Lecture 15- ANS, Endocrine and the Stress Response Flashcards
What links the hypothalamic nuclei. The pituitary gland?
Infundibulum
Secreted hormones?
Number and action?
Hypothalamus secretes 9 hormones (inhibitors + releasing)
Hypophyseal portal veins connect to the pituitary gland that secretes 7 hormones that control endocrine organs
These regulate: Growth, Development, metabolism, homeostasis
Hypophyseal portal veins
Link capillary beds on the pituitary gland so that the bloo doesn’t have to go back through the heart
HPA AXIS?
Hypothalamic- pituitary- adrenal axis
Enhancing the alarm response?
Uses the sympathetic nervous system
Pathway from cns–actions
- Sympathetic pre ganglionic neuron stimulated
- Modified post ganglionic “neurons” act as secretory cells
- Epinephrine and norepinephrine released into the BLOOD STREAM.
difference in response to ANS response?
uses the blood and so is slower acting but is longer lasting in its effects.
difference between epinepherin and adrenaline
no difference
ANS is immediately backed up by?
stress response of the Adrenal Medulla that is stimulated by ACh from sympathetic pre-ganglionic neurons. Causing NE and E to be released.
effects of NE and E from the Adrenal Medulla?
enhanced sympathetic ANS response that floods the system and prolongs effect.
stage 1 of the stress response?
fight or flight response
- immediate burst (ANS)
- sympathetic activation
- adrenal medulla involvements
- E and NE release and effects
Stage 2 of stress response?
Resistance Reaction
slower, longer lasting
associated with H-P-A cortex
corticosteroid (cortisol) production that dampens inflammation and alters immune response.
Stress response as a whole?
- sympathetic autonomic activation
- mobilise resources for immediate physical activity
- glucose and oxygen consumption
- alertness and activity
- ward off danger and flee
stage 2 of stress response action?
the Resistance reaction occurs after some time
Corticotropin releasing hormone (CRH) produced by the hypothlamus released into the primary hypophyseal plexus, then portal vein stimulates
Adrenocorticotropin hormone (ACTH) to be produced by the pituitary gland into the blood stream.
Causes Adrenal cortex to Glucocorticoids (eg. Cortisol)
This Cortisol increases the resistance reaction.
resistance reaction?
increased glucose, fatty acids, amino acids
sensitized vessels
reduced inflammation
immune suppression
second action of Adrenal Cortex?
and increase in K+ and angiotensin II in the blood causes mineral corticoids (eg. aldsosterone) to be relaesed. These incresed blood Na+ and water and decrease blood K+ leading to increase blood volume and pressure.
negative feedback effects effects on pituitary gland?
- high levels of cortisol in blood needs to be removed from blood after the stressor is removed to avoid damage.
- cortisol inhibits both CRH and ACTH
The stress response is a ______ system?
inducable
Reasons for effects of stress response?
to meet the immediate danger that is posed to the body. There is no point stopping cancer if you could die from being eaten by a bear.
effects of glucocorticoids (eg. Cortisol) ?
- protein breakdown
- gluconeogenesis
- lipolysis
- vasoconstriction
- anti-inflammatory
- immune depression
links between the neuroendocrine and immune system?
- Autonomic nerves go to some lymph tissue
- hormones (eg. cortisol) influence how some lymph cells act
- Cytokines- immune hormones have many effects on nervous cells.
Short term remedial action?
- change relationship to world
1. THREAT SYSTEM AROUSAL- blood (energy), muscle (motor), vigilance (sensory)
- DAMPEN UNNECESSARY
- immunity, digestion
- blood (energy), muscle (motor), vigilance (sensory)
types of stress?
EUSTRESS
- acute stress that is benficial/helpful in preparing to meet challenges
DISTRESS
- chronic as inducable stress response is turned on too long. associated with undesirable events and potentially harmful.
Hostility and the heart?
habitually hostile people have a long term sympathetic activation build up.
the heart must work harder and capillaries constrict.
GREATER RISK OF CARDIAC INFARCT…