Week 4 – Concepts of Endocrine Regulation (17.10.2022)
Comparisons between the Nervous and Endocrine System:
Similarities
o Functional – Both as a communication networks, causes actions at a distance, uses
chemical substances as mediators between cells.
o Anatomical – Adrenal medulla and hypothalamus: both contain specialised neurons
that secrete hormones into the circulation
Differences
o Nervous System – Fast response division, short lived effects, specific
o Endocrine System – Slower response to stimuli, responses last for longer, responses
more generalised.
Major Endocrine Glands:
What is a hormone?
Chemical Messengers
Secreted by endocrine glands
Carried in the bloodstream to distant target cells where they act
Endocrine and Exocrine Glands:
Endocrine Glands – Secrete hormones into extracellular space. Blood carries them to
organs or systems where their effects.
Exocrine Glands – Secrete their products through ducts to the exterior environment.
o Sweat, Saliva etc.
Control of Hormone Secretion:
Three types of stimuli
o Neural
o Hormonal
o Concentration of a substance in the blood
Secretion rates are maintained by a negative feedback mechanism.
Comparisons between the Nervous and Endocrine System:
Similarities
o Functional – Both as a communication networks, causes actions at a distance, uses
chemical substances as mediators between cells.
o Anatomical – Adrenal medulla and hypothalamus: both contain specialised neurons
that secrete hormones into the circulation
Differences
o Nervous System – Fast response division, short lived effects, specific
o Endocrine System – Slower response to stimuli, responses last for longer, responses
more generalised.
Major Endocrine Glands:
What is a hormone?
Chemical Messengers
Secreted by endocrine glands
Carried in the bloodstream to distant target cells where they act
Endocrine and Exocrine Glands:
Endocrine Glands – Secrete hormones into extracellular space. Blood carries them to
organs or systems where their effects.
Exocrine Glands – Secrete their products through ducts to the exterior environment.
o Sweat, Saliva etc.
Control of Hormone Secretion:
Three types of stimuli
o Neural
o Hormonal
o Concentration of a substance in the blood
Secretion rates are maintained by a negative feedback mechanism.
