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