Lab Practical -digestive terms Flashcards
digestive lab terms
1
Q
walls of hollow organs-inner to outer
A
- Mucosa (lining)
- Submucosa
- Muscularis Externa
2
Q
Mucosa (lining)
A
- made of epithelium over a thin layer of connective tissue called the lamina propia
- the digestive organs have a thin layer of smooth muscle called the muscularis mucosa- the muscle layer pulls the lining into folds like the rugae of the stomach & plicae circularis of the sm. intestine
3
Q
Submucosa
A
- the submucosa is made of dense regular connective tissue
- it is rich in blood, lymph, nerves.
- it is often in digestive system, filled with glands
- in digestive organs, the submucosal plexus, a network of nerves responsible for stimulating glandular secretion is found here
4
Q
Muscularis Externa
A
- AKA muscularis
- 1+ layers of smooth muscle
- in places along the tract, circular layer often thickens to form sphincters that act as valves to prevent backflow and control food passage between organs
- in digestive system, the inner layer is circular and outer, longitudinal -in urinary-reverse
*Stomach: 3 layers- oblique, circular, longitudinal
Bladder: 3 layers- longitudinal, circular, longitudinal
5
Q
Serosa or Adventitia
A
- organs covered by serous membranes have serosa
- those covered by connective tissue have adventitia
- some organs, like the bladder + L.intestine, have a serosa in some areas and an adventitia in others
6
Q
2 groups of organs in digestive system
A
- Alimentary canal
2. Accessory organs
7
Q
Alimentary Canal
A
- Mouth->Pharynx(oropharynx & laryngopharynx)-> esophagus-> stomach-> small intestine-> large intestine-> anus
- AKA GI Tract
- ~30’ long in a cadaver
8
Q
Accessory organs
A
- tongue
- teeth
- gall bladder
- liver
- pancreas
9
Q
Mouth
A
- oral cavity, buccal cav.
- bounded by lips, cheeks, palate, and tongue
- lining of stratified squamous epithelium
- continuous w/ oropharynx through the fauces
10
Q
tongue
A
- made of intrinsic muscle (longitudinal, vertical, and transverse skeletal muscle fibers)
- attached to bones of the skull or the soft palate by extrinsic muscle
- intrinsic muscle change shape, extrinsic change position
11
Q
Salivary glands
A
- Extrinsic (Parotid, Submandibular, and Sublingual; all paired): secrete watery slaiva containing SALIVARY AMYLASE, which breaks down starch and glycogen, as well as mucus to help bind food particles and aid in swallowing
12
Q
teeth
A
- mammals have both primary (deciduous) and secondary ( permanent) teeth
- 32 secondary teeth total; 16 on each jaw
- per jaw front to back: 4 INCISORS( for biting), 2 CUSPID( for tearing), 4 BICUSPID & 6 MOLARS (for grinding)
13
Q
enamel
A
- hardest substance in body, covers outside of tooth
- enamel producing cells die when tooth erupts
14
Q
dentin
A
- protein-rich, bone-like material beneath enamel cap, forms bulk of tooth
- new dentin formed throughout adult life
15
Q
Pulp cavity
A
- containing PULP
- beneath the dentin , the pulp cavity contains the connective tissue, blood vessels and nerve fibers that supply the tooth
- the pulp cavity extends into the ROOT, forming the ROOT CANAL
16
Q
Pharynx
A
-common passage from mouth for food and air; the oropharynx and laryngopharynx play a role in food passage
17
Q
Esophagus
A
- muscular tube, 10” long
- muscosa- strat. squamous epithelium
- the muscularis is a skeletal muscle for the upper third; a mix of the skeletal & smooth in the middle third, and entirely smooth in the inferior third
- the esophagus has an adventitia
- it is posterior to the trachea & heart, and passes through the diaphragm at the esophageal hiatus
- the esophagus joins the stomach at the CARDIAC ORIFICE, which is guarded by the CARDIAC (GASTROESOPHAGEAL)SPINCTER
18
Q
Stomach
A
- at the stomach, the digestive mucosa switches to simple columnar epithelium, rich in goblet cells. Thys type of epi. continues to the level of the anal canal, where there is a switch back to stratified sqaumous
- J-shaped, 10” long
19
Q
4 regions of the stomach
A
- fundus
- cardia
- body
- pylorus
20
Q
2 stomach curvatures
A
- greater omentum- hangs from the greater curvature over the small intestine, then goes superiorly to wrap the transverse colon
- lesser omentum- runs from the lesser curvature of the stomach to the liver
21
Q
gastric pits
A
- stomach:
- in muscularis
- deep pits that lead into gastric glands that produce gastric juice
- cells in this area produce mucus to protect the stomach wall as well as HCl and digestive enzymes
22
Q
Gastric Ulcers
A
- occur when the stomach wall becomes eroded
- most ulcers are linked to eh presence of the acid-resistant bacteria “ Helicobacter pylori”, that destroy the mucosal layer in the stomach
23
Q
Small intestine
A
- major digestive and absorptive organ
- 20’ long in cadaver
- 3 regions: Duodenum(1st 10”) , Jejunum(8’ long), Ileum(12’ long)
24
Q
Duodenum(1st 10”)
A
- Hepato pancreatic ampulla enters here
- the sphincter of Oddi controls it
- the hepato pancreatic ampulla is formed by the covergence of the common bile duct from the liver and the pancreatic duct
25
Q
Ileum(12’ long)
A
- it enters the L.intestine at the ileocecal valve
- the sm. intestine is supported by the mesentary
- mucosal folds of the sm. intestine are plicae circularis- these are finger-like projections called villi
- at center of each 1mm high villus is a central lacteal + capillary beds
- the villi are made, exteriorly of columnar epithelial cells- each of these cells has its membrane pleated into folds called MICROVILLI- these increase surface area to aid on absorption of digestive products
26
Q
Large Intestine
A
Regions are:
caecum-> ascending colon-> transverse colon-> descending colon->sigmoid colon->rectum-> anal canal
-contains goblet cells
* be able to label a diagram of L. intestine
27
Q
liver
A
- largest internal organ
- 4 lobes: right, left caudate, left caudate & quadrate
- blood flow to and from the liver is from 2 sources: the hepatic artery, hepatic portal vein
- blood leaves the liver through hepatic vein
- the bile ducts carry bile to the right and left hepatic ducts, which fuse to for the COMMON BILE DUCT
28
Q
Hexagonal lobules
A
- functional units of the liver
- at each six corners of the lobule is a triad
- a triad consists of a branch of the hepatic artery, and the bile duct
29
Q
Pancreas
A
- the pancreas is both exocrine and endocrine
- the organ is tadpole-shaped and lies partially retroperitoneal, with its tail posterior to the spleen and stomach and its head in the curve of the duodenum
30
Q
Islets of Langerhans
A
- in Pancreas
- functional endocrine units, these produce the hormones insulin and glucagon, which aid in metabolism of sugars
31
Q
Acini
A
- in Pancreas
- functional exocrine units are circular rings called acini
- each acini empties into a interlobular duct, these ducts eventually converge to form the main pancreatic duct
32
Q
pancreatic juice
A
- drained from hepatopancreatic ampulla into duodenum to aid in digestion
- only exocrine units of the pancreas drain into the pancreatic duct, the endocrine secretions go directly into the blood
