Lectures 31-32 Skeletal System Flashcards
Appendicular skeleton includes
-limbs
-girdles
Axial skeleton includes (3)
-vertebrae
-ribs
-sternum
There are over __ bones in most mammals
200
Components of the musculoskeletal system (5)
-bones
-joints
-muscles (skeletal)
-nerves
-blood vessels
Majority of bones are in the
Feet
Bones of the limbs and girdles are part of the
Appendicular skeleton system
Vertebrae, ribs and sternum are part of the
Axial skeletal system
Cranial means
Skull (head)
Vertebral column is comprised of
-cervical (C)
-thoracic (T)
-lumbar (L)
-sacral (S)
-caudal (Ca)
There are always __ in the cervix
7
Spinal cord passes through
Vertebral foramen
Typical vertebra consists of (4)
-body/centum
-neural arch (laminate and pedicel)
-processes (articular, spinous, and transverse)
-articular surfaces
There are always seven ____ vertebra
Cervical
First two cervical vertebrae are
-atlas
-axis
The atlas and axis are
The first two specialized cervical vertebra
The atlas (3)
-Holds up the head
-small and irregular
-large wings
What is cranial to the axis
Atlas
What is caudal to the atlas
Axis
The axis
-is caudal to the atlas
-C2
-has large spinous processes
The atlas lacks
Spinal processes
Thoracic vertebra (2)
-are the attachment sites to the ribs
-have tall spinous processes
Lumbar vertebra (2)
-have large, forward transverse processes
-are “locked” together for less movement
Sacrum (2)
-fusion of 3 vertebrae that articulate with pelvis
-have no movement
Horses/cattle have ___ sacral vertebrae
5 (increased # with increased size)
Fusion of the sacral vertebrae is for
Absorption of force during locomotion
Caudal/Coccygeal vertebrae (5)
-vary between and within species (tail)
-are long and narrow
-have small processes
-are mobile
-posses hemal arches and processes
Ribs consist of (3)
-sternal (true)
-asternal (false)
-floating
Ribs consist of
-sternal (true)
-asternal (false)
-floating
Asternal ribs
Have an indirect attachment to the sternum
Floating ribs
Have no connection to ribs, but connect to vertebral column
Sternum consists of (3)
-manubrium (most cranial)
-sternebra
-xiphoid cartilage (most caudal)
Costochondrial junction
Links costal cartilage to bone of ribs
Costochondrial junction means
Costo = ribs
Chondrial = cartilage
The knee is the
Stifle
The heel of your foot is
Tarsus/hock
Three phalanges
-proximal
-middle
-distal
Digit one lacks
Middle phalange
The most medial digit is
Digit I
The most lateral digit is
Digit V
The horse’s pentadactyl limb (2)
-has a fused radius/ulna
-moves on the fingernail of the middle finger
The thoracic/pectoral girdle is
The scapula
Scapula includes (4)
-clavicle
-supraglenoid tubercle
-spine
-glenoid cavity
The glenoid cavity of the scapula
Articulates with the shoulder
The spine of the scapula
Increases surface area for muscle attachment
Greater tubercle of humerus is used for
Muscle attachment
Trochlea of humerus
Most caudal groove
Main parts of the humerus (7)
-head
-greater tubercle
-deltoid tuberosity
-radial fossa
-olecranon fossa
-lateral epicondyle
-trochlea
The trochlear notch of the ulna
Articulates with the humerus
Carpals
two rows (proximal and distal) of four bones
Proximal carpals includes (4)
-radial
-intermediate
-ulnar
-accessory
There are ___ distal carpals
4
There are ___ metacarpals
5 (one for each digit)
Digits have
Phalanges (proximal, middle, distal)
Digit I is also called
Thumb / dewclaw
The pelvic limb is
Solidly joined directly to vertebral column via pelvic girdle
The hip joint is the
Acetabulum
Os coxae (2)
-makes up half the pelvic girdle
-includes ilium, ischium, and pubis
Acetabulum literally means
Acetum = vinegar
-abulum = small cup
The head of the femur
Articulates with the acetebulum to form the hip joint
The trochanter of the femur
Is a raised area of bone for muscle attachment (called Tubercule in the forelimb)
The knee cap is
The patella
The patella is (2)
-a sesamoid bone (sits on tendon and moves to reduce friction over a joint)
-also called the knee cap
The stifle joint
Sits caudal to the femur
Which is thinner: tibia or fibula
Fibula
Tibia
Weight bearing bone of hindlimb
Tarsals are divided into
-proximal (talus, calcaneous, central)
-distal (4)
The proximal tarsals are
-talus
-calcaneous
-centrale
How many distal tarsals are there
4
The metatarsalas and digits are
The same as the forelimb (5 for each)
Forelimb bones: (6)
-scapula
-humerus
-radius and ulna
-carpus
-metacarpus
-phalanges/digits
Hindlimb bones are (6)
-pelvis (ilium, ischium, and pubis)
-femur
-tibia and fibula
-tarsus
-metatarsus
-phalanges/digits
There are only ___ moveable joints in the skull
2
What are the moveable joints of the skull
-temporal-mandibular joint (jaw)
-tympani-hyoid joint (supports larynx)
Most joints in the skull are
Sutures (ie. immovable, rigid, stable, and short)
Young suture joints are ____ while adult suture joints are ____
Short and fibrous tissue; short and bony tissue
Facial bones (2)
-are more rostral
-include oral and nasal cavities
The cranial bones
Enclose the brain and ear
Facial bones include (6)
-maxilla
-incisive
-nasal bones
-palatine
-lacrimal
-zygomatic
Cranial bones include (6)
-occipital
-sphenoid
-pterygoid
-frontals
-parietals
-temporal
The maxilla houses
Canines, premolars, molars and hard palate
Incisive bone is
-the most rostral
-houses incisor teeth
Nasal bones are
Two long, thin bones on the roof of the nasal cavity
Palatine bone is
The soft palate
Lacrimal bone
Corner of the eye where tear ducts enter
Zygomatic bone
-located caudal to maxilla
-cranial aspect of zygomatic arch
The orbit is
The eyeball
The zygomatic arch
-helps protect the orbit
-cheek bone
The most caudal cranial bone is
Occipital
What articulates with the atlas
Occipital condyles
The spinal cord enters the brain through
Foramen magnum
What two structures are found in the sphenoid bone
-optic canal (round hole where optic nerve goes to retina)
-orbital foramen (oval hole where nerves go to eye muscles)
The optic canal and orbital foramen are located in
The sphenoid
Most ventral cranial bone
Pterygoid
Large part of the roof of the skull
Frontal bone
The parietal bone is
-caudal to frontal bone
-has a sagittal crest running through the midline
-also temporal lines
Temporal bone houses
The ear
Three parts of the temporal bone
-squamous
-tympanic
-petrosal
The squamous temporal is
The outer ear
The tympanic temporal is
The middle ear (contains malleus, incus, and stapes)
The squamous temporal extends to
The zygomatic arch
The malleus, incus, and stapes are in
Tympanic temporal (middle ear)
The petrosal temporal is
The inner ear
The petrosal temporal (inner ear) houses the
Cochlea
All bottom teeth are housed
In the mandible
The angular process does___ while the coronoid process does ____
Jaw down; jaw up
Jaw down motion is controlled by the
Angular process
Jaw up movement is performed by
The coronoid process
The mental foramen is located ___ and provides
Most rostral of the mandible; Nerves
Snakes can extend the ___ of the mandible
Symphysis
The chin is also called
Symphysis
