Chemical senses: Smell and taste

Question 1

two adaptive roles for chemical senses:

Answer 1

1. the evaluation of potential foods (i.e., encouraging the consumption of sources of energy and nutrients while avoiding toxins)
2. regulating social interactions. The members of many species release pheromones chemicals that influence the physiology and behavior of conspecifics (members of the same species) (humans probablt dont realease or respond to sexual pheromones)

Question 2

2 paden olfaction

Answer 2

1. olfactory bulb –> periform cortex (primary olfactory cortex) –> amygdala –> limbic system ( emotional response to odor)
2. olfactory bulb –> periform cortex (primary olfactory cortex) –> amygdala –> medial dorsal nucleus (thalamus) –> OFC (mediate conscious perception of odors)

Question 3

3 different types of tase buds cells

Answer 3

1.cells that detect bitter (25 metabotropic receptors)
sweet (2 metabotropic receptors) and umami (savory) (1 metabotrobic receptor)
2. cells that detect sour (3 iotropic receptors)
3. cells that detect salty (2 iotropic receptors)

Question 4

inabilaty to smell and taste:

Answer 4

1. anosmnia (smell) –> The most common neurological cause of anosmia is a blow to the head that causes a displacement of the brain within the skull and shears the olfactory nerves where they pass through the cribriform plate. Less complete deficits in olfaction have been linked to a wide variety of neurolog- ical disorders including Alzheimer’s disease, Down syndrome, epilepsy, multiple sclerosis, Korsakoff’s syndrome, and Parkinson’s disease
2. ageusia (taste) –> rare, presumably because sen- sory signals from the mouth are carried via three separate pathways. However, partial ageusia, limited to the anterior two-thirds of the tongue on one side, is sometimes observed after damage to the ear on the same side of the body. This is because the branch of the facial nerve (VII) that carries gustatory information