Neural Control And Oordination Flashcards
Functions of the organs / organ system in our body must be coordinated to maintain ____
Homeostasis
_____is the process through which 2 OR MORE ORGANS INTERACT AND COMPLEMENT THE FUNCTIONS OF ONE ANOTHER .
Coordination
What happens when we do physical exercise ?
The energy demand is increased for maintaining an inc muscular activity —>supply of oxygen is also inc ->which necessitates an inc in the rate of respiration , heart beat ,and inc flow of blood via blood vessels
In our body , the _____and ____ jointly coordinate and integrate al the activities of the organs so that they function in a synchronised fashion .
Neural system
Endocrine system
The ____provides an organised network of point-to-point connections for quick coordination .
Neural system
The endocrine system provides _____through hormones .
Chemical integration
The neural system of all animals is composed of highly specialised cells called. -
Neurons
The neurons can ____,____and ___diff kinds of stimuli .
Detect
Receive
Transmit
The neural organisation is very simple in ____.
Lower invertebrates (ex- hydra )
______is composed of a network of neurons .
Hydra
The neural system is ______ in insects where a __ is present along with ____and _______.
Better organised
Brain
A number of ganglia
Neural tissues
The __have a more developed neural system .
Vertebrates
The human neural system is divided into ____parts . Name -
2
CNS
PNS
The CNS includes -
Brain
Spinal cord
The CNS is the site of ______.
Information processing and control
The PNS comprises of -
All the nerves of the body associated with the CNS .
The nerve fibres of the PNS are of ____types .
2
Afferent fibres
Efferent fibres
The ___transmit impulses from tissues /organs to the CNS and the ____transmit REGULATORY impulses from the CNS to the concerned peripheral tissues /organs .
Afferent fibres
Efferent fibres
The PNS is divided into ____divisions . Name -
2
Somatic neural system
Autonomic neural system
The somatic neural system ( part of PNS ) relays impulses from __to ____.
CNS
Skeletal muscles
The ANS ( part of PNS ) transmits impulses form __to ___.
CNS
Involuntary organs and SMOOTH muscles of body
The ANS ( part of PNS )is further classified into -
Sympathetic neural system
Parasympathetic neural system
Visceral nervous system is a part of -
PNS
Visceral nervous system comprises the -
whole complex of nerves , fibres , ganglia , and plexuses by which impulses travel from the CNS to the viscera and from the viscera to the CNS .
A neuron is a microscopic structure composed of __ parts . Name .
3 major parts
Cell body
Dendrites
Axon
The cell body contains __with typical ___and certain ____.
Cytoplasm
Cell organelles
Granular bodies -called NISSL’S GRANULES
Short fibres which branch repeatedly and reject out of the cell body are called __and also contain ___.
Dendrites
NISSL’S granules
NISSL’S granules are present where ?
Cell body
Dendrites
The dendrites transmit impulses ___the cell body .
Towards
The axon is a long fibre , the _____ end of which is branched .
Distal
Each branch of axon terminates as a __like structure called __.
Bulb-like
Synaptic knob
__possess synaptic vesicles containing chemicals called neurotransmitters .
Synaptic knob
Neurotransmitter are contained within -
Synaptic vesicles
The __transmits nerve impulses away from the cell body .
Axon
The axon transmits nerve impulses to a _or ____.
Synapse
Neuromuscular junction
Neurons are divided into how many types ? And on what basis ?
3
On the basis of number of axons and dendrites
3 types of neurons ?
Multipolar- 1 axon , 2 or more dendrites
Bipolar- 1 axon , 1 dendrite
Unipolar- 1 axon only
Multipolar neuron is found in the _____.
Cerebral cortex
Bipolar neuron is found in the ___.
Retina of eye
Unipolar neuron is found where ?
Embryonic stage
Unipolar neuron has a cell body with __only .
1 axon
There are __types of axons . Name
2
Myelinated
Non-myelinated
The myelinated nerve fibres are enveloped with -
Schwann cells
Schwann cells form a _around _____.
