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.