Stress: Biological approach 1: Adrenaline and acute stress Flashcards
Define acute stress.
Acute stress is the most common form of stress experienced. It is short-term stress and the response to an immediate threat.
What does the autonomic nervous system do?
The autonomic nervous system (ANS) helps maintain internal homeostasis.
What does the sympathetic nervous system do?
The sympathetic nervous system (SNS) is often associated with the “fight or flight” response and prepares the body for action by increasing heart rate, dilating airways, and redirecting blood flow to muscles.
What does the peripheral nervous system do?
Conversely, the peripheral nervous system (PNS) is responsible for the “rest and digest” response, promoting relaxation and conservation of energy by reducing heart rate, constricting airways, and facilitating digestion.
Conclude the SNS paragraph.
The ANS plays a crucial role in controlling functions such as heart rate, blood pressure, digestion, respiratory rate, and body temperature. A threat will put the body into the SNS state and once it has passed, the body will return to the PNS state.
What is the SAM system.
The Sympathodrenomedullary (SAM) pathway is a rapid biological response to stress by the activation of the sympathetic nervous system and the adrenal medulla. This is what is activated when the body encounters acute stressors.
Describe the SAM system process (long).
When your brain detects a threat or stressful situation, it sends signals to the hypothalamus, which activates the sympathetic nervous system. This initiates the “fight or flight” response. The hypothalamus signals the adrenal glands to release adrenaline into the bloodstream. Adrenaline acts as a powerful hormone and neurotransmitter. Adrenaline stimulates the heart, causing it to beat faster. This increases the flow of oxygenated blood to muscles and vital organs, preparing the body for action.
What does adrenaline do?
Adrenaline relaxes and widens the airways in the lungs, allowing for increased oxygen intake. This helps improve physical performance.
What happens to nonessential functions?
The “fight or flight” response temporarily shuts down non-essential functions like digestion and immune system activity. This energy is redirected to the immediate physical demands of the situation.
What is the role of noradrenaline?
In addition to adrenaline, the sympathetic nervous system releases noradrenaline at nerve endings, further enhancing the body’s readiness for action. Noradrenaline increases heart rate and redirects blood flow to the muscles.
How is the ‘fight or flight’ response rooted in evolutionary influences?
The “fight or flight” response is deeply rooted in human evolution and reflects our ancestors’ adaptations to survival in the environment of evolutionary adaptiveness (EEA). In this environment, individuals faced various physical threats, such as predators or environmental dangers. Those who could rapidly mobilise resources for physical action, such as increased heart rate and energy release, and sharpen their senses for quick decision-making, had a better chance of survival and passing on their genes by reproduction. The “fight or flight” response evolved as an adaptive mechanism to enhance our ancestors’ chances of responding effectively to immediate threats, ultimately contributing to the survival and reproduction of those who possessed these advantageous physiological traits which provides explanation for the prevalence of fight or flight response today.
