ch 4 - boney skeleton Flashcards
role bones play
• Provide a framework that supports the body (keep us upright, provides mobility)
• Provides sites for muscle attachment
• Protective covering for certain organs and regions of the body (ex. Skull protects the brain)
• Certain bones contain red bone marrow (flat) which produces new red blood cells (hemopoietic tissue)
– Bones that don’t have red bone marrow contain yellow bone marrow that contains fat and serves as an energy storage
• Bone acts as a storage medium and “buffer” for calcium in the blood. (Homeostasis)
– This helps to maintain a stable pH
types of bones
classified according to
- type of bone tissue
- general morphology of bone
types of bone tissue
Compact bone and rims of the bone – solid
This is the external part of the bone
Contain pillar like structures called osteon
Osteon has many rings
Spongy bone (trabecular = web-like)
Spongy on the inside
Internal web like
general morphology of bone
– Long bones (humus, femur, finger bones, ribs)
– Short bones (wrist bones, ankle bones)
– Flat bones (sternum, skull bones)
– Irregular bones they don’t fit into any categories
- Sesamoid bones: bones that are not attached to other bones but are embedded in a tendon
what makes bones strong
– The pillar like structures called Osteon and millions of these line up parallel to each other in the compact region
– Osteon is made up of collagen fibres which prevent cracks in bones as they are lined up in a parallel formation
– This organization makes bones very strong
– This pillars are organized to withstand the pressures and forces that they are exposed to
osteon
Central canal is the centre of the Osteon
– This is where vessels are situated
– The gaps are filled in the center with these vessels – in parallel to the osteon and these to add strength
Hollow rods are more lighter than solid rods and that is why bones are hollow
axial skeleton
• These are bones that are near proximity to the axis of symmetry
A. Skull
B. Vertebral column
C. Bony thorax (ex. sternum)
skull
• Made up mostly of flat bones
• Brain’s protective shell, but it is quite thin. This thinness doesn’t not limit its strength because the shape of the skull ensures its strength
– The curvature of the skull distributes and force applied to the skull
skull - sutures
• Joined by sutures
– Sutures have a jagged appeared where the bones meet and are very strong
– Not stitches but fibrous joints
– These are Synarthrodial joint (suture) which means they are not easily movable (vs. amphi and di-)
– Sutures leave small little holes known as foramen (these are bones that have joined together, but not fully as they leave gap)
skull - foramen
• Contain foramina for passage of nerves and vessels
– A true foramen: is where the hole is completely in cased by bone (not cartilages, not a ligament, etc)
bones of the skull
Can be categorized into 2 groups Cranium and facial bones
– Cranial bones: has some contribution to the cranial cavity (space where brain lies)
o Participates or forms some of the cranial
– Facial bones: all the other bones of the skull
cranial bones
Cranium has 8 large cranial bones (2 paired bones -> Parietal and Temporal) UNPAIRED -> SINGLE BONES
frontal, parietal (x2), temporal (x2), occipital, sphenoid, ethmoid
frontal bone
– Forms the forehead and the anterior portion of the cranial cavity
– The suture that joints the frontal bone to the parietal is known as the coronal suture
parietal
– Forms the roof of the cranial cavity
– The two parietal bones are jointed by the sagittital suture ( in the sagittal plane)
temporal
– There are 2 landmarks on the temporal bone
– Mastoid process is part of the temporal bone (means breast like shape) (many ligaments and muscles are attached to this)
– Styloid process (means column like) is part of the temporal bone located in front of the mastoid process (THIN AND LENGTHY; attachment for muscles and ligaments)
– Temporal -> time
– Grain of the hair over the temporal region to indicate age and wisdom?
