Equine Skeletal System Flashcards
1
Q
What forms the Axial Skeleton?
A
Spine (vertebral column)
Skull
Ribs & Sternum
2
Q
Spine
How many Cervical Vertebrae are there,
A
7, including C1, known as Atlas, and C2, known as Axis
3
Q
Spine
How many Thoracic Vertebrae are there?
A
18
4
Q
Spine
How many Lumbar Vertebrae are there?
A
6
5
Q
Spine
How many Sacral Vertebrae are there?
A
3 (fused)
6
Q
Spine
How many Coxygeal Vertebrae are there?
A
Approx. 20
7
Q
Spine
What is the purpose of the Vertebral Body, and what sort of joint connects the Vertebral Bodies together?
A
Provide support
Fibrocartilagenous Joints
8
Q
Spine
What is the Vertebral/Neural Arch, and what does the sum of Vertebral Arches create?
A
Arch over theVertebral Body
Creates the Spinal Canal, housing the spinal cord
9
Q
Spine
Through what do the spinal nerves leave the spinal canal through?
A
Intervertebral Formina
10
Q
Spine
What are Intervertebral Discs, and what is there purpose?
A
Fibrous Cartilage between vertebrae
Shock absorbers
11
Q
Spine
What is the purpose of Vertebral Processes?
A
Influence how much movement there is in parts of the spine
Attachments for ligaments and muscles
12
Q
Spine
Which way do Transverse Processes project, and in which vertebrae are they primarily found?
A
Project to the side
Lumbar Vertebrae
13
Q
Spine
Which way do Dorsal Spinal Processes project, and in which vertebrae are they largest?
A
Project Dorsally (upwards)
Thoracic Vertebrae - forming withers
14
Q
Spine
What joints Articular Processes form, and what is their purpose?
A
Synovial Joints
Control range of motion vertebrae are capable of
15
Q
Spine
What are the 3main functions of the spine?
A
House and protect spinal cord
Allow movement
Allow transmission of strong, propulsive forces from the hind limbs
16
Q
Spine
In which directions does the Cervical Spine have movement?
A
Extensive mobility in all directions
17
Q
Spine
In which directions does the Thoracic Spine have mobility?
A
Can flex and extend in a dorsoventral and lateral direction
18
Q
Spine
In which direction does the Lumbar Spine have mobility?
A
Dorsoventral flexion, but no lateral mobility
19
Q
Spine
In which direction does the Sacrum have mobility?
A
None, it is a fused, direct link between pelvis and spine
20
Q
Skull
How many bones are there in the skull, and what types of bone are they mainly?
A
34
Flat bones
21
Q
Skull
What joints connect the bones of the skull?
A
Skull Sutures
22
Q
Skull
What are the two main parts of the skull?
A
Cranial and Facial skull
23
Q
Skull
What cavity is contained in the Cranial Skull?
A
Cranial Cavity - houses the brain
24
Q
Skull
What cavities are contained in the Facial skull?
A
Oral cavity (mouth) Nasal cavity (nostrils) Orbital cavity (eyes)
25
Skull
What bones are contained in the Nasal cavity, and to what sinuses is the Nasal cavity connected?
Turbinate Bones
| Paranasal Sinuses
26
Skull
What are the two jaw bones called?
```
Maxillary Bone (upper jaw)
Mandibular Bone (moveable lower jaw)
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27
Skull
What is the function of the skull?
Houses brain and other sensory organs
28
Ribs
How many pairs of ribs are there?
18
29
Ribs
Dorsally, what do all ribs form a joint with?
The small transverse processes of the thoracic vertebrae
30
Ribs
How many pairs of Sternal/True ribs are there?
8
31
Ribs
Where do True ribs attach to, and with what sort of joint?
Sternum
| Fibrocartilagenous Joint
32
Ribs
How many pairs of Asternal/Floating/False ribs are there?
10
33
Ribs
What is the difference between false and true ribs?
False ribs have no direct connection to the sternum, and have a larger range of motion than true ribs
34
Sternum
What shape is the sternum and where is it situated?
Elongated segmented shape
| Situated ventral,y in region of girth
35
What do the ribs, sternum and thoracic vertebrae form together?
Rib cage
36
Rib Cage
What does the rib cage surround and what's it's purpose?
Thoracic cavity and first part of the abdominal cavity
| Protects organs within
37
Rib Cage
What is the movement of ribs responsible for?
Expansion and contraction of rib cage - basis of breathing (inspiration and expiration)
38
What makes up the Appendicular Skeleton?
Limbs and pelvis
39
Proximal Forelimb
What makes up the proximal forelimb and how is it attached to the Axial Skeleton?
Scapula down to and including the Carpus?
| Not directly attached to Axial Skeleton - attached by muscle and ligament so has a large RoM
40
Proximal Forelimb
What is the shape of the Scapula?
