IB Biology Topic C3.1.12 Epinephrine (adrenaline) Secretion by the Adrenal Glands Revision Notes (SL/HL)

IB Biology Topic C3.1.12 Epinephrine (adrenaline) Secretion by the Adrenal Glands Revision Notes (SL/HL) | RevisionDojo

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Epinephrine Drives the Fight-or-Flight Response, Priming the Body for Action

Definition

Epinephrine

A hormone and neurotransmitter, also known as adrenaline, produced by the adrenal glands that prepares the body for "fight or flight" responses during stress or excitement.

Analogy

Before a race, your heart pounds, your breathing deepens, and your muscles feel ready to explode.
That surge is driven by epinephrine, also called adrenaline.

The Sympathetic Nervous System Triggers Adrenaline for Rapid Survival

The fight-or-flight response is an evolutionary survival mechanism that lets an organism react fast to danger or stress.
The sympathetic nervous system triggers it by stimulating the adrenal medulla to secrete epinephrine into the bloodstream.
1. If the body chooses to fight, energy is mobilised for combat.
2. If the body chooses to flee, energy is redirected to support escape.

Example

Suddenly facing a wild animal, your heart races and your breathing quickens.
That sudden surge of energy is epinephrine preparing you for action.

A Threat Signals the Hypothalamus, Which Activates the Adrenal Medulla

Detection: the brain detects a threat or opportunity.
Signal to the hypothalamus: the brain sends a distress signal to the hypothalamus, its command centre for hormonal control.
Activation of the adrenal glands: the hypothalamus sends nerve signals to the adrenal medulla, releasing epinephrine into the bloodstream.

Definition

Adrenal gland

Small glands located above the kidneys responsible for producing hormones, including epinephrine.

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Lorem ipsum dolor sit amet, consectetur adipiscing elit.
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Epinephrine Drives the Fight-or-Flight Response, Priming the Body for Action

Definition

Epinephrine

A hormone and neurotransmitter, also known as adrenaline, produced by the adrenal glands that prepares the body for "fight or flight" responses during stress or excitement.

Analogy

Before a race, your heart pounds, your breathing deepens, and your muscles feel ready to explode.
That surge is driven by epinephrine, also called adrenaline.

The Sympathetic Nervous System Triggers Adrenaline for Rapid Survival

The fight-or-flight response is an evolutionary survival mechanism that lets an organism react fast to danger or stress.
The sympathetic nervous system triggers it by stimulating the adrenal medulla to secrete epinephrine into the bloodstream.
1. If the body chooses to fight, energy is mobilised for combat.
2. If the body chooses to flee, energy is redirected to support escape.

Example

Suddenly facing a wild animal, your heart races and your breathing quickens.
That sudden surge of energy is epinephrine preparing you for action.

A Threat Signals the Hypothalamus, Which Activates the Adrenal Medulla

Detection: the brain detects a threat or opportunity.
Signal to the hypothalamus: the brain sends a distress signal to the hypothalamus, its command centre for hormonal control.
Activation of the adrenal glands: the hypothalamus sends nerve signals to the adrenal medulla, releasing epinephrine into the bloodstream.

Definition

Adrenal gland

Small glands located above the kidneys responsible for producing hormones, including epinephrine.

Definition

Paywall

(on a website) an arrangement whereby access is restricted to users who have paid to subscribe to the site.

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Note

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam quis nostrud exercitation.

Excepteur sint occaecat cupidatat non proident

Tip

Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum.

A - Unity and Diversity9 subtopics

B - Form and Function10 subtopics

C - Interaction and Interdependence9 subtopics

D - Continuity and Change12 subtopics

IB Biology Topic C3.1.12: Epinephrine (adrenaline) Secretion by the Adrenal Glands Notes

A - Unity and Diversity9 subtopics

B - Form and Function10 subtopics

C - Interaction and Interdependence9 subtopics

D - Continuity and Change12 subtopics

Epinephrine Drives the Fight-or-Flight Response, Priming the Body for Action

The Sympathetic Nervous System Triggers Adrenaline for Rapid Survival

A Threat Signals the Hypothalamus, Which Activates the Adrenal Medulla

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

Unlock the rest of this chapter with a free account

Epinephrine Drives the Fight-or-Flight Response, Priming the Body for Action

The Sympathetic Nervous System Triggers Adrenaline for Rapid Survival

A Threat Signals the Hypothalamus, Which Activates the Adrenal Medulla

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

Unlock the rest of this chapter with a free account