The Skeletal System Flashcards
Name functions of skeleton
Framework
Movement or Locomotion
Protection
Soft tissue attachment
Production
Storage
Framework (describe)
supports the body and gives it shape
Movement or Locomotion (describe)
bones form joints which act as levers
Protection (describe)
helps protect internal organs from being damaged
Soft tissue attachment (describe)
provides surfaces for the attachment of soft tissues
Production (describe)
certain bones produce red blood cells, white blood cells and platelets from their bone marrow
Storage (describe)
-stores minerals such as calcium/phosphorus to withstand powerful physical stresses
-fats are stored in yellow bone marrow
Axial skeleton
skull, spine, ribs, sternum
Appendicular skeleton
shoulder girdle, upper limbs, pelvic girdle, lower limbs
What bones make up the SKULL?
cranial
Number of cranial bones?
8
What bones make up the SPINE?
cervical
thoracic
lumbar
sacral
coccygeal
Number of cervical bones & their location?
7, neck
Number of thoracic bones & their location?
12, chest
Number of lumbar bones & their location?
5, lower back
Number of sacral bones & their location?
5, rump
Number of coccygeal bones & their location?
4, tail
What bones make up the CHEST & how many & purpose?
sternum
1
attachment of true ribs, false ribs & clavicle
What bones make up the SHOULDER & how many do we have?
scapula, 2
clavicle, 2
Describe shape & location of scapulae
triangular bones at rear of body
Describe shape & location of clavicle
‘S’ shaped bones above rib cage and at front of body
What bones make up the ARM?
humerus, radius, ulna
Humerus location
upper arm
Radius location/description
outer/shorter bone of forearms
Ulna location/description
inner/longer bone of forearm
What bones make up the HANDS & how many do we have?
carpal, 16
metacarpal, 10
phalange, 28
Carpal description
2 rows of 4 bones, forming wrist
Metacarpal description
Palm of hand
Phalange description (hand)
Finger bones
What bones make up the PELVIS & how many do we have?
Ilium, 2
Ischium, 2
Pubis, 2
Ilium description
large, flat bones of pelvis
Ischium location
lower, rear of pelvis
Pubis location
lower, front of pelvis
What bones make up the LEGS?
femur, patella, tibia, fibula
Femur description/location
longest bone in body
Patella description/location
kneecap
Tibia description/location
larger & inner bone of lower leg
Fibula description/location
smaller & outer bone of lower leg
What bones make up the FOOT & how many do we have?
tarsal, 14
metatarsal,10
phalange, 28
Tarsal description
bones of ankle
Metatarsal description
bones of foot
Phalange description (foot)
bones of toes
Types of classifications of bones
long
short
flat
irregular
sesamoid
LONG bones description
- longer than they are wide
- contain mostly compact bone in the shaft (diaphysis)
- contain cancellous bones at each end (epiphysis)
SHORT bones description
- as long as they are wide, consist of mainly cancellous bones
- the above makes them
strong/lightweight
FLAT bones description
- thin, cancellous bones sandwiched between 2 layers of compact bone
- provide large areas for muscle
attachment
IRREGULAR bones description
many different shapes, prevent them from being classified in any other group
SESAMOID bones description
- ‘seed like’
- located within tendons at site of tension/friction to protect joint & aid leverage
Examples of long bones
humerus
radius
ulna
tibia
fibula
metacarpals
phalanges
metatarsals
Examples of short bones
carpals
tarsals
Examples of flat bones
cranium
scapula
costals
sternum
ilium
Examples of irregular bones
vertebrae
Examples of sesamoid bones
patella
Epiphysis (epiphyses)
- bone ends, mainly comprised of
cancellous bone. - house much of red marrow involved
in RBC production - one of primary sites for bone growth
- can be vulnerable to breakage
during growth period
Diaphysis
- the shaft portion of a long bone
- is predominantly compact bone (although inside of shaft is hollow)
- principle role is to support
Epiphyseal line (plates):
- part of region connecting diaphysis
to epiphysis - is a layer of subdividing cartilaginous
cells where growth in length of
diaphysis occurs - cartilaginous cell multiply here
- they move toward diaphysis,
becoming more calcified as they go - osteoblasts continue & complete
process of bone formation
Articular (hyaline) cartilage
- ends of articulating bones are
covered with articular cartilage - is a hard, white, shiny tissue
- along with synovial fluid, helps
reduce friction - necessary for smooth joint action
Types of bone tissue
compact (cortical bone)
cancellous (spongy bone)
Compact bone
- dense material
- hard outer structure of skeleton
- comprised of lamellae-sheets of collagen aligned in parallel patterns
- these sheets give bones strength
- supplied with oxygen/nutrients through blood supply in Haversian canals/osteons
Cancellous bone
- less dense
- makes up ends of bone/is surrounded by compact bone
- highly vascularised and is where blood cells are formed
Periosteum
- forms tough fibrous membrane, coating bone
- contains nerves, blood vessels & bone producing cells
- inner surface provides materials for nutrition repair & facilitates growth in diameter of bone
- provides point of attachment for tendons
Medullary cavity
- space in centre of diaphysis
- contains fatty yellow marrow (predominantly comprised of adipose tissue-a useful energy reserve)
Endosteum
- connective tissue deep within bone
- a thin vascular membrane that lines inner surface of the bone that forms the medullary cavity
What cells play important roles in bone formation?
