Flashcards in The Endocrine System Deck (15)
How do endocrine glands differ from those that do not secrete hormones?
Endocrine glands are ductless, which means they secrete the hormones directly into the bloodstream
Explain why pancreas may be described as a dual-function gland
The pancreas is both an exocrine and endocrine gland.
Endocrine because it secrets insulin into the bloodstream.
Exocrine because it secretes digestive enzymes into the duodenum.
What is the chemical nature of many hormones?
In the case of each of two named hormones secreted in the human body state:
1. precise location
2. A function of the hormone
1. Thyroid - on trachea in neck
Thyroxin controls rate of metabolism
2.Islets of Langerhans - in the pancreas - Insulin-
reduce blood glucose level
In the case of named hormone (Thyroxin):
1- give a deficiency symptom
2- give a symptom of excess secretion
3- give a corrective measure for deficiency
1) slow metabolism/ little energy/ overweight
2) increased heart rate and blood pressure, weight loss
3) hormone supplements
Explain why hormonal respones are slower than nervous responses.
The hormones take time to travel in the blood to its target area and they control mainly long-term changes such as growth or metabolism.
What is a hormone?
Protein or steroid
Chemical messenger produced in an endocrine gland and transported in the blood to a particular (target organ) where they have their effect.
State two ways in which hormones are similar to growth regulators?
-their effect is long lasting and widespread
-both chemical based
-both produced in same location but act in different location
What is ment by feedback in relation to hormone action?
Means that the gland producing the hormone is affected by the level of hormone in the blood tp either speed up or slow down the hormone production.
Give a brief account of the feedback mechanism for a named hormone.
Pituitary gland releases a hormone called TSH (thyroid stimulating hormone) which causes the thyroid to release tyhroxine.
the build up of thyroxine in the blood inhibits the production of further TSH by the pituitary.
This stops the production of more thyroxine.
-> ensures that level of thyroxine in blood remains fairly constant
What term is used to describe the glands that secrete hormones in the human body?
Give two examples of the use of hormone supplements.
Insulin - reduces blood sugar levels
Thyroxine - brings levels of Thyroxine back to normal defeciency
Other than secretion of hormones, how does an endocrine gland differ from an exocrine gland?
Ductless, diffuse secretions directly into the blood.
State two ways in which hormone action differs from nerve action.
1) Nerve action : message is electrical
impulses to specific cell/tissue
2) Hormone: message is chemical
message sent to many regions