Study Questions 03 – The Skeletal System 1
1. List 6 functions of the skeletal system.
framework of the body, blood formation, protection of internal
organs, locomotion, mineral storage, fat storage.
2. Where are blood cells made?
in bone marrow (red marrow).
3. What 2 main minerals are stored in bone?
calcium and phosphorus.
4. How can bones store fat?
in yellow marrow – in long bones of adults.
5. Name the two types of bone tissue, and where in the bone they are found.
compact bone – found on the outside of bones, thickest in the shafts
of long bones.
cancellous bones – found inside bones, found in the ends of long
bones – the rest of the inside of long bones is taken up by the
marrow cavity or medullary cavity.
What is a “spicule”? needle-like structure
6. What is the cortex of a bone?
the outside part of the bone, composed of compact bone tissue.
What is the plural form of the word “cortex”?
cortices
7. What kinds of problems can bone marrow disease produce?
leukemia, cancer, anemia.
Briefly define anemia.
lack of functional RBCs.
8. Name 7 parts of the bone.
epiphysis, metaphysis, diaphysis, articular cartilage, epiphyseal
plate, periosteum, endosteum.
Which 3 of these parts of the bone refer to the two ends and the
middle of the bone?
epiphysis, metaphysic, diaphysis
Which refers to the tissue on the ends of long bones within a joint?
articular cartilage
Which is another name for the growth plate?
epiphyseal plate
Which 2 refer to the membranes surrounding the bone?
periosteum, endosteum.
9. Where is the epiphysis of a long bone?
either end
Where is the metaphysis of a long bone?
the flared part of the bone, just toward the middle from the
epiphysis.
Where is the diaphysis of a long bone?
it is the middle part between the metaphyses – the shaft.
10. What is articular cartilage?
the thin layer of hyaline cartilage covering the end of the bone
within the joint.
What type of cartilage is articular cartilage – hyaline cartilage,
elastic cartilage, or fibrocartilage?
hyaline cartilage
11. What is the epiphyseal plate?
the growth plate – where the bone grows longer.
What is the growth plate composed of?
hyaline cartilage
Can you see the growth plate on a radiograph (an x-ray)?
yes – it shows up as a black line between the white epiphysis and
metaphysis of the bone.
Will every bone you radiograph show a growth plate?
no – only the bones of immature animals – not done growing yet.
12. What is the periosteum?
the thin, tough, connective tissue membrane located on the outer
surface of the bone.
How does the periosteum function on bone growth?
the periosteum is where the bone grows wider. it also functions in
fracture repair.
13. What is the endosteum?
the thin membrane lining the inside of the bone, next to the marrow
cavity.
14. List the 6 ways to classify bones according to their shape.
long bones, short bones, flat bones, irregular bones, sesamoid
bones, pneumatic bones.
15. Give an example of a long bone.
femur, humerus, tibia.
Give an example of a short bone.
carpal bone
Give an example of a flat bone.
scapula, ribs, skull, pelvic bones.
Give an example of an irregular bone.
vertebra
Give an example of a sesamoid bone.
patella, fabellae, navicular bone.
Give an example of a pneumatic bone.
frontal bone (frontal sinus – air space), humerus of flying bird.
16. Which has a marrow cavity – a long bone or a short bone?
long bone
17. What are the 2 functions of flat bones?
protect underlying organs, muscle attachment
18. What are the functions of sesamoid bones?
they are embedded in some tendons that go around the “corner” when a
joint is flexed. they act like a pulley to decrease friction, or
change direction of the pull of the tendon.
19. What is the function of a pneumatic bone?
the air space decreases the weight of the bone.
20. What are the 3 parts of the skeletal system?
axial skeleton, appendicular skeleton, visceral skeleton.
21. What is the axial skeleton?
the bones on the midline of the body or attached to the midline of
the body.
List the 4 specific types of bones making up the axial skeleton.
skull, vertebrae, ribs, sternum.
22. Some skull bones are single and some are paired. What does this mean?
single bone – just one, straddles the midline.
paired bones – one on each side, left and right.
23. What do we call the often squiggly lines (immovable joints) between
skull bones?
sutures
If you see sutures in a skull, did that skull come from a relatively
young animal, or an older animal?
a young animal. the suture joints fuse, or ossify, at maturity.
24. What is a fontanel?
the “soft spot” between cranial bones found on top of the head of
some newborns. human infants, sometimes Chihuahua pups, etc.
25. What is the technical name for the eye socket in the skull?
orbit
26. Name the 3 basic skull shapes, and give a canine and feline breed
example of each.
dolichocephalic – Collie, Siamese
mesocephalic – normal head – wolf, DSH – domestic short hair
brachycephalic – English bulldog, Persian
27. What are the 2 parts of the skull?
cranium (around brain), facial bones (around nasal passages, mouth).
28. The spinal cord leaves the skull though what hole in what skull bone?
foramen magnum of the occipital bone.
29. Which of the following bones has a sinus: mandible, frontal bone, or
occipital bone?
frontal bone
30. What is the cornual process?
horn process – where the horn grows off of the skull.
What skull bones have cornual processes?
frontal bones
31. What 2 bones make up the zygomatic arch?
temporal bone, zygomatic bone
32. Which bone contains the tympanic bulla and the external acoustic
meatus – the zygomatic bone, the mandible, or the temporal bone?
temporal bone
33. What is the largest bone of the face?
mandible
Where are the left and right sides of the mandible connected together?
at the rostral end, at the mandibular symphysis.
