Module 2 Lecture 1 Flashcards
What are the organs of the GI Tract?
Oral cavity • Pharynx • Oesophagus • Stomach • Small intestine • Large intestine
What is the GI tract?
The GI tract is a continuous 9-10cm tube from the mouth the to anus, it is made up of smooth muscle –> the GI tract pushed materials from one end to the other
What are accessory digestive organs?
Accessory digestive organs include the liver, gallbladder, pancreas and salivary glands
How many digestive functions are there?
6
Define Ingestion?
Acquisition of nutrients
Define digestion
Mechanical and chemical breakdown of
ingested food
Define propulsion
Movement of food through GI tract
peristalsis and segmentation
Define secretion
• Release of mucins, water, acid, and enzymes
into the lumen of the digestive system
Define absorption
Transport of nutrients from the digestive
system to the circulatory system
Define defecation
Elimination of feces
What is peristalsis?
Wave muscular contraction that occurs
throughout the GI tract (similar to pushing
toothpaste through the toothpaste tube)
What is segmentation?
Back-and-forth churning that occurs mainly in
the small intestine
What is the mucosa (label)?
inner lining of epithelium
What is the submucosa?
layer of connective tissue
with blood/lymph vessels/nerves
What is the muscularis
2 layers of smooth muscle
(except esophagus; skeletal and smooth
muscle, and stomach; 3 layers)
What is the tunica serosa?
outer
connective tissue covering organ
What is the Parietal peritoneum?
Lines inner surface of body wall; is
attached to abdominal and pelvic
walls; secretes peritoneal fluid and
stores fat`
What is the visceral peritoneum?
(wrapped around the organs
within the Intraperitoneal space)
What are mesentries
Folds of peritoneum that support
the intraperitoneal GI tract
organs; contain vessels, nerves,
and lymphatics
What is the peritoneum?
the serous membrane lining the cavity of the abdomen and covering the abdominal organs.
What are the intraperitoneal organs?
Organs that are suspended into the peritoneal cavity CONTAIN mesenteries, are referred to as
intraperitoneal organs, and are movable
What are retroperitoneal organs?
Organs that are NOT suspended into the peritoneal cavity LACK mesenteries, are referred to as
retroperitoneal organs, and are immobile (or fixed) e.g. pancreas, kidneys, duodenum, ascending
& descending colon of LI
SADPUCKER
Label the liver, stomach and the greater omentum
-
Label the peritoneal cavity
-
What do mesentries contain?
Mesentries contain blood and lymph vessels and nerves for the small intestine
What are vestibules?
Vestibules is the space bewteen the teeth and the lips
Label the tonsils
–
What are tonsils?
patches of lymphatic tissue found at the entrance of the pharynx
• protection against ingested and inhaled pathogens
What are the pharyngeal tonsil?
Pharyngeal tonsils are in the
posterior wall of the
nasopharynx
What are palatine tonsils
Palatine tonsils are in the
posterolateral region of the oral
cavity
What are lingual tonsils?
Lingual tonsils are along the
posterior one-third of the tongue
What is enamel?
white outer surface of tooth (only in crown), calcified surface that is stronger than bone
What are the three levels of the tooth?
Crown, Neck and Root
What is dentin
▪ Dentin: surface directly beneath enamel that is less calcified, similar to bone
What is pulp?
▪ Pulp: inner most part of the tooth, houses the nerve and blood supply to the tooth
What is the crown?
CROWN (externally visible covered by enamel), NECK (covered by gingiva, lacks enamel, not located in
alveolar bone), ROOT (housed in alveolar bone, different teeth have different numbers of roots)
Label the tongue
–
Functions of the tongue
aids in chewing, sensory analysis by touch, temperature and receptors, secretion of mucins and the enzyme lingual lipase that aids in breaking down the triglycerides
Functions of the salivary glands?
Lubricate the oral cavity & moisten food
- Dissolve chemicals that simulate the taste buds
- Anti-microbial substances
- -Parasympathetic innervation simulates salivary gland secretion
What is the parotid?
Parotid • Anteriorly to the ear • 25-30% of the saliva passes into the oral cavity via the parotid duct • Glossopharyngeal nerve (CN IX)
What is the sublingual
Sublingual
• Inferiorly to tongue and internal to oral mucosa
• 3-5% of saliva passes to the inferior surface of
the oral cavity via the sublingual ducts
• Facial nerve (CN VII)
What is the Submadibular?
Submandibular • Inferior to the mandible • 60-70% of the saliva passes to the floor of the mouth (lingual frenulum) via the submandibular duct • Facial nerve (CN VII)
Function of the temporalis
TMJ elevation (Jaw closing); retraction; side to side movements
Function of the Masseter
TMJ elevation (Jaw closing); protraction; side to side movements
Function of the medial pterygoid
TMJ elevation (Jaw closing); side to side movements
Function of the lateral pterygoid
TMJ depression (Jaw opening); protraction; side to side movements
What are the oropharynx and laryngopharynx made up of?
they are lined with nonkeratinized stratified squamous epithelium
What is the oesophagus?
hollow muscular tube connecting the pharynx to the stomach • 25cm long •Located within the mediastinum • posterior to trachea • medial to aorta • through esophageal hiatus • wall secretes a lubricant • skeletal & smooth muscle
Label the lower and the upper oesophageal sphincter
-
Stomach functions
➢ Storage of digestive food ➢Mechanical breakdown of ingested food ➢Chemical digestion via acids and enzymes (preliminary protein digestion) ➢Ingested food now called chyme (viscous, acidic, soupy mixture) ➢Protein digestion begins here
Label the stomach
-
What are rugae?
ugae are a series of ridges produced by folding of the wall of an organ. Most commonly rugae refers to the gastric rugae of the internal surface of the stomach.
Label the different mesenteries
-
What is the function of the lesser omentum?
▪ Lesser omentum attached at the lesser curvature – stabilises position of stomach
What is the function of the greater omentum?
▪Greater omentum attached at the greater curvature – its adipose tissue protects the abdomen
What is the lesser and greater omenta house?
Lesser & greater omenta house (or convey) the blood vessels & nerves of the stomach
What do unpaired organs get?
Unpaired organs get blood supply from unpaired blood vessels (celiac trunk, superior
& inferior mesenteric arteries)
What blood supply does the organs located ABOVE the transverse mesocolon?
Organs located above transverse mesocolon get blood supply from celiac trunk
What blood supply does the organs BELOW the transverse mesocolon?
▪ Organs located below transverse mesocolon get blood from mesenteric arteries
What blood supply doe the organs of the right side of the M.P?
▪ Organs located on the right side of the mesentery proper get blood supply from the
sup. mesenteric artery
What blood supply doe the organs of the left side of the M.P?
▪ Organs located on the left side of the mesentery proper get blood supply from inf.
mesenteric artery
What is the celiac trunk?
The celiac trunk is a branch of the abdominal aorta and supplies all organs (liver, stomach,
spleen) which are located intraperitoneally and above the transverse mesocolon
What is the function of the celiac trunk?
It supplies only superior parts of the pancreas and duodenum as both these organs are located
above and below the transverse mesocolon
What does the SUP mesenteric artery supply?
Supplies (right side of mesenterium):
- ascending & 2/3 transverse colon
- small intestine
- parts of pancreas and duodenum
What does the INF mesenteric artery supply?
Supplies (left side of mesenterium):
- 1/3 transverse, descending
and sigmoid colon
- upper parts of rectum
