Chapter 7- Skeletal system Flashcards
List the cell types that compromise bone
Osteoblasts, osteocytes and osteoclasts
Describe the function of Osteoblasts
Rapidly dividing bone cells
Describe the function of Osteocytes
Mature bone cells- they can revert back to osteoblasts.
Make the matrix
Describe the function of osteoclasts
Eat away bone. Can allow the calcium level in the blood.
List the functions of bone
Support
Protection
Blood Cell formation
Leverage
Storage- Calcium
Differentiate between cancellous bone and compact bone
Cancellous- Light and spongey
Spicules randomly arranged throughout
Highly vascular
(bone marrow)
Compact- heavy and dense
tight, tiny, compacted cylinders of bone - Haversian Systems and canaliculi
Outside layer of all bones
Describe the process of endochondral bone formation and growth
Cartilage template replaced by bone
Primary growth center is diaphysis
Secondary growth center is epiphysis
- cartilage cells creates cartilage along epiphyseal plate
-Osteoblasts replace cartilage with bone
-when bone is full size epiphyseal plates ossify
Describe the process of intramembranous bone formation
Occurs only in certain skull bones
Bone develops from fibrous membrane tissues
List and describe four bone shapes
Long, short, flat, irregular
Long bones
Extremities
Main part is the diaphysis (long part)
Also has epiphysis (ends)
Short bones
In joints
Core of sponge y bone covered by thin layer of compact bone
Examples are carpal bones
Flat bones
Skull bones and scapula
Two thin plates of compact bone separated by layer of cancellous bone
Irregular bones
Vertebrae and sesamoid bones
(Patella is the largest sesamoid bones)
List the components of axial and appendicular skeletons
Axial - located along axis
- bones of the head, spine, hyoid and trunk
Appendicular
-bones of the limbs
Name the internal and external bones of the face
External (landmark)
Incisive bone
Lacrimal bones
Mandible
Maxilary bones
Nasal bones
Zygomatic bones
Internal (hidden)
Palatine bones
Pterygoid bones
Turbinates
Vomer bone
List the division of the spinal column
Cervical
Thoracic
Lumbar
Sacral
Coccygeal
Describe the structure of ribs and the sternum
Ribs-
Ribs
Costochondral junction
Coastal arch
Floating rib
Sternum-
Manubrium
Xiphoid process
Xiphoid cartilage
Sternebra
sternal attached to sternebra (7)
asternal ribs attached through costal arch (5)
floating ribs- not attached - 13
Ribs numbered cranially down
Name the bones of the thoracic and pelvic limbs
Bone
2nd hardest structure in the body
Connective tissue -
Sparse population if cells of cells embedded in a matrix
1/3 organic (collagen), 2/3 inorganic salts
Skeletal Matrix
The bone matrix is that part of the bone tissue and forms most of the mass of the bone. It is comprised of organic and inorganic substances. The organic component of the bone matrix includes the collagen and ground substance whereas the inorganic component is the inorganic bone salts
Lacunae
Small cavities within the matrix of some connective tissue (bone cartilage) that contain chondrocytes and osteocytes
Canaliculi
Tiny channels through bone connecting osteocytes
Ossification
Hardening of osteoblasts. Matrix is infiltrated with calcium and phosphate and hardens.
Haversian Systems
Makes up compact bone
Consists of central Haversian canal running lengthwise surrounded by concentric layers of bone
Epiphyseal Plates
Cartilage located between Epiphysis and Diaphysis
Sites where new bone develope
Red bone marrow
Majority of marrow in young animals but only a small amount in older
- In older, mostly in the epiphysis
Red bone marrow forms cell
Yellow bone marrow
Consists mostly of adipose connective tissue
Most common marrow in older animals
Can convert back to red bone marrow
Periosteum
Fibrous outer layer of the bones, except joint surfaces
Where tendons and ligaments connect
Has two layers
- inner: osteoblasts
- Outer: fibrous tissue
Endosteum
Fibrous membrane lining hollow interior of bone
Medullary Cavity
Inside the diaphysis
Volkman’s Canals
Blood supply to bones
Channels through bone matrix that contain blood vessels
Join at right angles to Haversian system
Nutrient Foramia
Large channels in long bones
Carry blood in and out of bone marrow
Also has lymph vessels and nerves
May resemble fracture in rads
Bone Marrow
Fills spaces within bone
Two types- yellow and red
hematopoietic tissue
Blood forming
List Bone features
Articular Surfaces - Joint surfaces
Processes - lumps, bumps and other projections
Holes and Depressions
Condyle
usually large, round articular surface
- distal end of femur and humorous are examples
Head (bone)
Somewhat spherical articular surface on proximal end of long bones
Joins with shaft of bone at the neck region
-humorous, femur, ribs
Facet
flat articular surface.
