Organ Systems

Review What is a tissue? What is an organ? What is an organ system?

Respiratory System Key functions Breathing Gas exchange

Nose Mouth Trachea Bronchioles Bronchi Alveoli Diaphragm

Breathing Process used to move air in/out of the lungs Occurs because of rib muscles & diaphragm

Inhale (Breathe in) Exhale (Breath out) Diaphragm Moves down Ribs Move up & out Result Air moves in

Inhale Exhale Diaphragm Moves down Moves up Ribs Move up & out Move down & in Result Air moves in Air moves out

Air’s Path Air is drawn into lungs through trachea (windpipe) to bronchi Bronchi narrow to smaller branches called bronchioles At the end of bronchioles end are alveoli (air sacs) Specialized epithelial tissue 1 cell layer thick Alveoli are surrounded by capillaries (blood vessels)

Gas Exchange Distance between the gases inside the alveoli and the blood is very small Why is this important? Exchange can happen quickly Oxygen needs to diffuse from alveoli (high concentration) into blood (low concentration) Carbon dioxide needs to diffuse from blood (high concentration) into alveoli (low concentration)

Digestive System Energy from food is obtained from 3 main sources Carbohydrates (sugar & starch) Protein Lipid (fat) Need to break these down into small useable parts

2 types of digestion Mechanical digestion Physical breakdown / tearing apart of food Chemical digestion Breakdown of large particles by enzymes (chemicals)

Mouth Esophagus Liver Stomach Large Intestine Small Intestine Rectum

Food’s Path 1. Mouth Mechanical digestion Teeth Chemical digestion Salivary glands Breaks down carbohydrates 2. Esophagus Connection between mouth and stomach Peristalsis Wave-like movement that squeezes food down to stomach Caused by involuntary muscle contractions

3. Stomach Chemical digestion of proteins Gastric juice Contains hydrochloric acid, digestive enzymes, mucus Mucus prevents stomach from digesting itself

4. Small intestine ~ 7.5m long, very thin Completes chemical digestion Small food particles are absorbed through villi Small, finger-like projections on the inner surface Function of villi is to increase the surface area More surface area = more absorption

Liver Produces bile which is pumped into the small intestine Helps break up large lipids (fats) Food does NOT enter 5. Large intestine ~ 1.5m long, thick No digestion Absorbs water, vitamins, minerals Any materials not absorbed are formed into feces Collected in the rectum and excreted

Circulatory System The main transportation system in your body Oxygen Nutrients Wastes 3 main parts A) Blood vessels B) Blood C) Heart

A) Blood vessels 1. Arteries Carry blood AWAY from the heart Have thick walls so they can handle the pressure 2. Veins Carry blood TOWARD the heart Not as thick as arteries Valves help blood get back to heart Aided by muscles

3. Capillaries Connection between arteries & veins Composed of 1 layer of cells Are easily broken Bruises Blood cells pass through single file

B) Blood Connective tissue Made of: 1. Plasma (55%) 2. Red blood cells 3. White blood cells 4. Platelets

2. Red blood cells (RBC) 1. Plasma Mostly water in which blood cells are suspended 2. Red blood cells (RBC) Contain hemoglobin which binds OXYGEN and carries it to all cells in the body Oxygen is needed to burn food to make energy Once oxygen has been dropped off, carbon dioxide can attach and be taken to lungs for removal

3. White blood cells Part of immune system Consume bacteria and viruses to fight off infection 4. Platelets Jagged shaped cells that cluster in groups at cuts to create scabs and stop bleeding

C) Heart 2 pumps that work side-by-side 1 pump to move blood to the body 1 pump to move blood to the lungs

Heart Structures Aorta (main artery) Pulmonary Artery (to lungs) Vena cava (main vein) Pulmonary Vein (from lungs) Right Atrium Left Atrium Left Ventricle Right Ventricle Septum

RIGHT side of the heart Receives DE-OXYgenated blood FROM BODY Pumps DE-OXYgenated blood TO LUNGS LEFT side of the heart Receives OXYgenated blood FROM LUNGS Pumps OXYgenated blood TO BODY

Atrium UPPER chamber Receives blood from BODY/LUNGS Blood enters through a vein Sends blood to VENTRICLE Valve controls the flow Ventricle LOWER chamber Receives blood from ATRIUM Sends blood to BODY/LUNGS Blood leaves through an artery

Heart Blood Flow

Excretory system Responsible for the removal of wastes from the body Carbon dioxide Ammonia (from digestion of proteins) Salts Organs: Lungs Liver Kidneys, bladder, ureter Skin

Liver Converts toxic ammonia (from protein digestion) into less harmful UREA Urea is released into the bloodstream

Kidney Removes excess water, salt & urea from blood NEPHRONS Filtration units in the kidneys Separates wastes from blood Produces urine Collected in a duct Filtered blood returns to the veins Are highly efficient ~ 180L of blood are filtered each day Only 1.5L of urine is produced

Urine excretion Ureters Long tubes that connect kidneys to the bladder The bladder is covered in muscular tissue When it is full the bladder muscles contract and push urine out through the urethra

Skin Contains sweat glands Sweat is produced to: Keep you cool Evaporative cooling Remove excess salt

Nervous system Detects & organizes appropriate responses to stimuli Eg. Changes in pressure, temperature, light, sound, chemicals

Impulses are sent from the body to the brain Brain organizes a response Sends a response message back to the stimulated tissue Neurons (nerve cells) Conduct electrical impulses (messages)

Structure of the neuron Dendrites Small branches that receive messages Cell body Contains necessary organelles (eg. Nucleus) Axon Tail-like extension of the body Passes message to next neuron

Nervous System Organization 1. Central Nervous System (CNS) Brain Spinal chord Receives stimuli from sensory organs Send response messages

2. Peripheral Nervous System (PNS) Nerve cells that travel to all parts of your body Detects stimuli Sensory neuron Send info to CNS Acts according to response from CNS Motor neuron

The PNS can be broken down into a) Somatic nerves Under conscious control b) Autonomic nerves Not under conscious control Heart rate Pupil dilation in response to light Digestion

Found throughout your skin Largest sensory organ Senses Sight Audition (hearing) Olfaction (smell) Taste Touch Found throughout your skin Largest sensory organ All found in specific places