Bone terminology

Question 1

Foramen

Answer 1

A hole or opening within a bone that allows passage of structures from one region to another as nerves, blood vessels and etc.

Question 2

Condyle

Answer 2

A rounded protruberance at the end of a bone, provides structural support to the hyaline cartilage, bears brunt of the force exerted from the joint.

Question 3

Crest

Answer 3

A raised area of bone, often a site where connective tissue attaches muscle to the bone.

Question 4

Fossa

Answer 4

A depression within a bone where another structure is found, as in three depressions in cranial cavity that accommodate the brain

Question 5

Groove

Answer 5

A depression in a bone surface that runs along the length of a vessel or a nerve, providing space to avoid compression by adjacent muscle.

Question 6

Process

Answer 6

An elongated projection in a bone

Question 7

Sinus

Answer 7

A narrow, hollow cavity within a bone

Question 8

Spine

Answer 8

Central part of the bone

Question 9

Trochanter

Answer 9

A rough prominent area of the femur that lies beneath the head of the femur. Serves attachment for the attachment of the muscles.

Question 10

Tubercle

Answer 10

A small rounded point of a bone

Question 11

Tuberosity

Answer 11

Area of a tubercle where the tendons attach.

Question 12

Medullary cavity

Answer 12

Central cavity of a bone shaft where red bone marrow and adipose tissue is stored. Also known as marrow cavity.

Question 13

Periosteum

Answer 13

Thin layer of connective tissue covering the bone in all places of the surface except at joints which are protected by articular cartilage

Question 14

Appendicular skeleton

Answer 14

One of two major bone groups in body. Consists of forelimb including the scapula and the hindlimb including the pelvis.

Question 15

Scapula

Answer 15

Bone of the appendicular skeleton/shoulder blade, large, flat, slightly triangular, has a ridge that goes lengthways down the bone called the spine. On the lateral surface of the trunk, cranial to the ribs.

Question 16

Clavicle

Answer 16

Absent in dogs - only remnant of bone present lying in the muscle cranial to the shoulder joint. Present in cats, 1 cm long curved bone, does not articulate with other bones so provides movement freedom.

Question 17

Humerus

Answer 17

Long, upper, forelimb bone. Proximally connects to the scapula to form the shoulder joint and distally connects to radius and ulna to form the elbow joint. Has

Question 18

Radius and Ulna

Answer 18

Lower forelimb bones that lie side by side. Radius lies cranially and Ulna lies caudally.

Question 19

Carpus

Answer 19

Wrist joint, consists of 7 short bones that are lined in two rows : 3 bigger bones on the top row, 4 smaller on the bottom row. All small bones are connected by ligaments.

Question 20

Metacarpus

Answer 20

Consists of 5 long bones known as metacarpals. 1st is smaller and known as dew claw, it connects separately to the carpus rather than metacarpals. Metacarpals 2,3,4,5 used for weight bearing.

Question 21

Phalanx/Phalanges

Answer 21

Phalanges are bones of the digits. Dew claw only has two : one long phalanx bone and one short ungual process which is a part of the claw. The rest 4 digits are made up of two long phalanx bones and one short ungual bone.

Question 22

Pelvis

Answer 22

Pelvis consists of four bones: the ilium (cranial/illiac wing), ischium (caudal/ischiatic tuberosity), pubis, acetabular bone.
Four bones are fused together to form pelvis and has a firm articulation with the sacrum and sacroiliac joint. Two halves of pelvis are joined at pubic symphysis.
The large holes on either side of symphysis are oburator foramen, it reduces the weight of the pelvis, allows blood vessels and nerves to pass from the pelvic cavity into the hindlimb.

Question 23

Pubic symphysis

Answer 23

Where two halves of the pelvis are joined.

Question 24

Oburator foramen

Answer 24

Holes on either side of pubic symphysis, allows blood vessels and nerves to pass from pelvic cavity into hind limbs.

Question 25

Femur

Answer 25

Proximal long bone of the hindlimb, similar to humerus. Has a head, neck and shaft. head is offset from the main shaft and articulates with acetabulum of the pelvis.

Question 26

Stifle

Answer 26

Stifle joint is made up of articulation between femur, tibia and fibula and 3 sesamoid bones : patella (knee cap) and 2 fabellae.

Question 27

Sesamoid bone

Answer 27

A small, round bone, shaped like a sesame seed. Forms in tendons, where a great deal of pressure is generated in a joint. Protects tendons and helps overcome compressive forces. (Patellae, fabellae)

Question 28

Patella

Answer 28

Small sesamoid bone located in the tendon of the quadriceps muscle.

Question 29

Fabellae

Answer 29

Two sesamoid bones located in the head of the gastrocnemius muscle.

