Flashcards in Week 2 Study Cards Deck (129):
What are the two most supportive tissues found in the human body?
cartilage and bone
In embryos, what is the skeleton mainly composed of?
In adults, what is the skeleton mainly composed of?
What are functions of the skeleton?
1) system of levers the skeletal muscles use to move the body
2) bones store lipids and many minerals
3) bones provide a site for blood cell formation in their red marrow cavities
What are the to subdivisions of the skeleton?
What is the axial skeleton?
bones that form the body's longitudinal axis
What is the appendicular skeleton
bones of the girdles and limbs
What are the scarred array of bumps holes and ridges in the bones?
What are the two categories that bone markings fall into?
projections or depressions
What are projections of the bone
process that grow out from the bone and serve as sites of muscle attachments or help form joints
What are depressions of the bone?
indentations, openings in the bone that serve as passageways for nerves and blood vessels
How many bones are in the body?
What are the two basic kinds of osseous tissue that differ in texture?
compact and spongy
What is compact osseous tissue?
dense and looks smooth and homogenous
What is spongy bone tissue?
small trabeculae of bone and lots of open spaces
What are the four groups that bones can be classified in?
long, short, flat, irregular
What are long bones. Give some examples.
bones that are longer than they are wide and generally consist of a shaft with heads at either end. Comprised of mostly compact bone. Examples: femur, phalanges
What are short bones. Give some examples.
cube-shaped and they contain more spongy bone than compact bone. tarsals and carpals
What are flat bones. Give some examples
thin with a layer of spongy bone sandwiched between two waferlike layers of compact bone. Example: skull are flat bones
What are irregular bones?
vertebrae and others that do not fall into one of the preceding categories
What is the diaphysis?
shaft of the bone
What is the periosteum?
fibrous membrane that covers the bone surface
What are perforating fibers/ Sharpey's fibers?
fibers of the periosteum penetrate into the bone
What is the epiphysis?
end of the long bone. thin layer of compact bone enclosing spongy bone
What is articular cartilage?
covers the epiphyseal surface in place of the periosteum. composed of glassy hyaline cartilage and provides a smooth surface to prevent friction at joint surfaces
What is epiphyseal plate?
a thin area of hyaline cartilage that provides for growth in bone length
In becoming an adult the epiphyseal plate goes away and forms what?
What are epiphyseal lines?
discernible remnants of the epiphyseal plate
What is yellow marrow?
storage region for adipose tissue
What is red marrow?
found in infants and is involved in forming blood cells, found in the central marrow cavities
What is endosteum?
lines the medulary cavity
What is the central (Haversian) canal?
central canal runs parallel to long axis of the bone and carries blood vessels and nerves through the body matrix
What is lacunae?
What are osteocytes?
mature bone cells
What are lamellae?
osteocytes arranged in concentric circles around the central canal
What is the central canal and all the lamellae surrounding it referred to as?
osteon or Haversian system
What are canaliculi?
tiny canals running from a central canal to the lucunae of the first lamella and then from lamella to lamella
What are perforating (Volkmann's) canals?
canals that run into the compact bone and marrow cavity from the periosteum, at right angles to the shaft
What are the three parts of the axial skeleton?
skull, vertebral column and bony thorax
What are the two bone sets that make up the skull?
What are the interlocking joints of the bones in the skull called?
What bone is attached to the skull with freely movable joints?
How many flat bones construct the cranium?
What is the function of the cranium?
to enclose and protect the brain
What is the frontal bone?
front portion of the cranium, forms forehead, superior part of the orbit, and anterior part of cranial floor
What is the parietal bone?
posterior and lateral to the frontal bone, forming sides of cranium
What is saggital suture?
midline articulation point of the two parietal bones
What is coronal suture?
point where the parietals meet the frontal bone
What is the temporal bone?
inferior to parietal bone of lateral part of skull
What is squamous suture?
point where temporal bone articulates with the parietal bone
What is zygomatic process?
a bridgelike projection that joins the zygmotic bone anteriorly. Together these two bones form zygomatic arch
What is external acoustic meatus?
canal leading to eardrum
What is styloid process?
Needle like projection inferior to external auditory meatus that serves as an attachment point for muscles and ligaments of the neck
What is mastoid process?
rough projection inferior and posterior to external auditory meatus, an attachment site for muscles
What is the jagular foramen?
Opening medial to styloaid process through which the internal jugular vein and cranial nerves pass
What is the carotid canal?
Opening medial to the styloid process that allows the internal carotid artery to enter the cranial cavity
What is the internal acoustic meatus?
Opening on posterior aspect of temporal bone allowing cranial nerves to pass
What is the occipital bone?
most posterior bone of the cranium: forms the floor and back wall, joins the sphenoid bone anteriorly
What is lambdoid suture?
point of articulation of occipital bone and parietal bone
What is foramen magnum?
large opening in base of occipital that allows the spinal cord to join with the brain
What is occipital condyles?
rounded projections lateral to the foramen magnum that articulate with the first cervical vertebra
What is the sphenoid bone?
bat shaped bone forming a plateau across the width of the skull
What are the greater wings?
portions of the sphenoid seen exteriorly on the lateral aspect of the skull, anterior to the temporal bones. Form part of the orbits of the eyes
What are the sella turcica? (turk's saddle)
A saddle-shaped region in the sphenoid midline which nearly encloses the pituitary gland
What are the lesser wings?
bat shaped portions of the sphenoid anterior to the sell turcica
What are the foramen ovale?
opening posterior to the sell turcica that allows a branch of cranial nerve to pass
What is the optic canal?
allows optic nerve to pass
What is the superior orbital fissure?
transmits cranial nerves to the eye
What is the ethmoid bone?
irregularly shaped bone anterior to sphenoid. Forms roof of nasal cavity, upper nasal septum, and part of the medial orbit walls
What is crista galli? (cock's comb)
Vertical projection to which the dura mater attaches
What is cribriform plates?
bony plates lateral to the crista galli through which olfactory fibers pass to the brain from the nasal mucosa
What is the supperior and middle nasal conchae?