34. The main part of a bone is called the what?
body
Name 3 bones discussed in class that have a part called the body.
mandible, vertebra, ilium
What is the vertical part of the mandible called?
ramus
What is the technical name for the jaw joint?
temporomandibular joint – TMJ
35. What is the function of the hyoid bone?
support the base of the tongue, pharynx, and larynx.
36. What does lacrimal refer to?
tearing, crying
Is the lacrimal bone located close to the orbit, the tympanic bulla,
or the cornual process?
orbit
37. Are the turbinate bones located by the hyoid bone, in the mandible, or
in the nasal passages?
in the nasal passages
38. List the 4 types of teeth.
incisors, canines, premolars, molars.
How many teeth does an adult dog normally have?
42
How many teeth does an adult cat normally have?
30
39. What are the bones making up the spine called?
vertebrae
What is the main part of a vertebra called?
body
What is the name of the hole in the vertebra that the spinal cord goes
through
vertebral foramen
Is the body of the vertebra dorsal or ventral to the spinal cord?
the body is ventral to the spinal cord.
When all of the vertebrae are articulated and their vertebral foramina
are lined up, what is the sum of the vertebral foramina called?
vertebral canal
40. In reference to bones, what is a process?
a part of the bone that sticks out.
Name the 3 types of processes that a generic vertebra has, briefly
give their locations on the vertebra, and state how many processes of
this type the vertebra has.
spinous process – dorsal – 1 per vertebra.
transverse processes – lateral – 2 per vertebra.
articular processes – basically on the 4 corners – 4 per vertebra.
41. Where are IV discs located?
between the bodies of adjacent vertebrae.
Are IV discs dorsal or ventral to the spinal cord?
IV discs are ventral to the spinal cord.
Write out the word that IV is an abbreviation for. What does this
word mean?
intervertebral – between the vertebrae.
Sometimes people make a mistake and say that an IV disc is an
intravertebral disc. What does intravertebral mean?
inside the vertebra.
Are you going to make this mistake?
no
42. What are the 2 parts of an IV disc? Which is the soft inside part and
which is the tough outside part?
annulus fibrosus – tough outside part.
nucleus pulposus – soft inside part.
43. Briefly define the following terms.
hernia – abnormal hole in a structure.
rupture – tear or break.
prolapse – outward displacement of a part.
paresis – partial paralysis.
44. Name the 5 types of vertebra, and give their locations.
cervical (neck), thoracic (chest, thorax), lumbar (lower back),
sacrum (hip), caudal or coccygeal (tail).
In reference to the spine, what does C3 mean? What does L5 mean?
C3 – third cervical vertebra, counting from cranial to caudal.
L5 – fifth lumbar vertebra.
45. What are the common names of C1 and C2?
C1 – atlas (named after the giant Atlas, who held the sky on his
shoulders in Greek mythology.)
C2 – axis (because it is at this point, between C1 and C2, that the
head can shake “no”, thus turning on its axis.)
46. How can you identify an individual cervical vertebra?
C1 and C2 can be identified by their unique shapes. C1 has “wings”,
and C2 has a very broad spinous process. the rest of the cervical
vertebra are identified by their boxy shape, and mainly because they
do not look like the rest of the vertebrae.
How can you identify an individual thoracic vertebra?
by its tall dorsal spinous process.
How can you identify an individual lumbar vertebra?
by its prominent transverse processes.
How can you identify a sacrum?
it is fused and segmented.
47. The withers of horses are composed of what?
the dorsal spinous processes of the first 9 or 10 thoracic
vertebrae.
Why is the height of horses measured at the top of the withers and not
at the top of their heads?
the head can move all over the place. the withers are more
consistent.
48. Do the dorsal spinous processes of thoracic vertebrae slant cranially
or caudally?
caudally
Do the dorsal spinous processes of lumbar vertebrae slant cranially
or caudally?
cranially
49. Where are IVD (intervertebral disc disease) problems most common?
lumbar area, thoraco-lumbar area, cervical area.
Where are IVD problems least common?
thoracic area
50. What do we call the fused sacral vertebrae?
sacrum
How many sacral vertebrae do dogs and cats have?
3
How many sacral vertebrae do sheep and pigs have?
4
How many sacral vertebrae do horses and cattle have?
5
51. What bones form the side of the thorax?
ribs
What is the costochondral junction?
in an immature animal - the place, about 2/3 of the way from the
dorsal end to the ventral end of each rib, where the rib changes
from bone to cartilage.
Is the costochondral junction visible on a radiograph?
yes
What happens to the costochondral junction in a mature animal?
the cartilage ossifies into bone, and the junction can no longer be
seen.
52. What are intercostal spaces?
the spaces between ribs.
How are intercostal spaces identified?
they are numbered for the rib cranial to them.
What is normally between the ribs?
intercostal muscles
53. What are the functions of the ribs?
protect the thoracic viscera – heart, lungs, etc.
aid in respiration, blood cell formation in marrow.
54. What is the technical name for the breastbone?
sternum
What is the sternum composed of?
7-8 sternebrae
What happens to the sternebrae as the animal matures?
they fuse together.
What is the most cranial sternebra called?
manubrium
What is the most caudal sternebra called?
xiphoid
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