chapter 7 - Bone Tissue And The Skeletal System Flashcards
major functions of bones
attach to muscles, some organs and certain soft tissue
protect softer tissues
haemopoiesis - produce blood cells and platelets
store salts, minerals and energy reserves
form blood vessels and nerve passageways
support the weight of the body
work with muscles to maintain body position and control movement
classifications of bones
Flat bones - ribs, scapulae, certain skull bones
Irregular bones - many facial bones, vertebrae of spine and pelvis
Short bones - wrists and ankles
Long bones - arms, forearms, thighs, legs, palms, soles, fingers, toes
Sutural bones - extra bone pieces that can occur within a suture in the skull
Sesamoid ,round, bones - inside tendons near joints in knees, hands and feet
examples of: Flat Bones
These resemble plates, with broad surfaces and include the ribs, sternum, scapulae, most skull bones.
They provide protection for underlying soft tissues and may be thin and slightly curved
examples of: Irregular Bones
Irregular bones have different and complex shapes and are often connected to other bones.
They include many facial bones and those that make up the vertebrae and the pelvis.
examples of: Short Bones
Small and often cube-shaped, short bones include the carpal bones and tarsal bones.
examples of: Long Bones
These have long bone shafts with expanded ends and are much longer than they are wide. Named for their elongated shape instead of their actual size.
The three bones of the finger are long bones.
All bones of the limbs are long bones except the patella, carpals and tarsals.
located in the arms, legs, palms, soles, fingers and toes.
examples of: Sutural Bones
also known as ‘Wormian Bones’.
these are small, flat and irregular bones between the flat bones of the skull.
ranging in size from a quarter to a grain of sand.
examples of: Sesamoid Bones
Small flat bones resembling sesame seeds located near joints of the hands, knees and feet.
The patellae are sesamoid bones.
May form in up to 26 locations in the body.
each individual has different numbers of sesamoid bones.
Some help to control the directions in which tendons pull.
some have unknown functions
Two divisions of the skeleton
Axial skeleton
Appendicular skeleton
how many bones in human body
206
including those of the middle ear
role of the: Axial skeleton
Support and protect the head, neck and trunk.
what bones are make up the axial skeleton
Skull
Hyoid bone (bone in neck that supports tongue)
Vertebral column
Thoracic cage
major features of the: Skull
made up of 22 firmly interlocked bones. divided into 8 Cranium bones enclosing the chamber, aka cranial cavity, that supports the brain and 14 Facial bones.
lines where skull bones lock are called Sutures
only movable bone is the Mandible aka lower jaw
houses and protects the brain.
air filled spaces inside cranial bones called ‘Paranasal Sinuses’ help the voice to resonate, also to reduce the weight of the skull.
major features of the: Spine
33 bones
Extends from skull to pelvis
made up of 26 bony vertebrae separated by intervertebral discs made of cushioning cartilage, connected by ligaments.
Each vertebrae had a drum shaped body, making up the thick anterior portion of the bone.
The trunk and head are supported by the vertebral column, which also protects the spinal cord.
The spinal cord passes through the vertebral canal created by openings in the vertebrae.
At the bottom some vertebrae are fused to form the sacrum, part of the pelvis, and coccyx aka tailbone which is attached to the end of the sacrum.
major features of the: Cervical vertebrae
7
allows arteries of the brain to pass through
Atlas - first vertebrae
Axis - second vertebrae
major features of the: Thoracic vertebrae
12
larger then the cervical vertebrae
their spinous processes slope downwards
increase in size down the spine to bear increasing loads of body weight
each thoracic vertebrae articulates with with ribs
the transverse processes of vertebrae T1 to T10 are relatively thick. They contain ‘transverse costal facets’ for rib articulation
major features of the: Lumbar vertebrae
5
even larger then thoracic vertebrae, supporting more body weight
have a triangular vertebral foramen
superior articular processes face medially
inferior articular processes face laterally
major features of the: Sacrum
5
triangular structure
forms the vertebral columns base
A ridge of tubercles project outward with rows of openings, the posterior sacral foramina, through which nerves and blood vessels pass.
The sacral canal continues through the sacrum to an opening called the sacral hiatus, where four pairs of anterior sacral foramina allow nerves and blood vessels to pass.
major features of the: Coccyx
4
also known as the tailbone
lowest part of the vertebral column
four fused vertebrae
attached to the sacral hiatus by ligaments
Thorax
composed of the thoracic cage which includes -
12 pairs of ribs connected posteriorly to the thoracic vertebrae. 7 true ribs, 5 false ribs.
The sternum - manubrium, gladiolus, xiphoid process
Costal cartilages which attach the ribs to the sternum anteriorly.
Supports the pectoral girdle and upper limbs
Protects the visceral organs inside the thoracic and upper abdominal cavities
Pectoral Girdle
made up of the clavicle and scapula
aids movement of arms
connects upper limb bones to axial skeleton
supports upper limbs and is where muscles that move upper limbs are attached.
major features of the: Ribs
one pair attached to each of the 12 thoracic vertebrae totalling 24 in all.
first 7 pairs are true ribs, aka vertebrosternal ribs, attached to the sternum via costal cartilages.
the last 5 pairs are false ribs, meaning their cartilages don’t reach the sternum directly.
the cartilages of the upper 3 false ribs join the cartilages of the 7th true rib.
the final 2 false ribs are called floating ribs, aka vertebral ribs, because they do not attach to the sternum via cartilage at all.
Ribs are curved with enlarged heads allowing them to attach to the sternum via facets.
The transverse process of the vertebrae articulates with a tubercle, aka projection, close to the ribs head.
define appendicular skeleton
contains upper and lower limb bones and the bones anchoring the limbs to the axial skeleton.
The appendicular skeleton includes the pectoral girdle, upper limbs, pelvic girdle and lower limbs.
major features of: clavicles
located at the base of the neck running horizontally between the manubrium and the scapulae.
The bones brace the scapulae to hold the shoulders in place and provide muscle attachment points for the upper limbs, chest, and back.
