Human Organ Systems

Organ Systems

• Nervous• Circulatory• Lymphatic• Respiratory• Digestive• Urinary• Reproductive• Endocrine

Nervous System

• Functions:– Senses changes in the environment and

coordinates appropriate responses.– Controls body functions.

Nervous System

• Components:– Central Nervous System (CNS)• Brain• Spinal cord

– Peripheral Nervous System (PNS)• Nerves connect body to CNS.

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:• Arteries:– Carry blood away from heart.

• Veins :– Carry blood toward heart.

• Capillaries: – Surround each body cell.– Allows oxygen and nutrients to enter cells.

Circulatory System

Circulatory System

Blood:• Red blood cells:

– Transports oxygen to cells.

• White blood cells:– Recognize and destroy foreign microbes.

• 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

Lymphatic System

Lymphatic Vessels• Runs alongside blood vessels.• Transports lymph (fluid with white blood

cells).

Lymphatic System

Lymph Nodes• Congregation of white blood cells.• Filters lymph and destroys

microbes.

Respiratory System

• Functions:– Provides oxygen needed

by the body.– Removes carbon dioxide

from the body.

Respiratory System

• Components:– Mouth and nose– Trachea– Lungs– Diaphragm

Respiratory System

Trachea:• Air from mouth and nose pass

through trachea.• Cartilaginous 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.

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– Small intestines– Large 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.

Digestive System

Stomach• Stores food.• Smooth muscle contracts to mix food with

digestive juices.

Digestive System

Small Intestines• Digestion and absorption of nutrients.

Digestive System

Large Intestines• Water reabsorbed into body.• Solid matter excreted as feces from anus.

Urinary System

• Functions:– To filter wastes from the blood.– Forms urine.

Urinary System

• Components:– Kidneys– Bladder

Urinary System

Kidneys• Filters wastes from blood.• Produces urine.

Bladder• Stores urine before

it exits the body.

Reproductive System

Functions:• To produce sperm in males.• To produce eggs in females.

Reproductive System

Components:• Female:– Ovaries– Uterus– Vagina

Reproductive System

Components:• Male:– Testes– Penis

Endocrine System

Functions:• Produces hormones that regulate bodily

functions.

Endocrine System

Components:• Pancreas• Adrenal glands• Ovaries• Testes

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 in females.

Testes• Produce testosterone secondary sex

characteristics in males.

Interactions of Systems

• Oxygen moves from air in respiratory system to blood in circulatory system.

• Carbon dioxide moves from blood to air (in lungs).

Interactions of Systems

• Nutrients move from food in digestive system to blood in circulatory system.

• Oxygen and nutrients move from circulatory system into body cells.

• Carbon dioxide and wastes move from body cells into circulatory system.

Interactions of Systems

• Wastes 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 (e.g., bacteria).

• Nerves stimulate the pacemaker (SA node) of the heart to control its rhythmic beating.

• The brain is supplied with constant blood flow so it always has oxygen in order to perform all its vital functions.

Interactions of Systems