Rat lab Flashcards
Rat teeth
- Grow throughout life
- lack enamel on their posterior surfaces
Gallbladder
absent in rats
Body cavities
- Peritoneum
- Two pleural (lung) cavities
- Pericardial (heart cavity)
Peritoneum cavity
- Membrane bonded to the abdominal wall
- surrounds the peritoneal cavity
- continuous with a double layer of the peritoneum (called mesentery) suspending the intestine
- further continuous with the peritoneum (called the visceral peritoneum) covering the intestines
Lungs
dark red and blood full due to death by CO2, normally bright pink in colour
What is the pleura?
the serous membrane that lines the lung
The anterior end (base) of the heart is overlapped by the two lobes of the ____ gland
thymus
The thymus gland produces:
- T-lymphocytes
- other lymphoid tissues
The heart is held in which cavity?
pericardial
Most contents of the abdominal cavity belong to the ___
gut
Name the three tubular portions of the gut
- esophagus
- small intestine
- large intestine
Name the two sacks in the gut
Stomach and caecum
In the gut system, secretion occurs in two large glands:
Liver and pancreas, which shed their secretions into the small intestine
Where does the stomach lie
Mostly to the left side
The esophagus travels from the throat through the ___ cavity, ___ to the heart and lungs
thoracic cavity
dorsal
Small intestine: main function
absorption of small molecules resulting from the digestion
Small intestine: parts
Starts after the stomach: duodenum -> jejunum -> ileum -> caecum
Pancreas
Releases an alkaline digestive juice containing enzymes (lipases, amylases, and proteases) into the duodenum
Liver
- largest gland in the body
- like pancreas functions as both endocrine and exocrine gland
- metabolic regulation
- bile salts aid digestion and absorption
- pancreatic ducts join to hepatic duct to discharge bile through a common duct into the duodenum
- receives venous blood from the gut wall and oxygenates blood from the aorta
Spleen
part of the lymphatic system where immune responses occur
Large intestine
- four parts: caecum, colon, rectum, and anus
- reabsorbs water and form feces
Caecum
- contains bacteria to break down cellulose
- terminates with the vermiform appendix
- between the ileocecal junction and ascending colon
Colon
- ascending, transverse, and descending parts
Rectum
the short passage leading to the anal outlet
Anus
Partial voluntary control:
- inner: involuntary
- outer: voluntary
Kidneys
- have adrenal glands (paired superior)
- hilus (inner curve)
- rich blood supply so dark red
adrenal glands
- small brown bodies near the anterior pole of both kidneys
- cortex: cortisol or other steroid hormones
- medulla, adrenalin
Urinary bladder (renal system)
- path of urine: kidney -> ureter -> bladder -> urethra
- pale cream or yellow in colour
- can expand to the size of a grape
The order that food passes through the gastrointestinal tract
esophagus stomach small intestine caecum colon rectum anus
The duodenum receives material from which three organs?
stomach, liver, and pancreas
The peritoneal, pleural and pericardial cavities of the rate share the following characteristics
- they allow internal organs to move without friction
- they are ventral in position (front of the body)
- they contain a small volume of fluid (serous fluid)
- they have visceral and parietal surfaces
When you start a dissection the first serous membrane you cut is the _____
parietal peritoneum
The livers ducts (_____ ducts) join the ____ intestine downstream of the _____ sphincter
hepatic
small
pyloric
The structure that prevents you from choking when eating is the ______
epiglottis
The liver receives venous blood from the gut wall via the ____ ____ ____.
Also receives oxygenated blood from the aorta via the ______ _____, a branch of the coeliac artery
hepatic portal vein
hepatic artery
_____ is for air and ______ is for food, and if coordination is lost during swallowing, food may enter the ___ which leads to violent coughing, or air may enter the ____ which leads to eructation (belching).
Trachea
esophagus
trachea
stomach
Name the two cavities that have organs within:
Abdominal and thoracic cavity
Name 4 ventral body cavities
- 2 pleural
- 1 peritoneum
- 1 pericardial
(all mesothelial membranes)
Location and function of the mesentery tissue
- connection between visceral and parietal peritoneum
- suspends the intestine and allows blood vessels (coeliac artery and superior mesenteric artery as well as the hapatic portal vein) to enter
Properties of serous membranes
- mesothelial cells (simple squamous) that secrete serous fluid
- inside, you have serous fluid
Organs not in the digestive system
spleen, lungs, heart, thymus, thyroid kidneys, adrenal glands, urinary bladder, reproductive organs
Structures found in humans but not in rates
- vermiform appendix
- sigmoid colon
- bulbous uterus
- gallbladder
- canine teeth
Two organs that secrete their products directly into the duodenum via a common duct
pancreas and liver
Where is bile produced in the rat?
liver
The function of the stomach: transparent region
food storage
greater curvature
The function of the stomach: pyloric/opaque region
glandular, for digestion
where does dehydration of digestive contents and reabsorption of water occur?
colon
Path of nutrient-rich blood as it leaves the small intestine?
Leaves the small intestine via the hepatic portal vein to the liver, and the liver is supplied by the hepatic artery aswell.
Path of oxygenated blood to the small intestine
Superior mesenteric artery and coeliac artery fan out through the mesentery into the small intestine
What’s chyme
partially digested food matter
How is the flow of chyme controlled?
Pyloric sphincter at the inferior (closer to the duodenum) end of the stomach controls flow of chyme
What parts of the GI tract are under partial voluntary control?
Outer part of the anal sphincter and the mouth
Location and function of epiglottis?
Epiglottis is a triangular flap of the trachea that prevents food entering it during swallowing (therefore, open during breathing and closed during swallowing)
It blocks the glottis, entrance to the trachea
What is the hepatic artery a branch of?
coeliac artery
Describe the position of the kidneys in relation to the peritoneum:
retroperitoneal
What gives rate incisors their curved chisel shape?
Lack of enamel on posterior surface
Number of teeth
4 incisors and 12 molars (3 on top and bottom of each side)
Location of the prepuce
between the 2nd and 3rd nipple
Where is the rat penis?
internal in abdominal wall when flaccid
The scientific name of the rat:
rattus norvegicus albinus
What is between the ileum and the caecum?
ileocecal junction
Describe the appearance of the mesentery:
fans out like spiderweb
Pancreatic secretions
Exocrine:
- Alkaline pH
- Lipases
- Proteases
- Amylases
Endocrine (hormones):
- insulin
- glucagon
Position of pancreas
inferior to greater curvature of stomach
Appearance of pancreas
- small lobules
- pink in colour
- leaf-like shape
What do bile salts break down?
Vitamins and fats
Order of ducts in rats
hepatic duct and pancreatic duct drain into the duodenum, just downstream of the pyloric sphincter
What does the liver look like?
largest organ
dark red
soft jelly-like texture
Appearance of spleen
dark red - high blood supply
leaf shape