Myelin sheath
Axon
The gaps between 2 adjacent ____ are called Nodes of Ranvier .
Myelin sheaths
Myelinated nerve fibres are found in the -
Spinal and cranial nerves
Unmyelinated nerve fibres are enclosed by a Schwann cell . T/F
T
__are enclosed by a Schwann cell that does not form a myelin sheath around the axon .
Unmyelinated nerve fibres
Unmyelinated nerve fibres are commonly found in -
Autonomic neural system ( ANS = sympathetic + parasympathetic )
Somatic neural systems
( both are a part of PNS )
Neurons are ___cell because -
Excitable cells
Becoz their membranes are in a polarised state
Why the membrane of a neuron is polarised ?
Becoz diff types of ion channels are present on the neural membrane , and these ion channels are selectively permeable to diff ions
When the neuron is not conducting any impulse i.e., RESTING , the ______membrane is permeable to Na and K .
Axonal
In the resting stage , the AXONAL membrane is comparatively more permeable to ____an nearly IMPERMEABLE TO _____.
K+
Na+
The axonal membrane is also IMPERMEABLE to _____present in the AXOPLASM .
Negatively charged proteins
The axoplasm inside the AXON (in the resting stage ) contains high conc of _____and _____ and LOW conc of ___.
K+
Negatively charged proteins
Na+
In the resting stage , the axonal membrane is impermeable to -
-vely charged proteins present in the axoplasm (- meaning - they cannot move out of the axon )
Na+ - cannot move in
In contrast , the fliud outside the axon contains a high conc of ___and a low conc of ____
Na+
K+
The low conc of K+ and high conc of Na+ outside forms a -
Conc gradient
The ionic gradients across te resting membrane are maintained by the ___ of ions by the ____.
Active transport
Na-K pump
The Na-K pump transports _Na+ ___ for__K+ ____.
3
Outwards
2
Inwards
As a result of the Na-K pump , the outer surface of he axonal membrane possess a __charge while its inner surface becomes __charged .
+ve
-ve
As a result of the Na -K pump when the outer side is + and inner -ve , the membrane is said to be -
Polarised
The electrical potential difference across the resting plasma membrane is called -
Resting potential
When a stimulus is applied at a site on the polarised membrane , what happens ?
1) The membrane at that site becomes FREELY PERMEABLE to Na+.
2) this causes rapid influx of Na +
3) reversal of polarity at that site
When a stimulus is applied at a site , the outer surface of the membrane at that site becomes ___charged and the inner membrane becomes ___charged .
-ve
+ve
When the polarity of the membrane is reversed , after applying stimulus , it is called -
Depolarised
The ELECTRIC POTENTIAL DIFFERENCE across the plasma membrane at the site of application of stimulus (site of depolarisation ) is called -
Action potential
The action potential is in fact termed as _____.
Nerve impulse
At the sites immediately ahead ( of the depolarised site) , the axon membrane has a ____charge on the outer surface and a __charge on the inner surface . As a result a current flows on the _____surface from ___site to __site .
+ve
-ve
Inner
Depolarised site ————> to polarised site , site immediately ahead
(+ve). (-ve)
(Becoz current flows from +ve to -ve )
On the outer surface o the membrane the current flows from ___ to __ to complete the circuit .
Polarised (+ve -outside) to ——> depolarised ( -`ve outside )
The ___generated at the DEPOLARISED site arrives at the POLARISED SITE . Due to circiut completion
Impulse
The rise in the stimulus -induced permeability to ___ is extremely ___ . It is quickly followed by _______.
Na+
Short-lived
Rise in permeability to K+
In a fraction of a second , ___diffuses ___the membrane and restores the ____potential of the membrane at the site of excitation and the fibres become once more responsive for ______.
K+
Outside
Resting
Further stimulation
A nerve impulse is transmitted from one neuron to another through ___.
Junctions called synapses
A synapse is formed by the _____.
MEMBRANES of a pre-synaptic neuron and a post-synaptic neuron
The pre- and post -synaptic membranes May or May not be separated by a __.
