Lab #4: Mammal Bones - Axial Skeleton

Question 1

Mammalian axial skeleton bones includes - BROADLY: (4)

Answer 1

(1) Skull (cranium + mandible)
(2) Vertebral column
(3) Ribs
(4) Sternum
-> same elements in all mammals but diff morphologies

Question 2

Skull/Vertebral column/Ribs/Sternum: Main critical roles (3)

Answer 2

(1) Protecting CNS and vital organs
(2) Support posture
(3) Support locomotion

Question 3

Dog: Which order?

Answer 3

Carnivora (terrestrial)

Question 4

Seal: Which order?

Answer 4

Carnivora (marine)

Question 5

Polar bear: Which order?

Answer 5

Carnivora (marine)

Question 6

Caribou: Which order?

Answer 6

Artiodactyla

Question 7

Muskox: Which order?

Answer 7

Artiodactyla

Question 8

Main differences between the order Carnivora vs Artiodactyla

Answer 8

Carnivora:
- Meat eating (-> Specialized carnassial teeth)
- 4-5 toes, all may touch the ground
Artiodactyla:
- Herbivorous (-> Flat molars for grinding plant material)
- Usually 2 main weight-bearing toes

Question 9

Main differences between carnivora terrestrial vs marine

Answer 9

Terrestrial (dog):
- Long, with well-developed elbow and knee joints for stride.
- Tail: Often long, used for balance.
- Skull: Strong sagittal crest and large zygomatic arches for bite force.
Marine (seal):
- Limbs = Shortened, transformed into flippers; reduced or fused joints.
- Tail: Very short or absent.
- Skull: Often more elongated and streamlined; reduced neck mobility for hydrodynamics.

Question 10

Cranium: functions (3)

Answer 10

(1) Protects the brain
(2) Provides sites for muscles attachments
(3) Houses sensory organs

Question 11

The cranium articulates with (2)

Answer 11

(1) Mandible
(2) Temporomandibular joint

Question 12

The mandible (aka lower jaw) varies alongside …

Answer 12

diet

Question 13

How many CERVICAL vertebrae?

Answer 13

7

Question 14

What are the name of the first two cervical vertebrae?

Answer 14

Atlas and axis

Question 15

Atlas and axis: main function

Answer 15

Permit rotation of the head

Question 16

What’s distinctive about the mammalian cervical vertebrae?

Answer 16

Noticeable holes and transverse processes (allows passage of vertebral arteries and veins)

Question 17

The THORACIC vertebrae articulate with …

Answer 17

RIBS

Question 18

How many THORACIC vertebrae

Answer 18

12-13

Question 19

Distinctive feature of thoracic vertebrae

Answer 19

Sharpest spinous process

Question 20

Ribs extend from the spine to the …

Answer 20

sternum

Question 21

Function of ribs

Answer 21

Protect internal organs

Question 22

Mammalian sternums are comprised of …

Answer 22

sternebrae
= small/block-like bones that are stacked in a row
= over time, begin to fuse together

Question 23

How many lumbar vertebrae?

Answer 23

5

Question 24

Main feature of lumbar vertebrae

Answer 24

larger centra, smaller spinous processes

Question 25

How many sacral vertebrae?

Answer 25

5 -> often fuse in the SACRUM

Question 26

Function of sacrum

Answer 26

provide secure connection between vertebral column and pelvic girdle

Question 27

How many caudal vertebrae?

Answer 27

Variable number! -> form bony foundation for the tail

Question 28

BON LAURA CONCLUSION: RACONTE LA COLONNE VERTÉBRALE

Answer 28

1- Cervical vertebrae (7) -> Atlas/Axis 2- Thoracic vertebrae (12-13) 3- Lumbar vertebrae (5) 4- Sacral vertebrae/Sacrum (5) 5- Caudal vertebrae (XX)