processing the food we eat
DESCRIPTION
Processing the food we eat. Why do we need food? . Reactants for cell respiration (energy) Building blocks for new cells, tissues, etc. Essential nutrients: minerals, vitamins, etc. . What happens to materials we can’t use? . Stored for later Excreted - PowerPoint PPT PresentationTRANSCRIPT
Processing the food we eat
• Why do we need food? –Reactants for cell respiration (energy)–Building blocks for new cells, tissues, etc. –Essential nutrients: minerals, vitamins, etc.
• What happens to materials we can’t use? –Stored for later–Excreted–Converted into something we can use
Two main systems involved:
• Digestive: Breaks down food into small molecules (monomers!) and absorb the nutrients into the blood stream for delivery
Two main systems involved: • Excretory: Maintain Homeostasis– internal balance of chemicals–Rids body of metabolic wastes•Wastes produced by body’s metabolism•Eg: Salts, Carbon Dioxide, Urea
• BUT how do we deliver the “good stuff”?
Salivary GlandsEsophagus
Liver
Gall Bladder
Stomach
PancreasSm. Intestine
Lg. Intestine
Swallow
ing
Peristalsis –
Small Intestine Villus
Circular folds
Villi
Epithelial cells
Capillaries
Lacteal
Vein
Artery
ExcretionMajor Excretory Organs–Skin – water and salts–Lungs – CO2–Large intestines –
excess/indigestible solid waste–Kidneys and associated organs -
Urea
Renal Vein RenalArtery
Ureter
Urinary bladderUrethra
Excretory System
Kidney
FiltrationMost filtration occurs in the glomerulus. Blood pressure forces water,
salt, glucose, amino acids, and urea into Bowman’s
capsule. Proteins and blood cells are too large to cross the membrane;
they remain in the blood. The fluid that enters the
renal tubules is called the filtrate.
ReabsorptionAs the filtrate flows through the renal
tubule, most of the water and nutrients are
reabsorbed into the blood. The concentrated
fluid that remains is called urine.
SecretionSubstances such as hydrogen ions are
transferred from the blood to the filtrate.
Communications In the Body
Two systems involved: 1.Nervous –
2.Endocrine –