Digestive System. Function – to break food down into simpler molecules that can be absorbed & used by cells Function – to break food down into simpler.

Digestive SystemDigestive System

Function – to break food down into simpler Function – to break food down into simpler molecules that can be absorbed & used by molecules that can be absorbed & used by cellscells

Food changed to energy (ATP) through Food changed to energy (ATP) through digestion & cell respirationdigestion & cell respiration

Cellular respirationCellular respiration::

GlucoseGlucose (simple sugar) + (simple sugar) + OxygenOxygen ATPATP (energy) (energy)

Takes place in the Takes place in the mitochondriamitochondria of the cell of the cell

NutritionNutrition

Study of food & it’s effectStudy of food & it’s effectCaloriesCalories

1 1 CalCal = 1000 calories or 1kc = 1000 calories or 1kc

1 calorie = amount of energy needed to 1 calorie = amount of energy needed to raise temp. of 1 gram of water by 1 degree raise temp. of 1 gram of water by 1 degree CelsiusCelsius

NutrientsNutrients are need by the body for are need by the body for growth, repair, and maintenancegrowth, repair, and maintenance

a.a. WaterWater

b.b. CarbohydratesCarbohydrates

c. Lipids (Fats)c. Lipids (Fats) e. Vitaminse. Vitamins

d. Proteinsd. Proteins f. Mineralsf. Minerals

a. a. WaterWater – our body is made of appr. 70% – our body is made of appr. 70% water, water, many cell reactions many cell reactions

b. b. CarbohydratesCarbohydrates – – main energy sourcemain energy source

StarchesStarches are broken down are broken down into simple into simple sugars to make sugars to make ATPATP

c.c. Lipids (Fats) Lipids (Fats) – – glycerol & fatty acidsglycerol & fatty acidsUsed to make Used to make cell membranes & hormonescell membranes & hormonesSaturated fats are Saturated fats are solidsolid at RT at RT

Unsat. Fats are Unsat. Fats are liquidsliquids at RT at RT

Diet high in fat leads to high BP, heart disease, Diet high in fat leads to high BP, heart disease, obesity & diabetesobesity & diabetes

ProteinsProteins- composed of - composed of AAAAUsed for Used for growthgrowthRepairRepairHormones & oxygen transportHormones & oxygen transport8 essential AA 8 essential AA must be obtained from dietmust be obtained from diet

VitaminsVitamins – organic molecules that – organic molecules that regulate body processesregulate body processesVitamin D- bone healthVitamin D- bone healthVitamin A – night blindnessVitamin A – night blindness

Minerals Minerals - inorganic molecules - inorganic molecules neededneeded by body by body

Calcium- bones & teethCalcium- bones & teethIron - hemoglobinIron - hemoglobinSodium nerve &Sodium nerve &Potassium impulse transmissionPotassium impulse transmission

Food PyramidFood Pyramid

Organs of Digestive Organs of Digestive System:System:

Mouth Mouth PharynxPharynx EsophagusEsophagus Stomach Stomach Small Intestine Small Intestine Large Intestine Large Intestine

Food & air can pass through the Food & air can pass through the pharynxpharynx

PeristalsisPeristalsis – muscle contractions in the – muscle contractions in the esophagus that squeeze food to the stomachesophagus that squeeze food to the stomach

Absorption of nutrients occurs in the Absorption of nutrients occurs in the small small intestineintestine

Water is removed from undigested material in Water is removed from undigested material in the the large intestinelarge intestine

Organs of Digestive System: Organs of Digestive System: (con’t)(con’t)

Accessory Organs:Accessory Organs: LiverLiver – produces bile that helps break down – produces bile that helps break down

fatsfats

Gall BladderGall Bladder – stores the bile – stores the bile

PancreasPancreas – – Produces Produces hormones hormones to regulate blood sugarto regulate blood sugar Produces Produces enzymes (insulin)enzymes (insulin) to break down nutrients to break down nutrients Produces a Produces a basebase that neutralizes stomach acid that neutralizes stomach acid

Functions of Digestive Functions of Digestive System:System:

Mechanical digestionMechanical digestion - chewing, mixing in - chewing, mixing in stomachstomach

Chemical digestionChemical digestion by enzymes, breaking by enzymes, breaking large food molecules into smaller partslarge food molecules into smaller parts

Example: Example: AmylaseAmylase - from salivary glands; breaks down - from salivary glands; breaks down

carbohydratescarbohydrates Hydrochloric acid and pepsin Hydrochloric acid and pepsin - digests protein in - digests protein in

stomachstomach BileBile - from liver that dissolves fat - from liver that dissolves fat

AbsorptionAbsorption of nutrient molecules of nutrient molecules into the bloodstream occurs in the into the bloodstream occurs in the small intestinesmall intestine

VilliVilli are small finger-like projections are small finger-like projections that increase the surface area of small that increase the surface area of small intestineintestine

DisordersDisorders

Stomach ulcersStomach ulcersDiarrheaDiarrheaConstipationConstipation

Excretory System

General Information:

Function is to remove wastes from the blood & excrete them from the body

Important in maintaining homeostasis

Organs of the Excretory System:

Skin, liver, and lungs – remove wastes from the body

Kidneys – the main organ: Remove wastes produced by the metabolism

of proteins in the cells Purify the blood Adjust the pH Maintain the water balance of the blood

(retain/eliminate water)

Organs of the Excretory System:

Nephron: Functional unit of the kidney Filters blood and many materials are

reabsorbed by veins Urine is collected and passes out

through the Loop of Henle where water is reabsorbed

Kidney function is controlled by:

Regulatory hormonesWater and salt concentrations in the

blood, which is influenced by what you eat and drink

Kidney Nephron

Cortex

Medulla Renal artery

Renal vein

Ureter

To the bladder

Bowman’s capsule

Glomerulus

Capillaries

Collecting duct

To the ureter

Loop of Henle

Artery

Vein

Kidney Stones: