10 - Skeletal System Flashcards
What is the anatomical position? What is left and right in this position?
Face forward, palms forward. Direction is with respect to the human, so from their vantage point left is left, and from ours left is right.
Define anterior, posterior, proximal, distal, superior, inferior, medial and lateral.
Anterior - To the front of the body Posterior - To the back of the body Proximal - Closer to the trunk Distal - Farther from the trunk Superior - Above Inferior - Below Medial - Toward the midline Lateral - Away from the midline
What are the two main divisions of the skeleton?
Axial (80 bones) - along the midline
Appendicular (126 bones) - sidelines
What are the main parts of the axial skeleton?
a) skull
b) hyoid bone
c) vertebral column
d) thoracic cage
sternum + ribs
What are the main parts of the appendicular skeleton?
limbs + bones that attach them to axial skeleton (girdles)
a) pectoral girdle
b) pelvic girdle
c) upper limb (arm, forearm, + hand)
d) lower limb (thigh, leg, + foot)
What is an articulation?
connections between bones = articulations
o e.g. the humerus articulates with the scapula
joints are articulations
What are the main bone groupings of the skull?
a) cranium – 8 bones (next to brain)
b) facial bones – 14 bones
c) auditory ossicles – 6 (3 bones on each side in the middle ears)
What are the cranial bones?
i. 1 frontal (forehead)
ii. 2 parietal
iii. 2 temporal
iv. 1 sphenoid
v. 1 ethmoid – forms superior + middle nasal chonchae
vi. 1 occipital
What are the facial bones?
i. 2 nasal
ii. 2 maxillae
iii. 2 zygomatic
iv. 2 lacrimal
v. 2 palatine
2 palatine + 2 maxillae = hard palate
vi. 2 inferior nasal chonchae
vii. 1 vomer
viii. 1 mandible
What are the bones of the auditory ossicles?
i. incus
ii. malleus
iii. stapes
Describe the hyoid bone.
no articulations (joints/connections to other bones)
attaches muscles of tongue and neck, assists in swallowing
How many vertebrae do you have?
26
What are the 5 regions of the spine?
a) cervical (7)
b) thoracic (12)
c) lumbar (5)
d) sacrum (1)
e) coccyx (1)
Think of meal times.
What are the parts of a vertebrae?
o body – thick anterior portion
o spinous process (1) – median posterior projection
o transverse process (2) – lateral bony projections for muscle attachment
o lamina (2) – connects the two processes
o pedicle (2) – connects body to transverse process
o vertebral foramen – hole for spinal cord
o superior + inferior articular facets – articulate with vertebrae above and below
o intervertebral foramina – exit for spinal nerves
What is the characteristic feature of the cervical vertebrae?
ALL have transverse foramina
Describe the atlas
C1 of cervical vertebrae
no body, no spinous process
o articulates with occipital condyle of skull
allows nodding (“yes”) motion
Describe the axis
C2 of cervical vertebrae
o dens (= odontoid process)
o pivot joint around which atlas swivels
allows shaking (“no”) motion
What is the characteristic feature of the thoracic vertebrae?
ALL articulate with ribs via costal facets
What is the characteristic feature of the lumbar vertebrae?
support upper body weight
ALL have large bodies & rectangular spinous processes
What is the characteristic feature of the sacrum?
= 5 fused vertebrae
articulates with ilium (appendicular skeleton) and 5th lumbar vertebra (L5)
What is the characteristic feature of the coccyx?
= 3-5 fused vertebrae, usually 4 = tailbone
Describe the curvature of the spinal column
a) cervical + lumbar
curved convex anteriorly = concave posteriorly
b) thoracic + sacrum
curved concave anteriorly = convex posteriorly
What are some abnormal spinal curvature conditions?
a) scoliosis spinal column curves laterally b) kyphosis exaggerated thoracic curve (hunchback) c) lordosis exaggerated lumbar curve (swayback)
What are the parts of the sternum?
