Topic 10: Skeletal System Flashcards
anatomical position
feet, face, & palms forward
- standing in an upright position
anterior
front- ventral
posterior
bcak- dorsal
proximal
close
distal
far
What are 2 divisions of the skeletal system?
1) Axial skeleton (80 bones)
2) Appendicular Skeleton (126 bones)
Axial Skeleton
80 bones) a) skull b) hyoid bone c) vertebral column d) thoracic cage sternum + ribs
- draw line from head down; axis of body
superior
above
inferior
down
Appendicular Skeleton
126 bones) 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)
how many bones are in the body?
206 IN TOTAL
articulations
connections between bones (joints)
e.g. the humerus articulates with the scapula
lateral
side view
List the 3 main groupings of skulls:
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)
List the bones in the cranium
i. 1 frontal (forehead)
ii. 2 parietal
iii. 2 temporal
iv. 1 sphenoid
v. 1 ethmoid – forms superior + middle nasal chonchae
vi. 1 occipital
List the bones in 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
List the bones in auditory ossicles:
i. incus
ii. malleus
iii. stapes
Hyoid Bone
no articulations (joints/connections to other bones)
attaches muscles of tongue and neck, assists in swallowing
How many vertebrae do we have?
26
List the 5 regions of the Vertebral Column:
a) cervical (7)
b) thoracic (12)
c) lumbar (5)
d) sacrum (1)
e) coccyx (1)
List the features of a typical vertebral structure:
o body o spinous process (1) o transverse process (2) o lamina (2) o pedicle (2) o vertebral foramen o superior + inferior articular facets o intervertebral foramina
body
– thick anterior portion
- supports weight of body
- main portion
spinous process
(1) – median posterior projection
transverse process
(2) – lateral bony projections for muscle attachment
lamina
(2) – connects the two processes
pedicle
(2) – connects body to transverse process
* bulky spehrical
vertebral foramen
hole for spinal cord
superior + inferior articular facets
– articulate (joints) with vertebrae above and below
facets= smooth surface
intervertebral foramina
– exit for spinal nerves
Describe the characteristics of cervical vertebrae by region:
a) cervical (C1-C7)
C1, C2 = atypical
C3-C7 = typical
C1
= atlas
o no body, no spinous process
o articulates with occipital condyle of skull
¦ allows nodding (“yes”) motion
C2
= axis
o dens (= odontoid process)
o pivot joint around which atlas swivels
=> allows shaking (“no”) motion
What do all of (c1-C7) have in common?
C1-C7: ALL have transverse foramina
thoracic
T1-T12)
ALL articulate with ribs via costal facet
lumbar
(L1-L5)
support upper body weight
ALL have large bodies & rectangular spinous processes
- way larger than atlas- as you go down body structures are larger to support more weigth
sacrum
= 5 fused vertebrae
articulates with ilium (appendicular skeleton) and 5th lumbar vertebra (L5
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
abnormal curvature:
a) scoliosis
spinal column curves laterally
b) kyphosis
exaggerated thoracic curve (hunchback)
c) lordosis
exaggerated lumbar curve (swayback)
What does the thoracic cage include:
a) sternum (breast bone)
b) ribs
sternum
breast bone) 3 parts: i. manubrium – superior ii. body – middle iii. xiphoid process – inferior
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)
true ribs
o 7 pairs
attach directly to sternum via costal cartilage (hyaline cartilage)
false ribs
5 pairs
- attach indirectly to sternum via costal cartilage (8-10) or not all =
floating ribs (11, 12 – embedded in muscle)
What bones does the pectoral girdle include?
a) clavicle
b) scapula
clavicle
(collarbone)
articulates with sternum (manubrium) & scapula (acromion process)
connects axial & appendicular skeletons
scapula
spine (on posterior)
acromion process
glenoid fossa/cavity
coracoid process
acromion process
articulates with clavicle
glenoid fossa/cavity
articulates head of humerus
coracoid process
attaches muscles for arm and chest
What does the pelvic girdle include?
composed of 2 os coxae (hip bones) each with 3 bones:
a) ilium
b) ischium
c) pubis
List the joints of the pelvic girdle
a) pubic symphysis
b) sacroiliac joint – sacrum + ilium
c) acetabulum – articulates with head of femur
¦ all 3 bones of os coxa join here
ilium
articulates with sacrum
ischium
most inferior part = ischial tuberosity
pubis
left and right joined by pubic symphysis
List the bones of 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
List the bones of 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)
How can you differentiate between left and right for the scapula and humerus?
