2.7 Bones, Joints Flashcards
What are the functions of bones?
Support Mineral storage (Ca2+, PO4-) Lipid storage Blood cell production Protection Leverage for muscles
What are the bones of the axial skeleton?
Skull Hyoid bone Ribs Sternum Vertebral column
Name the 8 cranial bones
Occipital Frontal Pariental (2) Temporal (2) Sphenoid Ethmoid
What are the 6 cranial sutures?
Frontonasal suture – between the frontal and nasal bones
Coronal suture – between the frontal and the parietal bones
Sagittal suture – between the two parietal bones
Squamosal sutures (2) – between the parietal and temporal bones
Lambdoid suture – between the parietals and occipital bone
(NOTE: metopic suture is in the middle of the frontal bone in development)
What are he 14 facial bones?
Mandible Maxilla (2) Zygomatic (2) Nasal bones (2) Lacrimal (2) Inferior nasal conchae (2) Palatine (2) Vomer
What are the bones of the orbit?
frontal bone sphenoid bone zygomatic bone maxilla lacrimal bone ethmoid bone palatine bone
What is the purpose of the paranasal sinuses?
cavities in some skull bones
Are clustered around and drain into the nasal cavity
Lighten the skull, resonate sound, produce mucus
Name the paranasal sinuses
Frontal – superior to nasal cavity
Ethmoidal – superior to nasal cavity
Sphenoidal – posterior to nasal cavity
Maxillary (2) – lateral to nasal cavity
Name the regions of the vertebral column. How many bones in each.
Cervical – 7 vertebrae Thoracic – 12 vertebrae Lumbar – 5 vertebrae Sacrum – 5 fused vertebrae Coccyx – 4 partially fused vertebrae
What are the two components of an intervertebral disk?
Annulus fibrosus – outer layer of fibrocartilage
Nucleus pulposus – inner gelatinous core
Describe a herniated disc
nucleus pulposus protrudes through the annulus fibrosus due to excessive compression
May put pressure on spinal cord and nerves
What are primary vs secondary spinal curvatures?
Primary – appear during fetal development and are present at birth, convex posteriorly
Thoracic
Sacral
Secondary – develop later, concave posteriorly
Cervical
Lumbar
What are kyphosis, lordosis, and scoliosis?
Kyphosis – exaggerated thoracic curvature, hunchback
Lordosis – exaggerated lumbar curvature, swayback
Scoliosis – lateral curvature of the spine
What is the os coxa?
The hip bones- made of the ischium, ileum, and pubis
What are the regions of long bones?
Epiphysis – ends
Metaphysis - neck
Diaphysis - shaft
Medullary cavity – center of bone filled with bone marrow
What are endosteum and periosteum?
Endosteum – internal lining of flattened cells
Periosteum – superficial external lining of fibrous CT and cells
What are the two types of bone marrow? Function?
Red bone marrow: forms blood cells
Yellow bone marrow: adipose (fat) tissue for lipid storage
What makes up bone matrix?
Collagen fibers: (“steel”)
1/3 of total bone weight, flexible, strong, resist compression
Calcium Phosphate: (“concrete”)
2/3 of total bone weight, hard, brittle
calcium phosphate, hydroxyapatite crystals
Ca10(PO4)6(OH)2
other: calcium carbonate, sodium, magnesium, fluoride
What are the 4 types of bone cells?
Osteocytes mature bone cells, majority of bone
in lacunae, divots within bone matrix
Osteoblasts: bone building cells, secrete bone matrix
Osteoclasts: bone “crushing” cells, absorb and remove bone matrix
Osteogenic cells: stem cells undergo mitosis to make osteoblasts
Describe calcium homeostasis
stimulus: calcium ion concentration in blood
IF TOO LOW:
parathyroid hormone (PTH) response increase blood Ca2+:
stimulate osteoclasts to breakdown bone matrix
increase small intestine calcium absorption via calcitriol (active Vitamin D)
decrease kidney excretion of calcium ions
IF TOO HIGH:
calcitonin hormone response decrease blood Ca2+:
inhibit osteoclasts
increase kidney excretion of calcium ions
What are the 2 types of ossification? When do they begin and and?
endochondral ossification:
long bones
hyaline cartilage framework, then ossification
intramembranous ossification:
flat bones
form within fibrous connective tissue
Begins 6 weeks after fertilization, ends at about 25 yrs
What are the epiphyseal plate and line?
Epiphyseal plate
Disc of hyaline cartilage at the epiphysis-diaphysis junction
Allows bone to grow in length
Epiphyseal line
Remnant of the epiphyseal plate in adults
Thin line of compact bone
Where does endochondral ossification occur? What are the steps?
hyaline cartilage framework, then 7 Steps: chondrocyte disintegration blood vessels and osteoblasts primary ossification center – shaft shaft remodeling secondary ossification center – epiphysis epiphyseal plate growth epiphyseal closure
How does HGH affect epiphyseal plate activity?
Growth Hormone and Thyroid Hormone stimulate bone growth through increasing all cell division and activity throughout the body
chondrocytes and osteoblasts stimulated
