Digestive System 1 Flashcards
What is conisisted within digestive system
-digestive tract
-accessory organs
what organs are consisted within the digestive tract.
-oral cavity
-pharynx
-eosophagus
-stomach
-small and large intestine
-amus
what organs are consisted within the accessory organs.
-primarily glands (secrete fluids into tract_
-salivary glands
-pancreas
-liver/gallbladder
-spleen
-teeth and tongue
state the 5 functions of the digsetive system
-food uptake
-mechanical processing
-digestion
-absoprtion of nutrients, minerals and water
-excretion
name some additional functions of the digestive system
-endocrine (eg. insulin, pancreas)
-immune (e.g. tonsils)
-detoxification
-storage nutrients (e.g. glucose) & regulation of their blood levels (liver)
name the 4 tunics of the anus
-mucosa
-submucosa
-muscularis
-serosa
describe the mucosa
-moist mucous epithelial membrane
-contains lymphoid tissue
describe the submucosa
-contains nerves, blood vessles and small glands
describe the muscularis
-lies in 2 planes
1.inner circular smooth muscle layer
2.outer longitudinal layer
-myernteric plexus between layers=nerves regulate movement & secretions
describe the serosa
-outer membrane
-called adventia over oesophagus
-inferior to diaphragm=visceral peritoneum
define peritoneum
serous membrane lining abdominal cavity & organs
state the function of Visceral peritoneum
covers the organs (serosa tunic)
define the function of parietal peritoneum
covers the interior surface of the body wall
state the fucntion of peritoneal cavity
between layers filled with serous fluid
state the fucntion of peritoneal cavity
between layers filled with serous fluid
peritoneum folds to make what?
folds to make mesenteries
unlike the pericardium, what does peritoneum have
lots of folds and extensions called=mesenteries
define mesenteries and its function
two layers of perironeum with thin layers of connective tissues between.
-holds organs to abdominal cavity
-routes by which vessels and nerves pass from body wall to organ
the name given to organs that lie against abdominal wall & have no mesenteries.
retroperitponeal
what organs are retroperitoneal
kidneys, rectum, bladder, accending and deceniding colon.
describe mesentery proper
associated with small intestine
describe transverse & sigmoid mesecolon
mesenteries of colon
describe messoappendix
mesentery of appendix
describe greater omentum
connects greater curvurture of stomach to transverse colon, lots of adipose and lymph
describe lesser omentum
connects lesser curvature of stomach & proximal duodenum to liver and diaphragm
define peritonitis
acute inflammation of peritoneal membranes, caused by rubbing together of inflamed peritonatal surfaces causes abdominal pain.
why is irritation caused in peritoneum
-escaped bile
-bacteria from external due to wound in abdominal wall
-ruptured appendix so bascteria enters peritoneum
define abdominal wall
boundaries of abdominal cavity (posterior, anterior, lateral)
list and describe the common layers of abdominal wall
deep-extraperitoneal fat, parietal peritoneum & fascia
more superficial-on anterior wall=layers of muscle
superficial-superficial fascia and skin
define a hernia
protrusion of an organ/fascia through wall of the cavity that normally contains it
when does a hernia often arise.
when pressure in the residing cavity is increased
where is the most comon location for a hernia to develop
-abdomen
discuss the formation of a hernia in the abdomen
-weakness in the abdominal wall evolves into a localized hole
-adipose tissue or abdominal orgnans with peritoneum can then protrude
describe a hiatal hernia
when stomach protrudes into mediastinum through oesophageal opening in diaphragm.
what are the symptoms of a hiatus hernia
-mostly no symptoms
-can cause pain from reflux gastric acid
why is a hiatus hernia often reffered to as the “great mimic”
symptoms can resemble many disorders
-e.g. dull pains in the chest, shortness of breathe & heart palputations
describe the oral cavity
-formed by cheeks, hard and soft palates & tongue
list the properties of the tongue
-forms floor of oral cavity
-chewing, swallowing and speech
strong skeletal muscle
-attatched posterior to hyoid bone, temporal bone and mandible
-free anteriorly
-attatched to floor via lingual frenulum
name and describe the muscles of the tongue
intrinisc muscle-no attatchment to bones, lie within tongue=tongue shape
extrinsic muscle-anchor tongue to surrounding bones=move tongue
what type of epithelium is found on the tongue
stratified squamous epithelium
what is the dorsum (upper surface) of tongue coverec in
papillae=projection of connective tissue (some contain taste buds)
where is lymphoid tissue embedded in the tongue
posterior surface=lingual tonsil
define mastication
‘chewing’
discuss the process of mastication
breaks food into smaller parts to increase surface area for digestion.
