ch.24 The Digestive System

lining of small intestine contains:

plicae

retroperitoneal organs

posterior to the peritoneum - kidneys, ureters, abdominal aorta

Where does the esophagus locate to the trachea?

posterior to the trachea

pancreatic islets function

produce hormons, insulin, glucagon & somatostatin

mucous neck cells

produce mucus

what is the end result of stomach's function?

production of chyme

peristalsis

propel material

what does the embedded glands in the tongue do?

release lingual lipase which begins digestion of fat

what type of epithelium is the stomach lined with?

simple columnar epithelium

Lamina propria contains

small blood vessels (capillaries) and a central lacteal (lymph vessel) in the small intestine, as well as nerves. Also contains glands with the ducts opening on to the mucosal epithelium

what type of muscle does the digestive tract consists of?

smooth muscle

sinusoids (location)

spaces created between the lines of hepatocytes

identify the pointed spot

submandibular duct

what of the enteric nervous system innervates the mucosa?

submucosal plexus

what is the main blood supply to small intestine?

superior mesenteric artery

accessory organs of the digestive system

teeth, tongue, salivary glands, liver, gallbladder, pancreas

enteroendocrine cells - produce and cause?

the g cells produce the hormone gastrin. gastrin causes the parietal and chief cells to release their products

the mesenteries associated with the stomach are called the ____?

the greater and lesser omentum

lingual frenulum of tongue

thin fold of mucous membrane that attaches the tongue to the floor of the mouth

hard palate

this is the palatine process of the maxilla and the palatine bone

how many layers of smooth muscle does the gastric rugae have? what are their names?

three smooth muscle layers - oblique muscles (inner most) - circular muscles - longitudinal muscles

structures within the oral cavity

tongue, uvula, palatoglossal arches, salivary glands, teeth

the esophagus is innervated by the ____ nerve from the esophageal plexus

vagus nerve

pancreatic enzymes & what they digest

•Lipases, Digest lipids •Carbohydrases, Digest carbohydrates •Nucleases, Digest nucleic acids •Proteinases, Digest protein

how waste material enter the rectum after leaving the ileum?

•Waste material goes "up" the ascending colon •Around the hepatic flexure •"Across" the transverse colon •Around the splenic flexure •"Down" the descending colon •Around the sigmoid flexure •To the sigmoid colon •Into the rectum

Villi definition

- Fingerlike extensions of the intestinal mucosa that increase the surface area for absorption

within each lobule of pancreas,

- acinar cells - pancreatic islets

intestinal crypts (location, contain what type of cells & the function of the cells?)

- appear at the base of the villi - contain enteroendocrine cells which produce intestinal hormones, including cholecystokinin and secretin

Sinusoids consist of

- capillaries: leading to the central vein - kupffer cells: phagocytic cells of the liver

what are the salivary glands composed of? produce? secrete?

- composed of mucinous and/or serous acini - produce salivary amylase (partially digests carbohydrates) - secrete salivary lipase (digestive enzymes); partially digests carbohydrates

duodenum - contains, produce, enter into the small intestine at ____ (details)?

- contains duodenal submucosal glands which produces large amounts of mucus - hepatopancreatic sphincter region (bile from the liver and gall bladder, beffers from the pancreas, digestive enzymes from the pancreas)

sublingual salivary gland - covered by - consist of?

- covered by the mucous membrane of the floor of the mouth - consist of numerous sublingual ducts that open along either side of the lingual frenulum

gastric pits (structure within the lining of the stomach)

- deep invaginations - contains stem cells to continuously replaces lost stomach cells

lacteal

- each villus also contains this - absorb material that cannot be absorbed by the capillaries, e.g. lipid-protein complexes called chylomicrons

Plicae - where, function, composed of?

- folds in the small intestine - increases the surface area for increased absorption - composed: mucosa, lamina propria, muscularis musosae, submucosa

jejunum - has? & function

- has prominent plicae and villi - most nutrient absorption occurs here

what branches (arteries) from the celiac trunk supply the stomach?

- left gastric artery - splenic artery - common hepatic artery

the stomach consist of

- lesser curvature - greater curvature - cardia - fundus - body - pylorus - rugae

falciform ligament

- marks the boundary between the left and right lobes

Name the digestive tract

- mouth - pharynx - esophagus - stomach - small intestine - large intestine

the esophageal wall is

- mucosa lining; non-keratinized stratified squamous & lamina propria - muscularis mucosae - submucosa - muscularis externa; circular & longitudinal - the esophagus does not have a serosa layer but has an adventitia

The mucosa - what type of membrane - the epithelial layer is either: - aka? (hint: related to muscle)

- mucous membrane - epithelial layer is either: - non-keratinized stratified squamous - simple columnar - the muscularis mucosa

Serosa - what layer of the digestive system - what type of tissue does it contain?

- outermost layer of the digestive system - contains connective and epithelial tissue

what type of cells do both muscularis mucosa and muscularis externa have in common? what does this cell produce?

- pacemaker cells - produce 2 types of muscle contraction, peristalsis & segmentation

as blood passes thru the liver, what do the phagocytic cells and liver cells do?

