Response To Stimuli Test

Question 1

Atrioventricular node AVN

Answer 1

A group of cells located between the atria that slow down the wave of excitation and pass it between the ventricles, along the bundle of his

Question 2

Autonomic nervous system

Answer 2

A branch of the motor nervous system that carries nerve impulses to muscles and glands. It controls involuntary activities and has 2 divisions: the sympathetic nervous system and the parasympathetic nervous system

Question 3

Auxins

Answer 3

A class of plant hormones that control cell elongation

Question 4

Bundle of his

Answer 4

A collection of purkyne fibres which run from the AVN down to the Apex of the ventricles

Question 5

Central nervous system CNS

Answer 5

Brain and spinal cord

Question 6

Chemoreceptor

Answer 6

A type of receptor found in the walls of the carotid arteries that detects changes in blood PH and transmits nerve impulses to the medulla oblongata. For example, if blood PH decreases, chemoreceptors increase the frequency of nerve impulses to the medulla oblongata

Question 7

Cone cells

Answer 7

A type of light receptor cell that transduces light energy into a generator potential. Cone cells are concentrated in the fovea, detect light of high intensity, and lead to colour images. One cone cell forms a synapse with a single bipolar cell, giving high visual acuity

Question 8

Effector

Answer 8

An organ tissue or cell that produces a response to a stimulus

Question 9

Fovea

Answer 9

The point on the retina opposite the pupil that receives the highest intensity of light. It contains the greatest concentration of cone cells but no rod cells

Question 10

Gravitropism

Answer 10

A plants growth response to gravity

Question 11

Indoleacetic acid IAA

Answer 11

A plant growth factor that is a type of auxin and controls cell elongation. It stimulates elongation in shoots and inhibits elongation in roots

Question 12

Iodopsin

Answer 12

Pigment found in cone cells

Question 13

Kinesis

Answer 13

A response to a stimulus that is non directional, changing the speed at which an organism moves and the rate at which it’s direction changes

Question 14

Medulla oblongata

Answer 14

The part of the brain that controls heart rate. It’s made up of 2 centres that are linked to the SAN. One centre is linked by the sympathetic nervous system and increased heart rate. The other is linked by the parasympathetic nervous system and decreases heart rate

Question 15

Myogenic

Answer 15

Describes cardiac muscle tissue that initiates its own contraction without outside stimulation from nervous inpulses

Question 16

Pacinian corpuscle

Answer 16

A sensory receptor that detects changes in mechanical pressure

Question 17

Parasympathetic nervous system

Answer 17

A branch of the autonomic nervous system that is active under normal, resting conditions. It inhibits effectors, slowing down activity

Question 18

Pressure receptors

Answer 18

A type of receptor found in the walls of the carotid arteries and aorta which detects changes in blood pressure and transmits nerve impulses to the medulla oblongata. Eg if blood pressure increases, pressure receptors increase the frequency of nerve impulses to the medulla oblongata

Question 19

Purkyne tissue

Answer 19

Specialised cardiac muscle fibres which conduct the wave of excitation from the AVN down the apex of the ventricles

Question 20

Retina

Answer 20

The inner layer of the mammalian eye. It consists of light receptor cells that’s cut as transducers, converting light energy into electrical energy

Question 21

Rhodopsin

Answer 21

The pigment found in rod cells which is broken down to create a generator potential

Question 22

Rod cells

Answer 22

A type of light receptor cell that transduces light energy into a generator potential. They are located at the periphery of the retina, detect light of low intensity and lead to black and white images. Many rod cells form a synapse with a single bipolar cell giving low visual acuity

Question 23

Sinoatrial node SAN

Answer 23

A group of cells in the wall of the right atrium that generate electrical activity. The SAN is often referred to as the hearts pacemaker

Question 24

Stretch mediated sodium channel

Answer 24

A type of sodium channel whose permeability to sodium changes upon distortion (pressure chnages and stretching ) they are found in the plasma membrane of the sensory neuron ending at the centre of the pacinian porcuscle

Question 25

Sympathetic nervous system

Answer 25

A branch of the autonomic nervous system that is active under stressful conditions. It stimulates effectors speeding up activity

Question 26

Taxis

Answer 26

A response to a stimulus that is directional like the movement of an organism towards or away from a stimulus

Question 27

Visual acuity

Answer 27

The clarity of vision