Ch 32 Anatomy

what is the digestive system? it has three other names. what are they?

digestive tract, gastrointestinal tract, alimentary canal

System of the body concerned with the breakdown of food and absorption of nutrients

digestive system organs exists as a...

continuous tube extending from the oral cavity to the anus

what lines the majority of the digestive tract?

enteric nervous system in a web-like fashion (part of the autonomic nervous system)

What is the peritoneum?

A large highly folded serous membrane located in abdomen

Define the following terms:

Parietal peritoneum

visceral peritoneum

peritoneal cavity

The portion of the peritoneum that lines the inner surface of the abdominal wall

The portion of peritoneum that is located on the surface of the organs of the abdomen

The cavity between these two layers which is also a potential space filled with a thin film of fluid

The entire peritoneal cavity is subdivided into two sacs. what are they?

greater sac

leser sac (omental bursa)

what is the greater sac

The main portion of the peritoneal cavity that extends from the diaphragm to the pelvic floor and from the anterior abdominal wall to the posterior abdominal wall

what is the lesser sac?

A small portion of the peritoneal cavity located posterior to the stomach and extending upward behind the liver and downward into the greater omentum

the only opening between the greater sac and lesser sac is called the

epiploic foramen of winslow

the epiploic foramen of winslow is bounded by:

1. Portal vein, hepatic artery proper, bile duct (in lesser omentum)

2. Duodenum-inferiorly

3. Inferior vena cava-posteriorly

4. Liver-superiorly

what are reflections of visceral peritoneum?

peritoneal folds and membranes

what is the falciform ligament

A ligament that extends from the liver to the anterior abdominal wall and contains in it's free edge the round ligament of the liver

what is the Greater omentum

Extends from the greater curvature of the stomach to the transverse colon, forming a fatty apron over the small intestines

what is the Lesser omentum?

Extends from the lesser curvature of the stomach to the liver and contains its right free edge the bile duct, portal vein, and hepatic artery proper.

what is the Mesentery (proper)?

Supports and suspend the jejunum and ileum from the posterior abdominal wall

what is the Transverse mesocolon?

Suspend the transverse colon from the posterior abdominal wall

what is the Sigmoid mesocolon

Suspend the sigmoid colon from the posterior abdominal wall

Retroperitoneal structures are the structures located _________ the peritoneum directly on the __________ wall and include what structures?

Behind; posterior

1) Duodenum

2) ascending colon,

3) descending colon,

4) pancreas,

5) kidney and ureter,

6) aorta

7) inferior vena cava

The _________ is referred to as the mouth and contains the...

oral cavity

tongue, teeth, openings of the salivary glands

what is the tongue? what is its function?

skeletal muscular organ that function in sense of taste, mastication, and food movement

And adult human has _____ teeth of four types which include:

32

incisors, canines, pre-molars, and molars

there are how many pairs of salivary glands? What are they called? are they endocrine or exocrine glands? how do you know?

3 pairs: parotid, submandibular, sublingual

Exocrine glands because they are drained by a DUCT all of which empty saliva into the oral cavity

where is the parotid gland located? what is it drained by?

Located just below the ear and drained by the parotid duct

where is the submandibular gland located? what is it drained by? it was formally known as...

Located just below the mandible and drained by the submandibular duct ; this gland was formally called the sub maxillary gland

where is the sublingual gland? what is it drained by?

Located just below the tongue and drained by the sub lingual ducts

The pharynx is composed of ________muscle and functions in _________. It is divided into three parts known as

skeletal muscle; swallowing

Nasopharynx posterior to the nasal cavity

Oropharynx posterior to the oral cavity

Laryngopharynx posterior to the larynx-also called hypopharynx

What specific structure in the pharynx is continuous with the esophagus?

The laryngopharynx

The esophagus is a _____ cm _________ tube extending from:

25 cm muscular tube

CV6-TV 11

(lower end of the pharynx to the cardiac opening of the stomach)

The esophagus exhibits the three regional parts known as the... what happens after it reaches the last regional part?

cervical, thoracic, and abdominal part.

The part located in the neck that lies posterior to the trachea - Cervical part

The part that lies posterior to the trachea in the upper half and posterior to the heart in the lower half of the thorax - Thoracic part

The part that pierces the diaphragm at the esophageal opening of the diaphragm and enters the abdomen is called the abdominal part

it runs a short course in the abdomen and terminates by joining the stomach (gastroesophageal junction)

Arterial supply of the esophagus comes from...

Esophageal and bronchial branches (aorta)

Inferior thyroid-superiorly (Thyrocervical trunk,subclavian artery)

Esophageal branches of the left gastric (celiac trunk)-inferiorly

Digestive organ responsible for the storage of food is the...

