Question

While walking in the snow, Jim falls and lands awkwardly on his head. Jim goes to hospital, but Jim’s doctor cannot explain why Jim fell. You are asked to investigate everything that Jim was doing before the accident, to try to find a cause for the fall.

After all his tests, doctors are now thinking that Jim’s endocrine system may be involved.  

1. Describe the overall function(s) of the i) nervous and ii) endocrine systems.
2. List the different types of cells you expect to find in the i) nervous and ii) endocrine systems.
3. Do the cells in the i) nervous and ii) endocrine systems generate action potentials? Briefly differentiate between the two systems and justify your response in the context of the overall function of each system.  
4. Is it possible that Jim may have taken a drug or unusual ions in an electrolyte solution that affects the electrical activity in the cells of the i) nervous and ii) endocrine systems? Clearly describe (with an example) how this could occur.

Answer 1

a) Both endocrine system and nervous system work together and impact many aspects like growth, reproduction, and metabolism.

(I) Nervous system is the integrating system for all other organ system. It includes three major functions such as: sensory unit: It senses the external stimuli via recptors adn sensory neurons; Integration centre: Typically CNS include brain and spinal cord, process the information carried by the sensory neurons and rely to the periphery via motor neurons; Motor unit: Composed of motor neurons which instruct the oeriohery and induce muscle contraction.

(II) The endocrine system secretes hormones into bloodstream and other body fluids which is crucial for metabolism, growth, water and mineral balance, and the response to stress.They are regulated by feedback mechanism which in turn involve the brain to affect neural processing.

b) (I) The cells of nervous system are glial cells and neurons. Neurons are functional unit of nervous system which comprises as sensory and motor neurons. Glial cells are supportive cells taht usually nourish, insulate neurons and remove waste products.

(II) The cells of endocrine system are secretory cells and suppportive cells. These cells are typically grouped together to form as endocrine glands. They are regarded as a chemical messenger secreted by internal glands directly into the circulatory system which can regulate distant target organs.

(c) No. Action potentials are attributed only to nervous cells. Neurons can be excited by the stimulus which in turn influenc ethe gated ion channels thereby creting potential difference across membrane and ultimately cause action potential. AP leads to release of NT cause effector function in target organs.

(d)  Drugs interfere with the way neurons send, receive, and process signals via neurotransmitters which can disturb the function of gated ion channels in the neurons. Example:  marijuana and heroin are capable of activating  neurons due tchemicalo their structural similarity with natural neurotransmitter in the body.

It also affect the release of hormones and disrupts hormonal balance by influenceing feed back loop mechanism. Example: Marijuana affect hormonal balance, reducing s@xual function and fertility.