body cells form tissues tissues form organs organs form systems (e.g., digestive) turnover require...
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Body Cells
Form tissues
Tissues form Organs
Organs form Systems (e.g., digestive)
Turnover
Require energy, adenosine triphosphate
Require nutrients
Cell Membrane
Double layers of lipid, CHO, and protein
Controls passage of substances
Distinct identification structures
Organelles
Cytoplasm
Mitochondria—Power plant
Major site for energy production
Nucleus
DNA
Endoplasmic reticulum - communication network
Rough endoplasmic reticulum - protein synthesis
Smooth endoplasmic reticulum -fat synthesis
Organelles
Golgi Complex
Packaging site for protein
Lysosomes
Cell’s digestive system
Peroxisomes
Detoxify harmful chemicals
Four Types of Tissues
Epithelial
Lines the outside surfaces and external passages
Connective
Holds structures together
Muscle
Able to contract
Nervous
Transport nerve impulses
Circulatory System
Heart and blood vessels
Systemic circuit
Pulmonary circulation
Lymphatic system
Blood
Portal Circulation
Transports nutrients
From the small intestine
Delivers to the liver
Allow liver to process nutrients before returning it to the bloodstream
Digestive System
Mouth to anus
Epithelium lines the lumen
Barrier to invaders
Submucosal layer
Muscularis
Taste and smell
The Mouth
MasticationSaliva
Enzymes to help breakdown simple sugarsMucus to lubricate the food for easier swallowingLysozyme to kill bacteria
TongueTaste receptorsEnzymes to help breakdown fatty acids
The Esophagus
Long tube
Connects pharynx to the stomach
Epiglottis prevents choking
Peristalsis, muscle contraction
Lower esophageal sphincter
Heartburn
The Stomach
Lower esophageal sphincter and pyloric sphincter
Capacity of ~4 cups
Secretion of acid, enzymes, and intrinsic factor
Holds food for 2-4 hours
Formation of chyme
Mucus layer prevents autodigestion
Stomach Acid
Destroys activity of protein
Activates digestive enzymes
Partially digests dietary protein
Assists in calcium absorption
Makes dietary minerals soluble for absorption
The Small Intestine
The walls are folded
Villi projections are located on the folds
Absorptive cells are located on the villi
Increases intestinal surface area by 600x
Rapid cell turnover
The Large Intestine
~3 1/2 feet in length
No villi or enzymes present
Little digestion occurs
Indigestible food stuff
Absorption of water, some minerals, vitamins
Contains bacteria
Formation of feces for elimination
Movement Along the Intestine
Peristalsis
A ring of contraction propelling material along the GI tract
Mass movement
Peristaltic wave that contracts over a large area of the large intestine to help eliminate waste
The Pancreas
Manufactures digestive enzymes
Produces glucagon and insulin
Secretes pancreatic juices
Bicarbonate needed to neutralize chyme
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