Pathophysiology Flashcards
What is the musculoskeletal system made up of?
Bones
Muscles
Cartilage, tendons, ligaments, joints and other connective tissues
The skeletal portion of the MSK system serves as main storage system for ____ and _______.
Calcium
Phosphorus
Why is the storage system important in the body?
Help regulate mineral balance in the bloodstream
Other than storage function, what does the skeleton do?
Contains critical components of the hematopoietic (blood production) system.
What is located in long bones?
Bone marrow
What is the distinctions of bone marrow?
Yellow and red
Where is the yellow marrow found, and what does it contain?
Found in marrow cavity
Contains fatty connective tissue
Function of yellow marrow
In times of starvation, body uses fat in yellow marrow for energy
Function of red marrow
Important site for hematopoeisis or blood cell production that replaces cells that have been destroyed by the liver. Here, all erythrocytes, platelets, and most leukocytes form in bone marrow from where they migrate into circulation.
Muscles keep ____ in place.
Bones
What causes muscles to contract?
Muscles are innervated - the nerves conduct electrical currents from CNS
Tendon connects ____ to ______.
Muscle to bone
What is a tendon?
Tough, flexible band made of fibrous connective tissue
What are joints?
Bone articulations allowing movement
What is a ligament?
Dense, white band of fibrous elastic tissue
Ligaments connect ______ to form ________.
Ligaments connect the ends of bones together to form a joint.
Function of ligaments
Limit joint dislocation and restrict improper hyperextension and hyeprflexion.
What are bursae made up of?
Fibrous tissue
Function of bursae
Provide cushions between bones and tendons
How many bones were we born with?
300 soft bones
How many bones do an adult have?
206
Major functions of bones (four)
- Provide structural support for the body
- Provide protection of vital organs
- Provide an environment for marrow (where blood cells are produced)
- Act as a storage area for minerals (such as calcium)
Osteoblasts are derived from?
Mesenchymal stem cells
Function of osteoblasts
Responsible for bone matrix synthesis and its subsequent mineralisation
What are osteocytes?
Osteoblasts that become incorporated within the newly formed osteoid, which eventually becomes calcified bone.
Osteocytes situated _______ maintain contact with __________ in ________, and with ________ and ________ on the bone surfaces
Deep in bone matrix
Newly incorporated osteocytes in osteoid
Osteoblasts and bone lining cells
What is a canaliculi?
Small canals running through the bone solid matrix, hosting osteocyte’s dendrites, and saturated by an interstitial fluid rich in ions
Function of canaliculi
Ideally situated to respond to changes in physical forces upon bone and to transduce messages to cells on the bone surface, directing them to initiate formation or resorption responses
Osteoclasts are derived from?
Hematopoietic lineage
What is osteoclasts?
Large multinucleate cells, like macrophages
Function of osteoclasts
Resorption of mineralized tissue
Where are osteoclasts found?
Attached to the bone surface at sites of active bone resorption
How do glucocorticoids affect osteoblasts?
Induces decrease in osteoblast differentiation and increase apoptosis of osteoblasts
How do glucocorticoids affect osteocytes?
Induce increase in osteocytes
