1. Unit 10 Human Body Systems
Searcy Ninth Grade Center  2012

2. Levels of Organization
The levels of organization in a multicellular organism include cells, tissues, organs, and organ systems.
Organism
Organ System
Organs
Tissues
Cells
Atoms

3. Cell Types and Tissue
A cell is the basic unit of structure and function in living things. Specialized cells are uniquely suited to perform a specific function.
Tissues are groups of cells that perform a specific function.
Muscle Tissue: along the bones, enables body to move.
Epithelial Tissue: glands and tissues that cover interior and exterior body surfaces.
Connective Tissue: provides support for the body and connects its parts.
Nervous Tissue: transmits nerve impulses throughout the body.

4. Cell Organization
Each organ in your body, which are made of tissues, is part of an organ system, a group of organs that work together to perform a major function.

5. Nervous System Structures: Function: 1. Central Nervous System (CNS)
2. Brain
3. Spinal Cord
4. Peripheral Nervous System (PNS)
Somatic-voluntary
Autonomic-involuntary
Function:
Recognizes and coordinates the body’s response to changes in its internal and external environments.

6. Digestive System Structures: Function: Mouth Pharynx Esophagus Stomach
Small Intestine
Large Intestine
Liver
Gall Bladder
Rectum
Function:
Converts foods into simpler molecules that can be used by the cells of the body; absorbs food; eliminates waste.

7. Excretory System Structures: Function: Kidneys Ureters Urinary bladder
Skin
Lungs
Kidneys
Ureters
Urinary bladder
Urethra
Function:
Eliminates waste products from the body in ways that maintain homeostasis.

8. Lymphatic/Immune System
Structures:
White blood cells (T-cells)
Thymus
Spleen
Lymph nodes
Lymph vessels
Function:
Helps protect the body from disease; collects fluid lost from blood vessels and returns the fluid to the circulatory system.

9. Integumentary System Structures: Function: Skin Hair Nails
Sweat glands
Oil glands
Function:
Serves as a barrier against infection and injury; helps to regulate body temperature; provides protection against ultraviolet radiation from the sun.

10. Skeletal System Structures: Function: Bones Cartilage Ligaments
Tendons
Function:
Supports the body; protects internal organs; allows movement; stores mineral reserves; provides a site for blood cell formation.

11. Muscular System Structures: Function: Skeletal muscle Cardiac muscle
Smooth muscle
Function:
Works with the skeletal system to produce voluntary movement; helps to circulate blood and move food through the digestive system.

12. Circulatory System Structures: Function: Heart Blood vessels Blood
Arteries
Veins
Capillaries
Blood
Function:
Brings oxygen, nutrients, and hormones to cells; fights infection; removes cell wastes; helps to regulate body temperature.

13. Respiratory System Structures: Function: Nose Pharynx Larynx Trachea
Lungs
Bronchi
Bronchioles
Alveoli
Function:
Provides oxygen needed for cellular respiration and removes excess carbon dioxide from the body.

14. Endocrine System Structures: Function: Hypothalamus Pituitary Thyroid
Parathyroids
Adrenals
Pancreas
Ovaries (in females)
Testes (in males)
Function:
Controls growth, development, and metabolism; maintains homeostasis.

15. Reproductive System Structures: Function:
Testes, epididymis, vas deferens, urethra and penis (in males).
Ovaries, Fallopian tubes, uterus, and vagina (in females)
Function:
Produces reproductive cells; in females, nurtures and protects the developing embryo.