Lecture 10 week 6 Flashcards
What is the role of hormones?
Modulates:
* Growth & development
* Homeostasis
* Reproduction
* Many other roles in the CCN e.g. neurodevelopment & immunity
What are the three origins of hormones
- Endocrine glands
- Nerves
- Organs (produce
hormones as a secondary function)
What two systems interact to form the foundation of the CCN?
Nervous and endocrine system
What are all primary endocrine glands and secondary endocrine tissues supplied neurons by?
By neurons of the autonomic nervous system
Where can some nerves release their neurotransimitters directly into and what are they called?
Directly into the bloodstream and they are called neurohormones
What can neurotransmitters modulate? Give an example.
Can modulate hormone secretion.
ex. norepinephrine increases epinephrine and decreases insulin
What do neurons in the CNS and PNS have? Give some examples
They have receptors for many hormones.
ex. insulin, estrogen, testosterone, etc
What are neurotransmitters?
Chemical messengers released by nerve cells (neurons)
What are neurohormones?
Neurotransmitters that are released into the bloodstream by neurons
How do neurotransmitters travel?
Transmit signals to adjacent cells, typically within nervous system
How do neurohormones travel?
Travel to distant target cells or glands where they exert their effects
Where do neurotransmitters act?
Act at synapses
ex. the junctions between nerve cells & their target cells (neuron, muscle, gland)
Where do neurohormones act?
Act more broadly on the body, influencing the function of endocrine glands and the release of hormones
What hormones do the posterior pituitary release?
Releases Oxytocin (OT) and antidiuretic hormone (ADH)
What is oxytocin responsible for?
What is ADH (vasopressin) responsible for?
Uterine contractions, milk ejection, positive mood (bliss, love, bonding)
Retention of fluid by the kidneys
Where does the neurohormones that the posterior pituitary releases come from?
These neurohormones are made in the hypothalamus.
What is the posterior pituitary similar to?
A collection of nerve endings
What are low levels of oxytocin associated with?
- Conditions such as ASD (implicated in social cognition & behaviour)
- Depression, anxiety, & stress
- Higher levels of perceived pain
When dooxytocin levels naturally increase?
Levels increase in breastfeeding individuals
* Initiate let-down & milk ejection
* Calming effect on mother
What is ADH also know as?
Vasopressin
What does ADH play an important role in?
Important role in blood pressure regulation
When is there an increased release of ADH? (heart)
Increased release with heart failure
* Mechanism to support blood pressure in response to reduced blood flow
* Leads to water retention & fluid overload that tends to worsen heart failure symptoms
When is there an increased release of ADH (response to something)
Increased release in response to severe blood loss or dehydration
* Mechanism to try to increase water retention & maintain blood pressure
* Hypovolemic shock can be life threatening
What does the anterior pituitary act like and why does it act like this?
Acts like a gland
-Contains endocrine cells that release many hormones
