Human Nervous System and Sensory Organs

Question 1

accommodation

Answer 1

the ability of the lens to alter its shape for clear vision

Question 2

Alzheimer’s disease

Answer 2

disease caused by nerve defects usually in older people and characterized by memory loss and confusion

Question 3

Astigmatism

Answer 3

Eye defect caused by an uneven corneal surface

Question 4

Auditory Nerve

Answer 4

nerve transmitting impulses from the ear to the brain

Question 5

Autonomic nervous system

Answer 5

nervous system containing a sympathetic and parasympathetic section

Question 6

Binocular vision

Answer 6

the use of 2 eyes to form an image, giving a wider field of vision

Question 7

Blind-spot

Answer 7

area in the retina that does not contain photoreceptors and therefore cannot form an image

Question 8

cataract

Answer 8

cloudy ,opaque portion in the lens of the eye

Question 9

central nervous system

Answer 9

nervous system made up of the brain and the spinal cord

Question 10

cerebellum

Answer 10

the part of the brain which co-ordinates voluntary actions and which is responsible for balance

Question 11

cerebrum

Answer 11

• the region of the brain associated with problem solving

- the part of the brain where the sensation of sound is interpreted

Question 12

choroid

Answer 12

a pigmented layer in the eye which absorbs light and prevents its reflection

Question 13

ciliary muscles

Answer 13

muscles that contract or relax to change the shape of the lens in the eye

Question 14

cones

Answer 14

Receptor cells, sensitive to colour found in the eye

Question 15

conjunctive

Answer 15

protection membrane situated over the cornea of the eye

Question 16

cornea

Answer 16

transparent part of the sclera in front of the eye

Question 17

cristae

Answer 17

receptors in the semi-circular canals of the ear that are sensitive to speed and direction

Question 18

dendrites

Answer 18

fibres that transmit impulses to a cell body in a neuron

Question 19

effector

Answer 19

structure that responds to a stimulus received by a receptor/sensory organ

Question 20

eustachian tubes

Answer 20

tubes which connects the middle ear to the pharynx

Question 21

grommet

Answer 21

structure inserted into the tympanic membrane to allow air to pass into the middle ear

Question 22

Interneuron

Answer 22

neuron that transmits impulses from the sensory neuron to the motor neuron

Question 23

Iris

Answer 23

the part of the eye which is colored black, brown, green, grey, or blue

Question 24

long-sightedness

Answer 24

the ability to see objects far away clearly, but not objects close by

Question 25

maculae

Answer 25

receptors in the sacculus and utriculus of the ear that are sensitive to the position of the body

Question 26

medulla oblongata

Answer 26

A part of the brain responsible for the involuntary actions such as breathing and dilation and constriction of blood vessels

Question 27

Meninges

Answer 27

protective membranes surrounding the central nervous system to effectors

Question 28

multiple sclerosis

Answer 28

Disease caused by damage to the myeline sheth of neurons and characterized by physical and mental disablities

Question 29

myelin sheath

Answer 29

the structure that insulates a neuron in order to speed up the transmission of impulses

Question 30

neuron

Answer 30

the structural unit of the nervous system

Question 31

optic nerve

Answer 31

nerve transmitting impulses from the eye to the brain

Question 32

Organ of Corti

Answer 32

the structure, within the cochlea, responsible for picking up the stimulus of sound

Question 33

peripheral vision

Answer 33

nerves linking receptor and effector organs with the brain and spinal cord

Question 34

pupillary mechanism

Answer 34

changes that occur in the diameter of the pupil under different light conditions

Question 35

radial muscles

Answer 35

the iris muscles that contract in dim light

Question 36

receptor

Answer 36

structure that receives a stimulus and converts it into an impulse for transmission

Question 37

Reflex action

Answer 37

A rapid, automatic (involuntary) response to an external stimulus

Question 38

Reflex arc

Answer 38

Path taken by an impulse during a reflex action

Question 39

Retina

Answer 39

The layer of the eye containing photoreceptors and where images are formed

Question 40

Rods

Answer 40

Photoreceptors in the retina that are stimulated under dim-light conditions

Question 41

Sensory neuron

Answer 41

the neuron that transmits impulses from the sense organs t the central nervous system

Question 42

short-sightedness

Answer 42

the ability to see objects close by clearly, but not objects that are far away

Question 43

suspensory ligaments

Answer 43

structures that hold the lens of the eye in position

Question 44

synapse

Answer 44

the physiological connection between the axon of one neuron and the dendrite of another

Question 45

Yellow spot

Answer 45

• the area of the retina with the highest concentration of cones
• the area of the retina that contains the highest amount of cones and therefore forms the clearest image