Digestive system Notes

Question 1

The Peritoneum

Answer 1

Covers the internal space (Lines) including organs. Helps hold these organs in place.

Question 2

Mesentery

Answer 2

A Peritoneal extension for organ support, contains vessels that transport nutrients to Cardiovascular system.

Question 3

Parts and functions of the Mucosa

Answer 3

Epithelium- Simple columnar & Stratified Squamous
Lamina Propria- Capillaries and WBC
Mucosa Pits- Can be glandular (Gastric glands). These are mitosis sanctuaries.

Question 4

Extromural gland

Answer 4

EG Pancreus

Question 5

Muscularus

Answer 5

Mostly smooth muscle. Has a inner circular layer and an outer longitudinal layer.
Promotes gut motility like peristalsis

Question 6

Peristalsis

Answer 6

Wave of contraction that moves digestra analward as a Bolus.

Question 7

Parts of the Alimentary Canal

Answer 7

Oral Cavity
Salivary glands 
Teeth
Esophagus
Stomach 
Intestines
Rectum and Anus

Question 8

Oral Cavity

Answer 8

In most verts a tonuge is possessed for food manipulation

Question 9

Salvatory glands

Answer 9

In tetrapods- Dissolve flavorants with saliva, lubricates, and produce enzymes.
These are modified as Venum glands in some reptiles.

Question 10

Teeth (or equivalent)

Answer 10

There are Keratin equivalents- Composed of dead Keratinocytes. (Example being the Balegn whales filter-feeding apparatus Balegn in the Agnathans.
The vast majority of teeth are made of bone.

Question 11

Parts of a human tooth

Answer 11

Crown
Root
Enamel
Dentin
Pulp Cavity
Root Canal
Peridontal Ligument

Question 12

Enamel

Answer 12

The matrix- Mostly Hydroxyapatite, the hardest surface in the body
Made by cells called Amyloblasts.

Question 13

Dentin

Answer 13

Bone-like matrix. Made by Odontoblast cells.

Question 14

Pulp Cavity

Answer 14

Vascular and Innerved. Lined with odontoblasts that help monitor Denton quality and make secondary Denton to accommodate for wear.

Question 15

Periodontal Ligament

Answer 15

Bioliogen holding the tooth in place.

Question 16

The Esophagus

Answer 16

Does the Peristalsus of swallowing and transfer of muscularous for skeletal muscle to smooth muscle. There is an abundance of mucus glands.

Question 17

Special adaptations of the Esophagus

Answer 17

A birds crop- food storage in fore-gut fermentors the esophagus portion.

Question 18

The Rumin

Answer 18

In a bird’s CROP! It is a chamber for microbial digestion of cellulose.

Question 19

The Stomach

Answer 19

Functions as food storage and has mucosal folds (Rugae to permit stretch).
Has three muscle layers that permit mixing
Gastric pits/glands secrete gastric juice (hydrochloric acid to protect, digest, and break down proteins.
It also secretes mucus to protect itself from digestion!

Question 20

Bird Stomach

Answer 20

2 stomachs- Secrotory and Gizzard

Question 21

Gizzards

Answer 21

Have Keritin like internal covering for grinding and can ingest rocks to assist.

Question 22

Digestive Product in Birds

Answer 22

Chyme- Acidic liquid that enters the duedeum of the small intestine

Question 23

Duodeum

Answer 23

Receives Chyme from stomach, enzymes from pancreas, bile from the liver, and alkaline (to neutralize) mucus from Brunners Gland.

Question 24

The Small Intestine

Answer 24

Lined with collumnar cells called enterocytes. Nature favors large SA of enterocytes. Enterocytes have apical “brush border” enzymes that finish digestion. Enterocytes perform all absorption

Question 25

How enterocyte surface is maximized

Answer 25

Great intestinal length
Spiral valve in some fishes e.g. sharks
Circular internal folds
Villi: finger-like mucosa projections
Microvilli of enterocytes

All of these together increase the SA by 600x

Question 26

Large Intestine

Answer 26

It absorbs H2O and feces, and helps control the animals’ water budget.

Question 27

Cecum

Answer 27

section joined with the small intestine (in the large intestine

Has an appendix in humans
Thin extension; lymphatic organ
Hindgut Fermenters e.g. horses and rabbits
Cecum large; 
houses microbial digestion of cellulose

Question 28

How does water enter and leave an animal?

Answer 28

In- Drinking, food, metabolic H2O

Out- Urine, feces, evaporation