Flashcards in Test yourself ?s Chpt 6 Bones Deck (35):
Besides supporting the other tissues of the body, what else do bones do?
Blood cell formation
What are the three kinds of bone cells? What role does each play in the life of a bone?
Osteoblasts, osteocytes, osteoclasts
1. What is the matrix of bone made of?
2. What makes it so hard?
1. Collagen fibers embedded in a gelatin-like ground substance made of protein and complex carbohydrates called polysacchrides. The matrix is secreted by osteoblasts.
2. Osteoblasts harden the matrix through ossification. Matrix is infiltrated with calcium and phosphate in the form of hydroxyapatite crystals. These crystals give bone its characteristic hardness.
1. Difference between the structures of cancellous bone and compact bone?
2. Why does the body need these two different types of bone?
1. Cancellous: Spongy appearance. It is light but amazingly strong and helps reduce the weight of bones of skeleton. Spicules of bone and bone marrow make up cancellous bond. Designed to withstand forces bone is subjected to.
Compact: Heavy, dense and strong. Makes up shafts of long bones, outside layer of all bones. in cross section, they look like growth rings of a tree.
2. Cancellous bone helps keep bones light while preventing them from being damaged by all the forces acting on them. Compact bone makes up shafts of long bones and outside layer of all bones. Haversian canals inside compact bone contain blood vessels, lymph vessels and nerves that supply the osteocytes.
Difference between haversian and volkmann's canal?
Haversian canals run lengthwise to the bone.
Volkmann's canals run at right angles to the long axis of bone and to the haversian canals. Blood vessels from both join to bring nutrition to the osteocytes in the haversian systems.
By which mechanism of bone formation do most bones in the animal body develop before birth, and how does the process take place?
Endochondral bone formation
Body first creates cartilage template later replacing it by bone.
Difference between primary and secondary growth center of a bone
Most bones start out as rods of cartilage in the developing fetus. These cartilage rods are prototypes of the bones that will eventually replace them. In long bones, such as the femur, bone begins developing in the shaft or diaphysis of the cartilage rod in what is called the PRIMARY growth center. Cartilage is removed gradually as bone is created and the growth center expands.
SECONDARY growth centers develop in the ends or epiphyses of the bone.
Where are epiphyseal plates and what do they do?
Also called growth plates are located between the shaft (diaphyses) of bone and and its ends (epiphyses). Remain as cartilage when animal is born. They allow long bones to lengthen as the animal grows.
What is bone marrow? Difference between red and yellow.
Fills the spaces within bones, incl. spaces between spicules of cancellous bones and large spaces with diaphyses of long bones.
Red: Forms blood cells; majority of marrow found in young animals; small portion in older animals confined to specific locations, such as ends of some long bones and interiors of pelvic bones and sternum.
Yellow: Consists primarily of adipose connective tissue. Most common type in adult animals. Can revert back to red if body needs larger amount of blood cells
Name the skull bones that make up each of these groups:
EXTERNAL BONES OF CRANIUM:
Frontal bones (2)
Interparietal bones (2)
Occipital bone (1)
Parietal bones (2)
Temporal bones (2)
INTERNAL BONES OF CRANIUM:
Ethmoid bone (1)
Sphenoid bone (1)
BONES OF EAR:
none external, just internal
EXTERNAL BONES OF THE FACE:
Incisive bones (2)
Lacrimal bones (2)
Mandible (1 or 2)
Maxillary bones (2)
Nasal bones (2)
Zygomatic bones (2)
INTERNAL BONES OF THE FACE:
Palatine bones (2)
Pterygoid bones (2)
Vomer bone (1)
In which skull bones are each of the following structures found:
Cribriform plate: Ethmoid bone (hidden bone of cranium)
External acoustic meatus: Temporal bone (only ear structure visible from outside)
Foramen magnum: Occipital bone (large hole in its center where spinal cord exits skull)
Frontal sinus: Frontal bone
Lacrimal sac: Lacrimal bone (part of tear drainage system of eye)
Lower teeth: Mandible
Pituitary fossa: Sphenoid bone (depression housing the pituitary gland)
Upper incisor teeth: Incisive bones
Upper cheek teeth: Maxillary bones
Which would likely be a greater threat to an animal's well-being: a fracture of the mandible or a fracture of the occipital bone? Why?
A fracture of the occipital bone would be the greather threat, as it is located at the base of the skull and the location where the spinal cord exits the skull through the foramen magnum. This is also the bone that articulates with the first cervical vertebra, the atlas.
