17 Digestive (Lecture) 7 Flashcards
Ingestion
Intake of food and water but also the drive to eat
digestion
breakdown of food and nutrients
Mechanical digestion
muscle action chewing and stomach muscles
Chemical digestion
enzymes that break down food
Absorption
movement of nutrients into the blood
Secretion 7 liters per day
saliva, stomach acid, enzymes, bile, mucus
Excretion
elimination of waste products
Motility (1-2 days)
muscle action of digestive tract
How many days for food to pass
1-2
*Alimentary Canal
mouth to anus
*GI tract
stomach to anus
*Digestive organs
segments of digestive tract
*Accessory digestive organs
salivary glands, pancrease, liver, gallbladder
Enteric Nervous System
part of the ANS that controls the digestive tract
*Visceral Motor
Parasympathetic increases digestion (rest and digest)
Sympathetic decreases digestion (fight or flight)
Visceral sensory
usually not conscious of
Peritoneal membranes
parietal and visceral
Parietal
attaches to abdominal wall
Visceral
attaches to outside of digestive tract
Mesenteries
membranes that hold the intestines in position
*Mesentery proper
holds small intestines in place
*Mesocolon
holds large intestines inplace
*Greater omentum
begins at stomach drapes down over abdomen, then it projects all the way back up again connects to large bowel.
*Lesser omentum
mesentary between stomach and liver
Layers esophagus through large intestines
Mucosa, sub-mucosa, muscularis, and serosa
Mucosa
Epithelium- columnar
Lamina propria- contains many capillaries that absorb nutrients
Muscularis mucosa-a layer of smooth muscle
Sub-Mucosa
a bunch of elastic connective tissue
Sub-mucosal plexus - mostly visceral sensory nerves
Muscularis
thick layer of smooth muscle that control motility
Myenteric plexus- all ANS motor nerves
Serosa
another name for visceral peritonial membranes
Mastication
chewing
Dentition
full set of teeth
Decidous (primary) dentition
Child 20 teeth
Dental succession
baby teeth fall out, adult teeth come in
Permanent (secondary) dentition
Adult 32 teeth
Incisors
front blade teeth 1 root 0 cusps
Cuspids
only found in carnavores used for piercing meat 1 root 1 cusp
Bicuspids
grinding teeth 2 root 2 cusps
Molars
grinding teeth 3-5 roots multiple cusps
Quadrants of teeth
4 quad top bottom L R
Each adult quad has how many teeth
8 2Incisor 1Cuspid 2Bicuspid 3Molar
Each child quad has how many teeth
5 1Incisor 1Cuspid 2Molar
Palatoglossal Arch
1st arch anterior boarder between oral cavity and throat
Palatopharyngeal Arch
posterior arch touch this with finger and you will puke
Fauces
narrowest portion of pharnyx
Deglutination
swallowing reflex
Common passage way
for food and air
Esophagus
is a tube that connects the throat to the stomach
UES
upper esophageal sphincter 1 of 6 sphincters
Hiatus
opening in the diaphram for esophagus
LES
lower esphageal sphinter cardiac sphincter 2 of 6 sphincters. Gaurds entrance to stomach
Mechanical digestion
muscles in the stomach
Chemical digestion
the action of pepsin
Chyme
food, saliva, stomach acid, enzymes
Secretion of intrinsic factor
Absorbtion of vitamin B-12
stomach defends how
acid
Cardia
entryway into the stomach
Z line
boarder between esophagus and stomach
Fundus
upper dome shaped portion
Body of the Stomach
verticle part this is where most of the acid comes from
Pylorus
horizontal part where acid secretion stops. Does secret pepsin
Pyloric antrum
wedge before pyloric canal
Pyloric canal
where stomach narrows
Pyloric valve
3 of 6 sphincters
Lesser curvature
superior curve
Greater curvature
inferior curve
Rugae
ridges that allow the stomach to expand and contract
*Gastric Pits are comprised of
Parietal cells, Cheif cells, Goblet cells, G cells
*Parietal cells
acid making cells also secrete intrinsic factor
*Cheif cells
cells that make pepsin
*Goblet cells
mucus making cells
*G cells
gastrin making cells
Small intestines
20 - 32 feet
Duodenum
about 10 inches long wraps round the pancrease Duodenum recieves digestive enzymes from pancrease
CCK
choleoystoskinin-a hormone that is secreted by cells in the duodenum and stimulates the release of bile into the intestine and the secretion of enzymes by the pancreas.