Thin delicately coiled plates of bone extending medially from the ethmoid into the nasal cavity
What is the function of the conchae?
to increase the surface area of the mucosa that covers them, warming and humidifying the air breathed in
What is the mandible?
lower jawbone, ariculates with the temporal bones in the only freely movable joints of the skull
What is the body of the facial bones?
horizontal portions, forms the chin
What is the ramus of the facial bones?
vertical extension of the body on either side
What is the alveolar margin of the facial bones?
superior margin of mandible, contains sockets for the lower teeth
What is the maxillae?
two bones fused in a median suture and form the upper jawbone and part of the orbits
What is the palatine process?
forms the anterior hard palate
What is the palatine bone?
paired bones posterior to the palatine processes; form the posterior hard palate and part of the orbit
What is the zygomatic bone?
Lateral to the maxilla; forms the part of the face commonly called the cheekbone and part of lateral orbit
What is lacrimal bone?
fingernail-sized bones forming a part of the medial orbit walls between the maxilla and the ethmoid. Passage way for tears
What is the nasal bone?
small rectangular bones forming the bridge of the nose
What is the vomer?
blade-shaped bone in median plane of nasal cavity that forms most of the nasal septum
What does vomer mean?
What is the inferior nasal concae?
thin curved bones protruding medially from the lateral walls of the nasal cavity
What is the hyoid bone?
located in the throat above the larynx and is the point of attachment for tongue and neck muscle. Has two pairs of horns
Where is the hyoid bone located?
In the throat, not considered a part of the skull
What are the horns on the hyoid bone called?
What are the four paranasal sinuses?
maxillary, sphenoid, ethmoid, frontal
Which is the largest sinus?
What is the function of the sinuses?
make skull lighter, voice resonance
What are fontanels in babies?
fibrous membranes between the bones of a fetal skull to allow compression during birth and brain growth later in life
What is the vertebral column?
How many single bones are composed in the vertebral column? What are the other two bones that compose it and what are the single bones called?
24 vertebrae, coccyx, sacrum
The vertebral column can be broken down into three section, what are they and how many bones in each one?
cervical vertebrae (very top)-7
thoracic vertebrae (middle)-12
lumbar vertebrae (lower)-5
What are the individual vertebrae separated by
pads of fibrocartilage called intervertebral discs
What is the function of intervertebral discs?
absorb shock while providing the spine flexibility
What is the structure of intervertebral discs?
outside ring that is tough collagen fibers that aid in stabilization of disk and central gelatinous region that behaves like a fluid
What are three abnormal spine curvatures?
scoliosis- s curve
What is the vertebral arch?
composed of pedicles, laminae, and spinous process, it represents junction of all posterior extensions from the vertebral body
What is the vertebral foramen?
opening enclosed by the body and vertebral arch through which the spinal cord passes
What is the transverse processes?
two lateral projections from the vertebral arch
What is the spinous process?
single posterior projection from the vertebral arch
What is the superior and inferior articular processes?
paired projections lateral to the vertebral foramen that enable adjacent vertebrae to articulate with one another
What do the seven cervical vertebrae form?
What is the first of the cervical vertebrae called and what is its specific function?
atlas. lacks a body and contains large depressions on their superior surfaces that receive the occipital condyles of the skull. enables you to nod yes
What is the second of the cervical vertebrae called and what is its specific function?
axis. It acts as a pivot for rotation of the atlas above
What is the large vertical process of the axis called?
dens. these act as the pivot point
Which vertebrae is considered vertebra prominens and why?
the seventh from the top because it is mos prominent
The next 12 form the thoracic vertebrae. What is different between cervical and thoracic?
they are larger and have a bigger body
What are characteristics of the thoracic vertebrae body?
heart shaped, with two small articulating surfaces on each side that articulate with the heads of the ribs
What are characteristics of the lumbar vertebrae body?
massive blocklike bodies and short thick hatchet-shaped spinous processes extending directly backward. They are most sturdy of all vertebrae due to stress
What is the sacrum?
formed from the fusion of 5 vertebrae and is the posterior border of the pelvis
What is the median sacral crest?
remnant of the spinous processes of the fused vertebrae
What are the winglike alae?
articulate laterally with the hip bones forming the sacroiliac joints
What is the sacral foramina?
passageways in the sacrum for blood vessels and nerves
What is the savral canal?
the end of the sacrum that terminates near the coccyx in the sacral hiatus
What is the coccyx?
fusion of three to five small irregularly shaped vertebrae and forms the tailbone
What is the bony thorax?
composed of sternum, ribs, and thoracic vertebrae
What is the bony thorax also referred to as?
What is the sternum? What three parts is it composed of?
fusion of three bones to form a flat bone and is attached to the first seven pairs of ribs. it is the breastbone. The three parts are manubrium, body, and xiphoid process
What is the manubrium?
looks like a knot of a tie. articulates with the clavicle (collarbone)
What does the body form?
What does the xiphoid process form?
the inferior end of the sternum
How many pairs of ribs form the walls of the thoracic cage?
What are true ribs and how many are there?
7 of them. they attach directly to the sternum by their own cartilage
What are false ribs and how many are there?
5 of them. They do not directly attach to the sternum by their own carilage
3 of them attach, 2 are floating ribs