Branchiostoma Flashcards Preview

Comparative Vertebrate Anatomy > Branchiostoma > Flashcards

Flashcards in Branchiostoma Deck (31):
1

v shaped muscle fibres

Myomeres

2

divisions between myomeres

myosepta

3

reproductive organs, located posteroventrally

gonads

4

external portion of feeding apparatus

oral hood

5

slender tentacles that fringe opening of oral hood

oral cirri

6

chamber into which water and suspended food particles first enter the amphioxus feeding apparatus

buccal cavity

7

entrance into the buccal cavity, located anteroventrally

inhalant aperture

8

smaller opening within velum

mouth

9

demarcates oral cavity from pharynx

velum

10

extends along dorsal surface of body

dorsal fin

11

filled by a gel-like substance, supports dorsal fin

fin ray boxes

12

lies along, approximately, the posterior quarter of the ventral surface

ventral fin

13

extends anteriorly from the dorsal fin and wraps around the rostrum

rostral fin

14

expansion of dorsal and ventral fin extensions into the postanal tail

caudal fin

15

ventrolateral fins extending anteriorly from the ventral fin almost to the anterior end of the body

metapleural folds

16

the exit of the atrium, lies just in front of the ventral fin

atriopore

17

exit of the digestive tract, opens ventrally just posterior to the ventral fin

anus

18

midventral groove extending longitudinally along the floor of the pharynx

endostyle

19

middorsal groove, extends longitudinally dorsally along the pharynx

epibranchial groove

20

extends from the tip of the rostrum into the tip of the tail, it has a striated appearance and lies just dorsal to the pharynx anteriorly and the digestive tract

notochord

21

lies dorsal to the notochord and extends almost as far anteriorly and posteriorly, for most of its length it is about a third as thick as the notochord

dorsal hollow nerve cord

22

dark, at the anterior end of the nerve cord

frontal eye

23

photoreceptors that appear as dark granules along the ventral part of the nerve cord

Hesse ocelli

24

a series longitudinal finger-like bands that are united posteriorly to form an organ

wheel organ

25

fringe the margin of the mouth

velar tentacles

26

second chamber water enters, after passing through pharyngeal slits

atrium

27

initial part of the postpharyngeal gut

esophagus

28

expanded region directly following esophagus

midgut

29

evagination of the ventral floor of the midgut to form a diverticulum

hepatic cecum

30

posterior to the diverticulum the midgut narrows gradually into its posterior portion, an easily recognizable dark band

iliocolon

31

a fairly straight, narrow tube that leads to the anus

hindgut