Axial skeleton Flashcards Preview

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Flashcards in Axial skeleton Deck (49):
1

Centra type: Chondrichthyes

Amphicoelous

2

Procoelous vertebrae (def)

Anterior: concave
Posterior: convex
Entire centrum solid with cartilaginous intervertebral disks

3

What structure carries blood vessels to the head through the cervical vertebra(e)?

Transverse foramen

4

Describe vertebrae of gnathostomes, generally (compared to early vertebrates & agnathans)

Vertebrae are main axial support, attachment site for body muscles

5

Amphicoelous vertebrae (def)

Centra concave on both ends, surrounds notochord from head to tail

6

Effect of neural spine angle on function

Grow to better withstand forces by making them compressive

7

Describe agnathan ribs

Non-existent

8

Form & function of ribs in gnathostomes

Cartilage/replacement bone struts
Muscle attachment, protect viscera

9

Opisthocoelous vertebrae (def)

Anterior: convex
Posterior: concave
Centrum solid, with cartilaginous intervertebral disks

10

Who has lots of cervical vertebrae & why?

Aves, parareptilia -> allows greater flexibility

11

Centra type: Osteichthyes

Amphicoelous

12

Describe the axial skeleton of Myxinoidea

None -> 2° loss

13

Sacrum: structure & function

Fused sacral vertebrae supporting pelvic girdle
Strong -> can withstand hind limb forces

14

Who has procoelous or opisthocoelous vertebrae?

Most sauropsids (except aves), many amphibians (not all)

15

Heterocoelous vertebrae (def)

Both ends saddle-shaped
Vertebrae can move in different directions relative to each other (flexible)
Cartilaginous intervertebral disks

16

Centra type: Mammals

Acoelous

17

Describe the axial skeleton of Petromyzontida

DORSAL (only) cartilaginous arches protecting spinal cord; no muscle connection or body support

18

Describe the axial skeleton of Osteichthyes

Ossified
Centra: Major axial support, surrounds notochord
Neural arches & hemal arches
Neural spines & ribs are large for muscle attachment

19

Function of intervertebral ligaments

Control/limit flexibility & movement of vertebral column

20

Who has an atlas?

Tetrapods

21

Function of neural spines in terrestrial mammals

Muscle attachment to pull vertebral column into arch to direct compressive forces into centra, then down into legs

22

Describe amniote ribs

Some, at least, connect to sternum

23

Centra type: Sauropsids other than Aves

Procoelous or opisthocoelous

24

Acoelous vertebrae (def)

Flat on both ends

25

Transverse foramen (def)

Holes in cervical vertebrae to carry blood vessels to head

26

Synsacrum structure

Fused sacral, lumbar, some thoracic & caudal vertebrae in aves

27

Describe bird sternum, function

Large carina/keel - for attachment of flight muscles

28

Describe the atlas

-most anterior cervical vertebra
-no centrum
-allows nodding motion
-seen in all tetrapods

29

Describe fish ribs

single-headed

30

Define zygapophyses & give their function

Processes on the anterior and posterior neural spine
Lock with those on adjacent vertebrae to prevent torsion

31

Describe axial skeleton regionalization in gnathostome fish and what it says about them

Trunk (has ribs), caudal (has no ribs)
Similar throughout because 1 function: muscle attachment for swimming

32

Who has amphicoelous vertebrae?

Chondrichthyes, osteichthyes, some amphibians

33

Function of synsacrum

Stability in flight
Strength in landing
Can be thinner/lighter b/c stronger, don't need muscles & ligaments to maintain posture

34

Describe vertebrae of early vertebrates, agnathans (general)

notochord acts as main axial support, vertebrae are cartilaginous arches protecting spinal cord (neural arches) and dorsal aorta (hemal arches)

35

Who has acoelous vertebrae?

Mammals

36

Describe the axial skeleton of Chondrichthyes

Cartilaginous
Centrum: support, surrounds notochord
Neural arches: protect spinal cord
Hemal arches (caudal vertebrae), ribs (trunk vertebrae): protect dorsal aorta & other blood vessels

37

Centra type: Mammals

Acoelous

38

Describe the axis

2nd cervical vertebra
Has odontoid process projecting anteriorly into atlas neural canal;
Allows head rotation

39

Describe amphibian ribs

Short (don't connect to sternum)

40

Describe axial skeleton regionalization in early tetrapods and what it says about them

Cervical: allows cranial mobility (not needed in fish b/c decreases streamlining)
Trunk
Sacral: for pelvic girdle attachment
Caudal

41

How does neural spine height affect function?

Increases length of lever arm -> same muscle can do more work in pulling column into arch

42

Who has zygapophyses?

Tetrapods

43

Centra type: Amphibia

Most: procoelous or opisthocoelous
Some: amphicoelous

44

Describe aves ribs

Uncinate processes connect vertebral (costal) ribs, expanding ribcage faster

45

Describe axial skeleton regionalization in early amniotes and what it says about them

Cervical (cranial motility), thoracic (ribs), lumbar (no ribs), sacral (pelvic girdle attachment), caudal
-Lumbar allows back to flex as hind limbs push forwards for more efficient propulsion; decreases protection

46

Function of sternum

Support & stabilize pectoral girdle

47

Who has an axis?

Amniotes

48

Who has heterocoelous vertebrae?

Aves

49

Effect of locomotion method on sternum size

Bigger if forelimbs important in locomotion (lots of forces)