Osteoblasts
Osteoclasts
Osteocytes
Osteoblasts
bone forming cells
Osteoclasts
bone destroying cells
Osteocytes
osteoblasts which have matured into bone cells
Ossification
creation of new bone tissue from either cartilage or stress and injury
When does ossification take place?
from birth and can be complete between ages of 18-30
Osteoblasts’ role in ossification
deposit minerals into bone tissue
Osteoclasts’ role in ossification
occupy cracks in bone and dissolve surrounding damaged tissue
Osteocytes’ role in ossification
mature osteoblasts that have created their own site within bone tissue to maintain the structure
What main mineral is require to covert cartilage into skeletal tissue?
Calcium
How is bone elongation achieved?
-through expansion of epiphyseal
growth plates at each end of the
diaphysis
-these plates expand, allowing new
cells to form and increasing the
length of the shaft at both ends
What causes ossification to stop?
-when the thickness of the epiphyseal
plates decreases
-occurs at different rates for different
bones
What are the 4 stages of bone growth & repair?
- Hematoma formation
- Bone generation
- Bony callus formation
- Bone remodelling
Hematoma formation
-blood vessels in the broken bone
tear & haemorrhage, forming blood
clot/hematoma at site of break
-severed blood vessels at broken
ends of bone are sealed by clotting
process
-bone cells deprived of nutrients
begin to die
Bone generation
-within days of the fracture,
capillaries grow into hematoma,
while phagocytic cells begin to clear
away dead cells
-fibroblasts & osteoblasts enter area
and begin reforming bone
-fibroblasts produce collagen fibres
that connect broken bone ends,
while osteoblasts start to form
spongy bone
Bony callus formation
-fibrocartilaginous callus is converted
into bony callus of spongy bone
-takes about 2 months for broken
bone ends to be firmly joined
together after fracture
Bone remodelling
-bony callus then remodelled by osteoclasts & osteoblasts with excess material on exterior of bone and within medullary cavity being removed
-compact bone is added, creating
bone tissue similar to original
unbroken bone
-this can take many months; bone
may remain uneven for years
What creates bone strength?
hardness of minerals combined with tensile properties of collagen
What does too little collagen in a bone cause?
shatter
What does too little minerals in a bone cause?
bend
What hormone predominantly regulates bone formation in pre-puberty years?
human growth hormone (HGH)
What bodily functions is calcium involved?
muscular contraction
transmission of nervous impulses
regulating fluid balance
What does body do when calcium is lacking?
-will be withdrawn from bones
-is why diets chronically low in
calcium tend to increase risk of
osteoporosis
Osteoporosis risk factors
- female sex
- inactive lifestyle
- calcium deficiency
- smoking
- alcohol
- family history
- low body fat
- overtraining
Prevention & Treatment for osteoporosis
- diet
- dairy products
- restful sleep
- calcium/vitamin D
- limit coffee
- stop smoking
- limit alcohol
What is osteoporosis?
(brittle bone disease)
- an imbalance of osteoblast &
osteoclast activity - osteoblast activity decreases,
causing drop in bone growth - this leads to gradual loss in bone
density
=skeletal system unable to
withstand forces placed on it
Factors effecting bone growth
- nutrition
- hormonal excretions
- exposure to sunlight
- physical exercise
