Chapter 1: An Introduction to Anatomy

and PhysiologyAnatomy• 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

How are living things organized?• Atoms:

– are the smallest chemical units • Molecules:

– are a group of atoms working together• Organelles:

– are a group of molecules working together• Cells:

– are a group of organelles working together• Tissues:

– are a group of similar cells working together• Organs:

– are a group of different tissues working together• Organ systems (11):

– are a group of organs working together• Organism:

– is an individual

Organizing a Muscle

• Protein molecules (chemical level)• Protein filaments (organelle level)• Muscle cells (cellular level)• Cardiac muscle tissue (tissue level)• Heart (organ level)

KEY CONCEPTS• The body is divided into 11 organ

systems• All organ systems work together• Many organs work in more than 1 organ

system• 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)

• Failure to function within a normal range results in disease

Mechanisms of Regulation• Autoregulation (intrinsic):

– automatic response in a cell, tissue, or organ

• Extrinsic regulation: – responses controlled by nervous and

endocrine systems

How are living things regulated?

Maintaining Normal Limits • Receptor: receives the stimulus • Control Center: processes the

signal and sends instructions • Effector: carries out instructions • Negative Feedback: response of

the effector negates the stimulus• Positive Feedback: response of

the effector reinforces the stimulus

Working Together

Table 1–1

What are the anatomical terms used to describe body sections, regions, and relative positions?

Anatomical LandmarksSuperficial characteristics: surface parts – can be names or adjectives

KEY CONCEPT

• Anatomical position: – hands at sides,

palms forward

• Supine: – lying down, face up

• Prone: – lying down, face

down

Figure 1–7a

Quadrants and Regions• 4 abdominopelvic

quadrants around umbilicus

• 9 abdominopelvic regions

Which Direction?

Figure 1–8

• Lateral: – side view

• Frontal: – front view

• Anatomical direction: – refers to

the patient’s left or right

3 Dimensions

Figure 1–9

• Plane: – a 3-

dimensional axis

• Section: – a slice

parallel to a plane

The Ventral Body Cavity

• Coelom: – divided by the

diaphragm into the thoracic cavity and the abdominopelvic cavity

Figure 1–10a

What are the major body cavities and their subdivisions?

Isolating the Organs• Serous

membranes: – consist of parietal

layer and visceral layer

Dividing the Cavities• Thoracic cavity:

– divided by the mediastinum into 2 pleural cavities