Part 9: Gastrointestinal system I Flashcards
(functions of GI system
1) Ingestion: food & liquid intake (oral cavity)
2) Mechanical processing: swirling, mixing, churning, propulsive motions in tract
3) Compaction: dehydration of undigested material & waste into feces (colon to anus)
4) Digestion: chemical & enzymatic breakdown of sugars, lipids, & proteins into small molecules
5) Secretion: acids, enzymes, & buffers by accessory organs
6) Absorption: movement of molecules, electrolytes, vitamins, & water into interstitial fluid
(blood vessels -> liver -> to the rest of the body)
7) Excretion: elimination of undigested residue & waste products
Label Gastrointestinal tract & accessory organs
left (top to bottom)
Oral cavity
Pharynx
Esophagus
Stomach
(small intest.) Duodenum
(small intest.) Jejunum & ileum
Large intestine
anus
right- accessory glands (top to bottom)
Salivary glands
Liver
Gallbladder
Pancreas
general histology of the GI tube
Mucosa
Submucosa
Muscular externis layer
Serosa
layers of mucosa
Epithelium : Stratified or simple (depending on stress/beginning & end)
Lamina propria (CT): Glands & immune cells
Muscularis mucosa: Propels content of glands in lumen
submucosa summary + conduit for _____ & contains _____
(connective tissue again)
Conduit for vasculature, nerves, & lymphatics
Immune cells, exocrine glands, submucosal nerve plexus
Muscularis externis summary + layers.
At the beginning & end of tube this layer is ______
(external muscle layer)
Inner circular smooth mm – Outer longitudinal smooth mm
- skeletal (somatic)
muscularis externis layer of stomach
has additional oblique smooth muscle
muscularis externis has this which controls GI motility
Myenteric plexus (controls GI motility)
Serosa (______) is _____ (______ membrane)
wrapping of the tube
Simple squamous epithelium + connective tissue
serous
Serosa continually produces _____ and has _____
watery fluid that lubricates the peritoneal surfaces
two layers = mesentery (see later)
label upper GI organs
blue: oral cavity
red: pharynx
green: esophagus
esophagus is found in ____
posterior mediastinum
abdominal organs you can only see in anterior view
liver
gallbladder
abdominal organs you can only see in posterior view
pancreas
kidneys
abdominal organs you can see in anterior &posterior view
diaphragm
stomach
spleen (ish)
small intestines
large intestines
anal canal (pelvis)
abdominal quadrants are ___
Vertical & horizontal planes intersecting at the umbilicus
label abdominal quadrants
red: RUQ - right upper quadrant
blue: LUQ - left upper quadrant
green: RLQ - right lower quadrant
yellow: LLQ - left lower quadrant
things in RUQ
liver, gall bladder, duodenum, head of pancreas, transverse colon, right kidney
things in LUQ
-stomach
-spleen,
-body & tail of pancreas
- jejunum
-transverse colon
-left kidney
things in RLQ
ileum, cecum, appendix, ascending colon
things in LLQ
ileum, descending & sigmoid colon
things not in any quadrants
rectum & anus (technically in pelvis so inferior to quadrants)
3 abdominal planes +where are they?
- Midclavicular plane: middle of clavicles
- Subcostal plane: below the ribs
- Intertubercular plane: tubercles of iliac crests (L5)
label abdominal regions & planes
yellow: subcostal plane
green: midclavicular plane
red: intertubercular plane
purple: flank or lumbar region
black: groin/iliac/ inguinal region
grey: pubic or hypogastric region
peritoneum (def.)
