nervous and hormonal communication

Question 1

stimuli

Answer 1

change in internal or external environment

Question 2

neurons

Answer 2

• sensory neuron transmit electrical impulses from receptors to CNS
• motor neuron transmit electrical impulses from CNS to effector
• relay neuron transmit electrical impulses between sensory and motor

Question 3

responding to stimuli

Answer 3

• receptor detects stimuli and sends electrical impulse along sensory
• when the impulse reaches the end of neuron neurotransmitters take information to next neuron which sends electrical impulse
• CNS processes information and sends impulse along motor to effectors

Question 4

respond to dim light

Answer 4

• stimuli is dim light
• light receptors in eye detect lack of light
• CNS processes information
• radial muscles in the iris are stimulated by motor
• radial muscles contract to dilate pupils

Question 5

glands

Answer 5

• they are a group of cells that are specialized to secrete useful substances
• glands are stimulated by an electrical impulse and when there is change in conc of a specific substance

Question 6

hormones

Answer 6

• hormones are chemical messengers and can be progesterone, steroids, peptides
• hormones secreted when glands are stimulated
• they diffuse into blood and carried around
• they diffuse out of the blood all over the body and bind to specific receptors for that hormone found on the membrane of cells
• hormone triggers response in target cells

Question 7

e.g. of hormone sending information

Answer 7

• stimulus is low blood glucose
• receptors on pancreas cell detect low blood glucose
• pancreas release hormone glucagon in the blood
• effector- target cells in liver break glucagon and convert glycogen to glucose
• glucose released into the blood

Question 8

• nervous
  *hormonal communication

Answer 8

• uses electrical impulses
• uses chemicals
• faster response as impulses are fast
• slower response as hormones travel with the blood
• localized response as electric impulse carried to specific cells
• widespread response as target cells can be allover the body
• short lived response as neurotransmitters are removed quickly
• long lived responses as hormones aren’t broken down very easily