The mandible is the lower jaw and houses all lower teeth. It's the only movable skull bone, but does not contain any life-sustaining parts, so it would be less threatening to fracture this bone.
Which groups of vertebrae make up the spinal column dorsal to the following regions?
What are the three kinds of processes found on vertebrae and what are their characteristics?
SPINOUS PROCESS: Dorsally projecting
TRANSVERSE PROCESSES: Two laterally projecting; vary in size among vertebrae.
All three, spinous and two transverse processes, act as sites for muscle attachment and leverage to move spine and trunk.
ARTICULAR PROCESSES: Located on cranial and caudal ends of the vertebral arches; help form joints between adjacent vertebrae
Where in the vertebra is the spinal cord located?
In the spinal canal (dorsal to the body of a vertebra is the hollow arch. When arches of all vertebrae are lined up they form a long, flexible tunnel)
Names of the first two cervical vertrebrae and their distinguishing characteristics.
The first, C1, ATLAS: Holds up the head; has two large, winglike transverse processes called the wings of the atlas; has no vertebral body; consists only of a bony ring through which the spinal cord passes
The second, C2, AXIS: Forms atlantoaxial joint with Atlas' caudal end; has large, bladelike spinous process projecting up dorsally and peglike dens fitting into caudal end of atlas to form joint.
Difference between a sternal, asternal and floating rib.
STERNAL: Make up cranial part of thorax; cartilages of ribs join the sternum
ASTERNAL: Make up caudal part of thorax; ribs joining the adjacent costal cartilage
FLOATING: Cartilage of the last ribs (2 on each side) may not join anything (unattached) and end in the muscles of thoracic wall
What is the manubrium?
First most cranial sternebra (sternebrae = rodlike bones making up the sternum or breastbone)
What is the xiphoid?
Last, most caudal sternebra (piece of cartilage extending caudally from xiphoid process; easily felt at caudal end of sternum)
Name the bones of the thoracic limb from proximal to distal.
Humerus (long bone of upper arm or brachium)
Radius (main weight bearing bone of antebrachium or forearm)
Ulna (major portion of elbow joint with distal end of humerus)
Carpal bones (Carpus = two rows of carpal bones)
What is the anatomical name for the shoulder blade?
What are the brachium and antebrachium, and which bones form them?
Brachium is the upper arm formed by the humerus.
Antebrachium is the forearm formed by the radius and ulna.
On which bone is the olecranon process found? What is its purpose?
Found on the proximal end of the ulna. Forms the point of the elbow, where the tendon of the powerful triceps brachii muscle attaches.
What are the anatomical names of the cannon bone and the splint bones in a horse?
Cannon bone: Metacarpal
Splint bones: Vestigial metacarpal bones
Which digit is the dewclaw on the front leg of a dog?
Digit I (contains only two bones: the proximal and the distal phalanx)
What is the common name for the distal sesamoid bone in the horse?
Name the bones of the pelvic limb from distal to proximal.
Tarsal bones (Tarsus)
Pelvis (Pubis, Ischium, Ilium)
What three pairs of bones make up the pelvis? What region of the pelvis does each form?
The ilium, ischium and pubis
ILIUM: Cranial-most bone of pelvis; forms the sacroiliac joints with the sacrum.
ISCHIUM: Caudal-most pelvic bone; the main, rear-projecting process of the ischium is the ischial tuberosity.
PUBIS: Smalles of three pelvic bones; located medially and forms the cranial portion of pelvic floor (while the ischium forms the caudal part)
What is the largest sesamoid bone in the animal body?
The patella or kneecap
Which bone is larger and supports more of an animal's weight, the tibia or fibula?
On which bone of the pelvic limb is the calcaneal tuberosity found? What is its purpose?
On the fibular tarsal bone (not the fibula itself!!!).
It projects upward and backward to form the point of the hock. Acts as the point of attachment for the tendon of the large gastrocnemius muscle and corresponds to our heel.
What are the main characteristics of fibrous, cartilaginous and synovial joints?
FIBROUS: immovable, bones are firmly united by fibrous tissue (e.g. sutures uniting most of skull bones)
CARTILAGINOUS: Slightly movable, capable of only a slight rocking movement (e.g. intervertebral disks between bodies of adjacent vertebrae in spine)
SYNOVIAL: Freely movable (e.g. shoulder or stifle joint)
What is synovial fluid and why is it important to the functioning of a synovial joint?
Normally transparent, viscosity of medium-weight motor oil; produced by synovial membrane; lubricates the joint surfaces
Difference between tendon and ligament
TENDON: Joins muscles to bones
LIGAMENT: Joins bones to other bones