Human Organ Systems
Organ Systems
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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).
Interactions of Systems
• 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.