serous membrane lining the peritoneal (abdominal) body wall & organs
Parietal peritoneum lines the ______
peritoneal cavity (body wall)
Visceral peritoneum lines the ______
peritoneal organs (viscera)
Mesentery (proper) (def.) + serves as a conduit for ______; also anchors ______); has specific names at different areas
sandwich of peritoneum (2 layers of peritoneum
vessels, nerves, & lymphatics
organs to body wall
Greater omentum is _____ from _____
mesentery
greater curvature of stomach to transverse colon (apron-like)
Lesser omentum is _____from ______
mesentery
lesser curvature of stomach to liver (important structures found here)
______ has _____ for ______ and it also has ____ function
Greater omentum
lipid deposition
temperature control
immunological
what is intraperitoneal? + list
within peritoneum
most of gut tube, liver
what organs ate retroperitoneal? + list
-outside the peritoneum
-Everything NOT associated with GI in the abdomen (adrenal glands & kidneys, ureters)
-Big vessels (abdominal aorta & IVC)
-Some anchoring organs (abdominal esophagus, most of the duodenum, pancreas, ascending & descending colon)
All pelvic organs below the peritoneum (rectum, urinary bladder, prostate, uterus)
label
red: visceral peritoneum
blue: mesentery
yellow: parietal peritoneum
Foregut (def.) + vasculature leading to it ____
-from abdominal esophagus to descending part of duodenum
-celiac trunk - same for innervation [celiac ganglia]
Midgut (def.) + vasculature leading to it ____
- from descending part of duodenum to left colic flexure of the transverse colon
-superior mesenteric artery - same for innervation [SMA ganglia]
Hindgut (def.) + vasculature leading to it ____
-from left colic flexure of the transverse colon to rectum
-inferior mesenteric artery - same for innervation [IMA ganglia]
label blood vessels
red: abdominal aorta
blue: celiac trunk
yellow: superior mesenteric artery
green: inferior mesenteric artery
Superior mesenteric artery (SMA) goes where?
- Pancreas (1/2)
- Duodenum (1/2)
- Jejunum
- Ileum
- Cecum & appendix
- Ascending colon
- Transverse colon
Descending aorta goes where?
Thoracic esophagus
Celiac truck goes where?
- Abdominal esophagus
- Stomach
- Spleen
- Liver
- Gallbladder
- Pancreas (1/2)
- Duodenum (1/2)
Inferior mesenteric artery (IMA) goes where?
- Descending colon
- Sigmoid colon
- Rectum
Renal artery goes where?
- Kidneys
- Adrenal glands
Gonadal artery goes where?
- Ovaries/testes
venous vasculature is ______ except _____
Generally similar to arterial vasculature except NO CELIAC VEIN (splenic vein instead).
splenic vein drains blood from ____
the spleen, the stomach fundus and part of the pancreas.
All vasculature from GI tube will ______
end up in liver to be filtered via the portal vein
Veins from the body wall (_________) will drain directly into _____
renal veins, common iliac veins, gonadal veins
the Inferior Vena Cava (IVC)
label arteries of GI
(left -> top to bottom)
superior mesenteric artery
renal artery
gonadal artery
(right -> top to bottom)
descending aorta
celiac trunk
inferior mesenteric artery
label vein of GI
green: portal vein
red: splenic vein
blue: inferior mesenteric vein
yellow: superior mesenteric vein
purple: inferior vena cava
oral cavity epithelium is ___ and protects from ____
stratified squamous epithelium
abrasion/stress
oral cavity is the site of ____
-Mechanical digestion (teeth, tongue, palatal surfaces, cheeks)
-Lubrication by mixing ingested material with saliva
-Start of chemical digestion -amylase (to start the digestion of LARGE carbohydrates)
label boundaries of oral cavity
- Pharyngeal tonsils
- Palatine tonsils
- Lingual tonsils
yellow: Soft palate to uvula (midline)
black: Hard palate (maxillae + palatine bones)
purple: lips (skin)
green: Cheeks: buccal fat pads + oral mucosa
orange: Mandible
pink: Floor of the mouth (mylohyoid)
brown: hyoid
grey: epiglottis
blue: Pharynx ; nasopharynx, oropharynx,laryngopharynx
Oral vestibule: ____
space btw lips, cheeks, & teeth
Gingiva (gum) is mucosa of ____
oral cavity
label (top to bottom)
left : crown, neck, root
right : enamel, dentin, pulp cavity, gingiva (gum), bone, cement, periodontal ligament (gomphosis), root canals (neurovascular bundle)
Different shape & function for each set of teeth:
Incisors: blade-like, clip/cut food
Canines: pointed, tears/slash food
Premolars (bicuspid): crush/mash/grind food
Molars (multi-cuspid): crush/grind food
Sensory innervation of teeth by _____
Upper dentition in maxillae is by _____
Lower dentition in mandible is by ______
trigeminal nerve
CN V2 (maxillary branch of trigeminal n. – superior alveolar n.)
