Lecture 6: Intro to Bone and Vertebral Column Flashcards
Main structures of skeletal system
Bone, cartilage, ligaments, tendons (all connective tissue types)
How do bone and surrounding soft tissues develop?
Living tissue composed of cells and extracellular matrix. Bone and surrounding soft tissue each depend on each other during their development and influences their organization and structure.
What are some major functions of the bone tissue?
Support framework of the body
protection of viscera (e.g., vertebral column protects spinal cord)
vital in movement
often paired with muscular system (e.g., musculoskeletal system)
salt and mineral storage (e.g., calcium)
production of blood cells, red and white via bone marrow.
What is the axial skeleton, what bones is it composed of?
Axial Skeleton: Central portion of the skeleton
Skull (22 bones),
hyoid,
vertebrae (33 total);
ribs (12 pairs),
chest plate (manubrium, sternum, xiphoid process)
What is the appendicular skeleton?
: bones associated with upper and lower limbs. Both sets
of limbs are similar to one another in organization
How are the bones of the appendicular skeleton organized?
Girdles, Stylopod, Zeugopod and Autopod
What are the girdles?
Girdles: Proximal bones of limbs that articulate with the axial skeleton.
- Pectoral (upper): Scapula,clavicle
- Pelvic (lower): Ilium, ischium, pubis
Stylopod
Stylopod: singular bone in proximal segment of limb
- Upper limb: Humerus
- Lower limb: femur
Zeugopod
Zeugopod: Paired bones in the middle segment of the limbs
- Upper limb: radius, ulna
- Lower limb: tibia, fibula
Autopod
Autopod: bones consisting of the hands and feet, distal segment of limbs
1. Upper limb: carpal bones, metacarpals, phalanges
2. Lower limb: tarsal bones, metatarsals, phalanges
Two types of bone compositions?
compact (dense, strength) and spongy (less dense,
spongy, elastic) bone tissue
What is medullary tissue?
Medullary tissue may replace spongy bone with marrow
(produces blood cells)
fibrous connective tissue that surrounds bone? What nerves sense tearing/tension/pain?
periosteum: perichondrium is the
equivalent that surrounds cartilage
periosteal nerves to sense tearing/tension pain
What are the 5 bone classification based on morphology, their shapes and some examples
i. Long bones: tubular (e.g., humerus)
ii. Short bones: cuboidal (e.g., carpal bones)
iii. Flat (squamous) bones: flat and protective (e.g., parietal bone of skull)
iv. Irregular: odd-looking (e.g., vertebrae)
v. Sesamoid: develop within tendons, help with redirecting muscle action across a joint (e.g., patella)
Condyle
Condyle: rounded articular surfaces
Facet
Facet: Smooth, flatter articular surface, covered with cartilage
Foramen / Notch; Nutrient Foramen
Foramen/Notch: opening into bone.
Nutrient foramen: Hole allowing blood vessels into bone to bone itself
Fossa
Fossa: Depression, a hollow
Line / Crest
Line/Crest: linear elevated ridge
Process / spine
Process/spine: cylindrical or linear projection
Protuberance:
Protuberance: low rounded elevation
Tubercle / Tuberosity
Tubercle/Tuberosity: small or large eminence
Meatus/Canal
tunnel-like features (meatus has no exit, canal does)
Articular Cartilage
Cartilage (semi-rigid, avascular connective tissue)
lining areas of articulation that provide low-friction gliding (i.e., smoother
action over the joint)
What are the 4 kinds of connections between joints?
Fibrous, Syndesmosis, Cartilaginous, Synovial
features of joints
Bone-to-bone
* Rich in blood supply
* Rich in nerve supply
* Proprioception
(Sense of 3D space)
* Several Kinds:
Hinge, Plane, Pivot,
Condyloid, Saddle, Ball
& Socket
Fibrous joint and example
Fibrous: Articulating bones attached with fibrous tissues.
