digestion (with epithelia) Flashcards
What is the function of chief cells?
make pepsin in the inactive form pepsinogen to digest proteins!
functions of saliva?
digestion, lubrication, buffering noxious substances, cleansing oral cavity
What type of epithelium lines the oesophagus? A simple collumnar B s.s non keratined C simple columnar D pseudostratified
Stratified Squamous non-Keratinised Epithelium
protects from hot/abrasive foods
where would Pseudostratified Columnar Epithelium be found?
found in the trachea and upper respiratory tract
> one layer close to blood vessels
> may have ciilia to waft mucous to larynx
where would Stratified Squamous Keratinised Epithelium be found?
found in the Filiformof the tongue to rub food into small pieces and the Masticatory Mucosa of the gums and hard palate
the function of sensory cells in taste buds?
attach to nerves and trigger signals in axons
> found inside fungiform papille
what type of bone cell eats away at the roots of baby teeth? osteoblast osetoclast osteocyte fibroblast chondrocyte
osteoclasts
WHY? adult teeth push on baby teeth and activate the osteoclasts allowing adult teeth to grow out
what muscle is the oesophogus made of? A skeletal B cardiac C smooth D keratinied E collumnar
skeletal and smooth transitionalas we move from voluntary (swallow) to involuntary control
Also seen in rectum/anus in the 2 sphincters
what controls contraction of muscularis mucosae?
A meissner plexus
B auberach plexus
meissners plexus
what type of epithelium is the masticatory mucosa?
stratified squamous keratinised epithelium
> found on gums and hard pallate
what type of epithelium is found in the ordinary lining mucosa? (ORAL MUCOSA) A simple collumnar B s.s non keratined C simple cuboidal D pseudostratified
stratified squamous non keratinised epithelium but can BECOME keratinised on cheeks with chewing
> found anywhaere where masticatory isnt (gums and hard palate)
which papillae of the tongue are pointy, rough and abrasive A foramen B vallate C filliform D fungiform
filiform papillae used to press food agaisnt pallate
> made of s.s. kerat
which area(s) can you find ordinary lining mucosa? A gums B soft palate C lips D anterior 2/3 tongue E posterior 2/3 tongue
soft palate and lips
Where is the sublingual major salivary gland located and what does type of secretion does it have?
Under tongue, mucous secretion
what controls the contraction of muscularis externa?
A meissner plexus
B auberach plexus
auerbachs plexus
Which epithelium cells are rounded, can slide across one another to allow stretching and are found in the bladder?
Transitional
Transitional epithelium transitions between collapsed and stretched when bladder empties and fills
where would simple epithelium be found vs. stratified (generally)
found on INSIDE as its thin and fragile but useful where diffusion is needed - absorption, diffusion.
stratified found on OUTSIDE where its exposed to chemical/mechanical stresses
What salivary glands secrete continuously A submandibular B minor C paratoid D sublingual
Minor salivary glands to keep the oral cavity moist!
> the others secreteON DEMAND
what are mesentries?
balls of visceral peritoneum that surround the intestine and help with regualr intestine folding
attatch other organs to the posterior wall of abdomen
> abdominal cavity lined with parietal peritoneum
what type of muscle is the tongue?
smooth
skeletal
cardiac
skeletal! as its under voluntary control!!
> intrinsic muscle extend and curve / extrinsic muscle makes it mobile
which part(s) of the large intestine have mesentries? Aascending trasnverse descending sigamoid colon
transverse and sigamoid have mesentries
> other don’t as they are ttatched to the rear abdominal wall
where is specialised oral mucosa found?
anterior 2/3 of tongue covered in ligual papille
which salivary gland has seromucous salivia A paratoid B submandibular C sublingual D minor
submadnibular as its a shorter duct
true or false?
the gut has its own intrinsic nervous system?
