Muscles involved in opening and closing of mouth Flashcards Preview

Comparative Vertebrate Anatomy > Muscles involved in opening and closing of mouth > Flashcards

Flashcards in Muscles involved in opening and closing of mouth Deck (28):
1

Shark opening muscles

levator hyomandibulae, epaxial, coracomandibularis, rectus cervicis, hypaxial

2

Levator hyomandibulae

moves hyomandibula dorsally

3

Epaxial

moves cranium caudally

4

Coracomandibularis

moves meckel's cartilage caudally

5

Rectus cervicis

moves hyoid arch cardally

6

Hypaxial

stabilizes coracoid or pectoral girdle

7

Palatoquadrate movement during opening

moves ventrally because it's not fused to the skull and the hyomandibular is pulled dorsally

8

Shark closing muscles

levator palatoquadrati, preorbitalis, interhyoideus, intermandibularis, adductor mandibulae

9

Levator palatoquadrati

moves palatoquadrate towards chondrocranium

10

Preorbitalis

moves meckel's cartilage towards orbits of chondrocranium

11

Adductor mandibulae

moves meckel's cartilage towards base of chondrocranium

12

Interhyoideus and intermandibularis

moves hyoid towards meckel's cartilage

13

Salamander opening muscles

depressor mandibulae, geniohyoideus, epaxial, sternohyoideus (rectus cervicis), hypaxial

14

Depressor mandibulae

unique to amphibians and opening can occur without the need of the depressor, moves the back of lower jaw towards skull

15

Sternohyoideus within salamander

moves the hyoid caudally

16

Salamander closing muscles

geniohyoideus, adductor mandibulae

17

Geniohyoideus of salamander

connects the mandible to the hyoid arch and is involved in both opening and closing. during opening the hyoid is moved caudally so geniohyoideus contracts and the lower jaw is also brought down/caudally. during closing the hyoid is stable so when geniohyoideus contracts the lower jaw is closed and pulled forward

18

Mammal opening phases

slow then fast

19

Mammal closing phases

fast then slow

20

Mammal slow opening muscles

geniohyoideus, anterior digastric, posterior digastric, masseter and pterygoid

21

Mammal fast opening muscles

geniohyoideus, anterior digastric, sternohyoideus, posterior digastric

22

Masseter and pterygoid

stabilizes the jaw joint to allow the mouth to be slightly open

23

Sternohyoideus of mammal

will pull back on the taught lower jaw

24

Posterior digastric, anterior digastric and geniohyoideus

constricts and stabilizes lower jaw to make it taught

25

Mammal slow closing muscles

posterior digastric, sternohyoideus, masseter, pterygoid, temporalis

26

Mammal fast closing muscles

posterior digastric, sternohyoideus, masseter, pterygoid, temporalis

27

Posterior digastric

will stabilize the hinge of the back of the jaw during fast closing and will stabilize the hyoid during slow closing

28

Sternohyoideus within mammal

will pull the lower jaw backwards during fast closing and pull the hyoid to its original resting position during slow closing