Question

Another type of sensory receptor are chemoreceptors. Chemorecptors are found in the nose and tongue. A student volunteer will be asked to block on nostril and then smell an odor until they become accommodated. They will then open the blocked nostril and indicate whether they can once again smell the odor. What do you think will happen?

1.      Describe 6 different neuroglial cells below, where are they located, what do they do?

2.      Describe the Flight or Fight Response, what are some changes that occur when the sympathetic nervous system is activated?

3.      Describe the physiology of these special senses below: Smell/Taste, Hearing/Equilibrium, and/or Sight. Be able to identify the anatomical structures discussed in lab that allow these sensations.

Answer 1

1. Six different neuroglial cells are:

(a) Astrocyte:
Location: Astrocyte reside in the brain and spinal cord. They are the most numerous cells in the human brain.
Function: Functions of astrocytes include physical and metabolic support for neurons, detoxification, guidance during migration, regulation of energy metabolism, electrical insulation (for unmyelinated axons), transport of blood-borne material to the neuron, and reaction to injury.

(b) Oligodendrocyte:
Location: Oligodendrocyte are found in the central nervous system of invertebrates and vertebrates
Function: Oligodendrocytes are highly specialized neural cells whose function is to myelinate central nervous system axons. Myelin sheaths are extraordinarily large extensions of the oligodendrocyte cell membrane and are highly complex structures.

(c) Microglia:
Location: Microglia are located throughout the brain and spinal cord.
Function: These cells mediate immune responses in the central nervous system by acting as macrophages, clearing cellular debris and dead neurons from nervous tissue through the process of phagocytosis (cell eating).

(d) Ependymal cell:
Location: Ependymal cells line the ventricles in the brain and the central canal in the spinal cord.
Function: Ependymal cells line the ventricular system of the brain and play a key role in the production of cerebrospinal fluid.

(e) Satellite cell:
Location: Satellite cells are found in the ganglia of the peripheral nervous system.
Function: They supply nutrients to the surrounding neurons and also have some structural function. Satellite cells also act as protective, cushioning cells. Additionally, they express a variety of receptors that allow for a range of interactions with neuroactive chemicals.

(f) Schwann cell:
Location: Schwann cells are found in close contact with axons in the peripheral nerves.
Function: Schwann cell myelinate the axons of the PNS. Myelin, which is a fatty layer that insulates the axon, helps to increase the saltatory conduction of the neuron. A myelinating Schwann cell wraps around a single axon.

2. Flight or Fight Response:
The fight-or-flight response is a physiological reaction that occurs in response to a perceived harmful event, attack, or threat to survival.
In response to acute stress, the body's sympathetic nervous system is activated due to the sudden release of hormones. In the face of something frightening, your heartbeat quickened, you begin breathing faster, and your entire body becomes tense and ready to take action.
The autonomic nervous system has two components, the sympathetic nervous system and the parasympathetic nervous system.

When the sympathetic nervous system is activated, it triggers the fight-or-flight response, providing the body with a burst of energy so that it can respond to perceived dangers.

3.
(a) Physiology of Smell/Taste: Both smell and taste use chemoreceptors, which essentially means they are both sensing the chemical environment. This chemoreception in regards to taste, occurs via the presence of specialized taste receptors within the mouth that are referred to as taste cells and are bundled together to form taste buds.

(b) Physiology of Hearing/Equilibrium: Receptors for two sensory modalities (hearing and equilibrium) are housed in the ear. The external ear, the middle ear, and the cochlea of the inner ear are involved with hearing. The semicircular canals, the utricle, and the saccule of the inner ear are involved with equilibrium.

(c) Physiology of sight: Vision is the special sense of sight that is based on the transduction of light stimuli received through the eyes. The eyes are located within either orbit in the skull. The bony orbits surround the eyeballs, protecting them and anchoring the soft tissues of the eye.