Biology Questions and Answers

Biology Questions and Answers

between them serves to modulate their

effects. For examplparasympathetic stimulatese, the (^) salivation
while the sympathetic inhibits it; the
parasympatheticthe sympathetic dilates it; the constricts pupils while
parasympathetic contracts the bronchi
while the sympathparasympathetic excitesetic relaxes them the genital; the
organs while the parasympathetic
inhibits the excitation.

36. Using examples of
    invertebrate nervous systems
    how can the process of
    evolutionary cephalization be
    described?

Considering the example of

invertebrates it is observed thatevolution makes the increasing of the (^)
complexity of the organisms to be
accompacells to spnied by convergence of nervousecial structures for controlling
and commanding: the ganglia and the
brain. In simple icnidarians, the nervous cells arnvertebrates, likee not (^)
concentrated but they are found
disperseplatyhelminthd in the body. Ines a beginning of (^)
cephalization with the anterior ganglion
concentrating verified. In annelids anneurons is alreadyd arthropods the (^)
existence of a cerebral ganglion is
evident. In cephalopod molluscscephalization is even greater and the the (^)
brain commands the nervous system.

37. What are some main
    differences of the vertebrate
    nervous systems comparing to
    invertebrates?

In vertebrates the nervous system is

well-characterized, dorsal neural cord protected having the brain andby rigid

skeletal structures. In most

invertebrates the nervous system ispredominantly ganglial, with ventral (^)
neural cords.

38. What are the protective
    structures of the central
    nervous system present in
    vertebrates?

In vertebrates thcord are protected e brain and the spinalby membranes, the (^)
meninges, and by osserespectively the skull anous structures,d the vertebral (^)
column. These protections are
fundamental for the integrity oimportant organs that commanf thosed the
functioning of the body.

39. What is the nature of the
    stimulus received and
    transmitted by the neurons?
    Neurons receive and transmit chemical

stimulireleased in the synapses. Alon through neurotransmittersg the (^)
neuron body however the impulse
transmission isconduct electric and chemical stimuli. electrical. So neurons

40. What are the two main
    ions that participate in the
    electrical impulse
    transmission in neurons?

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