i. manubrium – superior
ii. body – middle
iii. xiphoid process – inferior
Describe the ribs
12 pairs total (articulate posteriorly with T1-T12)
o 7 pairs = true ribs
attach directly to sternum via costal cartilage (hyaline cartilage)
o 5 pairs = false ribs
attach indirectly to sternum via costal cartilage (8-10) or not all = floating ribs (11, 12 – embedded in muscle)
Describe the Pectoral Girdle
a) clavicle (collarbone)
articulates with sternum (manubrium) & scapula (acromion process)
connects axial & appendicular skeletons
b) scapula
spine (on posterior)
acromion process – articulates with clavicle
glenoid fossa/cavity – articulates head of humerus
coracoid process – attaches muscles for arm and chest
Describe the Pelvic Girdle
composed of 2 os coxae (hip bones) each with 3 bones:
a) ilium – articulates with sacrum
b) ischium – most inferior part = ischial tuberosity
c) pubis – left and right joined by pubic symphysis
joints:
a) pubic symphysis
b) sacroiliac joint – sacrum + ilium
c) acetabulum – articulates with head of femur
all 3 bones of os coxa join here
Describe the Upper Limb
a) humerus
b) radius (lateral) / ulna (medial)
c) carpals (8) = wrist
d) metacarpals (5) = palm
e) phalanges (14) = digits (fingers and thumb)
note: all are LONG bones (except carpals)
Describe the Lower Limb
a) femur
b) patella (knee cap)
c) tibia (medial) / fibula (lateral)
d) tarsals (7)
talus – articulates with tibia
calcaneus = heal bone
e) metatarsals (5) = sole
f) phalanges (14) = digits (toes)
note: all are LONG bones (except patella and tarsals)
What two details do you need to know to differentiate the right vs the left bone in a pair?
o anterior/posterior
o medial/lateral
How do you determine right vs left in the scapula?
o spine (posterior) o glenoid fossa (lateral)
How do you determine right vs left in the humerus?
o olecranon fossa (posterior) o head (medial)
How do you determine right vs left in the femur?
o lateral/medial condyles (posterior) o head (medial)
How do you determine right vs left in the tibia?
o tibial tuberosity (anterior)
o medial malleolus (medial)
What are the 8 long bone components?
1) diaphysis – shaft (body)
2) epiphyses – proximal and distal extremities
3) epiphyseal plate
hyaline cartilage
used for bone growth (length)
4) epiphyseal line
replaces plate with bone when growth completed
plate/line – where the diaphysis and epiphyses meet
5) medullary cavity
red marrow in child, yellow marrow in adult
6) periosteum
external surface
2 layers of connective tissue
o outer = dense irregular
o inner = mainly osteoblasts + osteoclasts
allows bone to grow in diameter
7) endosteum
lines medullary cavity AND canals (contains osteoblasts + osteoclasts)
8) articular cartilage
hyaline (only at articulation points)
prevents friction between bones (no periosteum here)
What are the two types of bone connective tissue?
Compact Bone
Spongy Bone
Describe the structural components of compact bone.
covers external surfaces of ALL bones structure: o composed of osteons o each osteon contains: i. Lamellae concentric circles of matrix ii. Lacunae (with osteocytes) Between lamellae (space within matrix where osteocytes live) iii. Canaliculi small channels that connect osteocytes to blood supply and to each other iv. Central Canal contains blood vessels and nerves lined with endosteum v. Perforating Canal perpendicular to central canal carry blood supply from periosteum to central canals and medullary cavity
Describe the structural components of spongy bone.
structure:
o NO osteons
o have trabeculae (irregularly arranged lamellae)
o canaliculi connect osteocytes in lacunae
o found in:
flat & irregular bone (e.g. skull, ribs, vertebrae)
long bones
epiphyses
lining medullary cavity
o spaces contain bone marrow
red marrow produces blood cells
What are the two classes of classification of joints?
Structural and Functional
What does the structural classification of joints look for?
presence of joint cavity
type of CT
What are the types of structural joints?
Fibrous
Cartilaginous
Synovial
Describe fibrous joints
no joint cavity
fibrous CT
e.g. sutures in skull (fontanels in a newborn)
Describe Cartilaginous joints
no joint cavity
cartilage attaches bones
e.g. pubic symphysis, costal cartilages of ribs
Describe synovial joints
e.g. shoulder, elbow, hip, knee structure: • articular cartilage (hyaline) • joint cavity contains synovial fluid • articular/joint capsule outer layer = fibrous capsule • attaches to periosteum • may have ligaments within (capsule = thickened) or separate inner layer = synovial membrane (CT only) • secretes synovial fluid
What are the types of synovial joints?
• grouped according to shape of articulating bones i. plane/gliding flat surfaces e.g. sacroiliac ii. hinge concave/convex surfaces e.g. elbow, knee iii. pivot projection in ring e.g. dens (on axis) in atlas iv. ball & socket great freedom of movement e.g.1: humerus in glenoid fossa e.g.2: femur in acetabulum (hip)
What are the functional classifications of joints?
based on: o degree of movement types of functional joints: a) Synarthrotic immovable e.g. skull sutures b) Amphiarthrotic slightly moveable e.g. pubic symphysis c) Diarthrotic freely moveable e.g. hip, shoulder
