Lab 1: Rat dissection Flashcards
what are the main differences between the rat and humans?
rats lack gallbladder, lack vermiform appendix( have caecum), lack canine teeth
reproductive system: female rats’ uterus is “Y” shaped with 2 “arms” or horns in which embryos implant. In males, the penis is mostly WITHIN (Not outside) the abdominal wall.
where do absorption and secretion occur?
everywhere downstream of the oesophagus
where does the esophagus enter the stomach?
part-way along the lesser curvature
where does the esophagus enter the stomach?
part-way along the lesser curvature
what is the position of the esophagus in relation to the heart and lungs?
dorsal
what is the position of the translucent part of the rat’s stomach?
anterior and lateral
what is the function of the translucent part of the rat’s stomach?
food storage. Its lining resembles the esophagus with no glands and a protective stratified squamous epithelium.
does the human stomach have a transparent glandless portion like the one in the rat?
NO
what is the name of the opaque region of the stomach?
pyloric region
what is the position of the pyloric region?
medial and posterior
what is the function of the pyloric region of the stomach?
has numerous tubular glands that release acid and enzymes which break large molecules down into small ones- digestion
what is the name of the stomach outlet?
pyloric sphincter. A collar of smooth muscle which controls the flow of stomach contents (chyme) into the duodenum
what is the main function of the small intestine?
absorption of small molecules resulting from digestion
what are the 3 regions of the small intestine
DJ Ileum
Duodenum Jejunum and ileum
what are the arteries supplying the intestinal wall with oxygenated blood?
2 branches of the dorsal aorta: coeliac artery and superior mesenteric artery
what are the veins draining deoxygenated nutrient-laden blood from the wall of the small intestine?
tributaries of the hepatic portal vein which leads to liver( NOT directly back to the right heart as most systemic veins do)
what is the differences and similarities between human and rat pancreas?
in both humans and rats, the pancreas sits close to the greater curvature of the stomach, with the pancreatic duct extending from the medial end of the gland towards the duodenum
the rat pancreas is more diffuse than the human.
the pancreas is made of small scattered pink lobules suspended by mesentery.
what is the largest gland in the body?
liver
what organs are both exocrine and endocrine( “dual purpose”)?
liver and pancreas
what does bile contain?
mainly excretory products
how is bile delivered to the duodenum in the rat vs human?
RAT: the pancreatic ducts join the hepatic duct to discharge through a common duct into the duodenum
HUMAN: bile is stored in the gallbladder whose duct( cystic duct) joins the bile duct to discharge into the duodenum
what organ has a thin CT capsule and is very vulnerable?
liver
(spleen as well)
what organs have a rich blood supply?
spleen, liver, kidneys
what blood supply does the liver have?
dual
receives venous blood from the gut wall(via the hepatic portal vein)
also receives oxygenated blood from the aorta( via the hepatic artery, a branch of the coeliac artery)
what blood supply does the liver have?
dual
receives venous blood from the gut wall(via the hepatic portal vein)
also receives oxygenated blood from the aorta( via the hepatic artery, a branch of the coeliac artery)
what role does the pancreas play in the digestive system?
releases alkaline digestive juice containing enzymes( lipases, amylases, proteases) Aid digestion of proteins, fats, and carbs
is the spleen part of the digestive system?
NO
difference in the shape of the spleen in human vs rat?
human- more compact, fist-shaped
rat- leaf-shaped
Both sit in the same position beneath the greater curvature of the stomach on the extreme left side of the abdominal cavity
what are the 4 parts of the large intestine?
caecum, colon, rectum, and anus
the main function of the large intestine
reabsorption of water and formation of feces from undigested food residue. Resident bacteria contribute to the purification of this material. Faeces are retained in the rectum and voided periodically though the anus
caecum humans vs rats
flabby thin-walled bag within which the brown intestinal contents are easily seen. Here bacteria act on the gut contents while they are slow-moving. The human caecum terminates in a vermiform appendix, which contains lymphoid tissue BUT RATS LACK vermiform appendix
where are kidneys located?
dorsal wall of the abdominal cavity
why are kidneys said to be “retroperitoneal”?
“behind the peritoneum”
the ventral surface of each kidney is covered with the parietal peritoneum, the dorsal surface is attached to the body wall.
what is the colour of the urinary bladder?
pale cream or yellow
what is the position of the nasal passages in the rat?
in the head dorsal
what is the position of the trachea in the rat?
in the neck - ventral
position of epiglottis relative to the glottis
ventral
