CH 6: SKELETAL SYSTEM

ends of long bones

epiphysis

hyaline cartilage covering the ends of long bones within a joint

articular cartilage

growth plate between the epiphysis and diaphysis

epiphyseal plate

connective tissue that covers the bone

periosteum

small arteries that enter Volkman's canals, supply the periosteum and outer part of the bone

periosteal arteries

large artery that enters though a foramen near the middle of the diaphysis

nutrient artery

arteries that enter the epiphysis of a long bone

epiphyseal arteries

process of bone formation

ossification

2 processes involved in fetal bone formation

intramembranous ossification
endochondral ossification

a living tissue that can undergo repair

bone

4 stages of bone repair

hematoma formation
callus formation 
callus ossification
bone remodeling

cells that secrete calcitonin from the thyroid gland when blood calcium levels are elevated

parafollicular cells or C cells

hormone that inhibits osteoclast activity

calcitonin

a form of vitamin d that increases calcium in the small intestine

calcitriol

strong bands of fibrous connective tissue, hold bones together.

ligaments

4 components of the skeletal system

bones
cartilage
tendons
ligaments

protects the brain 

skull or cranium

protect the spinal cord

vertebral column

where can chondrocytes be found in bone

lacunae

is a double-layered outer layer of dense irregular connective tissue containing fibroblasts, surrounding most cartilage

perichondrium

2 types of cartilage growth

appositional growth
interstitial growth

{{c1::osteoprogenitor cells}} are precursor, unspecialized bone cells, undergo cell division, resulting into {{c2::osteoblasts}}

bone-building cells

osteoblasts

osteoblasts secretes {{c1::collagen}} and {{c2::proteoglycans}} to build extracellular matrix

mature bone cells, main cells of the bone

osteocytes

bone-destroying cells that break bown- bone resorption

osteoclasts

outer layer of bone and strongest part of bone tissue

compact bone

found beneath the periosteum of all bones

compact bones

consists of osteons or haversian systems

compact bone

are very small spaces between lamellae, contains osteocytes

lacunae

known as trabecular or cancellous bone tissue

spongy bone

porous, less bone matrix, no osteons, no haversian systems

spongy bone

lamellae arranged in an irregular pattern of thin collumns are called

trabeculae

trabeculae spaces are filled with {{c1::red bone marrow}}, {{c1::yellow bone marrow}}, and {{c1::blood vessels}}

osteocytes like in lacunae and ger nourishment through the {{c1::canaliculi}}

this type of bone is seen in short, flat, or irregular bones

spongy bone

central portion of the bone, composed mainly of compact bone tissue and a hollow center called {{c1::medullary cavity}}

articular cartilage are made up of {{c1::hyaline}} cartilage

The formation of cartilage begins at approximately the end of the fourth week of embryonic development

Endochondral Ossification

stage of fetal bone development where bones of the skull are formed

intramembranous ossification

average adult number of bones

206 bones

bones are grouped into: (2)

axial skeleton
appendicular skeleton

includes the skull, auditory ossicles, hyoid bone, vertebral column, and thoracic cage

axial skeleton

includes the pectoral girdle, upper limb, pelvic girdle, and lower limbs

appendicular skeleton

protects the brain

skull or cranium

are immovable joints that connects cranial bones

sutures

4 types of cranial sutures

coronal
sagittal
lambdoid
squamous

what functional classification of joint are cranial sutures

synarthroses

the forehead

frontal bone

between the two eye orbits

glabella

paired bones on lateral sides

parietal bones

3 parts of the temporal bone

squamous
petrous
tympanic

located posterior of the external ear

mastoid process

base of the skull

occipital bone

large opening, attachment for spinal vertebral column

foramen magnum

serves as neck muscles attachment for head movement

nuchal lines

bone in the internal side of skull

sphenoid bone

saddle shaped part that protects the pituitary gland, in the body of the sphenoid

sella turcica

air spaces of the sphenoid bone

sphenoidal sinuses

centrally located in skull and nasal septum

ethmoid bone

attachment for one of the meninges 

crista galli

air spaces of the ethmoid bone

ethmoidal sinuses

openings that communicates / opens into nasal cavity

paranasal sinuses

give 2 functions of the paransal sinuses

decrease the weight of the skull
serves as a resonance chamber when speaking

the 4 paranasal sinuses

ethmoidal sinuses
sphenoidal sinuses
maxillary sinuses
frontal sinuses

cone-shaped fodda, protects the eyes, serves as attchment of the eye muscles

orbits

rounded openings anteriorly, separated by nasal septum

nasal cavity

14 facial bones

paired:
zygomatic
palatine
nasal bone
maxillary
lacrimal
inferior nasal concha

unpaired:
mandible
vomer

8 cranial bones

paired:
parietal
temporal

unpaired:
frontal
sphenoid
ethmoid
occipital

the cheek bone

zygomatic bone

formed by temporal processes of zygomatic bone and zygomatic process of temporal bone

zygomatic arch

forms the upper jaw

maxilla

{{c1::palatine process}} forms the anterior 2/3 of the hard palate, while {{c1::palatine bones}} forms the posterior 1/3

joins the orbits and nasal cavity

nasolacrimal canal

forms bridge of the nose

nasal bone

forms the posterior part of the nasal septum

vomer

freely movable, forms the lower jaw

madible

the {{c1::mandibular condyle}} attaches to the mandibular fossa of temporal bone

found in nasal cavity that provide increased surface area for air to be filtered

inferior nasal concha

an unpaired bone and not really attached to any other bone

hyoid bone

muscles and ligaments attach from this bone to the skull

hyoid bone

this bone is bound in the soft tissues of neck below the mandible

hyoid bone

bones in the ears

auditory ossicles

3 bones in the ears

malleus
incus
stapes

supports the weight of the head and trunk

vertebral column

5 regions of the vertebra and the number of bones in each

cervical - 7
thoracic - 12
lumbar - 5
sacral - 1
coccyx - 1

made up of small bones that aid in head movement

cervical vertebrae

bones that have a split spinous process

cervical bones

first cervical vertebrae

atlas

second cervical vertebrae

axis

the axis has a superior process called the {{c1::dens}} where the atlas rotates for head movement

the least movable and has 5 vertebral regions

thoracic vertebrae

supports the throacic cage

thoracic vertebrae

supports the majority of body's weight and consists of 5 lumbar vertebra, has massive bodies

lumbar vertebrae

formed by 5 sacral vertebrae 

sacrum

has 3-5 semi-fused vertebrae, aka the tail bone

coccyx

the coccyx projects {{c1::inferiorly}} in females, and projects {{c1::anteriorly}} in males

semi rigid chamber that protects the lungs

throracic cage

how many pairs of ribs are in the thoracic cage

12 pairs

the true ribs

ribs 1-7