Joints movement between two facets a rocking motion
-carpal and tarsal bones
Processes (bone)
A general name for lump, bump or other projection on a bone
Foramen
Hole in bone that may contain blood vessels or nerves
Fossa
Depressed area on surface of bone
(example, wings of scapula)
Articular surfaces
Smooth areas of compact bones where bones contact each other and form joints
-Each is covered by hyaline cartilage called articular cartilage
Name the bones of the cranium
External
Frontal
interparietal
occipital
parietal
temporal bones
Internal
ethmoid
sphenoid
Name the bones of the ear
incus
malleus
Stapes
Function to transmit vibrations
They form the tympanic membrane in the inner ear
Name the bones of the thoracic limbs
Scapula
humerus
radius
ulna
carpal bones
metacarpal bones
Phalanges
Name the bones of the Pelvic Limbs
Pelvis-
-ilium
-ischium
- pubis
Femur
Tibia
Fibula
Tarsal bones
Metatarsal bones
Phalanges
Visceral skeleton
Heterotopic skeleton
Bones formed in soft organs
Skull
Most bones united by immovable, jagged joints called sutures
Mandibles are united by synovial joints
All skulls have 37 to 38 bones
Synovial joints
the ends of bones are encased in smooth cartilage
Sutures
The immovable fibrous joints that unite most skill bones
(Also know as synarthroses)
Vertebrae anatomy
Contains a body, arch and processes
Separated by intervertebral discs (made of fibrcartilage)
Processes include
- spinous process (Dorsal)
- transverse processes (lateral)
- articular process (cranial/caudal)
Vertebral foramen (where the nerves go)
Vertebral arch
Number of vertebrae in dogs and cats
7 cervical
13 thoracic
7 lumbar
3 sacral
lots - depending on individual- coccygeal
Vertebrae regions
cervical
thorax
lumbar
sacral
coccygeal
Number of vertebrae cattle
cervical -7
thorax -13
lumbar -6
sacral - 5
coccygeal 18 - 20
Number of vertebrae horse
cervical - 7
thorax - 18
lumbar - 6
sacral - 5
coccygeal - 15- 21
Cervical vertebrae
Always 7
Atlas is C1. It has wings
Axis is C2 - has a large spinous process and pens that fit into the atlas
Thoracic vertebrae
13 in dogs, cats, cattle and 18 in horses
have tall spinous processes
lateral articular facets form joints with ribs
Lumbar vertebrae
7 in dogs and cats, 6 in horse and cattle
most massive of the spine (support weight of abdomen without aid of ribs)
Sacral vertebrae
3 in dogs and cats, 5 in horses and cattle
Fuse to form the sacrum.
With pelvis forms the sacroiliac joint
Coccygeal Vertebrae
Bones of tail
Carpas
Wrist of dogs and cats, knee of horses
In dogs and cats made of 7 bones
Metacarpal bones
Numbered by roman numerals- lateral to medial - 5,4,3,2, the dew claw (our thumb), would be 1
Phalanges
Numbered lateral to medial (pinky towards thumb)
3 bones in each toe
Proximal, middle, distal
In horses 1 and 2 are vestigial
Cattle phalanges 3 and 4 fused
Thoracic limb
No bony connection to scapula
Scapula
Humerus
olecranon
radius
ulna
carpal
metacarpal
phalanges
Glenoid cavity
Socket of the scapula
Radius
The weight bearing bone
Shorter
brachium
Forearm/humerus
And antibrachium is the radius and ulna
Equine/Bovine
Radius and ulna fused together
Horses
From Carpus distal
They have an Accessory carpal
Horses only run on digit 3
Digit 2 and 4th metacarpal are vestigial and called the splint bone
Digit 3 metacarpal is the cannon bone
Then is proximal sesamoid
Long pastern - proximal phalanx
Short pastern - middle phalanx
Navicular (sesamoid bone - kind of like a pillow)
Coffin- distal phalanx
Canon bone is metacarpal number 3
Bovine
Sesamoid bones 2 proximal, 1 distal
Run on phalanges 3 and 4 which are fused
On hindlimb phalanges 2 and 5 are dew claws
Pelvic limb
Limb connected to axial skeleton through the sacroiliac joint
Pelvis
-ilium
-ischium
-pubis
Femur
patella
fabulae
tibia- thick
fibula- fine, frail (not weight bearing)
tarsal bones/hock- 7
metatarsal
phalanges
Horse pelvic limb
tibia/fibula joint fused
stifle - knee
hock- ankle
Pelvis
3 fused bones
Ilium largest of the 3 bones. Has “wings”
ischium posterior - posterior- ischium has obturator foramen
Pubis (middle) -the two pubis bones create a fusion line
Pelvic limb sesamoid bones
Stifle/knee joint
Patella - large sesamoid (true bone)
Fabellae - 2 small sesamoid bones
- not present in horse and cattles
Most sesamoid bones are cartilage only
Visceral skeleton
Heterotopic/Form in soft organs
Os cordis - heart in cow
Os penis - penis (bone in dogs, cartilage for cats)
Os rostri - nose (pigs)
Joints
Junctions between bones
3 types
-fibrous, cartilaginous, synovial
Fibrous joints
Immovable joints
Firmly united by fibrous tissue
Examples- suture in skull, equine splint bones
Cartilaginous joints
Slightly movable joints (slight rocking motion)
intervertebral discs, pubic symphys, mandible symphys
Synovial joints
Freely movable joints
Have articular surfaces on bones
Articular cartilage covering articular surfaces
Joint cavity - encloses joint
–synovial membrane and synovial fluid
ligaments (some) - fibrous connective tissue
Anatomy of joint
Joint capsule
meniscus
Extracapsular (part of joint capsule)- collateral
Intracapsular (inside joint) -cruciate
Synnovial joint moments
Flexion - decrease angle (bend joint)
Extension - increase angle
Adduction- movement towards median plane
Abduction- movement away from median plane (inrcease distance between joints)
rotation -twisting movement on own axis (palm moving up)
circumduction - movement of joint so distal end goes in circle. (moving hand in a circular movment)
Types of synovial joint
hinge (only flexion and extension) - elbow
Gliding-(example carpus) primarily rocking/some abduction/adduction possible
Pivot joints- one bone rotates on other - yes and no
Ball and socket - all types of movements