CN V3 (mandibular branch of trigeminal n. – inferior alveolar n.)
Deciduous teeth characteristics
20 teeth
No premolars
Eruption 6 to 24 months
Shed 6-12 years
Permanent teeth characteristics
32 teeth
Eruption 6-18 years
1st & 2nd premolars
1st, 2nd & 3rd molars
label
brown: Maxillary dental arcade
blue: Mandibular dental arcade
Most tongue muscles innervated by______
CN XII (hypoglossal nerve)
Two types of tongue muscles (controls what?)
Intrinsic -within tongue (no attachments outside tongue) (3 orientations): alter shape of tongue (speech)
Extrinsic -outside tongue(4 muscles): alter positioning of tongue; swallowing (push the tongue superiorly & posteriorly)
Label muscles of tongue
(left)palatoglossus
styloglossus
hyoglossus
genioglossus
(right) superior longitudinal
vertical
transverse
inferior longitudinal
septum
label muscles of tongue
red: palatoglossus
blue: styloglossus
yellow: hyoglossus
green: genioglossus
General sensation innervation of tongue
Mandibular n. (CN V3)
Glossopharyngeal n. (CN IX)
Taste receptors (_____) found throughout ____, innervated by _____,______
sweet, sour, salty, bitter & umami)
all papillae
facial n. (CN VII) via chorda tympani
Glossopharyngeal n. (CN IX)
label epithelium of tongue
green: fungiform papillae
blue: filiform papillae
red: vallate papillae
black: apex
purple: body
pink: terminal sulcus
grey: root
The human tongue is divided into anterior and posterior parts by ______
the terminal sulcus which is a V-shaped groove
salivary glands are ____
Exocrine glands with ducts into the oral cavity
salivary glands autonomic nervous system: ____
Parasympathetic stimulates secretion
Sympathetic inhibits secretion
Extra salivary secretion stimulated by: _____
Presence of food in mouth
Taste, sight, smell or thought of food
Pharynx epithelium
stratified squamous epithelium
pharynx innervated by _____
CN X (vagus nerve)
Glands in throughout pharynx secrete ____
serous & mucous substances
Palatal muscles (______) elevate soft palate during swallowing
tensor & levator veli palatini
______ (superior, middle, inferior) & ______ help elevate the larynx & push the bolus (chewed food mixed with saliva) towards the esophagus
Pharyngeal constrictor
suprahyoid muscles
label pharynx top to bottom
-Tensor & levator veli palatini
-Superior pharyngeal constrictor
-Middle pharyngeal constrictor
-Inferior pharyngeal constrictor
Peristalsis
propels bolus along the length of the tube
Coordination of circular & longitudinal muscles
Propulsion forward
Segmentation
Mainly circular muscle layer
Churn & mix contents
NO movement in any particular direction
Mechanical digestion
esophagus on vertebral column
C6 to T7
esophagus innervation
CN X (Vagus nerve)
Esophagus epithelium
stratified squamous epithelium
Esophagus Prevention of reflux & acid erosion
Lower esophageal sphincter (cardiac sphincter)
Peristaltic clearance
Submucosal glands (mucous)
Stratified squamous epithelium
Mucous from stomach