Joints of the skull
Syndesmosis (type of fibrous joint)
Syndesmosis: unites bone with a fibrous sheet
Connective tissue sheet between radius and ulna, and tibia / fibia
Cartilaginous joints
Cartilaginous joints: united by hyaline or fibrocartilage fibers. Provides some flexibility.
Cartilage surrounding condyle of humerous and femur
Primary cartilaginous
Synchondrosis (cartilage of fumr and humerus
Secondary cartilaginous
Symphysis (intervertebral discs)
Synovial Joint
Synovial: Joint within a fluid-filled space, lubricated. Most common joint
Clinical condition A result of aging, bone tends to degenerate, in other words, the capability to retain minerals/organic/inorganic components and maintain
structural integrity decreases.
Osteoporosis: more common in women than men
What is the vertebral column and its functions
Central, median part of body
Cranium, Appendicular attachments
- Supports head (“Appendage”)
- Weight-bearing
- Maintains Posture
- Protects Spinal Cord
- Attachment of many muscles
- Aid in locomotion
How many vertebrae in each section; function of intervertebral discs
Humans have 33 total
vertebrae
* 7 Cervical
* 12 Thoracic
* 5 Lumbar
* 5 Sacral (fused-sacrum)
* 4 Coccygeal (form coccyx)
* Intervertebral discs provide
cushioning, mobility, and
stability
What is the lumbosacral angle?
Lumbosacral Angle occurs at the lumbar and sacral junction
L5 - S1
* Change of angle
* Intervertebral disc: wedge shaped
* Common site of ‘slippage’ of L
Types of spinal curvatures
Kyphosis: Concave anteriorly
Lordosis: Concave posteriorly
Whats a primary curvature, and which parts of spine have this?
Primary Curvature: Thoracic & sacral curves formed during development
They are kyphotic
Secondary curvature
Secondary Curvature: Curves
form after birth for weight
bearing, cervical (head)
lumbar (body from walking)
Lordosis
3 types of abnormal curvatures and how the arise?
Abnormalities may arise in several ways including osteoporosis, poor posture, and unequal tone of postural muscles (e.g., weak
abdominal muscles with strong back muscles, vice versa).
1) Excessive Thoracic Kyphosis
2) Excessive Lumbar lordosis
3) Scoliosis
Excessive Thoracic Kyphosis
Thoracic region has strong curvature such that the neck and
head are more curved anteriorly (e.g., looking down at your phone habitually!)
Excessive lumbar lordosis
Lumbar region more curved than normal
scoliosis
Abnormal rotation about the vertebrae, laterally curved vertebral column, generally
caused by asymmetry of back muscles, failure of vertebrae to develop, differing leg lengths.
Vertebral body
y (centrum): Anterior region responsible for support, increases in
size inferiorly along the vertebral column. Roughly cuboidal/cylindrical in shape.
Neural (vertebral) Arch
Posterior portion that surrounds the spinal cord.
Pedicles
columns that attach the rest of the arch to the body
Laminae
flat posterior portions that meet at midline
Vertebral Foramen
Main opening between body and neural arch
Vertebral Canal
passageway through the column for the spinal cord and
associated soft tissues (fat, meninges, vessels)
Vertebral Notches
curved superior and inferior margins of the pedicle
Intervertebral Foramina
lateral opening formed by adjacent vertebral
notches (superior and inferior notches together form a foramen)
Spinous Process
Median process projecting posteriorly from laminae
Transverse Process
posterolateral projection from junction of lamina
and pedicle, bilateral
Articular Processes
paired superior and inferior projections that
articulate with adjacent vertebrae (a.k.a. pre-, postzygapophyses).
Characteristics of cervical vertebrae
body, foramen, transverse process, spinous process
i. Body: small, wide. Presence of uncinate processes on C3–6
ii. Vertebral Foramen: large, triangular
iii. Transverse Process: Foramina transversaria, absent/small in C7.
Passage for vertebral artery to cranium.
iv. Spinous Process: short and bifid, C6-7 long and prominent
What are the atlas and axis
Atlas (C1): Ring-like, no body and spinous process, mainly an anterior and posterior arch, articulates with the cranium
vi.
