why would you have a hard time learning and understanding physiology if you did not also understand anatomy?

23. The Language of Anatomy

24. I. THE LANGUAGE OF ANATOMY
Why use a special kind of language?
Why can’t we just say things like, above or below?
The human body has so many different shapes and areas to it that saying “above” or “below” is not specific enough
We need a special language in order to know exactly which location someone is talking about

25. II. ANATOMICAL POSITION
Most body terminology refers to the body when it is in anatomical position
Anatomical position = body is upright, feet parallel, and arms hang at the side with palms facing forward (thumbs pointing away from the body)

26. Anatomical Position

27. III. DIRECTIONAL TERMS
Directional terms = allow anatomists and medical personnel to explain where one body structure is in relation to another
How would YOU describe where your ears are in relation to your nose?
Anatomists would say the ears are lateral to the nose

28. Directional Terms
Superior (cranial or cephalad) = above, toward the head
Inferior (caudal) = below, towards lower part of body
Ventral (anterior) = in front of, on the front side of the body
Dorsal (posterior) = behind, on the backside of the body

29. Directional Terms Medial = towards the midline of the body
Lateral = away from the midline of the body
Intermediate = between a more medial and a more lateral structure

30. Directional Terms Proximal = close to the trunk of the body
Distal = away from the truck of the body
Superficial = towards or at the surface of the body
Deep = away from the surface, internal

31. Directional Terms

32. Practicing Directional Terms
Using the definitions above or Table 1.1 on pg. 15 of your text, use the correct direction term to complete the sentence.
The breastbone is ________________ to the spine.
The brain is ___________________ to the spinal cord.
The ankle is __________________ to the foot.
The skin is __________________ to the muscles.

33. IV. REGIONAL TERMS
Regional terms are used point to specific parts on the surface of the body
To make it slightly easier, we will split the regional terms up into two groups: anterior and posterior

34. Anterior Body Landmarks
Abdominal = anterior body trunk, inferior to ribs
Acromial = shoulder
Antebrachial = forearm
Antecubital = anterior surface of elbow
Axillary = armpit

35. Anterior Body Landmarks
Brachial = arm
Buccal = cheek
Carpal = wrist
Cervical = neck
Coxal = hip
Crural = leg

36. Anterior Body Landmarks
Deltoid = curve of shoulder made by the deltoid muscle
Digital = fingers and toes
Femoral = thigh
Fibular = lateral part of leg
Frontal = forehead

37. Anterior Body Landmarks
Inguinal = area where thigh meets body trunk, groin
Mental = chin
Nasal = nose area
Oral = mouth
Orbital = eye area
Patellar = anterior knee

38. Anterior Body Landmarks
Pelvic = area overlying the pelvis
Pubic = genital region
Sternal = breastbone area
Tarsal = ankle region
Thoracic = chest
Umbilical = navel

40. Posterior Body Landmarks
Calcaneal = heel of foot
Cephalic = head
Femoral = thigh
Gluteal = buttock
Lumbar = area of back between ribs and hips
Occipital = posterior surface of head, base of skull

41. Posterior Body Landmarks
Olecranal = posterior surface of elbow
Plantar = sole of foot
Popliteal = posterior knee area
Sacral = area between hips
Scapular = shoulder blade region
Sural = posterior surface of leg, the calf
Vertebral = area of spinal column

43. V. BODY PLANES AND SECTIONS
Section = cut
Plane = imaginary line in which a section is made through the body wall or organ
Three main types of sections:
Sagittal
Frontal
Transverse

44. Sagittal Section
Sagittal section = cuts along the lengthwise plane of the body
Divides the body into right and left parts
Median (midsagittal) section = sagittal cut directly down the midline of the body, making equal right and left halves
Any sagittal section that is not median, is parasagittal
Para = near

45. Sagittal Section

46. Frontal Section
Frontal section = lengthwise cut that divides the body (or organ) into anterior and posterior parts
Can also be called a coronal section

47. Frontal Section

48. Transverse Section
Transverse section = a cut along a horizontal plane that divides the body or organ into superior and inferior parts
Can also be called a cross section

49. Transverse Section

50. VI. BODY CAVITIES Two main body cavities: Dorsal Ventral
Each cavity (dorsal and ventral) also contains smaller cavities and regions

51. Dorsal Cavity Has two subdivisions:
Cranial cavity = space inside the bony skull
Brain is protected in this cavity
Spinal cavity = extends from the cranial cavity to the end of the vertebral column
Spinal cord is protected in this cavity by the vertebrae

52. Dorsal Cavity

53. Ventral Cavity Much larger than the dorsal cavity
Contains all structures within chest and abdomen

54. Ventral Cavity Three subdivisions:
Thoracic cavity = contains lungs, heart, trachea
Separated from the other two cavities by the diaphragm
Abdominal cavity = contains stomach, liver, intestines, pancreas, gallbladder, spleen
Pelvic cavity = contains reproductive organs, bladder, and rectum
Abdominal and pelvic cavities aren’t actually separated by anything, so they are usually referred to as the abdomoinopelvic cavity

55. Abdominopelvic Regions
Abdominopelivic region can be separated into four quadrants or nine regions
The nine regions are:
Umbilical region = center region, around navel
Epigastric region = superior to umbilical region
Hypogastric region = inferior to the umbilical region
Right and left iliac regions = lateral to hypogastric region
Right and left lumbar regions = lateral to the umbilical region
Right and left hypochondriac regions = lateral to the epigastric region

56. Abdominopelvic Regions

57. Other Body Cavities
Oral and digestive cavities = mouth and digestive organs leading to the anus, which opens to the exterior
Nasal cavity = within and posterior to the nose, part of the respiratory system
Orbital cavities = contain the eyes
Middle ear cavities = medial to the ear drums, contain our body’s three smallest bones