occipital
– Located in the posterior skull
– Lying within or on-top are not the occipital lobes but the cerebellum
– The brain stem exists the cranial cravity through this side
sphenoid
– Forms a portion of the floor of the cranial cavity as it spans the width of the skull
– NOT a paired bone
ethmoid
- Forms the border between cranial and nasal cavity
other sutures
Lambdoid suture is between the parietal bone and the occipital bone (looks like a lambda symbol)
Occipital-temporal suture is between the occipital and the temporal bone
The squamous suture (means scale like) between the parietal and the temporal bone
pterion
(aka the boxer’s temple) it is a point of weakness and there is the medal (middle) meningeal artery (provides blood to brain (DURAL)) -> not all the bones but SEVERAL of them.
o blow to this region -> damage
o underneath the skull leads to confusion
facial and associated bones
There are 14 facial bones and they are much smaller than cranial
nasal (x2), maxillae (x2), zygomatic (x2), mandible, lacrimal (x2), palatines (x2), conchae (x2), vomer
nasal bones
– Paired bone
there are 2
– Mostly cartilage
maxillae
– Paired bone
– It extends into the mouth
– Fuses together right between the two front teeth
– Hard pallete -> 1/3 of the region is made of paired bone called pallentine
zygomatic
– Paired bones
– Form the cheek (holes)
mandible
– Jaw
– Holds the lower teeth
lacrimal
– Paired bone
– Located in the eye orbit (where the eye is)
– Has a small fossa that looks like a thumb print in the bone (called the lacrimal fossa) -> Fossa: places where structures attach
– Lacriminal fossa has a hole in it called the lacriminal foramen
– Lacriminal duct associated with lacrimincal gland that goes through lacriminal foramen
o The lacrimal gland sits on the lacrimal fossa which is a passage way for tears
o Duct bring it to nasal cavity as well -> sometimes u get a runny nose while crying
palatines
– Paired bones
– Forms part of the hard pallet (roof of the mouth)
– Portion of maxillae and palatine form hard roof
conchae
– Paired bones
– Bones by themselves that are in the nasal cavity
– Superior, inferior, middle concha
vomer
– In the nasal cavity that forms part of the septum
inside nasal cavity
- We moisten and warm air as well are remove foreign material in the atmosphere; this is done by a membrane
- The Concha, the perpendicular plate, and the vomer help create a larger surface area for the air to come in contact with the membrane
inside nasal cavity - the bones
The ethmoid bone (a cranial bone) protrude into the concha
– The superior concha of the ethmoid bone (not stand-alone bones; its ethmoid)
– The middle concha of the ethmoid bone
The Inferior concha should be known as just a concha bone
The perpendicular plate is also part of the ethmoid, so it is known as the perpendicular plate of the ethmoid bone
o Perpendicular plate of the ethmoid, along with the vomer forms the septum
not facial bones but close
Palatine bone is the roof of your mouth
A little lower than the skull is the hyoid bone
– It is an unpaired bone
– Located below the jaw
o When we swallow, we move the hyoid that moves the larynx
forgotten bones of the head
3 paired ossicles in middle ear (smallest bones in the body)
– Malleus = Hammer; Incus = Anvil; Stapes = Stirrup
– Eardrum -> tympanic membrane
– Vibrations from the tympanic membrane move the malleus which triggers vibrations of the incus and stapes
o Cranial nerve is responsible for sound reception
cranial fossa
Anterior fossa
– The frontal lobes
Middle fossa
– Temporal lobes are situated
Posterior fossa
– This is where the cerebellum is located
Cribriform plate
located on the top of the ethmoid bone
– The olfactory nerves run through these hole
– Crista galli is in the centre of the cribriform plate; they are the small holes in this plate which run all the way through the ethmoid bone and are entrances into the nasal bones
– Has a ligament called the faix cerebri
lesser wing
• The top of the anterior fossa is the lesser wing (of the sphenoid bone)
greater wing
• The greater wing (of the sphenoid bone) forms a portion of the middle fossa
optic foramen
• Optic foramen (optic canal) is near the lesser wing (x2)
sella turcica
