Describe the structure and location of the parathyroid glands. Describe the structure and location of the adrenal glands. Include the organization of the following parts and their major role: Cortex and Medulla Explain how the adrenal medulla and the sympathetic nervous system interact. Describe the circadian cycle of melatonin. Describe how the HPA axis controls sex-hormone release. Describe what happens in the body in diabetes mellitus and explain the difference between Type 1 and Type 2 diabetes. Solution 1.Structure and location of parathyroid glands: Structure : Loaction :These glands are situated behind the left and right lobes of the thyroid. 2.Structure and location of adrenal glands: Structure : Cortex :It is the outermost layer and is made up of three zones: Zona glomerulosa :The outermost layer of the adrenal cortex is the zona glomerulosa and is made up of oval cells that separated by thin strands of connective tissue.They secrete aldosterone that function to regulate blood pressure. Zona fasciculata:Lies next to zona glomerulosa.It is the largest layer made up of columnar cells.They secrete hormone cortisol that is essential in maintaining homeostasis. Zona reticularis:Lies next to zona fasciculata and near to medulla.Cells are in form of irregular cords and they secrete androgen hormones for male reproductive functions. Medulla :Present in the centre of the adrenal gland.Presence of chromaffin cells that secrete hormones catecholamines adrenaline and noradrenaline. in response to fright and fear. Location of adrenal gland:The adrenal glands are located on both sides of the body in the retroperitoneum above the kidneys medially. 3.Adrenal and sympathetic nervous sytem interaction : In response to fear and fright , the sympathetic nervous sysyem is activated that in turn activates the adrenal medulla to secrete norepinephrine.Nor epinephrine prepares the body to respond to the situation immediately by increasing the blood flow to our skeletal muscles to act accordingly. 4.Circadian cycle of melatonin: Melatonin is secreted by the pineal gland controls our sleep and wake up cycle in a day.The internal clock of our body known as circadian rhythm regulates the amount of melatonin produced by pineal gland.Melatonin levels rise in the dark after the sunset and are at elevated levels at the night tht makes us asleep.In the morning,with sunrise the levels drop making us awake. 5.HPA axis controls sex hormones: Sex difference is the result of interactions between the gonadal hormone system and the HPA axis.In adulthood,androgen levels increase HPA activity while and estrogen level decreases HPA activity.Monoamine neurotransmitters norepinephrine and serotonin are released from HPA axis that determine differences in sex.Signals that originate from the brain and periphery are integrated together to influence the level of HPA axis activity, and these are sex-specific. 6.Diabetes Mellitus : In diabetes mellitus, the blood sugar level increase.

1. Describe the structure and location of the parathyroid glands.
Describe the structure and location of the adrenal glands. Include the organization of the
following parts and their major role: Cortex and Medulla
Explain how the adrenal medulla and the sympathetic nervous system interact.
Describe the circadian cycle of melatonin.
Describe how the HPA axis controls sex-hormone release.
Describe what happens in the body in diabetes mellitus and explain the difference between Type
1 and Type 2 diabetes.
Solution
1.Structure and location of parathyroid glands:
Structure :
Loaction :These glands are situated behind the left and right lobes of the thyroid.
2.Structure and location of adrenal glands:
Structure :
Cortex :It is the outermost layer and is made up of three zones:
Zona glomerulosa :The outermost layer of the adrenal cortex is the zona glomerulosa and is
made up of oval cells that separated by thin strands of connective tissue.They secrete aldosterone
that function to regulate blood pressure.
Zona fasciculata:Lies next to zona glomerulosa.It is the largest layer made up of columnar
cells.They secrete hormone cortisol that is essential in maintaining homeostasis.
Zona reticularis:Lies next to zona fasciculata and near to medulla.Cells are in form of irregular
cords and they secrete androgen hormones for male reproductive functions.
Medulla :Present in the centre of the adrenal gland.Presence of chromaffin cells that secrete
hormones catecholamines adrenaline and noradrenaline. in response to fright and fear.
Location of adrenal gland:The adrenal glands are located on both sides of the body in the
retroperitoneum above the kidneys medially.
3.Adrenal and sympathetic nervous sytem interaction : In response to fear and fright , the
sympathetic nervous sysyem is activated that in turn activates the adrenal medulla to secrete
norepinephrine.Nor epinephrine prepares the body to respond to the situation immediately by
increasing the blood flow to our skeletal muscles to act accordingly.
4.Circadian cycle of melatonin: Melatonin is secreted by the pineal gland controls our sleep and
wake up cycle in a day.The internal clock of our body known as circadian rhythm regulates the
amount of melatonin produced by pineal gland.Melatonin levels rise in the dark after the sunset

2. and are at elevated levels at the night tht makes us asleep.In the morning,with sunrise the levels
drop making us awake.
5.HPA axis controls sex hormones: Sex difference is the result of interactions between the
gonadal hormone system and the HPA axis.In adulthood,androgen levels increase HPA activity
while and estrogen level decreases HPA activity.Monoamine neurotransmitters norepinephrine
and serotonin are released from HPA axis that determine differences in sex.Signals that originate
from the brain and periphery are integrated together to influence the level of HPA axis activity,
and these are sex-specific.
6.Diabetes Mellitus : In diabetes mellitus, the blood sugar level increases.This is caused either
due to insufficient production of insulin or body not responding to insulin.