The Skeletal System
What two actions occur to decrease calcium levels in the blood due to hormone secretion?
1.) Stimulates bone formation, which removes calcium from the blood. 2.) Increases calcium absorption by the kidneys, removing calcium from the blood.
What three actions does PTH cause to increase calcium levels in the blood?
1.) Stimulates bone resorption, which releases calcium into the blood. 2.) Increases vitamin D, causing the digestive system to absorb more calcium. 3.) Decreases calcium absorption by the kidneys, allowing more calcium to stay in the blood.
What can be the result of decreased mechanical stress on the body?
A decrease in mechanical stress causes bones to lose mass. An increase in mechanical stress causes bones to increase in mass.
What type of exercise stimulates bone formation?
All types of exercise stimulate bone formation. Resistance training, like weightlifting, has or more significant effect.
What 2 things are required for the skeletal system to maintain homeostasis?
Calcium and bone mineralization
Describe how abundant calcium is in the body and where it resides.
Calcium enters the body through diet, The digestive system absorbs calcium with the help of vitamin D, Bones store 99% of calcium and blood 1%.
Tendons
Connect muscle to bone
Ligaments
Connects bones to bones, adds strength and support to joints.
For most people, bone formation outpaces bone resorption until what age? What else about the bones occurs at that age?
For most people, bone formation outpaces resorption into their 20s. Over time, excess resorption weakens bones. Bones typically reach peak mass and strength during this time.
What is the key to proper body mechanics when performing daily activities?
Good posture, the spine is in a "neutral" position where the torso does not lean forward or arch backward.
What is bone mineralization?
Introduces minerals, primarily calcium and phosphate into the bone structure, helping maintain bone mass.
What is the function of red bone marrow?
Involved in hematopoiesis, the production of blood cells.
What does poor posture cause?
It causes undue stress on the spine and back.
How does calcium enter the skeletal system and bloodstream?
It enters through the digestive system and then gets stored in the bones and blood.
What is hematopoiesis and where does it take place?
It is the process of blood cells and plasma, it takes place in the red bone marrow.
What are ways calcium helps the body?
It promotes bone mineralization, promotes muscle and nerve function, helps regulate the heart rate and contraction strength, and supports blood clotting.
What foods are high in calcium?
Milk, cheese, yogurt, almonds, some green vegetable (Spinach, kale, broccoli).
When calcium levels are too low, which endocrine gland secretes a hormone to increase calcium levels? What is the hormone?
Parathyroid glands secrete PTH, or hormones.
What are the functions of the skeletal system?
Protects organs, supports the body, helps with movement, stores minerals, produces blood cells, stores fat
What is the function of yellow bone marrow?
Stores fat, which acts as an energy source for the body.
Why must calcium be consumed in the diet?
The body cannot make calcium on its own.
Why is vitamin D important in relation to calcium?
The digestive system cannot absorb calcium without vitamin D
What four body systems play a role in calcium homeostasis?
The endocrine, skeletal, digestive, and urinary systems.
What is bone remodeling?
The process of bone formation and resorption.
How can someone increase their body's vitamin D?
The production of vitamin D starts with skin exposure to sunlight. Healthcare professionals often recommend a high vitamin D diet and supplements to increase the body's vitamin D.
When calcium levels are too high, which endocrine gland secretes a hormone to decrease calcium levels? What is the hormone?
The thyroid gland secretes calcitonin, stimulates bone formation, which removes calcium from the blood, increases calcium absorption by the kidneys, removing calcium from the blood.
Cartilage
Unlike bone, it is an avascular tissue (very little or no blood supply), it protects the ends of bones at joints, and serves as the structural component in many body parts.