Question

You are walking in the forest, and you hear a twig snap…

Explain the role of the endocrine system in one of your examples or scenarios. What organs, tissues and cells are involved?

What is the target cell and it’s response (and why is this important/relevant)?

Describe the effector pathway using the following hierarchy.

1. System
2. Organ/s
3. Tissue/s
4. Cells/s

Answer 1

In the middle of forest, the sound of twig snap can elicit fight of flight response from the body. There can be multiple reasons for twig snap, an animals on tree or a a tree branch is falling on you, whatever may be its a potent dangerous condition. Hence body must decide whether to fight or flight.

System:

• The first response comes from the nervous system - systemic nervous system, amygdala.
• It activates hypothalamus gland to further activate SAM and SNS pathway of endocrine system.
• Now, adrenal medulla a part of adrenal gland located above kidney is activated. Adrenal glands released hormones epinephrine and norepinephrine into blood stream.
• These hormones are taken up by the organ Liver, where the hormones trigger glycogen breakdown and release of glucose into blood.

Organs:

• Lungs, : increased breathing, increased oxygen intake
• Heart, :increased blood pumping, rapid breathing,
• Kidney: Decreaeed urine output, increased water retention
• Liver: conversion of glycogen into glucose
• Brain: releasing hormones and activating nervous system

Tissue:

• Skin: increased sweating, skin pale.
• blood: vasodilation, increased blood flow to lower extremities.
• pupil of eyes: size of pupils increased to intake more light
• spinal cord: increased impulses to motor cells and muscles
• muscle: increased blood flow or decreased depending on hormone response.

Cells:

• liver cells: increased glycogen breakdown
• Hypothalamus and pituitary gland cells: releasing hormones into blood stream
• sweat glands: increased sweat production

Overall physiological effects would be increase in  heart rate, increased breathing rate, sweating, dilated pupils...etc.