Lecture Human anatomy and physiology - Chapter 1: The human body: An orientation (part a)

Chapter 1 - The human body: An orientation (part a). This chapter presents the following content: Overview of anatomy and physiology, principle of complementarity, levels of structural organization, overview of organ systems, organ systems interrelationships, necessary life functions,...and other contents.

An Orientation: 

Part A

Chapter 1

Overview of Anatomy and

Physiology

body

surface, and systemic anatomy)

histology)

Overview of Anatomy and

Overview of Anatomy and

Physiology

Physiology: The study of

function of the body at many levels

Subdivisions are based on organ systems (e.g., renal,

digestive, cardiovascular

physiology)

Overview of Anatomy and

Physiology

physiology:

(from systemic to cellular and

molecular)

electrical currents, pressure, and movement)

What a structure can do

depends on its specific form

 Tissue: groups of similar cells (Chapter 4)

 Organ: contains two or more types of

Cardiovascular system

Organelle Molecule

Organ system level

Organ systems consist of different organs that work together closely.

Organismal level

The human organism is made up

of many organ systems.

Smooth muscle cell

Smooth muscle tissue

Connective tissue Blood vessel (organ)

Heart Blood vessels

Epithelial tissue

Smooth muscle tissue

3

4

5 6

Figure 1.1, step 6

Overview of Organ Systems

 Major organs and functions

of the 11 organ systems

Organ Systems Interrelationships

All cells depend on organ

systems to meet their survival needs

Organ systems work

cooperatively to perform

necessary life functions

Necessary Life Functions

between internal and external

environments

 Skin

muscle)

Necessary Life Functions

sense and respond to stimuli

Necessary Life Functions

5. Metabolism: All chemical

reactions that occur in body cells

 Catabolism and anabolism

Necessary Life Functions

7. Reproduction: 

 Cellular division for growth

or repair

 Production of offspring

8. Growth: Increase in size of a

body part or of organism

exchange in the lungs

stable internal environment despite  continuous changes both inside and  out

Homeostatic Control Mechanisms

Involve continuous monitoring and regulation of many factors (variables)

Nervous and endocrine 

systems accomplish the

communication via nerve

impulses and hormones

Components of a Control

Mechanism

controlled variables)

the variable is maintained

 Response acts to reduce or

enhance the stimulus (feedback)

Response

of effector feeds back

to reduce the effect of stimulus and returns variable to homeostatic level

Receptor Effector

Control Center

BALANCE

Afferent pathway

Efferent pathway

(an endocrine mechanism)

Afferent pathway

Afferent pathway

Efferent pathway

Efferent pathway

Information sent along the efferent pathway to effectors

Control Center

(thermoregulatory center in brain)

Response

Evaporation of sweat Body temperature falls;

stimulus ends

Response

Body temperature rises;

stimulus ends

Negative Feedback: Regulation

of Blood Volume by ADH

volume

stimulates pituitary gland to release antidiuretic hormone (ADH)

(effectors) to return more water to the blood

Positive Feedback

the original stimulus

by oxytocin (Chapter 28)

clotting

Feedback cycle ends when plug is formed.

Positive feedback cycle is initiated.

Positive feedback loop

Break or tear occurs in blood vessel wall.

Platelets adhere to site and release chemicals.

1

2 3

4

Figure 1.6, step 4

Homeostatic Imbalance

 Disturbance of homeostasis

 Increases risk of disease

 Contributes to changes

associated with aging

 May allow destructive

positive feedback mechanisms

to take over (e.g., heart failure)