Ch 1 Intro To Anat And Physio

Introduction to Anatomy and Physiology How you are put together and how you stay alive!

Definitions • Anatomy – Deals with structures or morphology

• Physiology – Deals with functions of structures – i.e., making urine, contraction of heart, digesting food

Levels of Organization

How you stay alive • Maintain homeostasis – Maintain a stable internal environment. – Keep the internal environment relatively stable. – Emphasis is on extracellular fluid that surrounds cells. – Homeostatic mechanisms maintain homeostasis.

Our Internal Environment

Homeostatic Mechanisms • Components of homeostatic systems: – Receptors • Provide information about internal environment

– Control center • Has a set point

– Effectors • Always a muscle or gland

Homeostatic Control System

Homeostatic Mechanisms • The idea: – Maintain relatively constant internal environment! – Receptor measures change in int. environ as a deviation from the set point. – Effectors are activated and return conditions to normal. – Deviation lessens and effectors are turned off.

Maintaining Room Temp

Maintaining Body Temp

Maintaining Glucose in the Blood

• Set Point: Amount of glucose in blood • Receptor: Pancreas detects rising levels of glucose • Control Center: Beta cells of pancreas produce insulin • Effector: Insulin moves glucose to specific cells

Organization of the Human Body • Axial, appendicular portions of body • Body cavities – Dorsal cavity • Cranial, vertebral canal

– Ventral cavity • Thoracic • Abdomenopelvic • Separated by diaphragm

Body Cavities

Serous Membranes • Line thoracic and abdomenopelvic cavities – Line body wall and fold back over organs – Secrete water, salts; slippery – Parietal, visceral layers

• Thoracic membranes – Pleural membranes with space, fluid between layers – Pericardial membranes with space, fluid between

• Abdominal membranes – Peritoneal membranes with space (peritoneal cavity between layers)

Pleural Membranes

Peritoneal Membranes

Anatomical Terminology Relative position Superior – Inferior Anterior (ventral) – Posterior (dorsal) Medial – Lateral Ipsilateral, contralateral Proximal – Distal Superficial (peripheral – Deep)

Four Quadrants

Nine regions