Bone terminology Flashcards
Foramen
A hole or opening within a bone that allows passage of structures from one region to another as nerves, blood vessels and etc.
Condyle
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.
Crest
A raised area of bone, often a site where connective tissue attaches muscle to the bone.
Fossa
A depression within a bone where another structure is found, as in three depressions in cranial cavity that accommodate the brain
Groove
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.
Process
An elongated projection in a bone
Sinus
A narrow, hollow cavity within a bone
Spine
Central part of the bone
Trochanter
A rough prominent area of the femur that lies beneath the head of the femur. Serves attachment for the attachment of the muscles.
Tubercle
A small rounded point of a bone
Tuberosity
Area of a tubercle where the tendons attach.
Medullary cavity
Central cavity of a bone shaft where red bone marrow and adipose tissue is stored. Also known as marrow cavity.
Periosteum
Thin layer of connective tissue covering the bone in all places of the surface except at joints which are protected by articular cartilage
Appendicular skeleton
One of two major bone groups in body. Consists of forelimb including the scapula and the hindlimb including the pelvis.
Scapula
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.
Clavicle
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.
Humerus
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
Radius and Ulna
Lower forelimb bones that lie side by side. Radius lies cranially and Ulna lies caudally.
Carpus
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.
Metacarpus
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.
Phalanx/Phalanges
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.
Pelvis
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.
Pubic symphysis
Where two halves of the pelvis are joined.
Oburator foramen
Holes on either side of pubic symphysis, allows blood vessels and nerves to pass from pelvic cavity into hind limbs.
Femur
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.
Stifle
Stifle joint is made up of articulation between femur, tibia and fibula and 3 sesamoid bones : patella (knee cap) and 2 fabellae.
Sesamoid bone
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)
Patella
Small sesamoid bone located in the tendon of the quadriceps muscle.
Fabellae
Two sesamoid bones located in the head of the gastrocnemius muscle.
Tibia and Fibula
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.
Tarsus
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.
Metatarsus
Consists of 5 long metatarsal bones. The first, the dew claw may be missing.
The axial skeleton
Formed by the skull, vertebral column, ribs and sternum.
Includes bones of the skull, hyoid apparatus, bones of middle ear.
Mandible
Part of the skull, lower jaw, formed by two bones joined together by a cartilaginous joint mandibular symphysis..
Cranium
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.
Hyoid apparatus
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.
Atlas and Axis
First two cervical vertebrae and allow head movement
Vertebral column
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.
Sacrum
Single bone fused by several vertebrae. Articulates with the pelvic girdle and ilium to form sacroiliac joint.
The ribs
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.
Sternum
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.
Splanchnic bone
Bone that develops in a soft organ, separate from the rest of the skeleton. Example: os penis or baculum.
Long bone
Cylindrical bone, longer than wide, describes shape and not size. Function as levers for movement. (Femur, tibia, fibula, humerus, radius, ulna, metatarsals, metacarpals, phalanges)
Short bone
Cube-like shape, equal in length, width and thickness. Provide stability, support and some movement. (Carpals, tarsals)
Flat bone
Thin, but often also curved. Serve as points of attachments, protects internal organs. (Scapula, sternum, ribs, cranium, ilium)
Irregular bone
Shape not easily characterised, to support internal structures, protects from compression. (Vertebra, maxilla, mandible)
Pneumatic bone
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.
Fibrous Joint
Little or no movement. Fibrous tissue between ends of bones. Allows extension of bones when growing.
Cartilaginous Joint
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.
Synovial joint
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.
