Anatomy and the Organization of the Human BodyBiology 2011

Defining Anatomy

• Anatomy = Body structure of an organism• OR the study of the body structure of organisms

• In Biology, we’ll study the structures of the human body by focusing on a few main body systems.• Examples: Circulatory System, Nervous System,

Digestive System, Skeletal System, Muscular System (Sometimes Skeletal and Muscular systems are put together)

• We’ll relate structure (what it looks like) to function (what it does).

The organization of the body: From Cell to Organ System

• Cell – smallest unit• Example: A cell in the lining of the stomach

• Tissue – group of cells working together to do a function• Example: The cells in the lining of the stomach make up the

epithelial (surface) tissue of the stomach.• Organ – group of tissues working together to do a function• Example: All of the different layers of tissue in the stomach

make up the organ of the stomach.• Organ System – group of organs working together to do a

function• Example: The stomach, along with the tongue, esophagus,

small and large intestines make up the Digestive organ system.

4 Types of Tissue• Remember: • Tissue = group of cells working together for a function

• 1. Muscle tissue• A. Internal Movement

• i. Veins and arteries (moving blood)• ii. Stomach contractionsB. External Movement

i. skeletal muscles (legs, arms, fingers, etc.)

• 2. Epithelial tissue• A. Covers surface of body

• i. Skin• B. Covers inside of internal organs

• i. Heart chambers, blood vessels• ii. Digestive tract• iii. Glands like the salivary glands, pancreas, etc.)

Epithelial Tissue (top view)

http://www.stegen.k12.mo.us/tchrpges/sghs/ksulkowski/TissueSlides.htm

Epithelial Tissue (side view)

http://www.mesacc.edu/~minckley/anatomy/skin.html

Skeletal Muscle

http://www.carlalbert.edu/dwann/tissue_images/cardiac%20muscle.jpg

4 Types of Tissue (continued)

• 3. Connective tissue• A. Holds organs in place• B. Holds different surfaces of the body

together• i. Tendons

• C. Pads and insulates the body• 4. Nervous tissue• A. Receives and sends messages to different

parts of the body• B. Controls heart beat

Loose Connective Tissue:Holds things together in the body

http://www.carlalbert.edu/dwann/tissue.htm

Nervous tissue (darker parts are cell bodies of neurons)

http://www.occc.edu/biologylabs/documents/cells%20membranes/Nervous_tissue.htm

Tissues Organs• Many different types of tissue can make up one organ or organ

system• Examples: • A. The muscular-skeletal system is made up of the muscles

(muscular tissue), bones (connective tissue), tendons (connective tissue), nerves (nervous tissue).

• B. The Skin is made up of epithelial tissue (skin cells), nerves (nervous tissue), muscles – the ones that make your hair stand up when you get goose bumps (muscular tissue)

• C. The stomach is made up of connective tissue (to hold it together), epithelial tissue (on the inside surface), and muscular tissue (to contract and digestive the food).

Nervous System• Basic cell type• 1. Neuron – a nerve cell

• Main Structures• 1. Brain• 2. Spinal Cord• 3. Peripheral Nerves

• Main Function• 1. Coordinates body’s response to changes in internal and

external environments.

The Neuron• Function: Transmits information in the nervous system by

signals called impulses.• Main parts:• 1. Dendrites

• -- Receives the signal, sends it to the cell body• --Can have many dendrites

• 2. Cell body • – largest part• -- contains nucleus and most of cytoplasm• -- control center of the neuron (does the “deciding” of where

information should go).• 3. Axon

• -- Sends the signal to the next neuron or body part• -- Neurons usually have only one axon

• 4. Synapse• -- The space between the axon and the next neurons’ dendrites

Neuron

http://thetechjournal.com/science/neuron-implantation-can-rewire-brain-itself.xhtml

Drawing of a Neuron

http://www.daviddarling.info/encyclopedia/N/neuron.html