- phagocytic cells remove old or damaged erythrocytes, similar to spleen - liver cells synthesize plasma proteins for blood clotting

acinar cells function

- produce digestive enzymes that travel thru the pancreatic duct to the small intestine

round ligament

- remnant of fetal umbilical vein along free edge of falciform ligament (the inferior portion becomes thick and round)

what does the non-keratinized stratified squamous epithelial layer do in mucosa? where does it locate?

- resists stress and abrasion - located in the oral cavity, esophagus, and anus

chief cells secrete?

- secrete pepsinogen, which is converted to pepsin via the action of hydrochloric acid - chief "pepsinogen"

soft palate - function & makes up? (identify 5, 12 & 13)

- separates the oral cavity from the naso pharynx - makes up the palatoglossal arch / palatopharyngeal arch / uvula

muscularis externa - donimate by ____ fibers - inner layer is ____ & outer layer is _____ - innervated by _____ of the enteric nervous system

- smooth muscle fibers - inner layer is circular & outer layer is longitudinal - myenteric plexus

dorsum - def, what does it contain? what is inside the thing it contains?

- superior portion of the tongue - contains the papillae - papillae contain the taste buds

intraperitoneal organs

- surrounded completely by the visceral peritoneum - stomach, liver, ileum

parotid salivary gland - feature (hint: size) - location

- the largest - lateral side of the face in the area of the ramus of the mandible

common hepatic artery branches to form? and supply?

- the right gastric and gastroduodenal artery to the right gastroepiploic - supply the lesser and greater curvatures

splenic artery branches to form ____ artery, which supplies the ____

- to form the left gastroepiploic artery - supply the greater curvature and fundus

main nerve supply to small intestine

- vagus nerve - superior mesenteric ganglion

each plica consist of? and what the function of the thing that plica consist of?

- villi - absorb the digested nutrients

Serosa is also called ____ which is ____ with the parietal peritoneum. Why?

- visceral peritoneum - is continuous with the parietal peritoneum - because there is no space in between so just called visceral peritoneum

what's the function of simple columnar with ____ in mucosa? ____ cells for secretion. located in?

- with microvilli for absorption - goblet cells for secretion - located in the stomach, small intestine and large intestine

pharyngeal muscles involved in swallowing

-Pharyngeal constrictors -Palatopharyngeus -Stylopharyngeus -Palatal muscles; tensor veli palatini & levator veli palatini

Duodenum; length and function

10 inches long; receives enzymes from the pancreas, bile from the liver and gallbladder

lleum

12 feet long

jejunum - length and function

8 feet long; most of the digestion and absorption occurs here

mesentery proper

All regions of the small intestine except the duodenum are suspended in a sheet of mesentery

lamina propria

areolar connective tissue underlying a mucous membrane/mucosal epithelium

lesser omentum

attaches stomach to liver

ileum

contains prominent lymphoid centers called aggregated lymphoid nodules (peyer's patches)

The falciform ligament spreads on the surface of the liver. this spreading is called ____

coronary ligament

submandibular salivary gland (location)

deep into the mandible

what's the anatomical direction of submucosa to the muscularis mucosae?

deep to muscularis mucosae

small intestine consist of

duodenum, jejunum, ileum

The esophagus enters the peritoneal cavity by passing through the _____ of the diaphragm at _____

esophageal hiatus; T10

the esophagus contains upper and lower ____

esophageal sphincters

greater omentum

extends from the stomach and covers the rest of the abdominal organs on the anterior surface

intrinsic factor - function

facilitates the absorption of vitamin B12, which is used during erythropoiesis

secondarily retroperitoneal organs - def - change occur when? - examples?

form as intraperitoneal but soon become retroperitoneal. The change occurs during embryonic development. examples are pancreas & duodenum

mesenteries

fused double sheets of peritoneal membrane

structures within the lining of the stomach

gastric pits, gastric secretory cells

The roof of the oral cavity consist of (identify A&B)

hard palate & soft palate

what shape does each lobule of the liver has? at each of the six corners is?

hexagonal •At each of the six corners is: •Branch of the hepatic portal vein •Branch of the bile duct •Branch of the hepatic artery proper The above three branches form the hepatic triad

Is the stomach intraperitoneal or retroperitoneal?

intraperitoneal

Parietal cells secrete

intrinsic factor and hydrochloric acid

hydrochloric acid - function

kills bacteria (microorganisms) in stomach & activates pepsinogen (gives an acidic environment for enzymes to work)

what type of vessels does the submucosa contain?

large blood and lymphatic vessels

the liver is ____ of the body other than veins

largest blood reservoir

left gastric artery supplies

lesser curvature and cardia

the oral cavity also houses the palatine tonsils. where are palatine tonsils?

lie between the palatoglossal and palatopharyngeal arches. they are lateral to the uvula

where does the abdominal organs lie?

lie within the peritoneal cavity aka the abdominal cavity

Segmentation

material is churned and fragmented

4 major layers of the digestive tract

mucosa, submucosa, muscularis externa, serosa

gastric secretory cells (structures within the lining of the stomach)

mucous neck cells, parietal cells, chief cells, enteroendocrine cells

The oral cavity is lined with oral mucosa. What type of cells does the oral mucosa consist of?

nonkeratinized stratified squamous cells

identify the pointed spot

parotid duct-lies on the masseter muscle

Name the 3 pairs of salivary glands (identify A, B & C)

parotid, submandibular, sublingual

what does the gastric rugae do?

permits expansion of the stomach