Secretin
a hormone released into the bloodstream by the duodenum (esp. in response to acidity) to stimulate secretion by the liver and pancreas.
*Jejunum
where absorption of nutrients begins
*80% of absorption…
occurs by difusion
*Plicaie
visable ridges inside small intestine they increase the surface area
*Villi
are microscopic projections on the plicae
*Blood capillary
absorbs 3 of the 4 organic compounds protien carbs and nucleic acids
*Lacteal
lymph capillary absorbs lipids
*Microvilli
projections of the cell membranes also increase surface area
*Intestinal crypts
projections into the wall of the small intestine location of stem cells
*Illeum
is redundant
Where does water absorption take place
large intestines
Large intestines
store and eliminate indigestible material.
when does chyme become feces
when it enters the large intestines
What type of relationship do humans and bacteria have
symbiotic
E. Coli
break down hard to digest material and release nutrients
Vitamin K produced in large intestine
is essential for immune and clotting
Haustra
sak like structures visable on the outside to the large bowel
Teniae coli
3 small ribbons of smooth muscle
Omental appencices
globs of fat on large intestine
Colon does not include
cecum or rectum
Parts of Large intestine in order
appendix, ileocecal valve, cecum, ascending colon, hepatic flexure, transverse colon, splenic flexure, descending colon, sigmoid colon, rectum
rectum is..
normally empty
when we feel the need to poop
poop is in the rectum
Anal canal
is an inch long
Anorectal flexure
90 degree curve
Anal columns
allow the anal canal to expand
*Pectinate line
at end of anal columns transitional zone from mucous membrane to cutaneous memebrane
External anal sphincter
we have control over
Internal anal sphincter
only relaxes as part of defication reflex
The gall bladder
stores bile it does not make bile
bile is made
by the liver
bile
helps digest lipids
Cystic duct
connects directly to the gallbladder
Hepatic duct
connects to the liver
Common bile duct
connects to duodenum
The pancrease
exocrine and endocrine
Exocrine function of pancrease
secrets into a duct
Endocrine function of the pancrease
are the pancreatic islet (islets of langerhorns)
pancreatic acini
the cells that make digestive enzyme (exocrine)
main pancreatic duct
travels through the duodenum (exocrine)
Hepatopancreatic sphincter
small sphincter in duodenal entrance (exocrine)
Glucagon
stimulates liver to release stored glucose between meals (endocrine)
Insulin
signals cells to absorb glucose (endocrine)
Head of pancrease
the small intestine wraps around the head of the pancrease
Body of the pancrease
the body of the pancreases projects to the left side
Tail of the pancrease
where pancrease narrow to a point
Falciform ligament
attaches liver to diaphram
liver has lobes
2 large upper 2 small lower
Hepatic portal system
a vein that brings blood from intestiens to liver
Biliary tree
ducts that transport bile
Lobules
microscopic lobes
*Portal triad
consist of bile duct a hepatic artery and hepatic portal vein
Hepatocytes
liver cells that process blood
Liver functions
Bile production, Metabolic regulation, Hematologic regulation, Detoxification
Metabolic regualtion
stores glucose in a form called glycogen. chain of glucose molecules. glucagon release signal to chop off glycogen.
Excess carbs and protiens are
stored as fat
Hematologic regulation
the liver stores RBC’s that is why it is burgandy
liver makes clotting factors
Detoxification
liver deactivates toxins
Gastic ulcers
due to infections primarily
Duodenal ulcers
due to stomach acid are far more common
