bones Flashcards
what two parts is the skeleton split into?
axial skeleton and appendicular skeleton
how many bones are there in the skeleton?
206
list the types of bone
- long bones
- short bones
- flat bones
- irregular bones
- sesamoid bones
give the structure of the long bone
long shaft, two articular surfaces, mostly compact bone. e.g. femur, tibia
give the structure of the short bone
cube shaped, thin layer of compact bone with spongy centre.
give the structure of the flat bone
parallel layers of compact bone and spongy centre
give the structure of the irregular bone
thin layers of compact bone surrounded in a spongy centre
give the structure of the sesamoid bone
bones embedded in tendons or muscle
what is the epiphyseal plate?
the place where long bones grow. closes when puberty begins
where is red bone marrow found? what is its purpose?
found in spongy bone, responsible for haemopoeisis.
where is yellow bone marrow found? what is its purpose?
medullary cavity - triglyceride store
what is the endosteum?
layer of connective tissue where a lot of bone forming cells reside
what is the periosteum?
contains bone forming cells, involved in protection of bone. location of tendon attachment
what effect do adipocytes have?
reduce capacity for haematopoiesis and osteoblast activity
what is a fibrous joint?
a joint in which bones are connected by fibrous connective tissue rich in collagen fibres
what is a cartilaginous joint?
a joint held together by cartilage
what is a synovial joint?
a joint in which bones are held together by connective tissue within a capsule and often by ligaments
which type of joint permits movement?
synovial
what is the benefit of warming up?
encourages production and secretion of synovial fluid, responsible for lubrication. also brings phagocytic cells to remove debris and microbes
what is the difference between ligaments and tendons?
LIGAMENTS join bone to bone
TENDONS join muscle to bone
what are the properties of ligaments?
- dispersed fibroblasts
- collagen is less well organised
- elastic and strong
what are the properties of tendons?
- parallel rows of fibroblasts
- well organised collagen
- non elastic and tough
what does cartilage consist of?
collagen, elastin fibres and proteoglycan
list the types of cartilage
- hyaline
- fibrocartilage
- elastic cartilage
what is hyaline cartilage?
the most abundant form of cartilage, present in many locations such as bronchi, larynx
what is fibrocartilage?
strongest form of cartilage, present in invertebral disks, menisci of knee joint
what is elastic cartilage?
cartilage that is not associated with bone, e.g. epiglottis
what are the potental effects of exercise on tendons?
MECHANICAL ADAPTATION - remodelling in response to strength and endurance training
INCREASED TURNOVER OF COLLAGEN - anabolism predominates and crosslinks increase
TENDON FIBROBLAST INVOLVEMENT - response to stretch and alteration of extracellular matrix
what is the effect of exercise on ligaments?
increased stretch and flexibility
what is the effect of exercise on cartilage?
increased thickness of hyaline cartilage, protection, reduced risk of injury and osteoarthritis
what is the effect of exercise on synovial fluid?
increased production, greater lubrication, cushioning and shock absorption
list the different types of synovial joint
- ball and socket
- pivot
- hinge
- planar
- condyloid
- saddle
what types of movement can occur at synovial joints?
gliding rotation angular flexion extension hyperextension abduction adduction circumduction
what is the role of osteocytes?
bone formation, mineralisation and the control of other cells and transduction of information
what is the role of osteoclasts?
resorption
what is the role of osteoblasts?
bone formation
why is it important to be able to extract calcium from bone?
metabolic needs outweigh skeletal needs, calcium is needed for cardiac contractility and nerve transmission
what is gigantism an example of?
a condition where bone resorption and formation are not matched - childhood secretion of pituitary growth hormone
what is acromegaly an example of?
a condition where bone resorption and formation are not matched - caused by adult hyper secretion of GH
how is bone mineral density measured?
dual X-ray absorptiometry - determines what proportion of the X-ray energy has been absorbed related to density
what is the response to exercise for bone regulation?
higher BMD
how does mechanical force cause bone remodelling?
exercise -> stress on bone -> altered fluid flow in lacuna canalicular fluid -> osteocytes detect shear stress and hydrostatic pressure waves -> hormonal/biochemical messenger release -> recruitment of osteoblasts and osteoclasts
what do osteoblasts cause?
protein secretion, mineralisation
what do osteoclasts cause?
resorption, autocrine and paracrine control of remodelling
