Zoology Midterm 2

Law of Specific Nerve Energies

detection of a nerve impulse is dependent on how the brain perceives it, not on the actual way the stimulus is coded. Created by Johannes Müller.

6 types of stimulus receptors

1. chemoreceptors (chemicals)

2. mechanoreceptors (touch)

3. photoreceptors (light)

4. thermoreceptors (hot and cold)

5. electroreceptors (electric fields)

6. nociceptors (pain)

parasympathetic nervous system

controls rest and digest response

sympathetic nervous system

controls fight or flight response

gustatory receptor cell

receptor cell within taste buds

olfactory epithelium

receptor for smell within the brain

Jacobson’s Organ

senses non-volitile chemicals in tetrapods

lateral line

sense structure within fish that detects water pressure changes

neuromast

sense organ within lateral line in fishes and amphibians

langena

the organ in which hearing is localized. in terrestrial vertebrates, it elongates. in mammals, it coils to become cochlea

protandrous

male turns to female

protogynous

female turns to male

oviparity

fetus develops in external egg (eg chickens, birds)

viviparity

fetus develops inside mother, AND gets nutrients from her (eg humans, mammals)

oviviparity

fetus develops inside organism, BUT does NOT get nutrients from host (eg male seahorses)

hermaphrodite

both male and female/has both testes and ovaries in one organism

innate immunity

mechanism of defense that doesn’t rely on prior exposure

acquired immunity

specific defense that relies on prior external factors, only in jawed vertebrates