Class Notes (1,100,000)
CA (620,000)
UOttawa (30,000)
BIO (3,000)
BIO 2135 (100)
Lecture 18

BIO 2135 Lecture Notes - Lecture 18: Neural Tube, Cecum, Tunicate


Department
Biology
Course Code
BIO 2135
Professor
Jon Houseman
Lecture
18

This preview shows half of the first page. to view the full 3 pages of the document.
Animal innovations (symplesiomorphies)
- Pharyngeal gill slits
- Dorsal hollow nerve cord
Hemichordata
Autapomorphies
- Stomochord proboscis complex
- Glomerulus
Protocoel (proboscis)
Mesocoel (collar)
Metacoel (branchiogenital trunk, hepatic trunk, intestinal trunk)
- They have a pumping heart → pumps blood AND squeezes the blood vessel that sits on
top of the stomochord)
- Heart rolls on the blood vessel, almost peristaltically, projects the blood forward
- Puts blood pressure, forces liquid component through the walls of the blood vessels →
filtrated by pressure
Glomerulus: a region with high blood pressure, sends a filtrate to a thin wall, where some can
exit
Feeding
- Proboscis is covered with cilia
- Propels particulate material back towards the preoral ciliary organ → sorts food
externally → rejects inappropriate food particles, consolidates a mucus string with
appropriate food, propels it into the digestive tract
- Cilia create water current that pulls in the mucus, then the water exits out the gills
Chordata
Autapomorphies
- Neurotube-notochord-mesoderm complex
- Pharyngeal slits and endostyle
- Post-anal tail and tadpole-like swimming
You're Reading a Preview

Unlock to view full version