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Flashcards in The Nervous system Deck (95):
1

Define synapse.

Synapse is the point of contact between the terminal branches of the axon of the neuron with the dendrites of another neuron separated by a fine gap

2

What is a nerve?

Nerve is a bundle of nerve fibres (axons) of separate neurons, enclosed in a tubular sheath.

3

What are the three types of nerves?

1. Sensory nerve
2. Motor nerve
3. Mixed nerve

4

What is a neurotransmitter? Which neurotransmitter is stored at the terminal end of the axon?

The end portions of the axons have swollen ends like “bulbs”, which store certain chemical like neurotransmitters. In the end of axon, the neurotransmitter is called acetylcholine.

5

What are the three types of neurons? Define their functions.

1. motor neuron
2. association neuron
3. sensory neuron

6

What are the functions of medulla oblongata?

functions are:
1. involuntary system
2. Internal organs

7

What are the functions of the cerebellum?

they are:
1. Balance
2. coordinate muscular activity

8

What are the functions of cerebrum?

they are:
1. think
2.memory
3. intelligence
4.voluntary system

9

State the main function of cerebrospinal fluid

It's acts like a cushion to protect the brain

10

Give reason. Alcoholic person walks unsteadily when drunk.

because of alcohol, is unable to coordinate muscular movements properly

11

Draw a neat, labelled diagram of a neuron.

see diagram

12

What are the coverings of the brain called?

Meninges

13

What is the corpus callosum?

Corpus callosum is a sheet of fibres connecting the two cerebral hemispheres.

14

What are the two sets of nerves of somatic nervous system called? How are they different?

Spinal nerves and cranial nerves. Spinal nerves have 31 pairs and Cranial nerves have 12 pairs.

15

What is a reflex action?

Reflex action is an automatic, quick and involuntary action in the body by a stimulus.

16

What is the difference between spinal cord and cerebrum based on the arrangement of nerve cell?

grey matter, white matter
in cerebrum the outer covering is with grey cells and the inner covering its has white cells, but in the spinal cord it is the reverse

17

Define reflex action

reflex action is an automatic , quick and involuntary action in the body brought by a stimulus.

18

Give the technical term for the protective covering of spinal cord and brain.

meningis

19

State the functions of cerebrospinal fluid.

1. it nourishes the brain.
2. its acts like a cushion to protect the brain.

20

Give reason: Injury to the medulla oblongata results in death.

because it is the part which controls our involuntary function.

21

Distinguish between reflexes and voluntary actions.

3. it involves muscles and glands .
3. its invloves only muscles .

22

What is the path of reflex action and reflex arc?

Receptor in skin > sersory neuron > dorsal root > association root > ventral root > motor neuron > effector ( musular ) .

23

Which part of the eye protects it from dust and rain?

Eyelids and eyebrows

24

What are the functions of cornea?

1. Protects front part of eye
2. Converges the light rays entering the eye

25

What is the function of the choroid layer?

1. Richly supplied with blood vessels for nourishing the eye
2. contains dark pigment that prevents light rays from reflecting and scattering inside the eye
3. Front part of eye has the pupil that controls the amount of light that falls on the lens.

26

What is the function of the iris?

Iris contains radial muscles to widen and circular muscles to constrict the pupil. The adjustment of the size of the pupil regulates the amount of light entering the eye.

27

What is the innermost layer of the eye?

Retina

28

What are the sense cells of the eye called? Where are they found?

Rods and cones. Retina.

29

What is rhodospin? Where is it found?

Rhodopsin or visual purple is a pigment found in rod cells of the eye. They help in seeing in dim light.

30

Distinguish between rods and cones.

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31

What is fovea centralis?

Fovea also called yellow spot lies at the back of the eye almost at the centre on the horizontal axis of the eyeball. This spot contains the maximum number of sensory cells and particularly the cones.

32

What is the blind spot?

The blind spot is an area in the eye where there are no rods and cones. Hence, it is the point of no vision. It is the point where all the nerve fibres from all sensory cells of the retina converge and bundle together to form the optic nerve,

33

How is the lens held in place?

Lens is held in place by sensory ligament which attaches to the ciliary body.

34

How does the lens change shape?

Lens is flexible. It is held in place by sensory ligaments that are attached to the ciliary body. The ciliary body contains muscles which on contraction and relaxation, change the shape of the lens.

35

Where is the aqueous chamber? What is its function?

It is the front chamber between the lens and cornea. It is filled with water-like liquid called aqueous humour which 1. keeps the lens moist 2. Protects it from physical shock 3. refracts light

36

Where is the vitreous chamber? What is its function?

It is a cavity of the eyeball behind the lens. It is filled with a transparent, jelly-like thicker fluid called vitreous humour. Functions: 1. Keeps the shape of the eyeball
2. Protects retina and nerve endings

37

What is accommodation?

The process of focusing the eye to see objects at different distances is called accomodation

38

Why cannot we see colours of some flowers in the moonlight?

Because at night our cones stop working

39

What is myopia? What are the reasons for myopia? How can it be corrected?

Myopia is a condition in which the near objects can be seen clearly while the distant objects appear blurred.

The two reasons are :
1) eye ball is lengthened from front to back
2) lens is too curved

It can be corrected by suitable concave lens.

40

What is hyperopia? What are the reasons for it? How can it be corrected?

it is a condition in which there is a difficulty in seeing near objects.

41

What is astigmatism?

it is a defect in which some of the objects are seen in focus while others are blurred.it arises due to the uneven curvature of the cornea.

42

What is the condition of the eye that affects older people?

presbyopia is a condition affecting older people who cannot see objects clearly .

43

What is cataract ?

it is a condition in which the lens turns opaque and the vision is cut down even to total blindness.

44

What is the tympanum? Where is it found?

