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
1. chemical
2. cellular
3. tissue
4. Organ
5. System
6. Organism
Claude Bernard
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
Claude Bernard 1813-1878
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)
1) External stimulus causes BP to rise
2) Baroreceptors (pressure sensitive cells) located in blood vessels detect higher BP
3) Message is sent to brain
4) 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. Ectoderm develops into nervous system, epidermis
2. Mesoderm gives rise to all connective tissues, most muscle, blood and blood vessels
3. Endoderm gives rise to GI tract, bladder, and respiratory tract
http://universe-review.ca/I10-13-layers.jpg
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