Quiz during Week 9 over the shark and mudpuppy viscera, and a written portion over that day's material.
If you are a graduating senior, be sure to mention this to your T.A. if you haven't already done so, and discuss the scheduling of your final.
In the shark, as in the cat, you will need to be able to trace the flow of blood from the heart to any organ and back again, so start paying attention to which blood vessels branch off each other and where they all lead.
During this lab, pay attention to the blood
flow through the heart, and learn the differences between the fetal and
adult hearts. Keep in mind that the fetus does not have to circulate blood through the lungs in order to pick up oxygen....
Lab sections on Wednesday and Thursday of Week 10 will be open labs for review. This is your chance to look over everything one more time, so bring along any questions over the material that you may have, and be sure you've seen anything you were previously unclear on.
As in the cat, the shark arteries are injected red,
but most of the veins are uninjected, appearing at best as a dark shadow under
the skin. The exception is the Hepatic Portal System, which is injected yellow.
The shark circulatory system is essentially a
simplified version of the cat's. A few differences that can be confusing: where in
the cat the Celiac Artery splits into 3 branches, in the shark it splits into 2
(one of which, the Gastrohepatic Artery, almost immediately re-splits into the
Gastric and Hepatic Arteries). 3 branches in the shark, rather than 2 in the cat,
come together into the Hepatic Portal Vein.
Note that the Dorsal Aorta and the Ventral Aorta in the shark are not the same vessel! They don't directly connect to one another at all.
For the shark blood vessels going to the gills,
remember that the Afferent Branchial Arteries (with an A) carry the
blood away from the heart, and are also in the part of the shark's jaw
(lower) that you'll be pulling away from the rest of the head. That
leaves the Efferent Branchial Arteries (with an E) to carry the blood back
towards the rest of the body, combining into the Dorsal Aorta. The mudpuppy has the same system.
None of the blood vessels in the mudpuppy are injected. We will only expect you to find the large, more obvious structures, and to know the circulation through the gills, as it's basically the same as for the shark.
Compare the shark, mudpuppy, and cat viscera, heart,
circulation, and respiration. The mudpuppy is essentially a combination of cat and
shark features; if you know the cat and shark, you pretty-much know the mudpuppy.
However, keep in mind where the similarities beween the 3 species are, and where they differ. For instance, if you're familiar with the cat and shark's digestive system by now, the mudpuppy will look very familiar. Note that the kidney structure is very similar to the shark rather than the cat. The cat/pig has a 4-chambered heart (2 atria, 2 ventricles), the mudpuppy has a 3-chambered heart (2 atria, 1 ventricle), and the shark has a
2-chambered heart (1 atrium, 1 ventricle). The cat respires via lungs, the shark via gills, and the mudpuppy in three different ways - mostly taking in oxygen through its skin, then through the gills, and finally through lungs as a last resort.
Nothing directly to do with the course ... this section will have an occasionally-changing recommendation for books of general scientific interest - guided by the whimsy of the web-site maintainer, of course. :) This week's pick is:
Health and Light: The Effects of Natural and Artificial Light on Man and Other Living Things by John N. Ott
(The effects of full-spectrum light - including ultraviolet - on the well-being of organisms from plants to humans to other animals. Very interesting counterpoint to the prevalence of "UV rays are deadly" thinking that is so common currently.)
