Parathyroid Hormone – Biology Final Exam
The key terms of Biology Final Exam include, Bone, Calcium, Hormone, Parathyroid, Vitamin, Blood, High, Increase, Release.
In the kidneys, parathyroid hormone acts to ________ production of calcitriol and to ________ excretion of calcium in urine.
increase, increase
increase, decrease – correct
decrease, decrease
decrease, increase
Parathyroid hormone and calcitriol:
stimulate osteoclasts to resorb bone and release calcium into the blood. – correct
stimulate osteoblasts to deposit bone by producing calcified matrix.
increase osteoblasts to resorb bone and lower blood calcium levels.
improve osteoclasts to move calcium from the blood and into the bone.
Parathyroid hormone release is triggered by _______ levels of calcium in the blood.
high
low – correct
High blood calcium and exercise cause calcitonin release to:
increase. – correct
decrease.
Calcitonin _________ osteoclast activity and _______ excretion of calcium from the kidney.
stimulates, increases
stimulates, decreases
inhibits, increases – correct
inhibits, decreases
The epiphyseal plates in the _________ are the last ones in the body to ossify.
femur
humerus
clavicle – correct
radius
tibia
Which hormone inhibits rather than stimulates bone growth?
Calcitonin
Estrogen and testosterone
Thyroid hormone
Parathyroid hormone – correct
Growth hormone
Glucocorticoids increase bone ________; high levels of serotonin lead to _____ bone density.
formation, high
formation, low
loss, high
loss, low – correct
Which vitamin is required for the normal synthesis of collagen?
D Vitamin
Vitamin B
A Vitamin
Vitamin C – correct
K Vitamin
To trigger bone growth, growth hormone stimulates the:
liver to produce somatomedin. – correct
liver to produce calcitonin.
brain to produce serotonin.
parathyroid to produce parathyroid hormone.
thyroid to produce calcitriol.
What explains the dramatic acceleration in lengthwise bone growth at puberty?
Improved activity of osteoclasts occurs in response to parathyroid hormone stimulation.
Increased rate of calcium deposition occurs due to high blood calcium levels.
Improved physical activity causes lengthwise growth in response to bone stress.
Increased secretion of sex hormones promotes epiphyseal plate growth. – correct
Increased absorption of dietary vitamins and minerals strengthens the matrix.
Rickets, a disease characterized by overproduction and deficient calcification of osteoid tissue, is caused by a lack of sufficient:
Vitamin D. – correct
Calcitonin.
Thyroid hormone.
Thyroid & Vitamin A.
Vitamin C.
Calcidiol circulates in the blood and is converted to calcitriol in the:
kidney. – correct
skin.
liver.
bone.
Parathyroid hormone and calcitriol:
stimulate osteoclasts to resorb bone and release calcium into the blood. – correct
stimulate osteoblasts to deposit bone by producing calcified matrix.
increase osteoblasts to resorb bone and lower blood calcium levels.
improve osteoclasts to move calcium from the blood and into the bone.
Parathyroid hormone release is triggered by _______ levels of calcium in the blood.
high
low – correct
High blood calcium and exercise cause calcitonin release to:
increase. – correct
decrease.
Calcitonin _________ osteoclast activity and _______ excretion of calcium from the kidney.
stimulates, increases
stimulates, decreases
inhibits, increases – correct
inhibits, decreases