The Skeletal System Flashcards
1
Q
Osteblasts
A
Cells that form bone, secrete the matrix
2
Q
The matrix
A
Intercellular substance
3
Q
Ossification
A
The matrix is infiltrated with calcium and phosphate in the form of hydroxyapatite crystals
4
Q
Hydroxyapatite crystals
A
Give bone its characteristic hardness
5
Q
Lacunae
A
The ossified matrix
6
Q
Canaliculi
A
Cellular processes in tiny channels through the bone, osteocytes obtain food and communicate w each other
7
Q
Functions of bones
A
Support, protection, leverage, and storage
8
Q
Two hormones that act as “cashiers” at the calcium bank
A
Calcitonin (prevents hypercalcemia) and parathyroid hormone (prevents hypocalcemia)
9
Q
Calciotropic
A
The hormones are involved in the regulation of calcium levels in the body
10
Q
Hematopoisesis
A
Blood cell formation
11
Q
Two main types of bone
A
Cancellous bone and compact bone
12
Q
Cancellous bone
A
Light and spongy, consists of tiny spicules of bone that appear randomly arranged w lots of spaces btwn them
13
Q
Compact bone
A
Heavy and dense, makes up shafts of long bones and the outside layer of all bones. Composed of tiny, tightly compacted cylinders of bone called Haversian systems
14
Q
Haversian canal
A
Contains blood vessels, lymph vessels, and nerves that supply the osteocytes
15
Q
Periosteum
A
A membrane that covers the outer surfaces of bones
16
Q
Endosteum
A
A membrane that lines the hollow interior surfaces of bones
17
Q
3 type of cells that make up bone:
A
Osteoblasts, osteocytes, and osteoclasts
18
Q
Osteocytes
A
Created once the osteoblast becomes trapped in the ossified matrix
19
Q
Osteoclasts
A
Instead of forming bone, they eat it away, also allow the body to withdraw calcium from the bones when necessary
20
Q
Volkmann’s canals
A
Tiny channels in the bone matrix, blood vessels here join w the blood vessels in the Haversian canals to bring nutrition to the osteocytes in the Haversian systems
21
Q
Nutrient foramina
A
Large blood vessels, along with lymph vessels and nerves,
also enter many large bones, especially long bones, through large channels called nutrient foramina
22
Q
2 ways bone is formed:
A
Grows into and replaces a cartilage model (endochondral or cartilage bone formation), or it develops from fibrous tissue membranes (intramembranous or membrane bone formation)
23
Q
Endochondral bone formation
A
The body creates a cartilage “template” that is subsequently replaced by bone
24
Q
Femur
A
Thigh bone
25
Diaphysis
Shaft of the bone, main part of long bone, consists of compact bone
26
Secondary growth centers
Additional growth centers, develop in the ends of the bone
27
Epiphyses
Ends of the bone
28
Areas of a long bone that remains as cartilage when an animal is born:
Epiphyseal plates / growth plates
29
Intramembranous bone formation
Bone forms in the fibrous tissue membranes that cover the brain in the developing fetus. Occurs only in certain skull bones and creates flat bones of the cranium
30
Callus
Healing tissue formed by osteoblasts when a bone is broken, gradually bridges the fracture gap
31
Long bones
Longer than they are wide, most bones of the limbs, has proximal & distal epiphysis
32
Epiphyseal fractures
Fractures through epiphyseal plates, common in young animals
33
Short bones
Shaped like small cubes or marshmallows, consists of a core of spongy bone covered by a thin layer of compact bone
34
Distal & proximal epiphysis
Consist primarily of light, cancellous bone covered by a thin layer of compact bone, located on long bone
35
Flat bones
Relatively thin and flat, structure is like a cancellous bone sandwich that consists of two thin plates of compact bone separated by a layer of cancellous bone
36
Irregular bone
Miscellaneous category, do not fit into the long, short, or flat categories. Either have characteristics of more than one of the other categories, or they have a truly irregular shape
37
Vertebrae
Bones of the spine, irregular bones
38
Sesamoid bones
Present in some tendons, where they change direction markedly over the surfaces of joints, irregular bones, resemble sesame seeds
39
Patella
Kneecap, largest sesamoid bone in the animal body
40
Bone marrow
Fills the spaces within bones
41
2 types of bone marrow:
Red and yellow bone marrow
42
Red bone marrow
Hematopoietic tissue, forms blood cells, makes up the majority of the bone marrow if young animals but represents only a small portion in older animals, older animals located at ends of some long bones and the interiors of the pelvic bones and sternum
43
Yellow bone marrow
Consists primarily of adipose connective tissue, most common type of marrow in adult animals, does not produce blood cells but it can revert to red bone marrow if the body needs to produce larger than normal number of blood cells
44
Articular surfaces
Joint surfaces: smooth areas of compact bone where bone come in contact w each other to form joints
45
