Human Organ Systems Review

Organ Systems Nervous Circulatory Lymphatic (Immune) Respiratory Digestive Excretory (Urinary) Reproductive Endocrine

Nervous System Functions: – Senses changes in the environment and coordinates an appropriate response. – Allows us to function the way we do.

Nervous System Components: – Central Nervous System (CNS) Brain Spinal cord – Peripheral Nervous System (PNS) Peripheral nerves connect body to CNS.

Nervous System Nerve Cell (Neuron): – Cell body has all components of the animal cell. – Dendrites receive information. – Axons send information.

Nervous System Central Nervous System Brain: – Receives and processes information from sensory receptors. – Causes a specific response in the body. – Allows us to learn, hold onto memories, reason, maintain balance, etc.

Nervous System Central Nervous System Spinal Cord: – Responsible for reflexes. – Very fast; occurs without conscious thought.

Nervous System Peripheral Nervous System Controls skeletal muscles. Carries information from the sensory organs to brain. Controls involuntary actions such as breathing, heart rate and digestion.

Circulatory System Functions: – Transports nutrients and oxygen to the body cells. – Remove wastes and carbon dioxide from the cells.

Circulatory System Components: – Heart – Blood Vessels – Blood

Circulatory System Heart: Cardiac muscle tissue causes the heart to contract as one unit. Epithelial tissue lines the inside and outside of the heart to protect it from friction.

Circulatory System Blood Vessels: Network of tubes that transport blood. Arteries: – Carry blood away from heart; under high pressure. Veins : – Carry blood toward heat; under low pressure. – Valves help direct blood back to heart. Capillaries: – Surround each body cell. – Allows oxygen and nutrients to enter cells.

Circulatory System Blood Vessels:

Circulatory System Blood: Type of connective tissue. Red blood cells: – Transports oxygen to cells. White blood cells: – Recognize and destroy foreign microbes (e.g., bacteria and viruses). Platelets: – Cell fragments involved with blood clotting. Plasma: – Protein-rich liquid that carries blood cells.

Lymphatic System Functions: To defend against disease. Works with the immune system.

Lymphatic System Components: Lymph vessels Lymph fluid Lymph nodes Spleen Thymus gland

Lymphatic System Lymphatic Vessels Run alongside blood vessels. Transport lymph (fluid with white blood cells).

Lymphatic System Spleen, Thymus Gland & Lymph Nodes Congregation of white blood cells (search for and destroy foreign invaders). Filters lymph and destroys any microbes.

Respiratory System Functions: – Provides oxygen needed by the body. – Removes carbon dioxide waste from the body.

Respiratory System Components: – Mouth and nose – Trachea – Lungs – Diaphragm

Respiratory System Trachea: Air from mouth and nose pass through trachea. Cartilagenous rings keep it open. Lined with ciliated epithelium. – Cilia ‘beat’ to move mucus and foreign debris away from lungs.

Respiratory System Lungs: Non-muscular organ filled with alveoli. Alveoli are small air sacs surrounded by capillaries.

Respiratory System Diaphragm: Dome-shaped muscle. Attached to bottom lungs.

Respiratory System Breathing: Inhalation Diaphragm contracts and flattens. Lungs increase in size (and decrease pressure). Exhalation Diaphragm relaxes and returns to dome- shape. Lungs decrease in size (and increase pressure).

Digestive System Function: – To take food into the body. – To breakdown food into smaller pieces. – To absorb nutrients into body. – To excrete solid waste.

Digestive System Components: – Mouth – Esophagus – Stomach – Intestines

Digestive System Mouth Breaks down food. – Chewing. – Digestive enzymes. Saliva produced by epithelial tissue.

Digestive System Esophagus Smooth muscle contracts and relaxes to push food to stomach (peristalsis).

Digestive System Stomach Stores food. Smooth muscle contracts to mix food with digestive juices.

Digestive System Intestines Digestion and absorption of nutrients. Water reabsorbed into body. Solid matter excreted as feces from anus.

Excretory (Urinary) System Functions: – To filter wastes from the blood. – Forms urine.

Excretory (Urinary) System Components: – Kidneys – Ureters – Bladder – Urethra

Excretory (Urinary) System Kidneys Filter wastes from blood. Reabsorb essential substances back into blood (e.g., glucose). Secrete any other wastes into urine.

Excretory (Urinary) System Ureters, Bladder & Urethra Ureters carry urine from kidneys to bladder. Bladder stores urine. Urine exits body via urethra.

Reproductive System Functions: To produce sperm in males. To produce eggs in females. Responsible for secondary sex characteristics. – e.g., Males: facial and body hair, deepening of voice. – e.g., Females: breast development, body hair.

Reproductive System Components: Female: – Ovaries – Fallopian tubes – Uterus – Vagina

Reproductive System Components: Male: – Testis – Vas deferens – Urethra – Penis

Endocrine System Functions: Produces hormones that regulate bodily functions.

Endocrine System Components: Pancreas Adrenal glands Ovaries Testis

Endocrine System Pancreas Produces insulin  lowers our blood sugar Adrenal Glands Produces adrenaline  short-term stress (“fight or flight” response)

Endocrine System Ovaries Produce estrogen  secondary sex characteristics. Testis Produce testosterone  secondary sex characteristics.

Interactions of Systems Oxygen diffuses from air in respiratory system into blood in circulatory system. Carbon dioxide diffuses from blood into air.

Interactions of Systems Nutrients diffuse from food in digestive system into circulatory system. Oxygen and nutrients diffuse from circulatory system into body cells. Carbon dioxide and wastes diffuse from body cells into circulatory system.

Interactions of Systems Wastes from metabolic processes pass from circulatory system into urinary system.

Interactions of Systems Endocrine system (prolonged response) and nervous system (rapid response) work together to regulate all bodily functions and organ systems.

Interactions of Systems Lymphatic system and circulatory system work together to protect the body from foreign invaders.