Sella turcica is on the lesser wing
– It is where the pituitary gland sits
o Major endocrine gland
foramen rotunrum
x2)
– Is circular and there is one of each side
– Maxillary nerve runs through
foramen ovale
– Mendivular nerve runs through (involved in chewing)
foramen spinosum
– The middle meningeal artery runs through this foramenno
foramen lacerum
– Nothing runs through it
– It is covered over by a membrane though
jugular foramen
(on the posterior fossa)
– Jugular vein, cranial nerve 9, 10, 11, run through this foramen
**Cranial nerve (CN) 10 is aka the vagus nerve -> responsible for all the a parasympathetic functions of the brain
foramen magnum
– Large hole near the occipital bone
– Brain stem runs through this
• Hypoglossal canal are the tiny little holes around the foramen Magnum and CN 12 runs through
cranial nerves
there are 12 1 - olfactory nerve 2 - optic nerve 3 - oculomotor nerve 4 - trochlear nerve 5 - trigeminal nerve 6 - abducens nerve 7 - facial nerve 8 - vestibulocochlear nerve 9 - glossopharyngeal nerve 10 - vagus nerve 11 - accessory nerve 12 - hypoglossal nerve
fissures
• They create a passageway for nerves to enter the cranial cavity (much like foramen)
o Inside the eye orbit
• Unlike foramen, they look like large slashes
• Superior and Inferior orbital fissure lie on the same opening and therefore can be collectively called the Orbital fissures
• The 3 cranial nerves that are responsible for eye movements run through this fissure
vertebrae column
• 26 bones
• There is stability and mobility because the vertebrae aren’t stacked upon one another
Constant battle between stability and mobility STABILITY IS WHY ITS CURVED (WAVED)
vertebrae curvature
– Primary curvature -> present at birth
– Secondary curvature -> develop after birth
Curvatures are described as either concave or convex
*Important how they are described since a lot of disorders are associated with it
in order from top down - list the curvatures
cervical thoracic lumbar sacral coccyx
cervical curvature
curvature contains 7 vertebrae
– Concave posteriorly
– Convex anteriorly
– Secondary curvature: this means that is wasn’t present at birth (that is why we have to support the baby’s neck) when baby can hold up his head, later than 4 months
thoracic curvature
contains 12 vertebrae (RIBS)
– Convex posteriorly
– Primary curvature: it is present at birth
– Lateral aspect -> Exaggerated curve can be developed with age known as kyphosis (hunch back)
lumbar curvature
contains 5 vertebrae
– Convex anteriorly
– Secondary curvature: this means that is wasn’t present at birth, formed after
– Lateral aspect -> This curvature is exaggerated when younger, in adults and with obesity known as lordosis
sacral curvature
contains 5 vertebrae
coccyx
is one bone (aka tail bone)
– Can be an exaggerated at birth
sacral coccygeal curvature
grouped together
– Primary curvature formed at birth
– Concave anteriorly
curvature anterior aspect
Scoliosis is a condition that causes a shift in the entire vertebrae
body or centrum
is anterior (spine process is posterior)
vertebral arch
– With the body make the vertebral foramen
– Pedicle: means little feet (x2)
– Lamina: where the ligaments attach to support vertebral arch (x2)
spinous process
– Creates the spine (feel on the back)
- is posterior
transverse process
x2
– These are on the horizontal plane
articular process
where the vertebrae stack and meet
– Vertebrate stack up on bodies (this is where they articulate)
– There is a superior process (x2) and inferior process (x2)
– Regulate the pace that vertebrae move
– The articular process lumbar vertebrae are in the sagittal plane
o When you flex and extend your vertebral colum; the lumbar vertebrae is what is moving it. They “butt up” against one another.
– The articular process thoracic vertebrae are in the frontal/coronal plane (making it harder to flex)
superior + inferior process
o We have a restriction of movement here; why we have these articular processes is to make sure we can regulate movement here. It is not completely freely able to move.
When a superior process articulates with inferior, we have two bones articulating the coronal plane and they move from like left to right making it harder to move forward and backward.
