1. Introduction to Anatomy and Physiology
Unit 1

2. Relationship Between Anatomy and Physiology
Introduction to Anatomy and Physiology
Relationship Between Anatomy and Physiology

3. Relationship between Anatomy and Physiology
The study of internal and external structures of the body and the physical relationships among body parts
Physiology
The study of how living organisms perform their vital functions
Someone studying anatomy might examine how and where a particular muscle attaches to the skeleton, whereas someone studying physiology might consider how a muscle contracts or what forces a contracting muscle exerts on the skeleton

4. Relationship between Anatomy and Physiology
Anatomical info provides clues about functions (physiology), and physiological mechanisms can be explained only in terms of the underlying anatomy
ALL SPECIFIC FUNCTIONS ARE PERFORMED BY SPECIFIC STRUCTURES!!!!!

5. Relationship between Anatomy and Physiology
Anatomy can be divided into gross (macroscopic) anatomy and microscopic anatomy
Gross Anatomy
Examination of relatively large structures
Usually visible with unaided eye
5 different forms of gross anatomy
Surface anatomy
Study of general form and superficial markings
Regional anatomy
Anatomical organization of specific areas of body (head, neck, trunk)

6. Relationship between Anatomy and Physiology
5 different forms of gross anatomy (con’t)
Systemic anatomy
Study of the structure of organ systems (skeletal system, muscular system, cardiovascular system, etc.)
Developmental anatomy
Describes the changes in form that occur between conception and physical maturity
Embryology – study of early developmental processes
Clinical anatomy
Subspecialities important in clinical practice
Medical anatomy (anatomical features that change during illness)
Radiographic anatomy (anatomical structures seen using imaging techniques)

7. Relationship between Anatomy and Physiology
Microscopic Anatomy
Study of structures that cannot be seen without magnification
Has 2 major divisions
Cytology – analysis of the internal structure of individual cells
Histology – examination of tissues

8. Relationship between Anatomy and Physiology
The study of the function of anatomical strucures
Can be divided into 4 major specialties
Cell physiology – study of the function of cells
Chemical processes within cells and chemical interactions between cells
Special physiology – study of the physiology of specific organs
Systemic physiology – study of the functioning of specific organ systems
Pathological physiology – study of the effects of diseases on organ or system fuctions

9. Levels of Organization
Introduction to Anatomy and Physiology
Levels of Organization

10. Levels of Organization
The Chemical (or Molecular) Level
Atoms can combine to form molecules with complex shapes
The functional properties of a particular molecule are determined by its unique 3D shape
The Cellular Level
Molecules interact to form organelles, each of which has specific functions.
Organelles are grouped to form cells
The Tissue Level
Groups of cells working together to perform specific functions
Heart muscle cells interact with other types of cells and extracellular materials to form cardiac muscle tissue

11. Levels of Organization
The Organ Level
Two or more tissues working in combination to perform several functions
Cardiac muscle tissue, in combination with connective tissue from the bulk of the heart.
The Organ System Level
Two or more organs interacting
The heart and blood vessels work together to form the cardiovascular system.
The Organism Level
Highest level of organization
All organ systems working together

13. Introduction to Anatomy and Physiology
Homeostasis
Introduction to Anatomy and Physiology

14. Homeostasis
One of the roles of the organ systems in an organism is to maintain homeostasis.
Homeostasis – maintaining a stable internal environment.
Absolutely vital to survival
Homeostatic regulation – adjustment of physiological systems to preserve homeostasis.

15. Homeostasis 2 mechanisms of homeostasis
Autoregulation (intrinsic regulation) – when a cell, tissue, organ or organ system adjusts its activities automatically in response to an environmental change
Ex: when blood oxygen levels decrease in a tissue, the cells release a chemical that dilate local blood vessels. This increases blood flow and, therefore, oxygen.

16. Homeostasis 2 mechanisms of homeostasis (con’t)
Extrinsic regulation – from activities of the nervous and/or endocrine systems.
Ex: During exercise, your nervous system increases heart rate so that blood will circulate faster. Will also decrease blood flow to less active organs.

17. Homeostasis
The nervous system directs rapid, short-term, and very specific responses
Response to placing hand on a hot stove
Endocrine system releases hormones that affect tissues and organs throughout the body.
Not immediate, not specific, may be long-term

18. Homeostasis Homeostatic regulatory mechanism consists of 3 parts
Receptor – sensor that is sensitive to a particular change in environment
Control center – receives and processes info from receptor and sends out commands
Effector – cell or organ that responds to the commands from control center.
Similar to thermostat in your house

19. Homeostasis Negative feedback
Most regulatory mechanisms involve this opposition to changing conditions
Example is body temperature control (thermoregulation)
Control center is the hypothalamus region of the brain
Hypothalamus receives info from two receptors: skin receptors and one in hypothalamus
Normal body temp is 98.6o. If temp increases, the control center targets two effectors:
muscles in the walls of the blood vessels supplying the skin
sweat glands

20. Homeostasis Negative feedback (con’t)
The muscles in the skin blood vessels relax, increasing blood flow to skin.
Sweat glands increase their secretion
The skin acts like a radiator by losing heat to the environment
Evaporation of sweat speed the process
As temp returns to normal, temp at hypothalamus declines, and the control center becomes less active
Blood flow and sweat production return to normal.

