Digestive System Slides Flashcards
Peritoneum:
lines coelom;
covers organs
Mesentery:
peritoneal extension
provides support; vessels draw
nutrients from canal
Extramural gland;
e.g.
salivary; pancreas
Mucosa
Epithelia mostly simple columnar
or stratified squamous.
Lamina propria with lots of WBCs
Mucosal pits
Some are glands e.g. gastric pits.
Also sanctuaries for mitosis.
Muscularis
Inner circular layer; outer longitudinal
Causes “gut motility” e.g. Peristalsis:
wave of contraction drives digesta
analward as a bolus
Oral Cavity
Tongue manipulates food
Salivary glands make saliva:
Lubrication
Digestive enzymes
Modified as reptile venom glands
Teeth typical
Keratin Teeth or equivalent
Epithelial outgrowths; are composed of keratinocytes
Agnatha
Baleen in whales
Most vertebrates have bony teeth
Ectoderm derivatives develop in connective tissue
Outer layer of human teeth
Pure hydroxyapatite.
Hardest substance in the body.
Made by cells called Ameloblasts.
Inner layer of human teeth
Bonelike matrix.
Made by cells called Odontoblasts.
Tooth held in place by
“Periodontal Ligament” of
dense connective tissue
Pulp Cavity
Vascular and innervated.
Lined with Odontoblasts
Odontoblasts
Monitor dentin condition;
make 2o dentin to accommodate wear
Esophagus Parts and pieces
Peristalsis of swallowing
muscularis transition
skeletal muscle to smooth muscle
abundant mucus glands
Esophagus adaptations
Crop in birds dilated portion; stores food Rumen in “Foregut Fermenters” e.g. Cattle houses microbes to digest cellulose