Introduction to Body Organization Anatomy-Physiology I … here we go!
Human Body Introduction • Made of about the same 20+ elements found in dirt. http://serc.carleton.edu/images/usingdata/nasaimages/carbon_atom.gif
What is the Body Made of? • A) 70-85% water • B) 10-20% protein • C) Remaining %: • salts, • Carbohydrates, • lipids, • nucleic acids
Six Levels of Organization 2. cellular 1. chemical 3. tissue 6. Organism 5. System 4. Organ
Claude Bernard Claude Bernard 1813-1878 • Said that “cells of many-celled organisms flourish because they live in relative constancy of the internal environment”. http://scienceworld.wolfram.com/biography/pics/Bernard.jpg
Walter B. Cannon 1871-1945 • Coined the term “homeostasis” = the condition of equilibrium in the body’s internal environment. It is dynamic and always responding to changes in the environment.
Feedback Systems • = a cycle of events in which the status of a body condition is continually monitored, evaluated, changed, re-monitored,… • Examples of controlled conditions: • Body temperature • Blood pressure • Glucose level in blood
Components of Feedback Systems • 1) Receptor • 2) Control Center • 3) Effector
Negative Feedback • = when the response reverses the original stimulus • EX) Blood Pressure (BP) • External stimulus causes BP to rise • Baroreceptors (pressure sensitive cells) located in blood vessels detect higher BP • Message is sent to brain • Brain decreases heart rate to lower BP http://www.clipartof.com
Positive Feedback • = when response enhances or intensifies the original stimulus • EX) Childbirth • 1) 1st labor contractions push baby downward into lower uterus • 2) stretch sensitive nerve receptors monitor the stretching (controlled condition) of uterus • 3) the more stretch, the more oxytocin is sent from brain to intensify the contractions • Cycle/loop is broken by birth
Tissues terminology • Histology • Pathologist • Biopsy http://www.nlm.nih.gov/medlineplus/ency/images/ency/fullsize/1102.jpg
Four primary tissues of the body • 1. Connective Tissue http://www.unm.edu/~vscience/image0
Four primary tissues of the body • 1. Epithelial Tissue http://www.stegen.k12.mo.us/tchrpges/sghs/ksulkowski/images/_Apical_Epithelial_Tissue.jpg
Four primary tissues of the body • 3. Muscle Tissue http://www.stegen.k12.mo.us/tchrpges/sghs/ksulkos_Apical_Epithelial_Tissue.jpg
Four primary tissues of the body • 4. Nervous Tissue
Primary Germ Layers • 1. Ectodermdevelops into nervous system, epidermis • 2. Mesodermgives rise to all connective tissues, most muscle, blood and blood vessels • 3. Endodermgives rise to GI tract, bladder, and respiratory tract http://universe-review.ca/I10-13-layers.jpg