Tympanum, also called the ear-drum is found in the outer ear, at the end of the auditory canal.

45

What are the different parts of the outer ear?

it consists of the projecting part pinna and the passage auditory canal leading to the ear drum .

46

What are the different parts of the middle ear?

It consists of three tiny bones - malleus
incus
stapes

47

What are the different parts of the inner ear?

the cochlea and the semicircular canals.

48

Where can you find Organ of Corti?

The middle canal of the cochlea

49

Eye: Optic nerve :: Ear: ?

Auditory nerve

50

Which part of the ear helps in static balance of the body?

Utriculus and sacculus

51

Which part of the ear helps in dynamic balance of the body?

Semi-circular canals

52

What is the function of the eustachian tube?

The eustachian tube equalises the air pressure on either side of the ear drum allowing it to vibrate freely.

53

Path of hearing

Pinna-auditory canal-Eardrum-ear ossicles-oval window-cochlea-auditory nerve-brain

54

What is static and dynamic balance of the body?

- Static balance refers to the balance when the body is stationary
- Dynamic balance refers to the balance when the body is in motion

55

What is attached to the ear drum?

Malleus or hammer bone

56

Where can you find the incus?

Incus (or anvil) is one of the ear ossicles. It is found in the middle ear and is connected to the malleus.

57

Where can you find stapes?

Stapes (or stirrup) is one of the ear ossicles. It is found in the middle ear and is connected to the incus.

58

State the part of the brain associated with memory.

Cerebrum

59

Sate the main function of cerebrospinal fluid.

It provides mechanical protection and nourishment to the brain .

60

Biological reason :
The hand automatically shows the direction to turn a cycle without thinking .

Because it is a conditioned reflex

61

Name the part of the human brain which is concerned with the following :
1) seat of memory
2) coordinates muscular activity

1) cerebrum
2) cerebellum

62

Differentiate between medulla oblongata and cerebrum

Medulla oblongata / Cerebellum
/
It controls the activities / It helps in maintaining
Of the internal organs . / the body balance .
/

63

The part of human brain which controls the body temperature

Hypothalamus

64

Name the ear ossicle which is attached to the tympanum

Malleus / hammer is the ear ossicle which is attached to the tympanum.

65

State the function of the suspensory ligament of the eye .

It helps the eye in holding the lens in position.

66

State the exact location of incus.

Incus is found in middle ear between malleus and stapes.

67

Biological reason :
Throat infections can lead to ear infection

The eustachian tube connects the middle ear to the throat .

68

An eye defect in which the cornea becomes uneven

Astigmatism

69

One feels blinded for a short time while,coming out of a dark room.

It happens because the diameter of pupil is reduced to allow less light to enter the eyes.

70

Explain the term stereoscopic vision.

If is the phenomenon of simultaneous focusing of an object in both eyes whose images by a kind of overlapping in the brain gives the three dimensional effect .

71

Differentiate between choroid layer and sclerotic layer .

Choroid layer
Through its blood supply ,it nourishes retina

Sclerotic layer
Gives shape to the eye ball.

72

Where is pinna located ?

Pinna is located in the external ear

73

Difference between dynamic balance and static balance

Dynamic balance
The balance which is achieved by the stimulation of endolymph present in the semi circular canals.

Static balance
The balance which is achieved through the gravity receptors located in the utriculus and sacculus .

74

Name the following

The photosnesitive pigment present in the rod cells pf the retina

Iodospin

75

The fluid present in the anterior part in the front of the eye which prevents reflection of eye .

Aqueous humour

76

The photosnesitive pigment present in the cone cells of the retina

Rhodospin

77

The internal layer of the eye which prevents refection of light

Choroid

78

What is lacrimal gland ?

It is secretory gland present in the top right part of the eye. Its secretion is called tear which lubricates the eye and is antiseptic in nature.

79

Differentiate between medulla oblongata and cerebrum

Medulla oblongata / Cerebellum
/
It controls the activities / It helps in maintaining
Of the internal organs . / the body balance .
/

79

The part of human brain which controls the body temperature

Hypothalamus

80

Name the ear ossicle which is attached to the tympanum

Malleus / hammer is the ear ossicle which is attached to the tympanum.

81

State the function of the suspensory ligament of the eye .

It helps the eye in holding the lens in position.

82

State the exact location of incus.

Incus is found in middle ear between malleus and stapes.

83

Biological reason :
Throat infections can lead to ear infection

The eustachian tube connects the middle ear to the throat .

84

An eye defect in which the cornea becomes uneven

Astigmatism

85

One feels blinded for a short time while,coming out of a dark room.

It happens because the diameter of pupil is reduced to allow less light to enter the eyes.

86

Explain the term stereoscopic vision.

If is the phenomenon of simultaneous focusing of an object in both eyes whose images by a kind of overlapping in the brain gives the three dimensional effect .

87

Differentiate between choroid layer and sclerotic layer .

Choroid layer
Through its blood supply ,it nourishes retina

Sclerotic layer
Gives shape to the eye ball.

88

Where is pinna located ?

Pinna is located in the external ear

89

Difference between dynamic balance and static balance

Dynamic balance
The balance which is achieved by the stimulation of endolymph present in the semi circular canals.

Static balance
The balance which is achieved through the gravity receptors located in the utriculus and sacculus .

90

Name the following

The photosnesitive pigment present in the rod cells pf the retina

Iodospin

91

The fluid present in the anterior part in the front of the eye which prevents reflection of eye .

Aqueous humour

92

The photosnesitive pigment present in the cone cells of the retina

Rhodospin

93

The internal layer of the eye which prevents refection of light

Choroid

94

What is lacrimal gland ?

It is secretory gland present in the top right part of the eye. Its secretion is called tear which lubricates the eye and is antiseptic in nature.