Chapter 6: The Skeletal System Flashcards
- internal frame of the bone
- body’s support structure
- allow body movements (joints)
skeletal system
functions of skeletal system
- body support
- organ protection
- body movement
- mineral storage
- blood cell production
- formed where two or more bones come together
- allow movement between bones
joints
covers the ends of bones within some joints, allowing the bones to move freely
smooth cartilage
allow some movement between bones but prevent excessive movements
ligaments
- formation of blood cellular components
- occurs during embryonic development and throughout adulthood
hematopoiesis
always contains collagen, ground substance and other organic molecules, as well as water and minerals
bone matrix
a tough, ropelike protein
collagen
large molecules consisting of many polysaccharides attaching to and encircling core proteins
proteoglycans
provides compressional strength
hydroxyapatite
- Imperfect bone formation
- a rare disorder caused by any one of a number of faulty genes that results in either too little collagen formation, or poor quality collagen
brittle bone disease (osteogenesis imperfecta)
3 bone cells:
- osteoblast
- osteocytes
- osteoclast
produce bone matrices and become osteocytes
osteoblast
- mature bone cells found in lacunae
- produce the components needed to maintain the bone matrix
osteocytes
- break down bone (with assistance from osteoblasts)
- bone destroying cells and results in bone resorption
osteoclast
4 bone shapes
- long bones
- short bones
- flat bones
- irregular bones
longer than they are wide
long bones
are approximately as wide as they are long
short bones
have a relatively thin, flattened shape
flat bones
have specialized functions, such as providing protection while allowing bending and flexing of certain body regions
irregular bones
Has many spaces
spongy bone
has more matrix and is denser, with fewer pores than spongy bone
compact bone
the formation of bone by osteoblasts
ossification
2 types of ossification
- Intramembranous ossification
- Endochondral ossification
bone formation that occurs within connective tissue membranes
intramembranous ossification
bone formation that occurs inside hyaline cartilage
endochondral ossification
occurs by the deposition of new bone lamellae onto existing bone or other connective tissue
bone growth
“As osteoblasts deposit new bone matrix on the surface of bones between the periosteum and the existing bone matrix, the bone increases in width, or diameter”
appositional growth
- bones are constantly changing
- removal of existing bone by osteoclasts and the deposition of new bone by osteoblasts
- responsible for changes in bone shape, the adjustment of bone to stress, bone repair, and calcium ion regulation in the body fluids.
bone remodelling
process of bone formation
- hematoma formation
- callus formation
- callus ossification
- bone remodeling
classifications of bone fractures
- linear
- complete
- comminuted
- incomplete
- impacted
- transverse
- spiral
- oblique
maintained by three hormones:
- parathyroid hormone (PTH) from the parathyroid glands
- vitamin D from the skin or diet,
- calcitonin from the thyroid gland.
calcium homeostasis
total number of bones in the average adult skeleton
206
depression in a bone
fossa
rounded projection on a bone
tubercle or tuberosity
sharp projection from a bone
process
smooth, rounded end of a bone, where it forms a joint with another bone
condyle
- composed of the skull, the vertebral column, and the thoracic cage
- forms the longitudinal axis of the body
axial skeleton
total number of bones in the skull
22
- encloses the cranial cavity
- consists of 8 bones that immediately surround and protect the brain
braincase (neurocranium)
- form the structure of the face
- consists of 14 bones
facial bone (viscerocranium)
the _____ and _____ form a large portion of the side of the head
- parietal bones
- temporal bones
a joint uniting bones of the skull
suture
- a large opening that is a prominent feature of the temporal bone
- a canal that enables sound waves to reach the eardrum
external auditory canal
4 major structures seen from the frontal view of the skull
- frontal bone
- zygomatic bones
- maxillae
- mandible
most prominent openings into the skull
- orbits (eye sockets)
- nasal cavity
cone-shaped fossae, so named because the eyes rotate within them
orbits
formed as the developing skull conforms to the shape of the brain
cranial fossae
located in the occipital bone near the center of the skull’s base
foramen magnum
- an unpaired, U-shaped bone
- It is not part of the skull, and has no direct bony attachment to the skull or any other bones.