Articular cartilage
Smooth thin layer of hyaline cartilage, covers articular surfaces
46
Condyle
Usually a large, round articular surface, somewhat cylindrical shape, major condyles are located at the distal end of the humerus and femur and on the occipital bone of the skull
47
Head
Somewhat spherical articular surface on the proximal end of a long bone, found on the proximal end of the humerus, femur, and ribs
48
Neck
The head of a bone is united with the main shaft portion of the bone by an often narrowed region called the neck
49
Facet
Flat articular surface, found on many bones, such as carpal and tarsal bones, vertebrae, and long bones like radius and ulna
50
Process
Term that includes all the lumps, bumps, and other projections on a bone
51
Foramen
A hole in a bone, usually something important, such as nerve or blood vessel, passes through, but there are exceptions
52
Fossa
A depressed or sunken area on the surface of a bone, usually occupied by muscles or tendons
53
Axial skeleton
Referred as this because the bones of the head and the trunk are located along the central axis of the body
54
Appendicular skeleton
Consist of bones of the limbs, which are appendages of the trunk
55
Visceral skeleton
These bones are formed in the viscera, or soft organs
56
Skull
Most complex part of the skeleton, in most domestic animals it consists of 37 or 38 separate bones
57
Sutures
Jagged, immovable, fibrous joints, which unite majority of skull bones
58
Synovial joint
Connects the mandible to the rest of the skull
59
Cranium
Portion of the skull that surrounds the brain, has 11 bones
60
Occipital bone
A single bone that forms that caudoventral portion or base of the skull, where the spinal cord exists the skull and it is the skull bone that articulates w the first cervical vertebra
61
Foramen magnum
A large hole in the center of the occipital bone: this is where the spinal cord exits the skull
62
Occipital condyles
Located on either side of the foramen magnum, articular surfaces that join with the first cervical vertebra to form the atlantooccipital joint
63
Atlas
First cervical vertebra
64
Atlantooccipital joint
Joint that connects the head w the neck
65
Interpartietal bones
2 small bones located on the dorsal midline btwn the occipital bone & the parietal bones, usually clearly visible in young animals, in older animals, they may fuse together into one bone, or they may fuse to the parietal bones and become indistinguishable
66
Parietal bones
The two form the dorsolateral walls of the cranium
67
Temporal bones
Located below or ventral to the parietal bones, they from lateral walls of the cranium, they contain the middle and inner ear structures, and they are the skull bones that form the temporomandibular joints with the mandible
68
External acoustic meatus
The bony canal that leads into the middle and inner ear cavities, the only ear structure that is visible from the outside
69
Frontal bones
Form the forehead region of the skull
70
The frontal sinus
A large paranasal sinus, contained within the frontal bone
71
The two hidden bones of the cranium:
The sphenoid bone and the more rostral ethmoid bone
72
Sphenoid bone
Forms the ventral part of the cranium and contains a depression
73
Pituitary fossa
The depression in the sphenoid bone, houses the pituitary gland
74
Sphenoidal sinus
A paranasal sinus present in the sphenoid bone in most animals
75
Ethmoid bone
A single bone located rostral to the sphenoid bone
76
Cribriform plate
Present in the ethmoid bone, through which the many branches of the olfactory nerve pass from the upper portion of the nasal cavity to the olfactory bulbs of the brain
77
Ethmoidal sinus
Small paranasal sinus present in the ethmoid bone of horses and humans
78
Ossicles; The 3 tiny bones in the middle ear
Malleus (hammer), incus (anvil), and stapes (stirrup)
79
Tympanic membrane
Eardrum
80
Function of the ossicles
To transmit vibrations from the tympanic membrane across the muddle ear cavity to the cochlea
81
Cochlea
Inner ear structure, receptor cells for hearing convert the vibrations to nerve impulses that are interpreted by the brain as sound
82
Incisive bones
2 bones, sometimes called the premaxillary bones, are the most rostral skull bones
83
Nasal bones
2 bones forming the bridge of the nose, which is the dorsal part of the nasal cavity
84
Dolichocephalic
Long-faced dog breeds
85
Maxillary bones
Two bones, make up most of the upper jaw, house all the upper teeth and the maxillary sinuses
86
Hard palate
Formed by the maxillary bones, the bony separation btwn the mouth and the nasal cavity or the roof of the mouth
87
Lacrimal bones
2 small bones that form part of the medial portion of the orbit of the eye
88
Lacrimal sac
Part of the tear drainage system of the eye, located in the lacrimal bones
89
Zygomatic bones