• We have allowance of lateral flection
o Articular process are sliding off each other in this coronal plane. When we move to the lumbar vertebrae
facets
(x4) = little face; where the articular process occur and are made up of hyaline cartilage (lowers the frictional tension)
articulating points for ribs
MANY ribs articulate with multiple vertebrae. When you look at the articulating points you can see that there are multiple articulating points with the ribs.
o We have demi-facets (French for half)
Coastal is always in reference to the ribs -> reminds you of half
In most veretebraes you have a demi facet in the superior and inferior points
Majoritiy of the ribs articulates with half a facet in one veretebrae and half of a facet on the vertebrae above it.
That’s why we use demi faucet cause its not the compelte articulating point its half of it.
Inferior vertebral notch -> creates the inter vertebral formaen
• Is a false foramen, not completely bordered by the bone. It is just a notch off of the vertebrae. As it sits in the vertebrae above it is something bone
vetebrae associated structures
spinal nerves
intervertebral disk (IVD)
nucleus pulpous
annulus fibrosis
Herniation is when a structure breaks through; a herniation disk is where the nucleus breaks through the annulus fibrosis
When nerve fibres go into the nucleus pulpous, it causes sensory pain when walking and standing
spinal nerves
extend off the spinal cord and innervate the organs of the body
intervertebral disk (IVD)
this disk is in between the bodies of a vertebrate
– Made up of hyaline cartilage like material
– Jelly-like on the inside and when pressure is put on the spine this jelly-like material wants to come out
nucleus pulpous
Gel inside the IVD and it held together by annulus fibrosis which keeps the gel in the center even under pressure
annulus fibrosis
contain the nucleus pulpous in the centre, made up of two fibres
were all vertebra made the same?
All vertebrae look different as they serve different roles
cervical - bifurcated
(means forked) spines are very different from all other vertebrae
– Can be bifurcated up to C7
cervical - body
• The Body is very small because the cervical vertebrae don’t have a lot of weight to bare (only the head)
cervical - facets
The Facets are in an oblique plane (not horizontal, frontal or sagittal)
– In the right position, the facet on the superior process will face posterior
– In the right position, the facet on the inferior process will face anterior
cervical - transverse process
The Facets are in an oblique plane (not horizontal, frontal or sagittal)
– In the right position, the facet on the superior process will face posterior
– In the right position, the facet on the inferior process will face anterior
special cervical vertebrae
• C1 and C2 are atypical
– C1 lacks a body
– C2 lacks a body (the Dens is NOT the body)
c1 atlas
different
– Holds up the skull as it articulates with the underneath of the skull beside the foramen magnum
– Point but not bifurcation
c2 axis
– Under C1 and allows C1 to pivot on top of it
• The Dens on C2 allows for this pivot (the Dens penetrates through the vertebral foramen)
c1, c2 yes/no
C2 is also known as the “no bone” and C1 is the “yes bone”
The superior articular process on C1 look like a small cradle
We have 2 rounded features which are called the occipital condials
A condial is a rounded component on a bone
Has no body, but attaches to a body like structure fused btw C1 and C2; on the C2 called Dens
The Dens makes a bony structure so that c1 can penetrate around it
The occipital condials sit with in the articular process and it enables it to rock back and forth (this motion occurs when we nod our head “yes”)
thoracic vertebrae
The vertebral foramen are very circular, opposed to triangular (from T1 to T12)
– The body is heart/kidney shaped which allows for the circular shape
On the bodies there are small little impressions which are in place for ribs, they are called superior and inferior costal/Demi facets (costal means rib)
On the transverse process there is a Transverse costal facet
Inferior vertebral notch become the vertebral foramen (but not true foramen because they are not enclosed by true bone )
rib orientation on thoracic vertebrae
The ribs articulate at the transverse processes (the costal facets) or at the body
Ribs only articulate at one transverse process
Ribs will articulate with the transverse costal process on the vertebrae with the same number (R3 articulates with T3)
– It articulates with the costal facet above
– Ribs 2 to 9 uses multiple vertebrate
– Rib 1, 10, 11, 12 have articulating surfaces with the same number
lumbar
Size of body is very large because they bear the weight of the vertebral column
– There is a curvature that starts to develop when we start walking
– Designed in a manor to withstand and bare the weight
– Much larger than any other vertebrae.