Stomach

what are the 3 parts of the stomach? describe them.

Fundus: Part of the stomach above the level of entrance of the esophagus

Body: Located between the fundus in the pyloric part of the stomach that compromises the main mass of the stomach

Pyloric part: A part of that extends toward the right from the lower part of the body of the stomach

define the following: pyloric opening and pyloric sphincter

Pyloric opening - An opening between the stomach in the first part of the duodenum

Pyloric sphincter - the pyloric opening is surrounded by circular smooth muscle

what is the greater curvature of the stomach?

The name given to the margin of the stomach that courses over the fundus and inferiorly on the left side of the stomach to the inferior side of the pyloris

Is the greater curvature convex are concave?

Convex

Attached to the greater curvature is the _______, which is...

Greater omentum

a connective tissue structure that is embedded with fat and is located between the stomach and the transverse colon

what is the lesser curvature?

A name given to the margin that is located on the right side of the stomach, it's curvature being concave

Attached to the lesser curvature is the ____, which is...

Lesser omentum

a connective tissue structure in which fat is embedded but is located between the stomach and liver

What two openings does the stomach present?

Cardiac opening and pyloric opening

why is the cardiac opening called cardiac opening?

cardiac opening is called cardiac bc of its close association with part of the diaphragm upon which the heart rests

what is the cardiac opening?

Lies between the cavity of the esophagus and the cavity of the stomach-and is located at the upper junction of the greater and lesser curvatures

what is the pyloric opening?

Lies between the stomach and the first part of the duodenum and is surrounded by the pyloric sphincter

The internal surface of the stomach presents folds called

Rugae

What is the arterial supply to the stomach?

Right and left gastric, short gastric, and right and left Gastroepiploic arteries

what is the small intestine?

A part of the intestine between the pyloric sphincter (where its connected to stomach) and the ileocecal junction (where it joins large intestine)

What is the length of the small intestine? what does it do throughout its length?

7 m -It gradually diminishes through its length

What is three parts is the small intestine subdivided into? put in order from stomach onwards.

Duodenum jejunum and ileum

what is the duodenum

A C-shaped organ, where its concave medial border recieves the openings of ducts draining the liver, gallbladder, and pancreas which extends from the pyloric sphincter to its attachment to the jejunum

The duodenum is subdivided into four parts known as...

as the 1st/superior, 2nd/descending, 3rd/horizontal, and 4th/ascending

what is special about the 2nd and 4th part of the duodenum?

2nd/descending - receives bile and pancreatic juices via major and minor duodenal papillae

4th/Ascending - courses upward to the suspensory ligament of Trietz/suspensory ligament of the duodenum, where it leads to the duodenojejunal flexure

Arterial supply to the duodenum is from...

Pancreaticoduodenal arteries arise from

Gastroduodenal and SMA

what is the jejunum?

The proximal 2/5 of the remainder of the small intestine

What is the Jejunum supplied by artery wise

Jejunal branches of the superior mesenteric artery

what is the ileum

The distal 3/5 of the remainder of the small intestine

What is the ileum supplied by artery wise

supplied by the ileal branches that arise from both the superior mesenteric artery and the ileocolic artery

T or F: no morphological line of demarcation exists between the jejunum and ileum.

True

what is the mesentery

connective tissue structure that suspends and surrounds the highly coiled structures of the jejunum and ileum from the posterior abdominal wall

what is the ileocecal junction?

Junction of the ileum portion of the small intestine and the cecum of the large intestine

what is the ileocecal valve?

The opening between the lumen of the ileum and the lumen of the cecum is the ileocecal opening, and is guarded by this valve

what is the large intestine?

Part of the intestine extending from the ileocecal Junction to the anus

The large intestine is divided into which parts? (hint: 6 parts)

cecum, vermiform appendix, ascending colon, transverse colon, descending colon, sigmoid

what is the cecum?

Part of the large intestine that lies at and below the level of entrance of the ileum

what is the vermiform appendix?

A lymphatic organ attached to the inferior end of the cecum which is typically in a retrocecal position

what is the ascending colon?

Portion of the large intestine that extends superiorly along the right side of the posterior abdominal wall to the liver

Where and what is the right colic flexure? its also called the...

Right colic aka hepatic flexure

Immediately inferior to the liver, the colon bends and courses to the left to form this flexure

what is the transverse colon?

Portion of the large intestine that extends from the right colic flexure on the right side of the abdomen to the spleen on the left side

Where and what is the left colic flexure? its also called the...

Left colic aka splenic flexure

When the transverse colon reaches the spleen it bends in courses inferiorly, forming this flexure

what is the descending colon?