-incisors and canines bite/cut food off
-molar teeth grind food
describe mastication reflex
chewing stimulated by sensory receptors.
-signals from brain provide conscious control to initiate or stope chewing or change rate
4 pair muscles move mandible/jaw bone
describe the partoid.
largest, anterior to ear, serous, produce watery saliva
describe submandibular
below mandible, serous, mucus
describe sublingual gland
below tongue, smallets, mostly mucous glands
where are small glands also found
mucous membrane of oral cavity itself
define: lingual, palatine, buccal
lingual=in tongue
palatine=in palate
buccal=in cheeks
how much saliva is produced per day.
1-1.5L per day
-constitutively produced but productions increased when eats.
what is the function of saliva
-prevents bacterial infection
-lubrication
-contains amalayse-breaks down starch
-helps form bolus for swalloing
what contributes to salivary production
parasympathetic nerve input
describe MUMPS
-infection of salivary glands caused by mums virus
-common especially partoid glands.
-can occur on both sides
-no treatment normally
-vaccination available
-in adult males, tetestes can become infected reult in sterility
describe swallowing
involves distict phases moving food from mouth-pharynx-oesophagus
role of the pharynx in swallowing
(throat)-oro&laryngo, not nasopharynx
-food moves voluntarily from mouth to oropharynx
role of the epiglottis in swallowing
prevents food from entering larynx
list the properties of the oesophagus in swallowing
25cm long muscular tube
-transport food from pharynx to stomach
-collapsible
-anterior to vertebrae, posterior to trachea
-begins at the end of laryngopharynx
-passes through esophageal hiatus of diaphragm & ends at stomach
-thick wall with 4 tunics
-sphincters at upper and lower end
-mucousa is moist stratified squamous epithelium
name the 3 phases of swallowing
-voluntary
-pharyngeal
-esophageal
describe voluntary
-bolus of food moved by tongue from oral cavity-pharynx
describe pharyngeal and its role in swallowing
-reflex/involuntary, controlled by swallowing, center in medulla oblongata.
1.soft palate elevates
2.eppiglotits tips posterior
3.prevents food passing into larynx
4.pharyngeal conscrictors successive contraction from sup-inferior
5.upper esophageal sphincter relaxes
6.elevated pharynx open eosophagus
7.food pushed into eopsophagus
describe esophageal and its role in swallowing
reflex, moves into stomach.
1.peristalic contractions
2.lower oesophageal sphinciter relaxed
3.food enters stoamch
name the diseases common in the digestive system
heartburn
vomiting
describe heartburn and how it can be treated
=lower oesophageal sphincter fails to close after food enters stomach, so stomach contents can go back up oesophagus.
-acid from the stomach can irritate esophagus and cause burning senstation
-treat with antacids to neuteralise acids
-heartburn less problematic if eat smaller amounts and dont lie down after
describe vommiting and the processes during it.
=forcible expulsion of stomach contents through mouth
-stimulated by irritation & distension of stomach
-stomach, diaphragm & abdominal walls all contract, oesophagel sphincter open.
-can lead ti disturbed fluid balanced if prolonged
describe propertes of the stomach
-enlarged segment of digestive tract
-connecs oesophagus and small intestine
-shapes and sizes varies between people.
-within people between meals
where does the stomach move food into
-the small intestine at small intervals after eaten .
discuss the absorption in the stomach after eating.
-there are very little absorption of nutrients.
(glucose and some drugs can be absorped though)
discuss the opening of the stomach
-gastroesophageal (cardiac)- from eosophagus through cardiac sphincter
-pyloric- to duodenum through pyloric sphincter
list and describe the parts of the stomach
cardiac-near oesophageal opening
fundus-letf tand superior to cardiac
body-largesr part, turns to the right
pyloric-narrow: antrum wider than canal, opens to SI through pyloric sphincter
list and describe the greater and less curvurture of stomach.
-created by curving of stomach
-attatchment of omenta peritoneum
what is the dorsal mesentery of stomach
greater omentum
name and describe the layers/structure of stomach
layers (outer-inner)
serosa-visceral peritoneum
muscularsis-three layers
submucousa & mucousa-folded into rugae when stomach empty, allow stomach lining to stretch
CONTAINS GASTRIC PITS