Question 30

Tibia and Fibula

Answer 30

Form the distal part of hind limb. Tibia is larger and its flat surface is proximal to the stifle so it articulates with the femur. Fibula is a thin long bone lateral to the Tibia.

Question 31

Tarsus

Answer 31

Similar to carpus. Made up of 7 short tarsal bones arrangement over 2 rows. (Arrangement can vary between domestic species). Articulate with tibia and fibula as part of hock joint. The calcaneous (os calcus) is visible point of the hock where Achilles tendon attaches.

Question 32

Metatarsus

Answer 32

Consists of 5 long metatarsal bones. The first, the dew claw may be missing.

Question 33

The axial skeleton

Answer 33

Formed by the skull, vertebral column, ribs and sternum. | Includes bones of the skull, hyoid apparatus, bones of middle ear.

Question 34

Mandible

Answer 34

Part of the skull, lower jaw, formed by two bones joined together by a cartilaginous joint mandibular symphysis..

Question 35

Cranium

Answer 35

Consists of number of bones fused together, cranium varies in both size and shape between species. Cranium protects and houses the brain, ocular, auditory, olfactory and gustatory senses. Provides an attachment for the mandible, hyoid apparatus and facial muscles.

Question 36

Hyoid apparatus

Answer 36

Made up of number of fine bones joined by a cartilaginous joint. Acts as a suspensory mechanism that allows larynx to swing cranially and caudally during swallowing.

Question 37

Atlas and Axis

Answer 37

First two cervical vertebrae and allow head movement

Question 38

Vertebral column

Answer 38

Made up of approximately 50 bones, protects the spinal cord, provides support for the head, and attachment for the muscles. Divides in to 5 regions : cervical (7 bones), thoracic (13 bones), lumbar (7 bones), sacral (3 bones), coccygeal (3-25). Each vertebra has vertebral foramen which allows nerves, arteries and veins to pass. Forms the spinal canal for the spinal cord. Intervertebral discs sit between the vertebra and permit small flexion, help prevent damage and absorb shock.

Question 39

Sacrum

Answer 39

Single bone fused by several vertebrae. Articulates with the pelvic girdle and ilium to form sacroiliac joint.

Question 40

The ribs

Answer 40

There are 13 ribs in cats and dogs but number varies between species. Ribs form a bony cage to protect lungs, heart and associated tissue. Each rib articulates with corresponding thoracic vertebra. Spaces between ribs are called intercostal spaces and contain intercostal muscle. 1-8 ribs articulate with the sternum and are known as true ribs. 9-12 articulate with the costal cartilage of the rib in front forming the costal arch. These do not touch the sternum and are known as arsenal/false ribs. 13th rib does not articulate with the costal cartilage or the sternum and it is known as a floating rib.

Question 41

Sternum

Answer 41

The sternum has manubrium in the cranial aspect and xiphoid process (prominent xiphoid cartilage) in the caudal aspect of the sternum. Bones are called sternebrae. There is an intersternebral cartilage disc between each bone.

Question 42

Splanchnic bone

Answer 42

Bone that develops in a soft organ, separate from the rest of the skeleton. Example: os penis or baculum.

Question 43

Long bone

Answer 43

Cylindrical bone, longer than wide, describes shape and not size. Function as levers for movement. (Femur, tibia, fibula, humerus, radius, ulna, metatarsals, metacarpals, phalanges)

Question 44

Short bone

Answer 44

Cube-like shape, equal in length, width and thickness. Provide stability, support and some movement. (Carpals, tarsals)

Question 45

Flat bone

Answer 45

Thin, but often also curved. Serve as points of attachments, protects internal organs. (Scapula, sternum, ribs, cranium, ilium)

Question 46

Irregular bone

Answer 46

Shape not easily characterised, to support internal structures, protects from compression. (Vertebra, maxilla, mandible)

Question 47

Pneumatic bone

Answer 47

Medullary cavity in these bones is largely replaced by air to make them light. Confined to the skull and contains paranasal sinuses. Sphenoid bone in the skull is an example. Otherwise found in birds, the medullary cavity is replaced by air and connected to the air sacs (respiratory system). To make skeleton lighter for flight.

Question 48

Fibrous Joint

Answer 48

Little or no movement. Fibrous tissue between ends of bones. Allows extension of bones when growing.

Question 49

Cartilaginous Joint

Answer 49

Little or no movement. Joints include a pad of fibro-cartilage, movement is created during the compression of cartilage. Include joints between juvenile diaphyses and epiphyses, that allow for movement.

Question 50

Synovial joint

Answer 50

Wide range of movement. Bones in the joint are separated by a fluid-filled joint capsule, bound by synovial membrane. Synovial fluid lubricates the articular cartilage.