Practical lab 4 Flashcards
Phylum Chordata defining features
- Nerve cord
- Notochord
- Presence of pharyngeal pouches
- gland or a tissue that concentrates I2
- post anal tail
lateral line system
modified scales that run from the operculum to the tail and serve to detect vibrations of low frequency in water
homologous features in the perches and the tetrapods
fins and the presence of paired appendages in tetrapods
axial muscles
longitudinal axis of the body
appendicular
associated with the appendicular skeleton i.e. limbs etc
the prominent muscles in the perch ?
axial
Myomere
zig zag patterned muscles that looks like a large W
horizontal septum
Divides the myomers into the dorsal and ventral myomeres
What is the function of the Gastrointestinal tract in perches?
it starts at the mouth and empties in the cloaca or the external environment via anus.
ingestion, digestion, absorption and the elimination of undigested food
caecum
junction of the small and the large intestine where the food would be held and processed by the microorganisms.
esophagus in perches
a short and straight tube leading from the orophraynx to the stomach
pyloric caeca
found at the junction of the intestine and the stomach.
they serve as secretory and absorptive functions
what does the length of the perch’s intestine indicate?
that its carnivorous and has a shorter intestine than the herbivores
description of pancreas in perches
light orange diffused mass of tissue that is found along the ventral border of the intestine
what is the main function of spleen in perches
production and maintenance of the blood cells
function of kidney in chordates
- eliminate nitrogenous waste
- maintaining the salt and water levels of the body
- maintain the pH and the sugar levels in the body
holobranchs
gills with double sets of filaments
how do perches perform gaseous exchange.
- water is constantly drawn into the mouth then into the pharynx while the opercula is closed.
- valves in the mouth are closed so the water is forced to pass through the gill rakers, then through the gill slits, over to the gill filaments and then behind the posterior free ends of the opercula which is now opened.
- as the water passes through the gill filaments the gaseous exchange takes place.
- counter current flow
counter current flow
the arrangement of the calipers are in such a way that the blood flows in the opposite direction to the flow of water in the gills to maximize the movement of O2 in the blood
other function of gills other than their respiratory function
excretory function, gills are used over kidneys
Circulatory system in perches
typical low pressure single type system, only the pumping of the deoxygenated blood
transverse septum
a heavy membrane separating the pericardial and the abdominal cavities
Sinus venosus
- receives blood from the common cardinal veins and hepatic sinus.
- opens directly into the atrium
equivalent structure to atrium in higher vertebrates
atria
locomotion in rats
digitigrade
Name the three salivary glands in a rat
- parotid gland
- submaxillary gland
- sublingual gland
Tear producing gland in rats
extraorbital lacrimal gland
name the teeth that rats dont possess
canines and premolars
and as herbivores their teeth continue to grow throughout their life time
viscera
it is found within the body cavity i.e. coelom.
the internal organs are suspended here
pertioneum
membranous tissue formed from the mesoderm
lesser omentum
membrane that joins the lesser curvature of the stomach to the liver
greater omentum
double walled peritoneal sac which extends from the greater curvature of the stomach to the spleen
three areas of the stomach
- cardiac portion (entrance from the esophagus)
- fundic portion
- pyloric portion
rugae
folds on the walls of the stomach
three regions of the small intestine
- duodenum - receives ducts from the digestive glands.
- jejunum
- ileum
spleen
spleen along with liver remove old RBCs from circulation and break them down
