GIT Flashcards
Another name for GIT is?
Digestive system or alimentary canal
List the Parts of the GIT?
- Mouth
- Oesophagus
- Pharynx
- Stomach
- Small intestine
- Large intestine
Examples of accessory organs to the GIT?
- Liver
- Tongue
- Salivary glands
- Pancreas
- Gall bladder
Semi liquid food in the stomach is known as?
Chyme
Another word for swallowing is?
Deglutition
What channels are responsible for action potential in the GIT?
Calcium-Sodium channels
The parotid glands are responsible for?
Secretion of saliva
The walls of the GIT is composed of
- Mucosa
- Sub-mucosa
- Muscularis externa
- Serosa / Adventitia
The muscularis externa comprises?
Inner circular muscle
Outer longitudinal muscle
The gut is composed of different layers of what muscle?
Smooth muscles
What is the Meissner plexus
It is located in the submucosa
It is a network of nerves that transmit stimuli to the CNS through sympathetic and parasympathetic pathways
Which organ is a house for useful bacteria in the body?
The appendix
A single cell containing multiple nuclei is called?
Synctium
The interstitial cells of cajal are?
The electrical pacemakers for smooth muscle cells
Electrical activities in the body is characterised by?
Slow waves, and
Spikes (excite muscle contraction)
The resting membrane potential in the GIT is?
-56mv
Mention some Factors that depolarise the membrane?
- Stretching of the muscles
- Hormonal secretions, specific to the GIT.
- Stimulation by acetylcholine
- Stimulation by parasympathetic nerves that secrete acetylcholine
Mention some factors that can hyperpolarise the GIT
- Effect of norepinephrine or epinephrine
- Stimulation of sympathetic nerves that secrete norepinephrine
When a membrane is depolarised, the membrane is?
Highly excitable
When a membrane is hyperpolarised, it is?
Less excitable
What causes contraction in smooth muscles?
Ca+ ions
Asides the parotid gland, what are other glands involved in saliva secretion.
- Submaxillary
- Sublingual
- Small buccal glands
What sphincter is responsible for controlling the emptying of the stomach into the duodenum?
The pyloric sphincter
What is the pH of saliva?
6.0-7.0
What is the daily amount of saliva secreted?
800ml - 1500ml
Average of 1000ml
What is the pH of gastric juices?
1.0 - 3.5 (very acidic)
What is the pH of pancreatic juices!?
8.0 - 8.3 (slightly alkaline)
The volume of bile juices is
1000ml
The pH of bile juices is
7.8
What is the volume and pH of secretions of the small intestine?
Volume: 1800ml
pH: 7.5 - 8.0
The pH of the Brunner gland is?
8.0-8.9
The volume and pH of secretions of the Large intestine?
Volume: 200ml
pH: 7.5-8.0
The volume of the total daily secretions of the entire GIT is?
6700ml
The saliva is composed of?
Water, digestive enzymes, mucin, kallikrein, lysozyme, uric acid and inorganic constituents
Examples of digestive enzymes in the saliva?
- Ptyalin
- Lingual lipase
The inorganic constituents of saliva include?
Bicarbonate ion, Cl-, PO-⁴ , Na+, K+, Ca²+ , Mg²+, NH⁴+
What are the functions of the saliva?
- It maintains healthy oral tissues
- It aids carrying of food particles and pathogenic bacteria
- It contains enzymes and lysosome that attack bacteria
- It prevents dental caries
A greenish-brown alkaline fluid secreted by the liver, which aids emulsification of fats is known as
Bile
An orange-yellow pigment formed from the breakdown of haemoglobin is called?
Bilerubin
Glands that secrete substances directly into the blood are called?
Endocrine glands
Glands that secrete substances through a duct opening on an external or internal surface of the body are known as?
Exocrine glands
What is hemolysis?
The breakdown of RBC’s
The specialised cells in the liver that destroy bacteria, foreign protein and worn out blood cells are called?
Kupffer cells
The internal hollow of a vessel or GI tract is called?
The Lumen
WBC’s that destroy invading micro organisms are?
Macrophages
What is PPN?
Partial Parental Nutrition
It contains all essential nutrients administered intravenously to supplement other means of nutrition
The contraction and relaxation of the oesophagus ia known as?
Peristalsis
The absence of HCl in the stomach is known as?
Achlorhydria
The bile is stored and concentrated in what organ?
The gall bladder
The 3 major sources of carbonhydrates are?
- Sucrose (from sugar cane)
- Lactose (from milk)
- Starch (from grain and most non-animal foods)
The basic enzyme for protein digestion in the stomach is?
Pepsin
The stages of protein digestion follows what pathway?
