Skeletal System - midterm 2 Flashcards
Anatomical position
feet, face & palms forward
What are the 2 divisions of the skeletal system
1) Axial Skeleton (80 bones)
2) Appendicular Skeleton (126 bones)
= 206 bones in total
what does the Axial skeleton include? (4)
- skull
- hyoid bone
- vertebral column
- thoracic cage (sternum + ribs)
what does the Appendicular skeleton include? (4)
- limbs + bones that attach them to axial skeleton (girdles)
- pectoral girdle
- pelvic girdle
- upper limb (arm, forearm, hand)
- lower limb (thigh, leg, foot)
what are the 3 main bone groupings of the skull?
a) cranium- 8 bones (next to brain)
b) facial bones- 14
c) auditory ossicles- 6 (3 bones on each side in the middle of ears)
Parts of the Cranium: (6 bone names but 8 in total)
- 1 frontal (forehead)
- 2 parietal (middle)
- 2 temporal
- 1 sphenoid in front of temple by eye)
- 1 ethmoid (forms superior + middle nasal conchae)
- 1 occipital (back bottom)
Facial bones: ( 8 bones but 14 in total)
- 2 nasal
- 2 maxillae
- 2 zygomatic
- 2 lacrimal
- 2 palatine
- 2 inferior nasal conchae
- 1 vomer
- 1 mandible
Auditory ossicles: (3)
- incus
- malleus
- stapes
Hyoid Bone
- no articulations (joints/connections to other bones)
- attaches muscles of tongue and neck, assists in swallowing
what 5 regions is Vertebral Column separated into? (26 in total)
- Cervical (7) breakfast
- Thoracic (12) lunch
- Lumbar (5) dinner
- Sacrum (1)
- Coccyx (1)
Typical vertebral structure (8)
- body = thick anterior 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
- vertebral foramen - hole for spinal cord
- superior + inferior articular facets = articulate with vertebrae above and below
- intervertebral foramina - exit for spinal nerves
Cervical (C1-C7) vertebrae characteristics
- C1, C2 = atypical
- C3-C7 = typical
- C1 = atlas > no body, no spinous process > articulates with occipital condyle of skull (allows nodding ‘yes’ motion)
- C2 = axis > dens (= odontoid process) > pivot joint around which atlas swivels (allows shaking ‘no’ motion)
Thoracic (T1-T12) vertebrae characteristics
ALL articulate with ribs via costal facets
Lumbar (L1-L5) vertebrae characteristics
- support upper body weight
- ALL have large bodies & rectangular spinous processes
Sacrum vertebrae characteristics
- = 5 fused vertebrae
- articulates with ilium (appendicular skeleton) and 5th lumbar vertebra (L5)
Coccyx vertebrae characteristics
- = 3-5 fused vertebrae, usually 4
- = tailbone
Curvature of spinal column:
a) cervical + lumbar
- curved convex anteriorly = concave posteriorly
b) thoracic + sacrum
- curved concave anteriorly = convex posteriorly
Abnormal curvature: (3)
a) scoliosis - spinal column curves laterally
b) kyphosis - exaggerated thoracic curve (hunchback)
c) lardosis - axaggerated lumbar curve (swayback)
Thoracic Cage consists of: (2)
a) sternum (breast bone) 3 parts: i) manubrium - superior ii) body - middle iii) xiphoid process - inferior
b) ribs
- 12 pairs total (articulate posteriorly with T1-T12)
-7 pairs = true ribs
> attach directly to sternum via coastal cartilage (hyaline cartilage)
- 5 pairs = false ribs
> attach indirectly to sternum via costal cartilage (8-10) or not at all = floating ribs (11, 12 - embedded in muscle)
Pectoral Girdle (upper limb girdle) parts: (2)
a) clavicle (collarbone)
- articulates with sternum (manubrium) & scapula (acrimony 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
Pelvic Girdle (lower limb 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 join - sacrum + ilium
c) acetabulum - articulates with head of femur > all 3 bones of os coxa join here
Upper limb (in anatomical position) includes: (5)
a) humerus
