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Fast stress signals and the HPA axis

Sciences · Le corps humain · de 21 à 22 ans

Nom ______________________ Date ____________

Where does cortisol come from during stress?
- The adrenal medulla
- The adrenal cortex
- The pancreatic islets
Which division of the nervous system drives the fast stress response?
- Parasympathetic
- Somatic
- Sympathetic
Adrenaline can trigger effects within seconds, while many cortisol effects develop over minutes to hours.
En entourer un : Vrai Faux
During recovery after a threat, which pair tends to lower heart rate?
- More sympathetic drive and more adrenal adrenaline release
- Less sympathetic drive and parasympathetic slowing of the heart
- More sympathetic drive and parasympathetic speeding of the heart
Which pair gives typical effects of cortisol during a stress response?
- More liver glucose production; less inflammation
- Less liver glucose production; more inflammation
- No liver glucose production; all immune activity switched off
Why do many cortisol effects take longer than adrenaline's rapid effects?
- Its hormone signal must first pass through the stomach and small intestine
- Its hormone signal must first be released from stores in skeletal muscle
- Many effects need changes in gene activity and protein production
Cortisol is elevated. Its negative feedback should increase further CRH and ACTH release.
En entourer un : Vrai Faux
A student says prolonged cortisol excess strengthens immunity and speeds wound healing. Which correction fits?
- It can suppress immunity and slow wound healing
- It must strengthen immunity and speed wound healing
- It can raise blood glucose but cannot affect wound healing

Corrigé

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Fast stress signals and the HPA axis W1-mt_4ZxCU21ziH-s1

The adrenal cortex · ACTH from the anterior pituitary stimulates the adrenal cortex to release cortisol.
Sympathetic · Sympathetic nerves act on organs and stimulate the adrenal medulla to release adrenaline into blood.
Vrai · This describes typical timing. Adrenaline can act rapidly at surface receptors, while many cortisol effects involve slower changes in gene activity and protein production.
Less sympathetic drive and parasympathetic slowing of the heart · Reduced sympathetic drive and parasympathetic slowing of the heart support a return toward rest. They do not reset every tissue at once.
More liver glucose production; less inflammation · Cortisol promotes liver glucose production and limits many inflammatory responses. It does not stop all immune activity.
Many effects need changes in gene activity and protein production · Many cortisol effects involve changes in gene activity and protein production. Those changes take time compared with adrenaline's rapid surface-receptor effects.
Faux · Cortisol's negative feedback reduces further CRH and ACTH release. Increasing those signals would stimulate more cortisol production rather than explain this limiting feedback.
It can suppress immunity and slow wound healing · Prolonged cortisol excess can suppress parts of the immune response and slow wound healing. These are possible costs, not guaranteed outcomes of every stressful experience.