UBC BIOL 155 Final 1 Exam Study Set 100% Pass
What 2 hormones are involved in nursing? - ANSWER PRL and oxytocin
Steps in the production of milk - ANSWER 1. Receptors in nipples are stimulated
2. impulses propagated to spinal cord
3. stimulation of hypothalamic nuclei (posterior pituitary gland)
4. Pituitary gland releases oxytocin
5. milk is ejected from the nipples
Function of PRL - ANSWER stimulates milk production - constricition of myofibril cells,
squeeze and push the milk out of the mammary duct
function of oxytocin - ANSWER uterine contraction and expression of milk from the
breast
Where is milk stored? - ANSWER - Alveoli and in small ducts adjacent to the cells that
secrete it compressing and flattening the cells
- lactiferous sinuses
How do actin and myosin interact by the thin filament? - ANSWER 1. calcium binds TnC
which changes the shape of the whole triponin molecule
2. tripomyosin is pulled off and the binding sites are fully exposed
3. myosin heads come in and bind simultaneously
4. once you get cross bridge formation, you get cross bridge cycling and leads to the
force of contractions
two hormones that control calcium plasma levels - ANSWER 1. parathyroid hormone -
when calcium levels get too low
2. calcitonin - when calcium levels get too high
what are the three target tissues of parathryoid - ANSWER bone - calcium storage organ
kidneys - distilled convulated tubule
digestive tract - food digestion
How does parathyroid hormone work? - ANSWER - Stimulates osteoclasts to chew up
more bone —> more calcium is released from bones to the blood
, and inhibits osteoblasts, so that new bone can not be put down
- controlled re-uptake of calcium from the filtrate back into the blood (recover more
calcium from urine when it goes through the nephron)
- stimulates the production of calcitrol in the kidneys enhancing the amount of calcium
and PO4 absorbed from the food digested
Ca PO 4 - ANSWER calcium phosphate crystals that get turned into calcium ions
How does calcitonin work? - ANSWER - increased reabsorption of calcium, which will
increase blood calcium levels and calcium will be retained in the kidneys and used to
make new bone
- inhibits osteoclasts decreasing the amount of bone chewed up, stimulation of
osteoblasts to use up more calcium
what are the target tissues of calcitonin? - ANSWER bone and kidney
steps of thyroid hormone synthesis - ANSWER 1. thyroglobulin synthesis
2. uptake of iodide from blood - the iodide that gets taken up is picked up by the thyroid
peroxidase and transported into the secretory vesicles before it gets released into the
follicular cavity - it also strips off an electron (I- becomes I)
3. iodine is attached to tryosin amino acids by iodination of enzymes
single iodination - Monoiodotryosin (MIT)
double iodination - diiodotryosine (DIT)
4. coupling enzymes attach to DIT, but have to have at least a MIT preferably a DIT
beside it. they reach over and grab the benzene ring from adjacent tryosine that has
been iodinated, cut it off and attach it to the benzene ring of the first tryosine and you
get pro T3 or t4 (still not active)
5. endocytosis of a droplet of colloid - internalized by a phagosome which fuses with
lysosomes (enzymes that break down peptide bonds)
- cut up thyroglubin into amino acids
6. T3 and T4 which are liberated, so they diffuse out of the cell and diffuse into the blood
where they are picked up proteins increasing solubility in the blood
uptake of iodide in blood - ANSWER sodium iodide co transporter increases the rate in
which iodine comes in
thyroglublin - ANSWER secretory vesicles that have thyrglobulin also have iodinating
ezymes that also have couppling enzymes that also have thyroid peroxidase (thyroid
peroxidase in the membrane, other two are in the vesicle)
What 2 hormones are involved in nursing? - ANSWER PRL and oxytocin
Steps in the production of milk - ANSWER 1. Receptors in nipples are stimulated
2. impulses propagated to spinal cord
3. stimulation of hypothalamic nuclei (posterior pituitary gland)
4. Pituitary gland releases oxytocin
5. milk is ejected from the nipples
Function of PRL - ANSWER stimulates milk production - constricition of myofibril cells,
squeeze and push the milk out of the mammary duct
function of oxytocin - ANSWER uterine contraction and expression of milk from the
breast
Where is milk stored? - ANSWER - Alveoli and in small ducts adjacent to the cells that
secrete it compressing and flattening the cells
- lactiferous sinuses
How do actin and myosin interact by the thin filament? - ANSWER 1. calcium binds TnC
which changes the shape of the whole triponin molecule
2. tripomyosin is pulled off and the binding sites are fully exposed
3. myosin heads come in and bind simultaneously
4. once you get cross bridge formation, you get cross bridge cycling and leads to the
force of contractions
two hormones that control calcium plasma levels - ANSWER 1. parathyroid hormone -
when calcium levels get too low
2. calcitonin - when calcium levels get too high
what are the three target tissues of parathryoid - ANSWER bone - calcium storage organ
kidneys - distilled convulated tubule
digestive tract - food digestion
How does parathyroid hormone work? - ANSWER - Stimulates osteoclasts to chew up
more bone —> more calcium is released from bones to the blood
, and inhibits osteoblasts, so that new bone can not be put down
- controlled re-uptake of calcium from the filtrate back into the blood (recover more
calcium from urine when it goes through the nephron)
- stimulates the production of calcitrol in the kidneys enhancing the amount of calcium
and PO4 absorbed from the food digested
Ca PO 4 - ANSWER calcium phosphate crystals that get turned into calcium ions
How does calcitonin work? - ANSWER - increased reabsorption of calcium, which will
increase blood calcium levels and calcium will be retained in the kidneys and used to
make new bone
- inhibits osteoclasts decreasing the amount of bone chewed up, stimulation of
osteoblasts to use up more calcium
what are the target tissues of calcitonin? - ANSWER bone and kidney
steps of thyroid hormone synthesis - ANSWER 1. thyroglobulin synthesis
2. uptake of iodide from blood - the iodide that gets taken up is picked up by the thyroid
peroxidase and transported into the secretory vesicles before it gets released into the
follicular cavity - it also strips off an electron (I- becomes I)
3. iodine is attached to tryosin amino acids by iodination of enzymes
single iodination - Monoiodotryosin (MIT)
double iodination - diiodotryosine (DIT)
4. coupling enzymes attach to DIT, but have to have at least a MIT preferably a DIT
beside it. they reach over and grab the benzene ring from adjacent tryosine that has
been iodinated, cut it off and attach it to the benzene ring of the first tryosine and you
get pro T3 or t4 (still not active)
5. endocytosis of a droplet of colloid - internalized by a phagosome which fuses with
lysosomes (enzymes that break down peptide bonds)
- cut up thyroglubin into amino acids
6. T3 and T4 which are liberated, so they diffuse out of the cell and diffuse into the blood
where they are picked up proteins increasing solubility in the blood
uptake of iodide in blood - ANSWER sodium iodide co transporter increases the rate in
which iodine comes in
thyroglublin - ANSWER secretory vesicles that have thyrglobulin also have iodinating
ezymes that also have couppling enzymes that also have thyroid peroxidase (thyroid
peroxidase in the membrane, other two are in the vesicle)