e.g. scapula
o spine (posterior)
o glenoid fossa (lateral)
e.g. humerus
o olecranon fossa (posterior)
o head (medial)
How can you differentiate between left and right for the femur and tibia?
e.g. femur
o lateral/medial condyles (posterior)
o head (medial)
e.g. tibia
o tibial tuberosity (anterior)
o medial malleolus (medial)
List the components of long bone
1) diaphysis
2) epiphyses
3) epiphyseal plate
4) epiphyseal line
5) medullary cavity
6) periosteum
7) endosteum
8) articular cartilage
diaphysis
shaft (body)
epiphyses
proximal and distal extremities
epiphyseal plate
hyaline cartilage
used for bone growth (length)
epiphyseal line
replaces plate with bone when growth completed
plate/line – where the diaphysis and epiphyses meet
medullary cavity
red marrow in child, yellow marrow in adult
periosteum
external surface 2 layers of connective tissue o outer = dense irregular o inner = mainly osteoblasts + osteoclasts allows bone to grow in diameter
endosteum
lines medullary cavity AND canals (contains osteoblasts + osteoclasts)
articular cartilage
hyaline (only at articulation points)
prevents friction between bones (no periosteum here)
Describe the composition of bone
a) cells
i. osteoblasts
ii. osteocytes
iii. osteoclasts
b) matrix
i. ground substance
hydroxyapatite = insoluble Ca2+ phosphate salts (strength)
water
ii. collagen fibres (flexibility
What are the 2 types of bone?
compact and spongy bone
compact bone
covers external surfaces of ALL bones
structure:
o composed of osteons
What does each osteon contain?
i. Lamellae
ii. Lacunae (with osteocytes)
iii. Canaliculi
iv. Osteonic/Central Canal
v. Interosteonic/Perforating Canal
Lamellae
concentric circles of matrix
Lacuna
Between lamellae (space within matrix where osteocytes live)
Canaliculi
small channels that connect osteocytes to blood supply
and to each other
Osteonic/Central Canal
contains blood vessels and nerves
¦ lined with endosteum
Interosteonic/Perforating Canal
¦ perpendicular to central canal
¦ carry blood supply from periosteum to central canals
and medullary cavity
Describe the structure of spongy bone
o NO osteons
o have trabeculae (irregularly arranged lamellae)
o canaliculi connect osteocytes in lacunae
spaces contain bone marrow
red marrow produces blood cells
Where is spongy bone found?
flat & irregular bone (e.g. skull, ribs, vertebrae)
long bones
¦ epiphyses
¦ lining medullary cavity
Describe the composition of hyaline cartilage
) cells
i. chondrocytes in lacunae
b) matrix:
i. ground substance
• contains chondroitin sulphate + hyaluronic acid
• water
ii. collagen fibres
c) non-vascular
Articulations / Joints
point of contact between 2 or more bones
What is the structural classification of Articulations / Joints based on
o presence/absence of joint cavity
o type of CT
List the types of structural joints
a) Fibrous
b) Cartilaginous
c) Synovial
Fibrous
no joint cavity
fibrous CT
e.g. sutures in skull (fontanels in a newborn)
Cartilaginous
no joint cavity
cartilage attaches bones
e.g. pubic symphysis, costal cartilages of ribs
Synovial
e.g. shoulder, elbow, hip, knee
Describe the structure of synovial joints
• 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
List the types of synovial joints
i. plane/gliding
ii hinge
iii pivot
iv. ball and socket
plane/gliding
¦ flat surfaces
¦ e.g. sacroiliac
hinge
¦ concave/convex surfaces
¦ e.g. elbow, knee
pivot
¦ projection in ring
¦ e.g. dens (on axis) in atlas
ball & socket
¦ great freedom of movement
¦ e.g.1: humerus in glenoid fossa
¦ e.g.2: femur in acetabulum (hip)
Functional Classification is based on:
degree of movement
List the types of functional joints
a) Synarthrotic
b) Amphiarthrotic
c) Diarthrotic
Synarthrotic
immovable
e.g. skull sutures
Amphiarthrotic
slightly moveable
e.g. pubic symphysis
Diarthrotic
freely moveable
e.g. hip, shoulde
