Bones Flashcards
What are the three types of cartilage?
Hyaline Cartilage: Smooth and flexible, found in joints and the respiratory tract. Most abundant, but it’s the weakest. Makes up foetal skeleton.
Elastic Cartilage: Contains elastic fibers, found in the external ear and epiglottis. It is resilient and flexible.
Fibrocartilage: Strong and resilient, found in intervertebral discs and certain joint structures. It acts as a shock absorber.
What are the main functions of bones?
Support: Provides a framework for the body.
Protection: Shields vital organs.
Movement: Serves as attachment points for muscles.
Mineral Storage: Stores calcium and phosphorus.
Blood cell production in red bone marrow.
What are the 4 main types of bone?
Long Bones: Examples include femur and humerus.
Short Bones: These are cube shaped. Examples include carpals and tarsals.
Flat Bones: Examples include skull bones and ribs.
Irregular Bones: Examples include vertebrae and facial bones.
That are the main structures in a long bone?
Diaphysis: Shaft or long central portion.
Metaphysis: Region between diaphysis and epiphysis.
Epiphysis: Enlarged ends.
What are the types of bone cells?
Osteocytes: Mature bone cells.
Osteoblasts: Bone-forming cells.
Osteoclasts: Bone-resorbing cells.
What hormones increase and decrease blood calcium levels?
Parathyroid Hormone (PTH): Increases blood calcium levels.
Calcitonin: Decreases blood calcium levels.
What happens in the parathyroid when the calcium levels are low in the blood?
The parathyroid releases parathyroid hormone. This stimulates osteoclasts, raising blood calcium.
What happens in the thyroid when calcium in the blood is high?
The thyroid releases calcitonin which inhibits osteoclasts. This lowers the blood calcium.
What is the bone matrix composed of?
25% water
25% collagen fibers
50% crystallized mineral salts (Calcium Phosphate; Hydroxyapatite)
Compact bone tissue is arranged in units called…
Osteons or Harversian Systems
What is the compact bone tissue and its function?
Compact bone tissue is the EXTERNAL layer of all bones and makes up the bulk of diaphyses of long bones.
It provides: Protection and Support to the bones.
What is spongy bone?
The porous inner layer with trabeculae (irregular latticework of thin columns of bone).
Does spongy bone contain osteons?
No
Give a reason why we lose bone?
Age-Related Bone Loss: Reduced bone density with aging.
What are the osteoporosis risks?
Postmenopausal women, inadequate calcium intake, and lack of weight-bearing exercise.
