Anatomy and Physiology

Anatomy and Physiology

PART A

Question 1 a

The sympathetic nervous system is the one that will be engaged. The reason is that the sympathetic nervous system functions in producing reflex adjustments and localized cardiovascular system adjustments. Under stress conditions, activation of the whole sympathetic nervous system happens, releasing the fight-or-flight response (Bechir 2010). An increase in heart rate, epinephrine release from the adrenal gland in large quantities, vasodilation of the skeletal muscle, cardiac output increase, dilation of pupillary piloerection and dilation of bronchial characterizes this response.

Question 1b

Name                                       Effect

Eyes                                 Pupillary dilation, distance vision focusing

Skin                       Increases secretion of sweat glands, contraction and erection of the hair

Respiratory system           Increases the diameter of airways, increases the rate of respiratory

Skeletal Muscle               Increases force of contraction and glycogen breakdown

Question 1c

The adrenergic family neurotransmitters and receptors are the ones activated in the sympathetic nervous system, specifically A1, B1 and B2. Vasoconstriction results due to receptors A1 activation by norepinephrine or epinephrine, in the heart arteries. A1 receptors lack in the vessels in skeletal muscle because they have to remain open to receive the increased blood flow from the heart during the response of fight-or-flight. Ganglia of the sympathetic nervous system are located on the sides of the spinal cord. Preganglionic sympathetic fibres are those that exit the synapse of the spinal cord. Acetylcholine, Ach is the ganglionic neurotransmitter. Released Ach from preganglionic synapse cements to nicotinic Ach receptors on the postganglionic cell. The postganglionic neuron is depolarized by Ach binding generating an action potential that elicits a response by travelling to the target organ.

Question 2a

The engaged nervous system is the Parasympathetic nervous system. This is because the primary function of the parasympathetic nervous system is to modulate visceral organs such as glands.  The parasympathetic system while providing important control of many tissues is not crucial for the maintenance of life despite controlling several tissues (Perry 2001). The stimulation of “rest-and-digest” activities that occur when the body is at rest is the sole responsibility of the parasympathetic nervous system.

Question 2b

Eye                              Pupil constriction; near distance focusing.

Skin                             Not innervated (none)

Respiratory system      Decreases the diameter of the airways, decreases respiratory rate

Skeletal muscle           Not innervated (none).

Question 2c

Neurotransmitters of the parasympathetic nervous system and receptors belong to the cholinergic family. The M2 and M3 receptors of the muscarinic cholinergic family are the specifics. Increased No production resulting in vasodilation is as a result of M3 receptor activation by acetylcholine. Preganglionic parasympathetic fibres related to vagal nerve enter their target organ by exiting the brain stem where synapsis is formed with postganglionic neurons. The neurotransmitter of parasympathetic ganglia is Ach just like the sympathetic ganglia and binds to nicotinic receptors found on postganglionic cell.

PART B

Question 1

I will not consider Jack to be an Alzheimer’s patient. The reason; difficulty in remembering things is the major symptom of Alzheimer’s, particularly new information. Ageing people may forget things normally as well but they will remember that they forget. However, Alzheimer’s disease patients forget something and don’t recall the information, even if someone reminds them, it doesn’t feel familiar.

Question 2

The treatment I would recommend for Jack is to stay social (Shaefer 2010). People are at higher risk for memory problem if they are not socially engaged with family and friends than people who have strong social ties. Stress can be reduced by quality face-to-face social interaction and it is a powerful medicine for the brain, so join a club or schedule time with friends.

References

Béchir, M. (2010). Sympathetic nervous system: Pathophysiological element of disease and potential therapeutic approaches. Zürich.

Perry, C. J. (2001). Drugs & poisons feature shows the parasympathetic nervous system.

Schaefer, R. B. (2010). Alzheimer’s: The identity thief of the 21st century. Baltimore: PublishAmerica.