21. Homeostasis
There are variations in normal homeostatic levels between individuals
95% of population has body temp between 36.7oC and 37.2oC
Physicians must keep this in mind when treating patients.

22. Homeostasis Positive feedback
Produces a response that enhances the change in the original conditions.
Usually produces extreme responses
What if your thermostat was connected to your heater instead of your air conditioner?
What would occur if the temp in your house increased?
When temp exceeds set point, thermostat would turn on the heater, and it would continue to run until someone turned off the thermostat, heater, or intervened in some other way.
This escalating cycle is called a positive feedback loop

23. Homeostasis Positive feedback (con’t)
In your body, these loops are found when a potentially dangerous process must be completed quickly before homeostasis can be restored.
Ex: immediate danger from a severe cut will decrease blood pressure and reduce efficiency of the heart
The response is to clot the blood.
Each step in the process accelerates the process until a clot is formed
Labor and delivery of a baby is another example

25. Introduction to Anatomy and Physiology
Frames of Reference for Anatomical Studies
Introduction to Anatomy and Physiology

26. Frames of Reference for Anatomical Studies
Early anatomists faced communication problems.
A “bump on the back” doesn’t give very precise info about its location
Prominent anatomical structures serve as landmarks, distances are measured in centimeters, and specialized directional terms are used

27. Frames of Reference for Anatomical Studies
Superficial Anatomy
Anatomical landmarks are used in reference to the anatomical position
Anatomical position – hands at side, palms facing forward, and feet together
Descriptions given are in reference to the anatomical position, unless otherwise noted
Prone – lying face down in the anatomical position
Supine – lying face up in the anatomical position

29. Frames of Reference for Anatomical Studies
Anatomical Regions
Abdominopelvic quadrants
Formed by a pair of lines that intersect at the umbilicus (naval)
Used by physicians to help determine possible cause of aches, pains, injuries.
Internal organs can be found in different quadrants
Abdomiopelvic regions
More specific than quadrants
Preferred by anatomists

31. Frames of Reference for Anatomical Studies
Anatomical Directions
The terms left and light always refer to the left and right sides of the subject, NOT of the observer

32. Frames of Reference for Anatomical Studies
Sectional Anatomy
Sometimes the best way to understand anatomy is to slice through it and look at the internal organization
Useful with imaging techniques
Radiologists use these when looking at films

33. Frames of Reference for Anatomical Studies
Planes and Sections
Transverse plane – right angle to long axis of object, dividing it into superior and inferior
A cut in this plane is called a transverse section
Frontal plane – parallel to long axis; extends from side to side, dividing the body into anterior and posterior
A cut in this plane is called a frontal section
Sagittal plane – parallel to long axis; extends from front to back, dividing the body in to left and right
A cut down the midline is called a midsagittal section
Parallel cuts are called parasagittal sections

34. Frames of Reference for Anatomical Studies
Body cavities
Internal chambers where many vital organs can be found
2 functions
Protect organs
Permit change of size and shape of the organs
Your diaphragm divides your torso into two cavities
Thoracic cavity
Abdominopelvic cavity
Viscera – organs enclosed (fully or partially) by these cavities

35. Frames of Reference for Anatomical Studies
Body cavities (con’t)
Thoracic cavity
Contains lungs and heart, associated organs of respiratory, cardiovascular, and lymphatic system; lower esophagus; thymus
Boundaries are the ribs and diaphragm
Subdivided into left and right pleural cavities, which each contain a lung.
Contains pericardial cavity, which surrounds the heart

36. Frames of Reference for Anatomical Studies
Body cavities (con’t)
Abdomiopelvic cavity
Extends from diaphragm to pelvis
Divided into a superior abdominal cavity and an inferior pelvic cavity
The peritoneal cavity surrounds the abdominal and pelvic cavities

37. Frames of Reference for Anatomical Studies
Body cavities (con’t)
Abdominal cavity contains the liver, stomach, spleen, small intestine, and most of the large intestine
The kidneys and pancreas lie posteriorly between the peritoneal cavity and the muscles of the abdominal cavity
The pelvic cavity contains distal large intestine, urinary bladder, and various reproductive organs