Aim How does the Respiratory System Maintain Homeostasis

Aim: How does the Respiratory System Maintain Homeostasis?

Respiratory System • Function: Gas Exchange – Inhale O 2 for cellular respiration to make ATP – Exhale CO 2, a waste product

Organs § Trachea § passageway from nasal cavity to the lungs § cartilage rings keep it open § Lungs § Alveoli § Tiny air sacs in the lungs for gas exchange by diffusion § Bronchi § extentions of the trachea that move gasses to and from the lungs

Lungs • Spongy texture • high surface area • gas exchange by DIFFUSION of O 2 occurs here

Gas Exchange in the Lungs • Occurs in the alveoli of the lungs – O 2 DIFFUSES from lung to blood – CO 2 DIFFUSES from blood to lung

Breathing • Diaphragm moves down & expands chest cavity pulls air into lungs inhale exhale

Respiration - Life Function - Chemical Reaction that produces ATP Energy in the Mitochondria(cell organelle) Equation O 2 + C 6 H 12 O 6 + H 2 O ATP + CO 2 + H 2 O

Alveoli in Lungs O 2 diffuses from lungs to blood CO 2 diffuses blood to lungs

FAILURE TO MAINTAIN HOMEOSTASIS ASTHMA CAUSE – REDUCTION IN THE AIR FLOW TO THE LUNGS FROM A REACTION PREVENTION / TREATMENT – INHALER

FAILURE TO MAINTAIN HOMEOSTASIS EMPHYSEMA CAUSE – DESTRUCTION OF THE ALVEOLI DUE TO SMOKING PREVENTION / TREATMENT – DON’T SMOKE / USE AN O 2 TANK

FAILURE TO MAINTAIN HOMEOSTASIS PNEUMONIA CAUSE – BACTERIAL OR VIRAL INFECTION THAT CAUSES FLUID IN THE LUNGS PREVENTION / TREATMENT – MEDICINE

Breathing and Homeostasis • Need to REGULATE O 2 in and CO 2 out in order to ensure adequate Energy (ATP) production EXAMPLE: • When you exercise, – You breathe faster O 2 • Need more ATP • Bring in more O 2 & remove more CO 2 ATP CO 2

Aim: How does the Excretory System Maintain Homeostasis?

Excretory System • FUNCTION: Removes metabolic waste from the body – Metabolic waste: CO 2, urea, water, salts – (metabolic waste = cellular waste) • MAJOR ORGANS – Lungs – removes CO 2 and H 2 O – Skin – removes salts and H 2 O – Kidneys – removes H 2 O and urea from blood – makes urine

What is Urea? • excess amino acids in to the bloodstream from digested proteins • the LIVER converts these poisonous amino acids into urea

Human Kidney • Maintains homeostasis by removing waste from the blood • Filters urea • Makes urine

Ureters – takes urine from kidneys to bladder Bladder – stores urine Urethra – transports from the bladder out of the body Liver – removes toxins - forms urea which is excreted

Kidney Stones • Cause - Occur when calcium, magnesium or uric acid salts in the urine crystalize • Stones block the ureter and cause pain • Treatment - Stones are treated with an ultrasound to break apart the stones

Kidney Failure Cause - toxic exposure to environmental pollutants or certain medications, certain acute and chronic diseases, severe dehydration Treatment – Dialysis - Blood is removed from the body through a tube inserted in the arm that pumped through a special tube that acts like the kidneys

Urinary /Tract Infection Cause – bacteria Treatment – proper hygiene, medicine

Aim: How does the Digestive System Maintain Homeostasis?

Digestive System • FUNCTION: to digest (break down) food into smaller molecules so they can diffuse into cells • ORGANS: Mouth, esophagus, stomach, intestines, accessory organs

mouth stomach liver gall bladder pancreas small intestines large intestines

Mouth • Teeth: break up food – • form of mechanical digestion • Saliva – contains enzymes for chemical digestion – Amylase enzyme: digests starch into simple sugars – Anti-bacterial enzymes: kill bacteria that enter mouth with food

Swallowing (& not choking) • Epiglottis – Flap of cartilage – Closes trachea when swallowing • Esophagus - connects mouth to stomach – Peristalsis (muscle contractions) move the food

Stomach • HCl (p. H 2) disinfects food by kills bacteria • Pepsin, an enzyme, digests protein • Fun Fact: The stomach can stretch to fit ~2 L food

Small Intestine • Chemical Digestion – Digest carbohydrates – into monosaccharides (glucose) • Amylase from pancreas – Digest proteins – into amino acids • Trypsin & chymotrypsin from pancreas – Digest lipids (fats) • Bile from liver & lipase from pancreas • Nutrients diffuse into body cells

Absorption in Small Intestines • Absorption through villi – finger-like projections – increases surface area for absorption

Pancreas • Produces digestive enzymes – Trypsin & protease: Digest proteins – Amylase: Digest starch – Lipase: Digest lipids small intestine pancreas

Liver • Produces bile – Breaks up fats • Gallbladder stores bile, but does not make it – that’s why you can have your gall bladder removed bile contains colors from old red blood cells collected in liver = iron in RBC rusts & makes feces brown

Large Intestines (colon) • Re-absorbs water – water is reabsorbed by diffusion Fun Facts – we use ~9 liters of water every day in digestive juices – > 90% of water is re-absorbed

Appendix Vestigial organ The function of the appendix is unknown. One theory is that the appendix acts as a storehouse for good bacteria, “rebooting” the digestive system after diarrheal illnesses. Other experts believe the appendix is just a useless remnant from our evolutionary past. Surgical removal of the appendix causes no observable health problems

Rectum • Last section of large intestines – eliminates feces – What’s left over? • Undigested materials – Mainly cellulose from plants - roughage or fiber – Keeps everything moving & cleans out intestines • Masses of bacteria

Ulcers Free of H. pylori Colonized by H. pylori • Caused by bacterial infection of stomach – H. pylori bacteria – Cure with antibiotics inflammation of stomach inflammation of esophagus H. pylori • Treatment – medicine – diet inflammatory proteins (Cag. A) cytokines cell damaging proteins (Vac. A) helper T cells neutrophil cells white blood cells

Diarreah • Caused when large intestine does not absorb enough water • Treated with medicine

Constipation • Caused when the large intestine absorbs too much water • Treatment is medicine