Large flat bone, triangular with a broad section of cartilage on the upper edge acting as a shock absorber
41
Proximal Forelimb
What is the purpose of the Spine of Scapula?
Attachment for muscles which flex and extend the shoulder
42
Proximal Forelimb
What is the Spine of Scapula?
Large bony process on the outer surface of the scapula
43
Proximal Forelimb
What sort of joint does the Humerous form with the Scapula at the proximal end?
Ball and socket (shoulder joint)
44
Proximal Forelimb
What sort of joint does the Humerous form with the Radius and Ulna at its distal end?
Hinge joint (elbow)
45
Proximal Forelimb
What is the usual angle between the Scapula and the Humerous?
90 degrees
46
Proximal Forelimb
Where is the Humerous found?
Top of the forelimb, between the shoulder and elbow joints
47
Proximal Forelimb
Where are the Radius and Ulna?
Radius extends from elbow to carpus
| Ulna forms lower part of elbow but only makes up the upper 3rd of the radius
48
Proximal Forelimb
What is the large bony protuberance at the top of the Ulna called, and what is its purpose?
Olecranon
| Attachment for muscles which extend elbow
49
Carpus
How many bones are in the proximal row of carpal bones?
4
50
Carpus
What is the outermost bone in the proximal row of carpal bones?
Accessory Carpal Bone
51
Carpus
How many bones are there in the distal row of carpal bones?
3-4
In a fully grown horse two of the bones may be fused
52
Carpus
What is the joint between the Radius and the proximal row of carpus bones called?
What kind of joint is this, and what movement does it have?
Radiocarpal joint
Incongruent synovial joint
Allows flexion, extension and a certain degree of rotation
53
Carpus
What is the joint between the proximal and distal row of carpal bones called?
What type of joint is this, and what movement does it have?
Intercarpal joint
Incongruent synovial joint
Flexion, extension and a certain degree of rotation
54
Carpus
What is the joint between the distal row of carpal bones and the metacarpal bones (cannon and splint) called?
What type of joint is this and what movement does it allow?
Carpometacarpal joint
Arthrodial joint
Small range of gliding motion
55
Hindlimb
Where is the proximal hindlimb?
Pelvis down to and including the tarsus
56
Pelvis
What are the 3 fused bones that make up each half of the pelvis?
Ilium - largest, most cranial part - creates points of hip
Pubic bone - centre on ventral aspect
Ischium - most caudal part, extending into points of buttock (Ischial Tuberosity)
57
Pelvis
What is the cavity of the hip joint where the 3 bones join known as?
Acetabulum
58
Pelvis
What is the fibrocartilagenous joint which joints the two halves of the pelvis together called?
Pubic Symphis
59
Pelvis
What is the joint created by the wings of the iliac bones and the sacrum called?
Sacroiliac joint
60
Pelvis
What type of joint is the sacroiliac joint and why does it have a very limited range of motion?
Synovial joint
Strong ligaments - firm connection endures efficient transfer of propulsive forces generated by hind limbs to spine and trunk
61
Proximal hindlimb
What movement does the hip joint allow?
Flexion and extension, with minimal adduction and abduction
62
Proximal hindlimb
What bones create the hip joint, and what type of joint is it?
Acetabulum of pelvis and the femur
| Ball and socket joint
63
Proximal hindlimb
What is the large bony protuberance below the hip joint called, and what is its purpose?
Trochanter major
| Muscle attachment
64
Proximal hindlimb
What bones create the stifle joint?
Distal end of femur, patella and tibia
65
Proximal hindlimb
What does the patella glide through when the stifle is flexed?
The groove between the trochanter ridges of the femur
66
Proximal hindlimb
What is the joint between the femur and patella called (part of stifle)?
Feneropatellar joint
67
Proximal hindlimb
What is the joint between the femur and tibia called?
Femerotibial joint
68
Proximal hindlimb
What type of joint is the femerotibial joint, and what else is in the joint to make it a better fit?
Incongruent joint with two cartilangenous discs (menisci)
69
Proximal hindlimb
Which ligaments help stabilise the stifle joint?
Two cruciate ligaments (patellar and colateral)
70
Proximal limb
What is the horses lower leg known as?
Gaskin
71
Hindlimb
Which bone is the only fully developed one in the lower leg?
Tibia
72
Hindlimb
Where do the patellar ligaments attach on the tibia?
Tibial Tuberosity (bony protuberance st the front below the stifle joint)
73
Hindlimb
Which bones does the tibia articulate with at its distal end?
Proximal row of tarsal bones
74
Hindlimb
Where is the fibula situated?
Thin vestigal bone which runs alongside the side and back of the upper half of the tibia - sometimes fused to the tibia
75
Tarsus
How many tarsal bones are there, and in how many rows are they arranged?
