Human Anatomy & Physiology, Sixth Edition Elaine N. Marieb 1 Introduction to Anatomy & Physiology

Overview of Anatomy and Physiology  Anatomy  Structure of body parts and their relationships  Gross  Microscopic  Physiology  Function & interaction of tissues & organs  histological, cellular & molecular level  Chemistry & Physics  ions/molecules, concentrations, stoichiometry, kinetics, thermodynamics  electrical currents, blood pressure, and bone movement

Structure – Function Relationship  Function always reflects structure  What a structure can do depends on its specific form

Levels of Structural Organization  Atomic –  Molecular –  Cellular –  Histological –  Organ –  Organ system –  Organismal –

Chemical level Atoms combine to form molecules Cellular level Cells are made up of molecules Tissue level Tissues consist of similar types of cells 5 Organ system level Organ systems consist of different organs that work together closely Organ level Organs are made up of different types of tissues 6 Organismal level The human organism is made up of many organ systems Atoms Molecules Smooth muscle cell Smooth muscle tissue Connective tissue Smooth muscle tissue Epithelial tissue Blood vessel (organ) Heart Blood vessels Cardiovascular system Levels of Structural Organization Figure 1.1

Organ Systems  Integumentary  Muscle  Skeletal  Nervous  Cardiovascular  Lymphatic/Immune  Endocrine  Digestive  Urinary  Reproductive

Necessary Life Functions I  Maintaining boundaries –  Cellular level –  Organismal level –  Movement –  Responsiveness –  Digestion –  Metabolism –  Excretion –  Reproduction –  Cellular –  Organismal –  Growth –

Survival Needs  Nutrients –  Oxygen –  Water –  Homeostatic maintenance

Homeostasis  Maintenance of a relatively stable internal environment  State of dynamic equilibrium  Chemical, hormonal, & neural factors interact to maintain homeostasis  Homeostatic imbalances

Homeostatically Controlled Physiological Variables  Osmotic state  Blood pH  Internal temperature  Metabolite levels  Blood pressure

Stimulus: Produces change in variable Change detected by receptor Input: Information sent along afferent pathway to 5 Response of effector feeds back to influence magnitude of stimulus and returns variable to homeostasis Variable (in homeostasis) Imbalance Receptor (sensor) Control center 4 Output: Information sent along efferent pathway to Effector Homeostatic Control Mechanisms Figure 1.4

Feedback Regulation  Negative Feedback  The output shuts off the original response to the stimulus  Example: Regulation of blood glucose levels  Positive Feedback  The output further enhances the original response to the stimulus  Example: Clotting

Figure 1.5 Homeostatic Control

Negative Feedback Figure 1.5 rising glucose detected by pancreas pancreas secretes insulin insulin stimulates cells to take up glucose from blood blood glucose rises pancreas secretes glucagon glucagon stimulates liver to break down glycogen to glucose dropping glucose detected by pancreas

Positive Feedback  Output enhances original stimulus  Example: Regulation of blood clotting Figure 1.6

Human Anatomy & Physiology, Sixth Edition Elaine N. Marieb 1 The Human Body: An Orientation Part B

Anatomical Position  body erect  palms forward  thumbs out Figure 1.7a

anterior posterior ventral dorsal

Figure 1.8 sagittal plane Body Planes

Regional Terms: Anterior View  Axial - head, neck, and trunk  Appendicular- limbs  Specific regional terminology Figure 1.7a

Body Cavities Figure 1.9a

Body Cavities Figure 1.9b

Ventral Body Cavity Membranes  Parietal serosa lines internal body walls  Visceral serosa covers the internal organs  Serous fluid separates the serosae

Other Body Cavities  Oral and digestive –  Nasal –  Orbital –  Middle ear –  Synovial –