Also known as the malar bones, two bones forming a portion of the orbit of the eye and join w a process from the temporal bones to form the zygomatic arches on either side of the skull
90
Zygomatic arches
Easily palpable, bony landmarks below and behind the eyes that form the widest part of the skull in dogs and cats
91
Mandible
Lower jaw, houses all the lower teeth and is the only movable skull bone
92
Mandibular symphysis
Cartilaginous joint, unites the separate bones on either side of the mandible at their rostral ends
93
Shaft of the mandible
The horizontal portion that houses all the teeth
94
Ramus of the mandilbe
Vertical portion of the mandible, at the caudal end of the shaft of the mandible
95
The internal bones of the face:
Palatine bones, the pterygoid bones, the vomer bone, and the turbinates
96
Palatine bones
Make up the caudal portion of the hard palate, which separates the mouth from the nasal cavity
97
Pterygoid bones
Two small bones that support part of the lateral walls of the pharynx
98
Vomer bone
Located on the midline of the skull and forms part of the nasal septum
99
Nasal septum
The central "wall" btwn the left and right nasal passages
100
Turbinates
Also called the nasal conchae, are 4 thin, scroll-like bones that fill most of the space in the nasal cavity
101
Hyoid bone
Also called the hyoid apparatus, looks somewhat like the letter H w its 2 legs bent back to form a U-shaped structure, located high in the neck, just above the larynx, btwn the caudal ends of the mandible
102
Spinal column
Also called the vertebral column, is made up of a series of individual irregular bones called vertebrae that extend from the skull to the tip of the tail
103
The spinal column is divided into 5 regions:
Cervical, thoracic, lumbar, sacral, and coccygeal
104
Intervertebral discs
Made of fibrocartilage, acts as shock absorbers, separates adjacent vertebrae
105
Spinal canal
Long, flexible tunnel, houses and protects spinal cord
106
Spinous process
Single, dorsal projection process, act as sites for muscle attachment and provide leverage to move the spine and trunk
107
Transverse processes
Two laterally projected processes, act as sites for muscle attachment and provide leverage to move the spine and trunk
108
Articular processes
Located on the cranial and caudal ends of the vertebral arches and help form the joints btwn adjacent vertebrae
109
Cervical vertebrae
Located in neck region, nearly all mammals have
110
Atlas
First cervical vertebrae, C1, has 2 wing like transverse processes called wings of the atlas
111
Axis
Second cervical vertebrae, C2, has large bladelike spinous process that projects up dorsally and the peg like dens that fits into the caudal end of atlas to help form the atlantoaxial joint
112
Thoracic vertebrae
Located dorsal to the thorax, the # of thoracic vertebrae is the same as the number of pairs of ribs the animal has
113
Lumbar vertebrae
Dorsal to the abdominal region, most massive looking bones of the spinal column
114
Sacral vertebrae
Fuse to form a single, sold structure called the sacrum
115
Sacrum
Located dorsal to the pelvic region and forms a joint w the pelvis on each side in what is called the sacroiliac joint
116
Coccygeal vertebrae
The bones of the tail
117
Coccyx
Tailbone
118
Costal cartilage
Cartilaginous part of the rib
119
Costochondral junction
Bony part of rib
120
Sternal ribs
The ribs whose cartilages join the sternum and make up the cranial part of the thorax
121
Asternal ribs
Ribs that join the adjacent costal cartilage and make up the caudal part of the thorax
122
Floating ribs
Unattached ribs, may end in the muscles of the thoracic walls
123
Sternum
Breastbone, forms the floor of the thorax
124
Sternebrae
Series of rodlike bones that make up the sternum
125
Manubrium
The first, most cranial sternebra
126
Xiphoid
The last, most caudal sternebra
127
Appendicular skeleton
Made up of the bones of the main appendages of the animal body
128
Thoracic limb
Front leg
129
Pelvic limb
Hind leg
130
Glenoid cavity
The socket portion of the ball-and-socket shoulder joint, connected w the main body of the scapula by a narrowed area known as the neck
131
Humerus
Long bone of upper arm
132
Brachium
Upper arm
133
Antebrachium
Forearm
134
2 bones that form the forearm:
Ulna and radius
135
Ulna
Forms a major portion of the elbow joint w the distal end of the humerus
136
Olecranon process
Forms the point of the elbow, where the tendon of the triceps brachii muscle attaches
137
Trochlear notch
A half-moon shaped, concave articular surface that wraps around art of the humeral condyle to help make the elbow joint a tight, secure joint
138
Anconeal process
A beak-shaped process, located at the proximal end of the trochlear notch
139
Radius
The main weight-bearing bone of the antebrachium
140
Styloid process
Pointed process located at the distal end of radius
141
Carpus
Consists of two rows of carpal bones, in humans it's wrist, in horses knee
142
