Skeletal System Flashcards
5 basic tissues comprising of the muscoskeletal system
1) bones
2) ligaments
3) cartilage
4) skeletal muscles
5) tendons
Function of ligaments
Attaches bones together
Function of cartilage
Protective gel like substances lining joints and discs
Functions of tendons
Attaches muscles to bones
5 types of bones:
-flat bones
-long bones
-short bones
-irregular bones
-sesamoid bones
How many bones are there at birth and how many in an adult?
270 at birth
206 bones in an adult
Functions of the skeletal system
- to provide structure and body framework
- attaches muscles and tendons to allow movement
- forming boundaries and protects the organs
- stores the minerals
Features of spongy bones tissue
- porous and highly vasucularised
- honeycomb like
Spongy bone tissues function
- reduces bone density
-allows end of long bones to compress due to stress
Features of compact bone tissue
- contains nerves and blood vessels
- the hard outer layer
-gives bones the smooth, white solid appearance
Features of long bones
-diaphysis (shaft)
-epiphyses ( extremities)
What is diaphysis composed of?
- fatty yellow bone marrow
What is epiphyses and what does it contain?
- outer covering of compact bone with spongy bone
- hyaline cartilage
- vascular membrane
- Bone cells for production and breakdown
- has its own blood supply
- full of nerves
Types of bone cells
- osteoblasts
- osteocytes
- osteoclasts
What’s the function of osteoblasts?
- Bone building cells
- They deposit new bone issue around themselves , becoming trapped
- differentiates into osteocytes
What’s the function osteocytes?
- mature bone cells
- they do not divide
- responsible for bone formation
- responsible for calcium homeostasis
Function of osteoclasts?
- bone reabsorbing cells
- destroys old bone cells
Stage 1 of osteogenesis
Osteoblasts secretes osteoid which replaces cartilage in foetus
Stage 2 of osteogenesis
Calcium and phosphate calcify and become a hard, rigid mature bone
Stage 3 of osteogenesis
Cells become trapped and become osteocytes
How bones grow
- starts as cartilage and becomes harder from the centre going outwards
- diaphysis lengthens
- blood vessels and and nervous tissue assists with growth
- compact bone (epiphyses)
- spongy bone growth stimulated by osteocytes becoming osteoblasts
What hormones promotes bone growth in foetus?
Human growth hormone
Thyroxine
Tri-iodothyronine
What does testosterone and oestrogen do to the bone mass and density?
Increases it
Which hormone controls calcium uptake?
Calcitonin