Protein- Peptone- Polypeptide- Amino acids
After deamination, protein is excreted as?
Urea in the urine
What emulsify fats in the body?
Bile and Lecithin
What are the functions of the GIT?
Transportation, Digestion and absorption of food
The epithelium found in the mouth is?
Stratified squamous epithelium
The gastro-oesophageal or cardiac sphincter prevents?
Reflux of gastric contents
Abnormal number of platelets in the body is known as?
Thrombocytopenia
Total Parental Nutrition is popularly known as?
DRIP.
It contains dextrose and amino acids
What is the effect of parasympathetic nervous system on digestion
It promotes digestion
What is the effect of the sympathetic nervous system on digestion?
It inhibits digestion
The parasympathetic nervous system regulates activities occurring when the body is?
At rest.
Examples; salivation, digestion, and defecation
The sympathetic nervous system regulates activities occurring when the body is?
Fight or flight mode
Pain in swallowing is also known as?
Dysphagia
The sphincter of oddi is located at?
The duodenum
Endocrine functions of the pancreas include production of what hormones?
- Insulin
- Glucagon
- Somatostatin
The exocrine functions of the pancreas include?
Secretion of digestive enzymes and bicarbonate
What body organs is both endocrine and exocrine?
The pancreas
Mention the functions of the liver
- Phagocytosis
- Detoxification of hormones
- Production of all vitamin K dependent factors
- Kuppfer cells aid Immunity
- Metabolism of carbohydrates
- Metabolism of protein
- Production of bile
- Synthesis of blood clotting factors
- Conjugation of bilerubin
The cells of the liver, responsible for filtration of blood are called?
Kuppfer cells
Blood supply to the liver is through?
Portal vein and Hepatic artery
The functional unit of the liver is?
Lobule or acinus
Which body organ is fully regenerative
The liver.
Any part that is cut out, grows back again
Bile is composed of?
- Water
- Bile salts
- Bile pigment
Bile pigment consist of what constituents
- Bilerubin
- Cholesterol
- Phospholipids
The gall bladder is innervated by?
- Splanchnic nerve
- Right branch of vagus nerve
Blood supply to the gall bladder is through
- Cystic artery
- Hepatic artery
The enzyme responsible for contraction of the gall bladder?
Cholecystokin (CCK)
Surgical removal of the gall bladder is known as?
Cholecystectomy
A pear shaped sac-like organ, attached to the liver is known as?
Gall bladder
The functions of the large intestine are?
- Absorption of K, Na, Cl ions
- Production of mucus which lubricates the intestinal wall and holds produced faeces together during excretion
The part of the colon In between the descending colon and rectum is called?
Sigmoid colon
The large intestine is divided into 4. Name them!
- Ascending colon
- Transverse colon
- Descending colon
- Sigmoid colon
The origin and termination of the large intestine is at?
Origin: ileum
End: rectum
Blood supply to the small intestine is through?
- Celiac artery
- Superior mesenteric artery
Innervation of the small intestine and what organ are the same?
The stomach
Mention the enzymes in the small intestine
- Lipase
- Amylase
- Maltase
- Lactase
- Sucrase
- Somatostatin
- Serotonin
- Enterokinase
- Enterogastrone
- Cholecystokin
- Gastric Inhibitory polypeptide (GIP)
- Vasoactive Intestinal peptide (VIP)
Daily, the small intestine absorbs what amount of water?
8000ml
Absorption of vitamins, nutrients and electrolytes take place in the?
Small intestine
Duodenum, jejenum, ileum are parts of what body organ?
The small intestine
Innervation to the stomach occurs through?
- Intrinsic innervation via Meissner plexus & mesenteric plexus
- Extrinsic Innervation via parasympathetic and sympathetic nerves e.g vagus nerve
Blood supply to the stomach is through?
- Splenic artery
- Gastro duodenal artery
- Right and left gastric artery
Examples of cells in the stomach?
- Goblet cells (secretes mucus)
- Parietal cells (secretes HCl)
- Cheif cells (secrete pesinogen)
- G-cells (secrete gastrin)
________ plexus controls the outer activities of the GIT
Myenteric
____ plexus controls the inner activities of the GIT
Submucosal (Meissner)
Under normal conditions in saliva secretion ___ and ___ ions are easily absorbed
K and HCO³
Under hypersalivation in saliva secretion ___ and ___ ions are easily absorbed
Na & Cl
Accumulation of food in the oesophagus due to stiffening of the oesophageal sphincter is called?
Achalasia
When the oesophageal sphincter becomes weak and easily allows the reflux of food, it is called?
Chalasia
The muscle of the stomach responsible for churning of food in the stomach is known as?
Rugae