Metacarpal bones
Extend distally from the distal row of carpal bones to the proximal phalanges of the digits, in hums bones of wrist to first knuckle, horses have only one large, dogs/cats have 5
143
Phalanges
Individual bones that make up the digits
144
Ungual process
Each distal phalanx contains one, surrounds the claw
145
Pelvic sumphysis
Cartilaginous joint joining the two halves of the pelvis ventrally
146
Ilium
The cranial-most bone of the pelvis, hips
147
Ischium
The caudal-most pelvic bone, you sit on it
148
Pubis
The smallest of the 3 pelvic bones, located medially and forms the cranial portion of the pelvic floor, and the ischium forms the caudal part
149
Acetabulum
A deep socket that tightly encloses the head of the femur to form the relatively stable hip joint
150
Obturator foramina
2 large holes located on either side of the pelvic symphysis, lightens the pelvis
151
Femur
The long bone of the thigh
152
Stifle joint
Equivalent to our knee, the shaft of the femur is fairly straight and extends down to the distal end to form this
153
Patella
Kneecap, largest sesamoid bone, helps protect tendon
154
Fabellae
2 small sesamoid bones located in the proximal gastrocnemius or calf muscle tendons just above and behind the femoral condyles of dogs and cats
155
Tibia
The main weight-bearing bone of the lower leg
156
Tibial crest
Ridge on tibia distal from tibial tuberosity
157
Fibula
A thin but complete bone in dogs and cats that parallels the tibia and consists of a proximal extremity, a shaft, and a distal extremity
158
Tarsus
Our ankle, in 4-legged animals commonly called hock, consists of 2 rows of short bones known as tarsal bones
159
Calcaneal tuberosity of the fibular tarsal bone
Projects upward and backwards to form the point of the hock
160
Metatarsal bones
Almost exactly the same as metacarpal bones, bones of our feet
161
Visceral skeleton
Consists of bones that fomr in soft organs or viscera
162
Os cordis
A bone in the heart of cattle and sheep that helps support valves of the heart
163
Os penis
A bone in the penis of dogs, beavers, racoons, and walruses that partially surrounds the penile portion of the urethra
164
Os rostri
A bone in the nose of swine that strengthens the snout for rooting behavior of pigs
165
Arthro-
Refers to joints
166
3 general classifications of joint in the animal body:
Immovable fibrous joints, the slightly movable cartilaginous joints, and the freely movable synovial joints
167
Anatomic term for fibrous joints:
Synarthroses
168
Fibrous joints
Are immovable in that the nones are firmly united by fibrous tissue
169
Cartilaginous joints
Termed amphiarthroses, capable of only a slight rocking movement
170
Synovial joints
Termed diarthroses, freely movable joints, contain a joint cavity, a joint capsule, and ligaments
171
Diarthroses
Anatomic term for synovial joints
172
Another term for joint cavity
Joint space
173
Synovial membrane
Thin barrier than lines the inside of some joints
174
Synovial fluid
Lubricates the joint surfaces, produced by the synovial membrane, typically transparent and a thicker viscosity
175
Ligaments
Bands of fibrous connective tissue that are present in and around many synovial joints
176
Meniscus
Shallow, concave, half-moon shaped fibrocartilage structures
177
Stifle joint
Equivalent to our knee
178
Patellar ligament
Provides support on the front of the stifle joint
179
Quadriceps femoris tendon
Patella and kneecap are embedded into this
180
Collateral
Means "on both sides"
181
Flexion
Decreases the angle between two bones, opposite of extension
182
Extension
Opposite of flexion, increases the angle between two bones
183
Adduction
The movement of an extremity toward the median plane, opposite of abduction
184
Abduction
Opposite of adduction, movement away from the median plane
185
Rotation
Twisting movement of a part on its own axis
186
Circumduction
The movement of an extremity so that the distal end moves in a circle
187
Types of Synovial Joints
Hinge joints, gliding joints, pivot joints, and ball-and-socket joints
188
Hinge joints
Also called ginglymus joints, one joint surface swivels around another, example is elbow joint
189
Gliding joints
Also known as arthrodial joints, the joint surfaces of a gliding joint are relatively flat and the movement btwn them is a rocking motion of one bone on the other, example is carpus or wrist
190
Pivot joints
Also known as trochoid joints, one bone pivots or rotates on another, the only movement possible is rotation. Only one true pivot joint found in animals is the joint btwn the first and second cervical vertebrae-the atlantoaxial joint
191
Ball-and-socket joints
Also called spheroidal joints, allow the most extensive movements of all the joint types and allow the synovial joint movements. Permits flexion, extension, abduction, adduction, rotation, and circumduction. Hip and shoulder joints are examples
192