6 arranged in 3 rows - proximal, middle and distal
76
Tarsus
What is the bone called which has two large rounded trochlea?
Talus
77
Tarsus
What is the joint called that is formed by the trochlea of the Talus and the distal end of the tibia?
Tibiotarsal / Tarsocrural joint
78
Tarsus
What kind of joint is the tibiotarsal / Tarsocrural joint, and how much mobility does it have?
Hinge joint - only tarsal joint with a lot of mobility
79
Tarsus
What is the bone called which lies behind Talus?
Calcaneous
80
Tarsus
What is the purpose of the Calcaneal Tuberosity?
Site of attachment for tendons of hock flexor muscles
81
Tarsus
What are the joints called between the upper, middle, and lower rows of tarsal bones?
Proximal and Distal Intertarsal joints
82
Tarsus
What is the joint called between the distal roe of tarsal bones and the metatarsal bones (splint and canon)?
Tarsometatarsal joint
83
Tarsus
What types of joints are the Intertarsal and tarsometatarsal joints, and what is there function?
```
Amphiarthrodial joints (practically immobile, minimal forward and backward gliding motion)
Shock absorption
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84
Tarsus
What is arthritis of the Intertarsal and tarsometatarsal joints known as?
Bone spavin
85
Distal limb (fore and hind)
What are the bones of the canon region known as in the fore and hind limbs?
Metacarpal /Metatarsal bones
86
Distal limb (fore and hind)
Which metacarpal/tarsal is fully developed, and what are the splint bones?
3rd (canon bone)
| Remains of 2nd and 4th metacarpal/tarsals
87
Distal limbs (fore and hind)
Which joints are formed between the canon bone and the distal carpal/tarsal bones?
Carpometacarpal / tarsometatarsal joints
88
Distal limb (fore and hind)
Which joint is formed by the central logitudinal ridge of the distal edge of the canon and the corresponding groove on the Articular edge of the proximal phalanx?
Fetlock / metacarpophalangeal joint (hinge joint)
89
Distal limb (fore and hind)
What is the difference between the canon bone in the fore and hind limbs?
Hind canon is longer and has a more roundish cross section compared to oval cross section of forelimb canon
90
Distal limb (fore and hind limb)
How far above fetlock X do the splint bones end?
10cm above fetlocks
91
Distal limb (fore and hind)
How are the splints bones attached to the canon bone, and what is it called when they become ossified?
Strong bands of fibrous tissue
| Splints
92
Distal limb (fore and hind)
What are the joints called between the canon bone and proximal phalangeal bones?
Metacarpophalangeal (fore) / metatarsophalangeal (hind)
93
Distal limbs (fore and hind)
Where are the proximal sesamoid bones located and what shape are they?
Two triangle bones with the base at the distal end and apex at proximal end, located at the back of the fetlock
94
Distal limbs (fore and hind)
What apparatus are proximal sesamoid bones embedded within, and what tendons does the smooth outer surface act as a guide pulley for?
Suspensory apparatus
| DDFT /SDFT
95
Distal limbs (fore and hind)
What forces are the proximal sesamoid bones subject to?
Strong tensile and compressive forces
96
Distal limbs (fore and hind)
What does extension of the fetlock cause?
Tensile strain on suspensory apparatus
| Considerable compressive forces on sesamois by canon bone and flexor tendons
97
Distal limbs (the digit)
Approximately how long is the proximal phalanx/long Pastern bone/P1?
Approx. 10cm
98
Distal limbs (the digit)
What joint does the proximal phalanx form with the middle phalanx, and what sort of joint is it?
Pastern joint / proximal Interphalangeal joint
| Saddle joint
99
Distal limbs (the digit)
What joint does the middle phalanx / short Pastern bone/ P2 form with the Pedal bone and what sort of joint is it?
Coffin joint / Distal Interphalangeal joint
| Saddle joint
100
Distal limbs (the digit)
What bone does the back of the middle phalanx articulate with?
Navicular bone
101
Distal limbs (the digit)
Why is the cortex of the distal phalanx/pedal bone/coffin bone not well developed?
Many holes in the cortex (Formina) for blood vessels to supply the dermis of the hoof
102
Distal limbs (the digit)
What is the main function of the smooth back of the navicular bone/distal sesamoid bone?
Guide pulley, guiding the DDFT round the coffin joint
103
Distal limbs (the digit)
What are the two colateral cartilages attached to the medial and lateral processes at the back of the pedal bone called?
Hoof and Ungular cartilages
104
Distal limbs (the digit)
What is the purpose of the hoof and Ungular cartilages?
Shock absorbers during movement
105
Distal limb
What diseases are the distal limb joints likely to suffer from?
Chronic Inflammatory Disorders such as arthritis and arthrosis
