Biology

Front 1

Homeostasis

Back 1

Tendency of living organisms to maintain their internal environment constant with narrow limits irrespective of changes in the external environment

Front 2

Nervous System

Back 2

1. Detects changes in environment

2. Enables coordination of various activities of the body

Front 3

Nervous System

Back 3

Nerves»Nerve fibres»Neurons

Front 4

Sensory Neurons

Back 4

Carry impulses from receptor(nerve endings / sense organs) to central nervous system(brain+spinal cord

Neurons damaged= no stimuli picked up

Front 5

Motor Neurons

Back 5

Carry impulses from central nervous system to efectors(muscles or glands)

If damaged, you will not be able to respond to stimuli. You will not feel pain

Front 6

Connector neurons/ interneurons

Back 6

Carry impulses inside central nervous system from sensory neuron to motor neuron

Located in spinal cord

Front 7

Neurons consist of:

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1. Cell body

2. Dendrites

3. Axon

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Axon

Back 8

Conducts impulses away from body

Front 9

Myelin Sheath

Back 9

Provides electrical insulation

Helps speed up the transmission of impulses

Front 10

Synaptic Contact

Back 10

Nerve impulses are carried along neuron electrical impulses but communication across synapse is by means of chemical called neurotransmitters

Front 11

Central nervous system

Back 11

Brain+spinal cord

Front 12

Peripheral nervous system

Back 12

Made up of all nerves outside CNS

Hint 12

Physical

Front 13

Somatic nervous system

Back 13

Parts of nervous system that enable the body to react to external changes in environment

Front 14

Autonomic nervous system

Back 14

Parts of nervous system that control internal environment e.g. sweating, breathing

Front 15

BRAIN

Back 15

Upper, enlarged part of spinal cord(protected by cranium)

Front 16

Meninges

Back 16

Protective membranes surrounding brain and spinal cord

Front 17

BRAIN functions

Back 17

1. Receives and interprets sensations

2. Controls higher thought processes

3. Voluntary and involuntary actions

4. Maintains muscle tone and balance

Front 18

Corpus callosum

Back 18

Mass of white fibres which connect the right and left side of the brain

Front 19

Cerebrum

Back 19

Grey matter on the outside, white matter on the inside.

1. Controls voluntary actions

2. Receives and interprets all sensations.

3. Controls higher thought processes

Front 20

Medulla Oblongata

Back 20

Contains cerebrospinal fluid

White outside, grey inside

1. Involuntary actions

2. Conducts impulses from spinal cord to higher parts of brain

Front 21

SPINAL CORD

Back 21

Formed by successive vertebrae

SPINAL nerves arise from spinal cord and leave spinal canal through tiny openings formed between successive vertebrae

Surrounded and protected by meninges

White matter on the outside, grey matter on inside

Front 22

Sensory neurons

Back 22

Enter dorsal root of spinal nerves

Bring impulses from receptor to SPINAL cord

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Dorsal root swelling

Back 23

Dorsal root ganglion

Front 24

Sensory nueron

Back 24

Has cell body centrally situated

Front 25

Dorsal root

Back 25

Has dorsal root ganglion to accommodate all cell bodies of sensory neurons

Front 26

Connector neurons

Back 26

Found in spinal cord between sensory and motor neurons

Transmits impulses from sensory neurons to motor neurons

Front 27

Motor neurons

Back 27

Leave spinal cord through ventral root of spinal nerves

Take impulses from spinal cord to effector organ(muscle/gland)

Front 28

SPINAL cord

Back 28

1. Conducts impulses between brain and receptors and defectors

2. Serves as reflex centre for blinking, knee jerking etc.

Front 29

PERIPHERAL NERVOUS SYSTEM

Back 29

Made up of all nerves outside the central nervous system

Front 30

PERIPHERAL NERVOUS SYSTEM divide into:

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Somatic nervous system

Autonomic nervous system

Front 31

Somatic nervous system

Back 31

Parts of nervous system that enable the body to react to changes to external environment

Front 32

Somatic nervous system made up of:

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1. Free nerve endings and sense organs which pick up change in external environment

2. Sensory nerves carrying impulses from receptors

3. Motor nerves carrying impulses back to muscles/glands

4. Defectors which react to these impulses

Front 33

Autonomic nervous system made up of:

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1. Centres in brain and spinal cord

2. Nerve cells in smooth muscles, glands and internal organs

3. Sympathetic and parasympathetic nerves running to these muscles,glands and internal organs

Front 34

Sympathetic nerves + Parasympathetic nerves

Back 34

Function metaphorically

e.g. Sympathetic nerves of heart increase heart rate, while Parasympathetic nerves slow down heart rate

Front 35

Reflex Action

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Rapid, automatic/ involuntary response to stimulus received by an organ or other receptor

Front 36

Reflex Arc

Back 36

Path taken by an impulse in bringing about a response to a stimulus during a reflex action

Front 37

Eye

Back 37

Long sightedness (Hypermetropia)

Short sightedness (Myopia)

Front 38

Hypermetropia

Back 38

Eyeball too rounded

Lense of eye unable to become more convex

Front 39

Hypermetropia

Back 39

The image of the near object that falls on the retina is blurred while the best image falls behind the retina