Autonomic and Endocrine 2 Stress Response L15 Flashcards
What are some key features of the Hypothalamus?
is a cluster hypothalamic nuclei
Major linked between the nervous and endocrine systems
9x hormones
Starting point of controlling the endocrine system
Secretes Releasing (production) and Inhibiting (production) hormones for the axon termini to control the Pituitary
Communicates with Pituitary via hormone release
hormones are released into the Hypophyseal Portal veins
What is between the Hypothalamus and Pituitary gland?
Connected by Infundibulum
Hypophyseal portal veins within
What is the Infundibulum?
connects between the Hypothalamus and Pituitary gland
- Releasing and Inhibitory hormones are released by the axon termini here
What is the Pituitary?
7x hormones
Controls the endocrine organs, via its hormone release into the BLOODSTREAM
What is the Hypophyseal portal veins?
Portal system between the 2x capillary beds.
Then hormones diffuse into ANTERIOR pituitary gland stream/cells and further through body
capillary bed - portal vein - capillary bed
Artery –> arteriole –> capillary –> portal veins –> capillary –> venules –> veins –> heart
What is the pathway of a substance through a portal systems?
Artery –> arterioles –> capillary –> portal vein –> capillary –> venules –> veins –> heart
What are the 4x things that the Hypothalamus function together to regulate?
Grandma GDMH
- Growth
- Development
- Metabolism
- Homeostasis (to maintain constant over body)
What are the components of the Adrenal Gland?
2x adrenal glands (one over each kidney)
- Adrenal Medulla (middle/inner)
- Adrenal Cortex (“bark”/outside)
- functionally and structurally different (different cellular structure)
What are some features of the 2x adrenal glands?
Triangular organ
sits on top of the kidney in the Retroperitoneal space
Made up of 2x Structurally (cellularly different) and functionally distinct areas
Cortex = outer = 80-90% of gland = majority
Highly vasculated
Produces steroid/Lipid soluble hormones
Where are the adrenal glands located?
On top of the kidney
in the Retroperitoneal space
What is the innervation of the Adrenal Medulla like?
Spinal cord –> Myelinated Sympathetic preganglionic neuron –> ACh —> Adrenal Medulla’s Modified Post ganglionic neurons which act as secretory cells which have No Axons –> can Release Neurotransmitters called NE and E –> NE and E secreted into Bloodstream –secs-mins–> effector tissue (smooth, heart and glands)
-last steps regarding NE facilitates and maintains levels of sympathetic activity/broader stress response
What are some features of the Adrenal Medulla?
Stimulated by: ACh form the preganglionic neurons
Hormones released: NE and E
Principal actions: Enhances the sympathetic nervous alarm response
a. Neurotransmitters are sent through the Blood stream to Circulate
b. Affects tissue in a more Prolonged manner
-slow affects - more sustained that the autonomic systems’ activation
c. can enhance and extent the activation process
Alarm response Has to be switched on rally fast in order to DEAL WITH IMMEDIATE danger -thinking and use of Cerebral Cortex is NOT FAST ENOUGH, therefore this process is Automatic as to deal with the immediate threat
Spinal cord –> Myelinated Sympathetic preganglionic neuron –> ACh —> Adrenal Medulla’s Modified Post ganglionic neurons which act as secretory cells which have No Axons –> can Release Neurotransmitters called NE and E –> NE and E secreted into Bloodstream –secs-mins–> effector tissue (smooth, heart and glands)
-last steps regarding NE facilitates and maintains levels of sympathetic activity/broader stress response
Which part of the adrenal gland secretes two types of hormones?
Adrenal cortex (think cortex = bigger = secretes two)?
What is the two types of hormones that the Adrenal cortex secretes?
Mineralocorticoids (e.g. aldosterone)
Glucocorticoids (e.g. cortisol)
What is Hormone A produced by the Adrenal Cortex?
MINERALOCORTICOIDS
“mineralo-“ = to do with metal ions (controls balance of Na+ and K+ ions etc)
“corticoids” + made by the adrenal Cortex
e.g. ALDOSTERONE
Made and secretes from the adrenal Corte which REGULATES Metal Ion concentrations
Simulated by:
1. Increased K+ ions
2. Angiotensin II hormone in blood
Principal actions
1. Increased Na+
2. Increase Water reabsorption (alters Kidney filtration and it’s selectivity when filtering certain ions)
3. Decreased K+ in blood
Overall results in: Increased BP Blood Pressure and BV Blood volume
What is an example of a mineralocorticoids?
aldosterone
What are the 2x things that the adrenal cortex is stimulated by in relation to mineralocorticoids?
- Increased K+ ions
2. Angiotensin II in blood
What are the 3x Principal actions of the adrenal cortex in relation to mineralocorticoids?
- Increased Na+ ions
- Increased water H2O reabsorption (affects the filtration of the Kidney and its selectivity when filtering certain ions)
- Decreased K+ in blood
Overall results in: Increased BP Blood pressure and BV Blood Volume
What is the pathway from the hypothalamus to the Pituitary + the Negative feedback effects on the Pituitary?
Hypothalamic neurosecretory cells releases CRH (corticotropin Releasing hormone)
–>hypophyseal portal vein –>
Anterior Pituitary gland releases ACTH (adrenal corticotropin hormone)
–> Adrenal Cortex
–> cortisol lipid soluble hormone
–3x pathways–>
1. Hormone Degradation / breakdown
2. Elevated levels of cortisol inhibits the release of ACTH from the anterior pituitary corticoTROPHS
3.elevated levels of cortisol inhibits the production of CRH Corticotropin Release Hormone by the Hypothalamus neurosecretory cells
-2x Feedback loops
-Negative Feedback control
What does CRH stand for?
Corticotropin Releasing Hormone
What does ACTH stand for?
Adreno Cortico Tropin Hormone
Where does CRH originate from?
Hypothalamic neurosecretory cells
Where does ACTH?
Anterior pituitary corticoTROPHS
Why does the cortisol pathway take more time?
This process involving the adrenal Cortex and Cortisol takes More time compared to the sympathetic release effect, as it is a purely hormonal driven process ( ms vs sec-min)