hyoid bone
the central axis of the skeleton, extending from the base of the skull to slightly past the end of the pelvis
vertebral column or spine
in adults, the vertebral column (spine) consists of ____ individual bones
26
the vertebral column is grouped into ____ regions
5
number of cervicalvertebrae in the vertebral column
7
number of thoracic vertebrae in the vertebral column
12
number of lumbar vertebrae in the vertebral column
5
The weight-bearing portion of each vertebra
body
surrounds a large opening called the vertebral foramen
vertebral arch
encloses and protects the spinal cord and protects it from injury
vertebral canal
protects the vital organs within the thorax and prevents the collapse of the thorax during respiration
rib cage
12 pairs of ribs can be divided into:
- true ribs
- false ribs
divided into three parts:
- the manubrium
- the body (handle)
- the xiphoid (sword) process
sternum
- depression at the superior end of the sternum
- located between the ends of the clavicles where they articulate with the sternum
jugular notch
appendicular skeleton consists of the bones:
- pectoral girdle
- upper limb
- pelvic girdle
- lower limb
Consists of four bones:
- two scapulae
- two clavicles
pectoral girdle or shoulder figure
a flat, triangular bone
scapulae
also called as collarbone
clavicle
consists of:
- arm
- forearm
- wrist
- hand
upper limb
the region between the shoulder and the elbow which contains the humerus
arm
2 bones of the forearm
- ulna
- radius
- located between the forearm and the hand
- composed of 8 carpal bones
wrist
- attached to the carpal bones and from the bony framework of the hand
- consists of 5 metacarpal bones
hand
place where the lower limbs attach to the body
pelvic girdle
consists of:
- thigh
- leg
- ankle
- foot
lower limb
- region between the hip and the knee
- contains the femur
thigh
- Region between the knee and the ankle
- Contains two bones: Medial Tibia and Lateral Fibula
leg
Consists of the distal ends of the tibia and fibula forming a partial socket that articulates with the bone of the foot (talus)
ankle
consists of 7 tarsals
foot
3 primary arches in the foot
- anterior transverse arch
- medial longitudinal arch
- lateral longitudinal arch
commonly named according to the bones or portions of bones that join together
joints (articulation)
classifications of joints acc to structure:
- fibrous joint
- cartilaginous joint
- synovial joint
- articulating surfaces of two bones united by fibrous connective tissue
- They have no joint cavity and exhibit little or no movement
fibrous joint
- unite two bones by means of cartilage
- no movement
cartilaginous joint
connecting cartilage can be:
- hyaline cartilage (synchondroses)
- fibrocartilage (symphyses)
freely movable joints that contain fluid cavity surrounding the ends of articulating bones
synovial joint
types of synovial joint
- plane joints
- saddle joints
- hinge joints
- pivot joints
- ball-and-socket joints
- ellipsoid joints
consists of two opposed flat surfaces that glide over each other
plane joints
movement can occur in two planes
saddle joints
movement in one plane only
hinge joints
restrict movement to rotating around a single axis
pivot joints
allows a wide range of movement in almost any direction
ball-and-socket joints
movement is limited due to the shape of joints
ellipsoid joints
classification of joints acc to function:
- synarthroses
- amphiarthrosis
- diarthroses
non-movable joints
synarthroses
slightly movable joints
amphiarthrosis
freely movable joints
diarthroses
types of movement
- flexion
- extension
- hyperextension
- abduction
- pronation and supination
- eversion
- inversion
- rotation
- circumduction
- protraction
- retraction
- elevation
- depression
- excursion
- opposition
- reposition
A bending movement that decreases the angle of the joint to bring the articulating bones closer together
flexion
A straightening movement that increases the angle of the joint to extend the articulating bones
extension
extension of a joint beyond 180 degrees
hyperextension
Movement away from medial or midsagittal plane
abduction
Unique rotation of the forearm
pronation and supination
turning the foot so that the plantar surface faces laterally
eversion
turning the foot so that the plantar surface faces medially
inversion
turning of a structure around its long axis, as in shaking the head “no” as well as the rotation in our arms
rotation
Arm moves tracing a cone-like shape where the shoulder joint is at the cone’s apex
circumduction
glides anteriorly
protraction
glides posteriorly
retraction
Movement of a structure in a superior direction.
elevation
Movement of a structure in an inferior direction
depression
Movement of a structure to one side, as in moving the mandible from side to side
excursion
A movement unique to the thumb and little finger
- opposition
- reposition
