Rat Practical: Internal Organs Flashcards
*Submaxillary salivary gland
appearance: roughly oval, large, elongate
function: secrete saliva that lubricates food and contains amylase
*Thyroid gland
appearance: two lobes of gray or brown swelling on either side of the trachea; lays beneath the sternohyoid muscles
function: secretes thyroxin that regulates the metabolic rate of the body. The two lobes are connected by a narrow band of tissue known as the isthmus of the thyroid.
*Trachea
appearance: composed of a series of incomplete rings of cartilage forming a tube.
function: conducts air to and from the lungs
*Esophagus
location: pierces the diaphragm
function: conducts food from the mouth to a muscular enlargement of the digestive tract (called the stomach)
*Thymus gland
location: lies directly over the upper part of the heart
function: functions in the developing immune system and is larger in young rats than in old rats.
*Right/Left atrium
function: receives blood from the veins
*Ventricles
function: pumping chambers of the heart
*Diaphragm
function: thin layer of muscle, separates the thoracic cavity from the abdominal cavity.
Normal contraction of the diaphragm helps breathing and avoid abnormal twitching
*Right/Left lungs
function: where air enters from the bronchial tubes branching from the trachea
alveoli
function: thin-walled air sacs where gas exchange occurs
coelom
body cavity where viscera is suspended
viscera
internal organs
peritoneum:
what is it? In what 4 regions does it occur?
membranous tissue that covers the abdominal cavity and viscera; occurs in 4 regions:
- parietal peritoneum
- visceral peritoneum
- mesenteries
- Omentia
Parietal peritoneum
covers the walls of the abdominal cavity
visceral peritoneum
covers the internal organs
mesenteries
thin membranes continuous between the parietal and viscera peritoneum. They attach the internal organs to the dorsal body wall.
omentia
are thin membranes extending from the visceral peritoneums and connect organ to organ.
*Liver
location/appearance: dark-colored organ suspended just under the diaphragm.
functions:
- produces bile to help digeszt fat
- storing glycogen
- transforming nitrogenous wastes into less harmful substances
- transforming digested nutrients into various molecules needed for the body
What are the four parts of the liver?
- Median/ cystic lobe
- Left lateral lobe
- Right lateral lobe
- Caudate lobe
Median/cystic lobe
located atop the organ. There is a cleft in its central part.
Right lateral lobe
is partially divided into an anterior and posterior lobule, is smaller than the left lateral lobe
Caudate lobe
is small, folds around the esophagus and stomach, and appears to be in two small sections seen most easily when the liver is raised.
*Stomach
location: left side just under the diaphragm
function:
- food storage
- physical breakdown of food
- initial enzymatic digestion of protein
cardiac sphincter
entrance of the esophagus to the stomach
pyloric sphincter
attachment of stomach to intestines
*spleen
location: attached to the greater curvature of the stomach
function: formation, storage, and destruction of blood cells.
pancreas
- produces digestive enzymes conducted to the intestinal tract through small ducts.
- secretes and releases insulin into the bloodstream to regulate glucose metabolism.
