What are the levels of organization in the human body?

Respiratory System l Function: l Breathing brings air into the lungs and removes waste gases l Cellular respiration converts oxygen and glucose to carbon dioxide, water and energy

Diseases of respiratory system l Lung Cancer -3rd leading cause of death in men and women in the U.S. l Emphysema ( causes aveoli to enlarge) l Asthma (lung disorder)

The Nervous System l Receives information about what is happening inside and outside your body l Directs the way that your body responds to this information l Helps maintain homeostasis l Has 2 divisions that work together: –Central nervous system –Peripheral nervous system

Central Nervous System l Control center of the body l The brain is part of the central nervous system that controls most functions in the body. l The spinal cord is the thick column of nerves that links the brain to most of the nerves in the body.

Peripheral Nervous System l Consists of nerves that branch out from the central nervous system and connect it to the rest of your body. l 43 pairs of nerves in peripheral nervous system –One nerve in each pair goes to the left side of the body and the other nerve goes to the right side. Start at the spinal chord.

Organs of the circulatory system l Heart l Veins l Arteries l Capillaries

Heart l Made of cardiac muscle tissue l Has 4 compartments called chambers: two upper are atriums, two lower are ventricles. l Heart has arteries just and veins just like any other muscle

Veins l Veins carry blood back to the heart. l Veins have valves

Arteries l Carry blood away from your heart l Have thick, elastic walls made of tissue and smooth muscle

Capillaries l Microscopic blood vessels. l Walls are only one cell thick l Nutrients and oxygen diffuse from body cells into capillaries

Blood l Carries oxygen from lungs to body l Takes carbon dioxide away l Carries waste products to kidneys l Transports nutrients l Red blood cells: transport oxygen l White: help fight bacteria, viruses, etc

Excretory System l Gets rid of waste from the body l Kidneys filter toxins from the blood

Digestive System l Esophagus connects mouth to stomach l Stomach contains acid to break down food even more l The small intestine is where nutrients from food are absorbed into the blood. l Large intestines removes not absorbed food and waste

Skeletal System l Provides shape and support for the body l Protect organs and soft tissues l Cartilage is located at the end of bones to cushion movement l Bones are connected by joints

Muscular System l Helps move the body l Voluntary muscles: you choose to move them. l Involuntary: Contract on their own, ex: heart

Muscles l 3 types l Skeletal: attached to bones to help you move l Cardiac: heart, pushes blood through the body l Smooth: intestines, bladder, blood vessels, internal organs. These contract involuntairaly.

Endocrine System l Endocrine system produces hormones which are that control many of the body’s daily activities as well as long term changes such as growth and development l Metabolism is affected by hormones, aging and exercise.

Reproductive System l Sexual reproduction involves the production of eggs by the female and sperm by the male, which join together during fertilization. l Each sex cell (egg or sperm) contains half (23) of the chromosomes required. (46 for humans)