Axis (C2): Presence of the dens that allows Atlas to pivot (the dens is the body of C1 that C2 incorporates with itself during development, neat!)
Thoracic Vertebra
body, foramen, transverse p, spinous p
i. Body: Heart-shaped, one or two facets to articulate with head of rib (parapophysis)
ii. Vertebral Foramen: circular, smaller than in cervical, lumbars
iii. Transverse Process: long and strong, decreases in length inferiorly, facet
present to articulate with tubercle of the rib (diapophysis)
iv. Spinous Process: long, slopes posteroinferiorly and overlaps subsequent
vertebra
Lumbar
i. Body: Massive, kidney-shaped faces.
ii. Vertebral Foramen: triangular, large
iii. Transverse Process: long and slender, accessory processes on posterior
surface
iv. Articular Process: Mammillary process on posterior surface of superior
process (multifidus muscle attachment)
v. Spinous Process: short, sturdy, hatchet-shape
Sacrum
5 total: Large wedge shape fusion of all five sacral vertebrae
Sacro-illiac joints
articulation with the ilia, provides support and strength
base of pelvis
: Superior surface of S1
Promontory
anterior projection of S1 body
Median Crest
fused spinous processes of the sacral vertebrae
Intermediate Crest
: fused articular processes of the sacral vertebrae
Lateral sacral crests
: Fused tips of the transverse process of the sacral
vertebrae
Sacral Hiatus
Absence of the laminae and spinous process of S4-5
Sacral Cornua
Inferior articular process of S5
coccyx
4 total: Remnants of our tail that is now adapted into the pelvis for
additional stability and support, especially with the pelvic floor muscles.
What is spina bifida occulta
Congenital anomaly, the laminae of L5/S1 fail to fuse normally. In
spina bifida cystica, one or more vertebral arches may almost completely fail to develop.
Present with herniation of the meninges (meningocele) or even the spinal cord itself (myelomeningocele).
Anulus Fibrosus
ring of fibrocartilage forming the intervertebral disc
Nucleus Pulposus
Center of intervertebral disc. Compresses and
tenses but loses elastic ability through aging
Uncovertebral “Joints”
: Between uncinate process of C3-C6, on body
Anterior Longitudinal Ligament
strong fibrous ligament that runs on the anterior surface of the vertebral bodies from C1 to the sacrum. Prevents hyperextension.
Posterior Longitudinal Ligament
Strong fibrous ligament that runs on the posterior surface of the vertebral body from C2 to the sacrum. Relatively weaker than its anterior counterpart. Prevents hyperflexion
Zygapophysial joint:
Zygapophysial joint: Synovial articulations between the superior and inferior articular processes (zygapophyses) of adjacent vertebrae.
Joint Capsule
Encloses each zygapophysial joint.
Ligamentum Flava
Broad, elastic fibrous tissue connecting laminae of
adjacent vertebrae. Resist separation
Interspinous Ligaments
Connect adjacent spinous processes
Supraspinous Ligaments
Connect adjacent spinous processes
posteriorly on their apexes
Nuchal Ligaments
merges with supraspinous ligament, strong median
ligament of the neck and back of the skull (external protuberance).
: Herniation of Nucleus Pulposus.
Posterior longitudinal ligament and/or anulus fibrosus
degenerates, the nucleus pulposus may herniate. May compress the roots of a spinal nerve and
cause localized and/or chronic pain. Common in cervical and lumbar regions.
Movements of the vertebral columns
Flexion, Lateral flexion, Extension, lateral extension, Rotation
Movement limitations of vertebral column
Movement Limitations: Elasticity of the intervertebral discs, orientation of the
articular facets, tension of joint capsules, resistance by ligaments/muscles, rib
cage, bulk of surrounding tissues (skin, fat, etc.,)
Whiplash
Hyperextension of the neck cause the anterior longitudinal ligament to strain
and may tear or damage. Usually occurs during read-end accidents during driving.
