1. Human Anatomy and Body Systems

2. Levels of Organization
Remember, the human body is organized in several levels, from the simplest to the most complex. . .
Cells – the basic unit of life
Tissues – clusters of cells performing a similar function
Organs – made of tissues that perform one specific function
Organ Systems – groups of organs that perform a specific purpose in the human body
***The purpose of the 11 organ systems is for the human body to maintain homeostasis.

3. The 11 Human Body Systems The 11 human body systems are as follows:
-- nervous system -- integumentary system
-- respiratory system -- digestive system
-- excretory system -- skeletal system
-- muscular system -- circulatory system
-- endocrine system -- reproductive system

4. The Respiratory System
Purpose: to provide the body with a fresh supply of oxygen and remove the waste product carbon dioxide
Major Organs and Their Functions
Trachea – the “windpipe”, or what connects your mouth to your lungs
Diaphragm is the muscle that causes you to breath
-- hiccups are involuntary contractions of the diaphragm
Lungs - make up one of the largest organs in your body, and they work with your respiratory system to allow you to take in fresh air, get rid of stale air, and even talk

5. Image of the Respiratory System

6. The Circulatory System
Purpose: to deliver oxygenated blood and nutrients to the various cells and organ systems in your body
Major Organs and Their Functions
Heart – the major muscle of the circulatory system
-- pumps blood through its four chambers (two ventricles and two atria)
-- pumps deoxygenated blood into the lungs, where it gets oxygenated, returned to the heart, and then pumped out through the aorta to the rest of the body
-- valve regulate the flow of blood between the chambers

7. Arteries – carry blood away from the heart and
Arteries – carry blood away from the heart and to the major organs of the body
Veins – carry blood back to the heart away from the major organs of the body
Blood – the cells that flow through the circulatory system
-- red blood cells carry oxygen to other parts of the body
-- white blood cells function in the immune system
-- platelets help in blood clotting

8. Image of the Circulatory System

9. The Skeletal System
Purpose: to provide structure and support to the human body (like a cell wall does for a plant cell)
Bones are where new blood cells are generated (in the marrow), hard to support and protect the body, and require the mineral calcium for strength
Ligaments – hold the bones together
Major Bones of the Human Body
-- femur (thigh bone) -- humerus (upper arm)
-- radius and ulna (lower arm) -- cranium (skull)
-- sternum (breastbone) -- clavicle (collar bone)
-- fibula and tibia (calf) -- vertebrae (back)
-- scalpula (shoulder) -- pelvic bone
-- coccyx (tail bone) -- phalanges (fingers/toes)

10. Major Muscles in the Human Body
The Muscular System
Purpose: works with the skeletal and nervous system to produce movement, also helps to circulate blood through the human body
-Skeletal muscles-move the bones
-Smooth muscles-involuntary muscles like the esophagus
-Cardiac muscles-heart muscle
Tendons - special cords made of tough tissue attach your body's muscles to your bones
Major Muscles in the Human Body
-- biceps -- triceps -- deltoids
-- glutes -- hamstrings

11. The Endocrine System
Purpose: to control growth, development, metabolism and reproduction through the production and delivery of hormones
Major Organs
-- pituitary gland
-- thyroid
-- adrenal glands
-- pancreas
-- testes
-- ovaries

12. Major Organs and Their Functions
The Nervous System
Purpose: to send electrical signals throughout the body (send messages from the brain to the rest of the body)
Major Organs and Their Functions
Brain – control center of the body
Spinal Cord – sends instructions from the brain to the rest of the body and vice versa
Nerves – conduct impulses to muscle cells throughout the body

13. Diagram of a Nerve Cell

14. The Integumentary System
Purpose: protects the body from the outside world and infections (like a cell membrane does for a cell)
Includes the:
- Skin
- Nails
- Hair

16. The Digestive System
Purpose: to convert food particles into smaller molecules that can be absorbed into the bloodstream and used by the body (make food usable by the body like a mitochondria does for a cell)
Major Organs and their Functions:
Mouth – to chew and grind up food (mechanical digestion)
Saliva Glands - begins the chemical breakdown (chemical digestion)
Tongue - begins the mechanical break down (mechanical digestion)
Esophagus – pipe connecting mouth to stomach
Stomach – secretes an acid that breaks down of food (chemical and mechanical digestion)

17. Pancreas – produces the hormone insulin that regulates
Pancreas – produces the hormone insulin that regulates blood sugar levels (chemical digestion)
-- also help neutralize stomach acid
Liver – produces bile, which breaks down fats in foods (chemical digestion)
Gallbladder – pouch-like organ that stores bile for future use (chemical digestion)
Small Intestine – after digestion is complete, the broken down food enters the small intestine where it is absorbed into the bloodstream
Large Intestine – removes water from the broken down food and gets the waste ready for excretion (poop!)
Anus - the opening where your bowel movements (also known as poop) come out

18. The Digestive System

19. The Excretory System
Purpose: to get rid of the body’s waste, including excess water and salts (like the lysosome does for a cell)
Major Organs and Their Functions
Kidneys – the main organs of the excretory system
-- filters out urea, excess water and other waste products, which eventually travel out of the kidney as urine
Bladder - holding area for liquid waste

20. Skin – sweat glands remove excess water and salts from the body
Lungs – expel the waste gas carbon dioxide
The Excretory System

21. The Reproductive System
Purpose: used to reproduce (make babies)
Female reproductive system:
Ovaries – produce eggs and estrogen
Uterus – place for the baby to develop
Vagina – connects the outside of the body to the uterus
Egg – female sex cell
Male reproductive system:
Testicles – produce sperm and testosterone
Penis – delivers sperm
Sperm –male sex cell