musculoskeletal system Flashcards
what does the axial skeleton include?
the skull, thoracic cage and cerebral column
what does the appendicular skeleton include?
the shoulder (pectoral) gridle, upper limbs, pelvic gridle and lower limbs
how do bones support the body?
the bones form a framework that supports the body and cradles its soft organs
how to bones protect the body?
bones protect soft organs
how does bones enable movement?
most skeletal muscles are attached to bones so bones act as levers for muscles. when muscles contract they pull on bones allowing the movement of the body and parts
what do bones store?
- calcium and phosphorus
- fat (stored in yellow bone marrow)
where does haematopoiesis occur in the bone?
in red marrow of the bones
what is haematopoiesis?
blood cell formation
where is hyaline cartilage and what is its function?
- located in the ears, nose, respiratory system and where ribs attach to the sternum
- it gives these structures some form while allowing for some flexibility - it also acts as a shock absorber and reduces the friction between bones
where is fibrocartilage and what does it do?
- located in the pubic symphysis and the intervertebral discs
- it provides rigidity and structural support to resist shear forces and compression
where is elastic cartilage and what does it do?
- located within the ear and epiglottis, elastic cartilage
- it maintains the shape of these structures while allowing a lot of flexibility
what are some organic components of bone?
- bone cells
- collagen fibres
- proteins
what are some inorganic components of the bone?
- calcium phosphate salts
what are the three types of bone cells?
- osteoblasts
- osteocytes
- osteoclasts
what is bone matrix?
it is hard inorganic component formed mainly by calcium phosphate
osteoclast does what?
it breakdown bone tissue
osteocyte does what?
maintains bone matrix
osteoblast does what?
bone growth
what is compact bone?
- it can also be called cortical bone
- it forms the dense, outer layer of a bone providing strength, protection and movement to the body
- additionally it plays a role in storing and releasing calcium into the blood stream
what is compact bone made up of?
- it is made up of units called osteons
what can spongy bone also be called?
cancellous bone
what does canaliculus do?
it allows osteocytes to communicate with each other and the Haversian canal via cytoplasmic processes
what does lacunca do?
it hosts an osteocytes in a small, fluid-filled space
what does the central canal do?
provides a pathway for nerves, lymphatics and blood vessels
what does osteon do?
resists mechanical stress and strengthens bone
what does osteocytes do?
responds to mechanical stimuli, communicates with osteoblasts and osteoclasts and regulates the bone matrix
what does chrondroblast do?
secrets cartilage matrix
what is the diaphysis?
- the shaft/long axis of the long bone
- a thick layer of compact bone surrounding the medullary cavity which contains yellow marrow in adults
what is ossification?
bone growth occurs throughout life, it starts in fatal like with the development if cartilage and fibrous membrane bone model. over time cartilage is replaced by bone and is known as ossification
what is the last part os a long bone to be ossified?
the epiphyseal plate
what type of bone cells will be laying down new bone matrix as is formed or extended during ossification?
osteoblasts
what type of bone cell will be dissolving bone matrix as its remodelled?
osteoclasts
which hormone stalemates the breakdown of bone matrix by osteoclasts?
parathyroid hormone
what effect would increase osteoclast activity have on bone density?
it would decrease bone density
what bones belong to the face?
- mandible
- nasal bone
- maxillary bone
- zygomatic bone
what bones belong to the cranium?
- temporal bone
- frontal bone
- parietal bone
- occipital bone
what is sagittal suture?
joins the parietal bones
what is coronal suture?
joins the frontal bone and parietal bones
what is lambdoid suture?
joins the parietal and occipital bones
what is squamous suture?
joins the parietal and temporal bones
how many vertebra are in the cervical?
7
how many vertebra are in the thoracic?
12
how many vertebra re in the lumbar?
5
how many vertebra are in the sacral?
5
how many vertebra are in the coccygeal?
4
what are the two concave curvatures of the spine?
cervical and lumbar
what are the two convex curvatures of the spine?
thoracic and sacral
describe synarthroses
- skul sutures
- immoveable
describe amphiarthroses
- slightly moveable
- pubic symphysis
describe diarthroses
- most limb joints
- freely moveable
fibrous joints:
- bone ends joined by collagen fibres
- skull sutures
- immobile
cartilaginous joints:
- joints between ribs and sternum
- pubic symphysis
- bone ends joined by cartilage
- slightly moveable
synovial joints:
- synovial
- enclosed by a fluid filled capsule
- freely moveable
- knee joint
- bone ends covered with articular cartilage
- space between bone ends
what is acetylcholine?
a neurotransmitter that causes an action potentials in a muscle causing it to contract
when does muscle contraction occur?
when actin and myosin interact, generating force within the muscle
what happens when muscle fiber is stimulated?
the muscle depolarisation results in the reals of ionised Ca2+ from the sarcoplasmic reticulum where it is store
what happens when Ca2+ is removed?
it is removed by uptake into the sarcoplasmic reticulum, the troponin again prevents this interaction and the muscle relaxes
what is the functional unit of skeletal muscle fiber called?
sarcomere
the electrolyte necessary to create muscle contraction include??
Ca2+ (calcium ion)
the removal of which ion causes the muscle to relax after contraction?
Ca2+
when ATP binds to myosin it…
extends, preparing to bind with actin
what does isotonic mean?
AS THE MUSCLE LENGTH CHANGES, THE SAME TENSION IS MAINTAINED DURING THE CONTRACTION
what does isometric mean
that the length of the muscle is unchanged during the contraction
describe agonist muscles
they are sometimes called “prime movers” as they are the primary muscle responsible for generating movement through their contraction
describe antagonist muscles
muscles control specific movement and return the muscle to its initial position. depending on the movement, agonist and antagonist muscles may change roles