Very thick of vertebral arch
lumbar spinous process
Spinous process has a hatchet like shape and is VERY THICK.
o Is very different than the thoaracic. Not so distinctive from T12 to l1. As you move down the thoracic they become more hatchet like. (SMALL AXE)
lumbar transverse process, inferior vertebral foramen, articular process
• The transverse processes is present but thinner/smaller
- The inferior vertebral foramen is present
- The inferior articular process is in the sagittal plane (allowing flexibility)
- There are all typical vertebrae
lumbar vertebral foramen
The vertebral foramen is triangular (look at the border)
When you get to T12 and L1 they are hard to tell apart but certain features change.
Veretebral foramen in the throaic region (down) are circular and then become automatically triangular
The articular processes in the thoracic region are in the coronal plane but the second you get to L1 they shift to the sagittal plane.
Fused Vertebrae: Sacral-Coccygeal
Anterior side looks like the posterior side
o Posterior side -> see the faucets because the superior articular faucet are going to articulate in the inferior articular process L5
o You can see a spine like structure and they are the spinour process for the fused veretebrae.
The spinous processes all form together
The facets on the superior articulate processes face posteriorly
There are true intervertebral foramen because the disks have fused together
ligamentum
Need for stability Supraspinous Ligament Attaches to the spinous processes Anterior Longitudinal Ligament Posterior Longitudinal Ligament Attaches to all the body and moves down the vertebral column Interspinous Ligament Between the spinous processes Keeps spinous processes aligned Ligamentum Flavum - Yellow tinge, attaches from one lamine from the next Spinal nerves exit through black dot mark
rib cage
• Rib cage composed of sternum, ribs and costal cartilages (attaches the ribs to the sternum and it is hyaline cartilage)
o Necktie like structure made up of three bones. (Sternum)
We often have cartilage where bones are joining.
sternum
manubrium, body, xiphoid process
true ribs
have their own costal catrtilage articulating to the sternum
false ribs
a rib that doesn’t have a costal cartilage articulating them to the sternum BUT some may have costal cartilage but the costal cartilage doesn’t articulate from the sternum it articulates to another costal cartilage of another rib
rib numbers
we have 12 ribs
10, 9, 8 articulates to the costal cartilage of 7
This indirectly articulates to the costal cartilage of the sternum.
FLOATING RIBS
1-7 are True Ribs because they have a dedicated/connect to sternum by costal cartilage
8-12 are False Ribs do not have a costal cartilage that goes directly to the sternum
8, 9,10 attach to costal cartilage of 7
11, 12 are Floating Ribs because they have no costal cartilage
manubrium
(knot of the tie)
– Connects to the body
– Articulates to rib 1 and rib 2
– At the top of the manubrium is the Jugular Notch which is directly across the aorta and also line up with T2 and T3
– If you count down from T2 to T5 is where the top of the heart is
sternal angle
o Where the manubrium articulates with the body is identified as the sternum angle
o Where the body of the sternal articulates with the xyphoid process is known as the xyphisternal junction.
o Xyphoid process is not a bone until you are in your 30s
typical rib cage - going in order
Head of ribs
- Most ribs have articulating surface where 2 areas articulate with vertebrae
Head has neck just down from it
Down from the neck is the Tubercle
- Articulates with transverse costal facet
Articular surface
- Glossy appearance and looks different from rib because its hylaine cartilage which articulates with bone
Angle of rib
- Rib takes sharp turn to come towards sternum just below the tubercle
Shaft/body of rib just below it
Costal Groove
- Inside of inner surface of rib (inferior portion)
- Inner costal nerve provide innervention to inner costal muscles
Costalchondral join
- Chondral is reference to main cell line in hyaline cartilage
Costal cartilage
