Human Body Systems

1. Human Body Systems Miss Melissa Sears 12th Grade Biology Click arrow to continue

2. Main Menu: Listed below is a list of some of the main systems in the human body. Click on the following terms to learn more about them. Respiratory System Excretory System Circulatory System Digestive System Muscular System Nervous System Endocrine System Immune System Once you have reviewed all of the systems, click here to answer a review question

3. The Respiratory System • Function: carry air into and out of lungs (oxygen and carbon dioxide are exchanged). • Main Parts: • Nose: traps dust, entrance for air • Epiglottis: Covers windpipe. Prevents water and food from entering windpipe when swallowing. • Trachea: Windpipe. Carries air to bronchi. • Bronchi: Carry air to right and left lung. • Bronchioles: Tiny tubes branching from bronchi. Composed of 300 million air sacs called alveoli. • Lung: Site of gas exchange (breathe in oxygen, exhale carbon dioxide). • Diaphragm: Skeletal muscle that separates chest from rest of body. Click here to return to main menu

4. The Circulatory System • Function: Distributes oxygen and nutrients to all parts of the body and picks up wastes, such as carbon dioxide, from all cells of the body • Major Structures: • Heart: made up of 4 chambers in humans. • 2 atria, right and left. Upper chamber of heart. Receives blood. • 2 ventricles, right and left. Lower chamber of heart. Pumps blood. • Blood: Blood is pumped into vessels. • Left side of heart contains oxygenated blood. • Right side of heart contains deoxygenated blood. • Blood vessels: Transport blood. Click here to return to main menu

5. The Excretory System • Function: Eliminates metabolic waste from the body (carbon dioxide from cellular respiration and nitrogenous compounds from the breakdown of proteins). • Major Structures: • Kidneys: Primary organs is excretory system. Their job is to regulate the chemical composition of blood and to help the body maintain homeostasis (balance). • Ureter: Tube through which urine flows from renal pelvis to the bladder. • Bladder: Muscular sac that stores urine. • Urethra: Tube through which urine flows from bladder out the body. Click here to return to main menu

6. The Digestive System • Function: Stores and digests food, absorbs nutrients, and eliminates wastes. • Major Structures: • Mouth: Chew/break down food into smaller pieces (food forms into a ball called a bolus). • Esophagus: Carries food to stomach. • Stomach: Helps break down and digest food. • Liver: Breaks down toxins. • Pancreas: Secretes pancreatic fluid that helps to break down fats and carbs. • Small intestine: Helps breakdown food molecules into nutrients. • Large intestine: Water is taken out of waste and feces forms. Click here to return to main menu

7. The Nervous System • Function: Controls and coordinates body movements and senses; controls consciousness and creativity; helps monitor and maintain other body functions. • Major Structures: • Brain: Made up of… • Cerebrum: Largest portion of the brain that is responsible for memory. • Cerebellum: Allows for coordinated movement. • Medulla Oblongata: Brain stem. Controls attention. • Spinal cord: Carries messages from body to brain. • Nerves: Fibers that transmit impulses to the brain. Click here to return to main menu

8. The Muscular System • Function: Provides structure; supports and moves trunks and limbs; moves substances through body. • Types of Muscles: • Skeletal: Moves the parts of the body; considered voluntary since contractions can be controlled. • Smooth: Found in blood vessels and organs in the digestive tract. Considered involuntary since its movements can not be consciously controlled. • Cardiac: Found in the heart; involuntary. Click here to return to main menu

9. The Immune System • Function: Provides protection against infection and disease. • Major Structures: • Lymph nodes: Small glands throughout the body that carries nutrients and waste material between the body tissues and bloodstream. • White blood cells: Defend body against disease; formed in red bone marrow; produce antibodies that help destroy unwanted substances and fight infection. Click here to return to main menu

10. The Endocrine System • Function: Maintains homeostasis; regulates metabolism, water and mineral balance, growth and sexual development, and reproduction (produces hormones). • Major Structures: • Glands: An organ that releases hormones. • Hypothalamus: Portion of the brain that controls body temperature, hunger, thirst, fatigue, and sex drive. Click here to return to main menu

11. Review Question: Click on one of the three choices that is the correct answer. • The liver, pancreas, small intestine, and large intestine are apart of what human body system? • Respiratory • Endocrine • Digestive

12. Sorry, try again! • The major structures of the respiratory system is the nose, epiglottis, trachea, and lungs. These structures aid in breathing and gas exchange. Click here to return to the review question.

13. Sorry, try again! • The major structures of the endocrine system are glands and the hypothalamus. Click here to return to the review question.

14. That’s correct! • The liver, pancreas, small intestine, and large intestine are all structures of the digestive system. These structures make breaking down toxins and food molecules into nutrients possible. Click arrow to continue

15. Congratulations! You have successfully completed this lesson! • Click here to return to title slide