(first midterm) Lecture 2 (4.6.16) PT. 1 Flashcards
Where does the midgut end?
Where large intestine starts to go downward (descending colon)
left colic flexure
Parasympathetic nerve of the midgut:
Vagus (X)
According to Sumida, why don’t you want to lose your greater omentum?
The transverse colon is attached to it; keep the colon from “slumping down”
What makes up the hindgut?
Descending colon
Sigmoid colon
(through to) Rectum
Hindgut…
Sympathetic innervation:
Lesser and Least Splanchnic nn. & Lumbar splanchnics (T10-L2)
Hindgut…
Where does the sympathetic innervation synapse?
Inferior mesenteric ganglion
Hindgut…
Parasympathetic innervation:
Sacral outflow (S2-4)
Hindgut…
Arterial supply:
Inferior Mesenteric Artery and its branches
Hindgut…
Venous drainage:
Inferior Mesenteric Vein and its tributaries
When we have a system with capillary beds at BOTH ends, it is called….
a portal system
What is the system called that contains capillary beds in the large intestine connecting to the capillary beds in the liver?
hepatic portal system
The hepatic portal system draining the abdominal region has 3 major vessels:
Splenic
Superior mesenteric vein
Inferior mesenteric vein
The splenic, superior mesenteric vein, and inferior mesenteric vein are considered ________, NOT branches.
tributaries
What do tributaries do?
they act as “rivers” by dumping into something bigger
Hindgut…
Unpaired branch of abdominal aorta:
Inferior mesenteric artery
Hindgut…
Unpaired tributary of hepatic portal vein:
Inferior mesenteric vein
Hindgut…
Sympathetic nerve:
Lumbar Splanchnics
Lesser and Least Splanchnic Nerves
Hindgut…
Sympathetic nerve segmental levels:
L1-2
Hindgut…
Sympathetic Ganglion:
Inferior mesenteric ganglion
Inferior mesenteric plexus
Hindgut…
Parasympathetic nerve:
Pelvic outflow (S2-4) via pelvic splanchnic nerves
What is it called when the organs are surrounded by visceral peritoneum?
Intraperitoneal
What is it called when a structure is between peritoneum on one surface and the body wall on the other?
Retroperitoneal
Difference between Primarily Retroperitoneal and Secondarily Retroperitoneal?
Primarily - starts that way
Secondarily - gets pushed and becomes that way after the fact
These are primarily retroperitoneal:
Aorta
Kidneys
Vena cava
Other small veins
These are secondarily retroperitoneal:
Duodenum
Pancreas
Some “bits” of the liver
Metabolism:
all chemical reactions that occur in the body
Anabolism:
combining smaller molecules into larger ones
Catabolism:
breaking large molecules into smaller ones with release of energy
Enzymes:
proteins that act as catalyst to speed up chemical reactions
What is the primary sugar used by the body?
Glucose
How are the sugars stored in the body?
as long chains called polysaccharides
Monosaccarides:
Short; fruits and sugar cane
Polysaccarides:
Chains; grains and vegetables
A surplus of glucose is converted to what?
glycogen
A surplus of glycogen is converted to _________ and is stored where?
triglycerides
stored in adipose tissue
Phospholipids examples:
cell membranes, myelin sheaths
What is a molecule that is used to make certain steroids?
cholesterol
How many types of amino acids are there?
20
The liver can convert excess amino acids to…
triglycerides
Large excess of amino acids is lost….
in urine
Functions of proteins:
structure transport cell movement enzymes specialized functions such as hemoglobin
Note: catalytic amount refers to a very small amount
Minerals are taken in catalytic amount
Macrominerals examples:
Calcium Phosphorus Sulfer Sodium Potassium Chlorine Magnesium
*macromineral = needed at levels of over 100 milligrams a day
Microminerals examples:
Iron Iodine Copper Zinc Fluorine Manganese Cobalt Chromium Selenium
*microminerals = need trace amounts
Vitamins
Fat soluble vs. water soluble
Fat = body holds onto them much longer and stores them
Water = not stored; excess excreted in urine
Digestion:
mechanical and chemical processes involved in breaking larger food particles down into smaller ones
Absorption:
process by which these (resulting) molecules pass from the gut tube to the bloodstream and lymphatic circulation
Mechanical digestion innervations:
- V3 (manipulation of food by muscles of mastication)
- VII (buccinator)
- XII (tongue)
What is the initial carbohydrate breakdown?
Salivary amylase; starch breakdown
There is little or no absorption that happens in the mouth, EXCEPT…
alcohol
Incisors:
4
tearing and nipping
Canines:
2
slashing, tearing, shearing, biting
Premolars:
4
larger, complexly surfaced, chewing and grinding
Molars:
6
even larger grinding teeth
Enamel on the teeth is derived from…
neural crest material
In what location is there NO chemical or mechanical digestion?
the esophagus
The esophagus is the first place in which ________ takes place.
(and define _________)
peristalsis
wave of muscular action that propels bolus of food down gut tube
What is the opening into the stomach called?
the cardiac sphincter
What may absorb some water, does not absorb food, acts as storage, and tests for “poisonous ingestion”?
the stomach
Rugae:
folds on internal surface of stomach
-increases surface area
The inner surface of the stomach is derived from ________
endoderm
The three layers of smooth muscle in the stomach are derived from _________
mesoderm
What innervated the stomach?
Vagus (X)
What is the primary gastric secretion in the stomach? From where?
Hydrochloric Acid (HCl) Parietal Cells
What protects stomach lining from HCl?
mucous
What do zymogenic cells release?
Pepsinogen
HCl cleaves pepsinogen into what?
And what does this do?
Pepsin; it digests proteins
What secretes hormones?
What are some things the hormones do?
Entroendocrine cells
regulate stomach functions such as peristalsis, other secretions, etc.
What does gastrin do?
stimulates secretion of HCl
stimulated by smell, taste, chewing, swallowing
What innervates the gastrin secretion?
Vagus (X)
