Labs Flashcards
(187 cards)
Rats - teeth
Dentition adapted for gnawing Paired incisors grow throughout life and lack enamel on their posterior surfaces --> rapidly wears --> characteristic chisel-shape Lower jaw (mandible) is in 2 pieces, hinged in the middle Space between incisors can be varied at will
Rats - gall bladder
Absent in rats
Rats - reproductive system vs in humans
Rats:
Female - uterus is Y-shaped
Male - penis mostly within abdominal wall
Humans:
Female - uterus is pear-shaped
Rats - nostrils/nares
May be closed under water
Rats - identifying male vs female
Male:
Scrotum (which contains testes) will be seen near anus
Anterior to scrotum is prepuce (skin fold concealing glans of penis)
Flaccid penis contained within abdominal wall
Female:
Three openings - anus, vaginal opening, urethral opening
Rats - thymus gland is _____ to the heart
Anterior
Rats - when making the first cut and you hit resistance, what have you reached
The diaphragm
Exposes abdominal cavity - not thoraric cavity, which lies anterior to diaphragm and beneath rib cage
Rats - peritoneum
A wet, slippery, thin membrane bonded to the abdominal wall
Surrounds the peritoneal cavity
Rats - Parietal peritoneum, visceral peritoneum and mesentery
Parietal peritoneum (lining abdominal wall) continuous with mesentery (double layer of peritoneum suspending intestine), further continuous with visceral peritoneum (covering intestine)
Rats - ventral cavities
Two pleural cavities (lung)
Pericardial cavity (heart
Peritoneal cavity
Humans vs rats - pericardium
Much thicker, stronger and fibrous in humans
Rats - What are organs wrapped in?
Serous membrane
Rats - Serous fluid
Allows organs to move over each other easily
Rats - parietal vs visceral peritoneum
Parietal: attached to skin
Visceral: attached to organs
Humans - order of digestion
Oesophagus (tube) Stomach (bag) Small intestine (tube) Caecum (bag) Sigmoid colon (tube)
Rats - liver
Large gland
Has both exocrine and endocrine functions
Highly vascularised
Rats - lung colour
Since killed humanely with CO2(g), lungs will appear dark red and blood-filled (haemorrhage)
Normally is a bright pink colour and spongy texture
Rats - heart
Anterior end (‘base’) is overlapped by 2 lobes of the thymus gland
Rats - why is the gut tube convoluted
So it is long, to gain increased SA for absorption and secretion
Rats: Gut - portions
3 tubular portions: oesophagus, small intestine, large intestine
2 sacs: stomach and caecum
Rats: Where do absorption and secretion occur in gut
Everywhere downstream of oesophagus
Secretion occurs in 2 large glands (liver and pancreas) which are derived embryologically from gut lining and shed their secretions into small intestine
Humans and rats: Where is the stomach located
Lies mostly on the left side
Rats: Stomach - greater and lesser curvature
Oesophagus enters part-way along the lesser curvature (from throat through thoraric cavity, dorsal to heart and lungs, to diaphragm)
Rats: Lining of stomach
Divided into 2 distinct types
Anterior and lateral portion:
Has a thin and translucent wall so gut contents often visible
Specialised for food storage
Lining resembles that of oesophagus - no glands and a protective stratified squamous epithelium
Human stomach doesn’t have such a glandless portion compared to rat
Pyloric region (medial and posterior): Glandular and opaque Numerous simple tubular glands release acids and enzymes which break large molecules down (digestion)