Chapter 1: An Introduction to Anatomy and 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

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 How are living things regulated? Mechanisms of Regulation Autoregulation (intrinsic): automatic response in a cell, tissue, or organ Extrinsic regulation: responses controlled by nervous and endocrine systems

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 Landmarks Superficial characteristics: surface parts – can be names or adjectives

KEY CONCEPT Anatomical position: Supine: Prone: hands at sides, palms forward Supine: lying down, face up Prone: lying down, face down

Quadrants and Regions 9 abdominopelvic regions 4 abdominopelvic quadrants around umbilicus Figure 1–7a

Which Direction? Lateral: Frontal: Anatomical direction: side view front view Anatomical direction: refers to the patient’s left or right Figure 1–8

3 Dimensions Plane: a 3-dimensional axis Section: a slice parallel to a plane Figure 1–9

The Ventral Body Cavity What are the major body cavities and their subdivisions? The Ventral Body Cavity Coelom: divided by the diaphragm into the thoracic cavity and the abdominopelvic cavity Figure 1–10a

Isolating the Organs Dividing the Cavities Serous membranes: consist of parietal layer and visceral layer Dividing the Cavities Thoracic cavity: divided by the mediastinum into 2 pleural cavities