TRUE
this allows peristaltic control of the gut (enteric nervous system)
> plexus are branching network of nerves!
what does the stomach produce thats needed for vitamin b12 absoprtion
intrinsic factors!
true or false?
the small intestine is controlled by peristaslis only
FALSE
there is also segmentation + peristaslsis = intermitant churning
> controlled by myenteric/auerbach plexus nerve
why do we feel the need to poo?
as the rectum expands, the wall streches - stretch receptors
what is a disadvantage of ruminant digestion
> needs lots of water to chew and ruminate
> and lots of gas produced = warming
what can hydrochloric acid release be stimutaled by? Ghrelin, leptin and histamine Gastrin, insulin and histamine Ghrelin, insulin and histamine Gastrin, CCK and histamine Gastrin, acetylcholine and histamine
OPTION E
gastrin (from g cells), acetylcholine and histimine!
what sphichters are involved in the stomach?
cardia - slight control over
pylouric - autonomic control
which sphincter in anal canal is invlunatary?
internal or external?`
internal involuntary - relazes when pressure is high and made of SMOOTH MUSCLE
> external sphinchter is skeleltal muscle
Which of these is NOT a satiety signal? Insulin Glucagon-like-peptide-1. CCK. Ghrelin. Peptide YY (PYY).
Ghrelin is a hunger signal!. It is the only hormone released by the GI tract that works to INCREASE hunger.
> CCK is secreted in response to eating. It REDUCES appetite and inhibits eating (makes us feel full by acting on the hypothalamus).
GLP-1 and PeptideYY is released from the intestine in response to food injested, acts back in the brain to suppress eating. - ileal brake
insulin supress appetite
During the gastric phase, what does the neural negative feedback cause?
As the stretch receptors and chemoreceptors send impulses via the submucosal complex to stimulate peristalsis, food moves along. As food moves further away, the stimulus increases as distension lessens.
As the stretch receptors and chemoreceptors send impulses via the submucosal complex to stimulate peristalsis, food moves along. As food moves further away, the stimulus lessens as distension lessens.
As the stretch receptors ad chemoreceptors send impulses via the submucosal complex to stimulate peristalsis, food moves along. As food moves further away, the stimulus increases as distension increases
OPTION B
Distension and stimulus are proportional. As the distension is stimulating the stretch receptors and chemoreceptors, so when it decreases, the stimulus will also decrease.
as stomach swells, the FEEDBACK is to inhibit appetite = feel full
In the inhibitory part of the intestinal phase of gastric secretion, which hormones are secreted by G-cells lead to inhibited gastric secretion and inhibited gastric peristalsis and emptying?
Secretion of (CCK), gastric inhibitory peptide (GIP) and secretin from enteroendocrine (G) cells.
caused by:
- Detection of chyme in the duodenum by stretch receptors (detect distension).
- Detection of chyme in the duodenum by chemoreceptors (detect fatty acids and glucose).
what controls short term appetite GIP, CCK, leptin GLP-1, CCK, peptideYY GIP, CCK, secretin GLP-1, CCK, ghrelin
OPTION B
these act on the ‘ilealbrake’ to slow gastric emptying and supress appetite (satiety signal)
c- these inhibit gastric emptying
What is the job of Rugae in stomach?
Allow stomach to stretch without bursting
Increase surface area of stomach
reduction of solid food to semi solid chyme
absorption
OPTION A
name the 4 stomachs in ruminant animals
rumen - rumination, chewing, rechewing
recticulum - sort out particles
omasum - water + VFA absorb, regulate entry into abomasum
abomasum - true stomach`
recticulo-rumen - fermentation chamber, anaerobic
what is GIP
GIP is gastric inhibitory peptide, relaed by enteroendocrine cells in small intestine to inhibit gastric emptying/secretion as a protrctive mechanism
what cell secretes inctrinsic factor and Hcl?
parietal cells in the stomach do this!
intrinsic facotr needed for VB12 absorption
in ruminant organisms, there is an oesophagal groove. where is this and what it do?
in abomasum
it allows milk to pass straight to abomasum and AVOID FERMENTATION in neonatals when suckling