b) radius (lateral) / ulna (medial)
c) carpals (8) = wrist
b) metacarpals (5) = palm
c) phalanges (14) = digits (fingers)
* note: all are LONG bones expect for carpals
Lower Limb (in anatomical position) includes: (6)
a) femer
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) = digets (toes)
* note: all are LONG bones except petal and tarsals
Long bone components: (8)
1) diaphysis
2) epiphyses
3) epiphyseal plate
4) epiphyseal line
5) medullary cavity
6) periosteum
7) endosteum
8) articular cartilage
Diaphysis (long bone component)
1) diaphysis - shafts (body)
Epiphyses (long bone component)
2) epiphyses - proximal and distal extremities
Epiphyseal plate (long bone component)
3) epiphyseal plate
> hyaline cartilage
> used for bone growth (length)
Epiphyseal line (long body component)
4) epiphyseal line
> replaces plate with bone when growth completed
> plate/line - where the diaphysis and epiphyses meet
Meduallary cavity (long bone component)
5) medullary cavity
> red marrow in child, yellow marrow in adult
Periosteum (long bone component)
6) periosteum
> external surface
> 2 layers of connective tissue - outer = dense irregular
- inner = mainly osteoblasts + osteoclasts
> allows bone to grow in diameter
Endosteum (long bone component)
lines medullary cavity AND canals (contains osteoblasts + osteoclasts)
Aritcular cartilage (long bone component)
- hyaline (only at articulation bones)
- prevents friction between bones (no periosteum here)
Bone consists of: (2)
a) Cells-
i) osteoblasts
ii) osteocytes
iii) osteoclasts
b) Matrix-
i) ground substance > hydroxyapatite = insoluble Ca2+ phosphate salts (strength)
ii) collagen fibers (flexibility)
iii) water
what are the 2 types of bone
- compact 2. spongy
Compact bone:
- covers external surfaces of ALL bones
structure: - composed of osteons
- 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
Spongy bone
structure:
- NO osteons
- have trabeculae (irregularly arranged lamellae)
- canaliculi connect osteocytes in lacunae
- found in:
>flat & irregular bone (eg. skull, ribs, vertebrae)
>long bones-epiphyses, lining medullary cavity
- spaces contain bone marrow
> red marrow produces blood cells
Cartilage (CT)
Hyaline cartilage structure: a) chondrocytes in lacunae b) matrix: i. shiny ground substance contains chondroitin sulphate + hyaluronic acid ii. collagen fibres iii. water c) non-vascular
What are articullations/joints?
point of contact between 2 or more bones
what are the 2 classes of articulations/joints?
structural & functional
Structural classifications of joins are based on
- presence/absence of joint cavity
- type of CT
types of structural joints: (3)
- fibrous
- cartilaginous
- synovial
Fibrous structural joints:
- no joint cavity
- fibrous CT
- eg. sutures in skull (fontanels in a newborn)
Cartilaginous structural joints:
- no joint cavity
- cartilage attaches bones
- eg. pubic synthesis, costal cartilages of ribs
Synovial structural joints:
- eg. 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
types of synovial structural joints: (4)
- grouped according to shape of articulating bones
i) plane/gliding - flat surfaces
- eg. sacroiliac
ii) hinge - concave/convex surfaces
- eg. elbow, knee
iii) pivot - projection in ring
- eg. dens (on axis) in atlas
iv) ball & socket - great freedom of movement
- eg. humerous in glenoid fossa
- eg. femur in acetabulum
Functional Classification (physiological) articulations/joints
based on:
- degree of movement
Types of functional joints (3)
a) Synarthrotic
- immovable
- eg. skull sutures
b) Amphiarthrotic
- slightly moveable
- eg. pubic symphysis
c) Diarthrotic
- freely moveable
- eg. hip, shoulder