Portion of the large intestine that extends from the left colic flexure inferiorly along the left side of the posterior abdominal wall

what is the sigmoid colon? what is its shape?

Part of the large intestine that extends from the descending colon to the pelvis, where is continuous with the rectum. it forms a loop, the shape and position of which depend on the degree of filling

The portion of the colon proximal to the splenic flexure are supplied by...

branches of the superior mesenteric artery specifically the ileocolic artery which supplies Cecum, appendix, and ascending colon

What supplies the ascending and transverse colon?

Right colic artery

The transverse colon is also supplied by what else besides the right colic artery?

Middle colic artery from the SMA

Left colic artery from the inferior mesenteric artery

The portion of the colon at and distal to the splenic flexure is supplied by branches from...

Inferior mesenteric artery

What supplies the descending colon? artery wise

Left colic artery

What supplies the sigmoid colon? artery wise

2 to 3 sigmoid arteries from the inferior mesenteric artery

What supplies the rectum? artery wise

Superior rectal artery from the inferior mesenteric artery

teh right and left _________ lie _______ to the ascending and descending colons respectively

paracolic gutters; lateral

what is the rectum?

Portion of the digestive system between the sigmoid colon and anus

what is the anal canal?

inferior narrowing of the rectum

what is the anal verge

The boundary between the external environment and the internal environment at the anus

what is the dentate line? why is it clinically important? what is another name for it?

aka Pectinate line

The boundary between the internal mucosa and the external epithelium.

This marks the division between internal hemorrhoids above and external hemorrhoids below, as well as great sensitivity below the lesser sensitivity above the dentate line

what is the anus?

A sphincteric muscle located at the termination of the anal canal, which functions in the retention of feces

Arterial supply to the rectum and anus includes

Superior rectal artery (inferior mesenteric artery), middle rectal artery (internal iliac artery), inferior rectal artery (internal pudendal artery)

8 Branches of the aorta that matter in the abdomen. what r they

1. Inferior phrenic arteries,

2. celiac trunk,

3. superior mesenteric artery,

4. suprarenal arteries,

5. renal arteries,

6. gonadal arteries,

7. inferior mesenteric artery,

8. common iliac artery

Vessels associated with digestive organs include... (hint: 5 things)

Celiac trunk, superior mesenteric artery, inferior mesenteric artery, marginal artery of Drummond, portal vein

Where does the celiac trunk arise from?

From the aorta immediately below the aortic opening of the diaphragm

celiac trunk is embedded within...

the dense meshwork of nerves that constitute the celiac plexus

What are three arteries does the celiac trunk give rise to

Left gastric artery, splenic artery, and common hepatic artery

what is the left gastric artery?

A small branch that courses toward the left and then along the lesser curvature of the stomach which gives rise to the esophageal branches

What is the splenic artery?

A large branch of the trunk that has a tortous course along the upper margin of the pancreas as it courses to the spleen. Gives off numerous branches that directly supply the body and tail of the pancreas

What branches does the splenic artery give off and what do they supply?

Short gastric arteries - supply the fundus of the stomach

Left Gastroepiploic (gastro-omental) artery- supplies the greater curvature of the stomach

right before the splenic artery ends, what does it do?

it gives off many branches to the spleen

The branch off the celiac trunk that course is to the right is known as

Common hepatic artery

The common hepatic artery gives rise to what 2 arteries?

Hepatic artery proper - going up

Gastroduodenal artery - going down

The hepatic artery proper ascends in the ___________ toward the ______ and gives off ______ to the _____________ of the stomach and then divides into _____ and ____ which supply the _______

lesser omentum

liver

Right gastric arteries

lesser curvature

Left hepatic artery

right hepatic artery

liver

The right hepatic artery gives off the _____ to the _____________

Cystic artery; gallbladder

The gastroduodenal artery descends behind the what and does what?

behind the duodenum, where it gives off the Right Gastroepiploic artery to the greater curvature of the stomach and the common stem of the 2 pancreaticoduedonal arteries to the pancreas head and duodenum

Where does the superior mesenteric artery arise from? describe its course.

From the aorta just below the celiac trunk. at its origin, it lies posterior to the pancreas. it descends in front of the lower part of the duodenum, enters mesentery, and supplies the small intestine

What is the most proximal branch of the SMA?

The pancreaticoduedonal artery- supplies the pancreas and the duodenum

What does the Superior mesenteric artery give off next after the pancreaticoduedonal artery?

Jejunal and ileal branches - to the small intestine

Ileocolic, right colic, and middle colic arteries - to the large intestine (ileocolic also branches to supply the terminal ileum)