The Nervous System in One Shot
Parts of the Brain The Central Nervous System The Central Nervous System
The human brain is broadly divided into: Structure of a Neuron The Pathway (Reflex Arc)
Stimulus
Receptor
Afferent/Sensory neuron
Brain/Spinal cord
Efferent/Motor neuron
Effector muscle/Gland
Response Parts of the Eye
Sclera
Conjunctiva - covers/protects sclera
Cornea - covers pupil and iris
Choroid - Blood vessels for nourishment
Iris - Coloured part
Pupil - Aperture at the centre of iris
Ciliary muscles - Hold iris in place
Lens - (biconvex) Parts of the Eye
Retina - Innermost and light sensitive layer (contains photoreceptor cells)
Yellow spot - Area of best vision
Blind spot - No vision
Aqueous humor - Nourishment to lens
Vitreous humor - Holds spherical shape of the eyeball Accommodation
The ability of the eye to change its focus from distant to near objects (and vice versa) Outer ear
Consists of:
➢ Pinna - Catches sound waves; passes them deeper into ear
➢ Auditory canal
➢ Tympanic membrane (eardrum) - Boundary between the external and middle ear Middle ear
- Amplifies sound waves
- Consists of:
➢ Ear ossicles (malleus/hammer, incus/anvil, stapes/stirrup)
➢ Eustachian tube - controls the pressure within the middle ear, making it equal with the air pressure outside the body
- Has two membrane-bound openings:
❖ the oval window
- Also called “labyrinth”
- 2 main functions:
❖ Convert physical vibrations into electrical impulses ❖ Helps maintain equilibrium
- Consists of
➢ Vestibule - to help in static equilibrium
➢ 3 semicircular canals - for dynamic balance
Pinna collects the vibrations, and conducts them through the auditory canal.
Vibrations strike on the eardrum
This vibrates the ear ossicles
The stirrup transmits vibrations to the oval window
Fluid in cochlear canal receives vibrations, and stimulates sensory cells (in organ of corti) of the cochlea
Impulses picked up by auditory nerves - sent to brain
The Team
Q. A reflex arc is best described as movement of stimuli from (2012)
A Receptor cell, sensory nerve, B Receptor cell, efferent nerve, relaying neuron, effector muscles relaying neuron, muscles of body
C Receptor cell, spinal cord, motor D Receptor cell, synapse, motor neuron, relaying neuron neuron, relaying neuron Q. A reflex arc is best described as movement of stimuli from (2012)
A Receptor cell, sensory neuron, B Receptor cell, efferent neuron, relaying neuron, effector muscles relaying neuron, muscles of body
C Receptor cell, spinal cord, motor D Receptor cell, synapse, motor neuron, relaying neuron neuron, relaying neuron Q. The smallest ear ossicle is
A Malleus B Incus
C Stapes D Cochlea Q. The smallest ear ossicle is
A Malleus B Incus
C Stapes D Cochlea Q. Passage connecting middle ear with nasopharynx is
A Eustachian tube B Auditory canal
C Cochlea D Pinna Q. Passage connecting middle ear with nasopharynx is
A Eustachian tube B Auditory canal
C Cochlea D Pinna Q. The structure of the ear which helps in balancing of the body
A Eustachian tube B Auditory canal
C Cochlea D Semicircular canals Q. The structure of the ear which helps in balancing of the body
A Eustachian tube B Auditory canal
C Cochlea D Semicircular canals Q. The type of nervous system that helps in emergency situations
A Central nervous system B Somatic nervous system
C Sympathetic nervous system D Parasympathetic nervous system Q. The type of nervous system that helps in emergency situations
A Central nervous system B Somatic nervous system
C Sympathetic nervous system D Parasympathetic nervous system Q. The nutritive layer of the eye which also helps prevent reflection of light
A Choroid B Iris
C Retina D Pupil Q. The nutritive layer of the eye which also helps prevent reflection of light
A Choroid B Iris
C Retina D Pupil Q. Part of the brain which helps in balancing of the body
A Cerebrum B Cerebellum
C Pons D Medulla Q. Part of the brain which helps in balancing of the body
A Cerebrum B Cerebellum
C Pons D Medulla Q. Part of the brain which controls respiration
A Cerebrum B Cerebellum
C Diencephalon D Medulla Q. Part of the brain which controls respiration
A Cerebrum B Cerebellum
C Diencephalon D Medulla Q. The number of cranial nerves in man
A 31 B 12
C 10 D 32 Q. The number of cranial nerves in man
A 31 B 12
C 10 D 32 Well done!
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