1. Chapter 1: Introduction to Anatomy and Physiology

2. For the first lecture test, I should be able to…
A. Define anatomy and physiology.
1. Explain how they are related.
2. Describe major specialties of each.
B. Define homeostasis and explain its importance for survival.
1.Compare/contrast intrinsic and extrinsic regulation and provide an example of each.
2.Compare/contrast negative and positive feedback and provide an example of each.
3.Discuss the relationship between homeostasis and disease.

3. Anatomy Physiology Describes the structures of the body
What they are made of
Where they are located
Associated structures
Physiology
Is the study of:
Functions of anatomical structures
Individual and cooperative functions
Biochemistry, Biology, Chemistry, Genetics

4. Relationships between Anatomy and Physiology
Gross anatomy, or macroscopic anatomy, examines large, visible structures
Surface anatomy: exterior features
Regional anatomy: body areas
Systemic anatomy: organ systems
Developmental anatomy: from conception to death
Clinical anatomy: medical specialties

5. Relationships between Anatomy and Physiology
Microscopic anatomy examines cells and molecules
Cytology: study of cells and their structures
cyt- = cell
Histology: study of tissues and their structures

6. 1-4 Relationships between Anatomy and Physiology
Cell physiology: processes within and between cells
Organ physiology: functions of specific organs
Systemic physiology: functions of an organ system
Pathological physiology: effects of diseases

7. 1-5 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. 1-5 Levels of Organization
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. Figure 1-1 Levels of Organization
Cellular Level
Chemical and Molecular Levels
Heart muscle cell
Protein filaments
Complex protein molecule
Atoms in combination 9

10. Figure 1-1 Levels of Organization
Organism level
Organ system level
Organ Level
Tissue Level
Cardiac muscle tissue
The heart
The cardiovascular system 10

11. KEY CONCEPT The body is divided into 11 organ systems
All organ systems work together
Many organs work in more than 1 organ system

12. 1-6 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)

13. 1-6 Homeostasis Mechanisms of Regulation Autoregulation (intrinsic)
Automatic response in a cell, tissue, or organ to some environmental change
Extrinsic regulation
Responses controlled by nervous and endocrine systems

14. 1-6 Homeostasis Receptor Control center Effector Receives the stimulus
Processes the signal and sends instructions
Effector
Carries out instructions
CONTROL CENTER

15. Figure 1-2 The Control of Room Temperature
RECEPTOR
Information affects
Normal condition disturbed
Thermometer
STIMULUS: Room temperature rises
HOMEOSTASIS
CONTROL CENTER (Thermostat)
Air conditioner turns on
Air conditioner turns off
Normal room temperature
RESPONSE: Room temperature drops
20°
30°
40°
Room temperature (°C)
Normal range 22
Normal condition restored
EFFECTOR
Sends commands to
Air conditioner turns on
Time
In response to input from a receptor (a thermometer), a thermostat (the control center) triggers an effector response (either an air condi- tioner or a heater) that restores normal temperature. In this case, when room temperature rises above the set point, the thermostat turns on the air conditioner, and the temperature returns to normal.
With this regulatory system, room temperature fluctuates around the set point. 15

16. 1-7 Negative and Positive Feedback
The Role of Negative Feedback
The response of the effector negates the stimulus
Body is brought back into homeostasis
Normal range is achieved

17. Figure 1-3 Negative Feedback in the Control of Body Temperature
RECEPTORS
Temperature sensors in skin and hypothalamus
Information affects
Normal temperature disturbed
CONTROL CENTER
STIMULUS: Body temperature rises
HOMEOSTASIS
Thermoregulatory center in brain
Normal body temperature
Vessels dilate, sweating increases
Vessels constrict, sweating decreases
RESPONSE: Increased heat loss, body temperature drops
37.2
Normal temperature restored
EFFECTORS
Sends commands to
Body temperature (°C)
Normal range 37
• Sweat glands in skin increase secretion • Blood vessels in skin dilate
36.7
Time
Events in the regulation of body temperature, which are comparable to those shown in Figure 12. A control center in the brain (the hypothalamus) functions as a thermostat with a set point of 37°C. If body temperature exceeds 37.2°C, heat loss is increased through enhanced blood flow to the skin and increased sweating.
The thermoregulatory center keeps body temperature fluctuating within an acceptable range, usually between 36.7 and 37.2°C. 17

18. 1-7 Negative and Positive Feedback
The Role of Positive Feedback
The response of the effector increases change of the stimulus
Body is moved away from homeostasis
Normal range is lost
Used to speed up processes

19. Figure 1-4 Positive Feedback: Blood Clotting
Wouldn’t you want to speed this up?
Clotting accelerates
Positive feedback loop
Chemicals
Chemicals
Blood clot
Damage to cells in the blood vessel wall releases chemicals that begin the process of blood clotting.
The chemicals start chain reactions in which cells, cell fragments, and soluble proteins in the blood begin to form a clot.
As clotting continues, each step releases chemicals that further accelerate the process.
This escalating process is a positive feedback loop that ends with the formation of a blood clot, which patches the vessel wall and stops the bleeding. 19

20. 1-7 Negative and Positive Feedback
Systems Integration
Systems work together to maintain homeostasis
Homeostasis is a state of equilibrium
Opposing forces are in balance
Dynamic equilibrium — continual adaptation
Physiological systems work to restore balance
Failure results in disease or death