Gap called SYNAPTIC CLEFT
There are _types of synapses .name -
2
Chemical
Electrical
At ___synapses , the membranes of pre- and post - synaptic neurons are in close proximity .
Electrical
_____can flow directly from one neuron to another .
Electrical current ( through electric synapse = no space in btw )
Transmission of an impulse across electrical synapses is very similar to -
Impulse conduction along a SINGLE NEURON
Impulse transmission across a __is always faster than that across a ____.
Electrical synapse
Chemical synapse
_____synapses are rare in our body systems .
Electrical
At a _____ synapse , the membranes of the pre and post- synaptic neurons are separated .
Chemical
At the chemical synapse , the the membranes of the 2 neurons are separated by a _____
Fluid -filled space -called SYNAPTIC CLEFT
__are involved in the transmission of impulses from the pre to the post synaptic neuron in chemical synapses .
Neurotransmitters
The ___contains vesicles filled with neurotransmitters .
Axon terminals
When an impulse ( action potential ) arrives at the axon terminal , it stimulates the _____.
Movement of synaptic vesicles towards the membrane (pre-synaptic membrane )
Describe the various processes through which pre -synaptic neurons transmit action potential acros synaptic cleft to the post -synaptic neuron .
1) When an impulse arrives at the axon terminal , it stimulates the movement of synaptic vesicles towards the pre-synaptic membrane .
2) these vesicles then fuse with the plasma membrane
3) now they release their neurotransmitter into the synaptic cleft
4) the released neurotransmitters bind to their specific RECEPTORS , present on the post-synaptic membrane .
5) this binding opens ion -channels allowing the entry of ions which can generate anew potential in the post-synaptic neuron .
The new potential developed in the post-synaptic neuron may be __or ____.
Excitatory
Inhibitory
The released neurotransmitters bind to ____present in the post-synaptic membrane .
Specific receptors
The brain acts as the -
Command and control system
Functions of brain -
controls
1) the voluntary movements
2) balance of body
3) functioning of vital involuntary organs ( lung,heart,kidneys)
4) thermoregulation
5) Hunger and thirst
6) CIRCADIAN rhythms of our body
7) Activities of several endocrine glands
8) Human behaviour
9) site for processing of vision , hearing , speech , memory , intelligence , emotions ,thoughts
Inside the SKULL the brain is covered by___.
Cranial meninges
The cranial meninges is composed of how many layers ? Name
3
Outer- dura mater
Middle , very thin- arachnoid
Inner -piamater
The __layer of meninges is in contact with the BRAIN TISSUE .
Piamater ( innermost)
The __layer of meninges is very thin .
Arachnoid -middle
The brain can be divided into __major parts . Name
3
Forebrain
Midbrain
Hindbrain
The forebrain consists of -
3
Cerebrum
Thalamus
Hypothalamus
___forms the major part of the brain .
Cerebrum
A dep cleft divides the cerebrum ____ into 2 halves , which are termed as the right and left CEREBRAL HEMISPHERES .
Longitudinally
The 2 cerebral hemispheres are connected by a tract of ____called ____.
Nerve fibres
Corpus callosum
The layer of cells which covers the cerebral hemispheres is called -
Cerebral cortex
The cerebral cortex is thrown into __.
Prominent folds-gyri and sulci
The cerebral cortex is referred to as __matter due to its ___appearance .
Grey
Greyish
The ___are concentrated in the cerebral CORTEX giving it the ____colour .
Neuron CELL BODIES
Grey
The cerebral cortex contains ____ and __Areas and LARGE regions that are _______.
Sensory areas
Motor areas
Neither clearly sensory or motor
The LARGE regions in the cerebral CORTEX which are neither clearly sensory nor motor are called -
Association areas
TheASSOCIATION areas are responsible for -
Complex functions like -
Inter sensory associations
Memory
Communication
Where are association areas located ?
In the cerebral CORTEX -grey matter
The nerve fibres ( of corpuscallosum ) which connect te hemispheres are covered with _____ ,which constitutes the ______.
Myelin sheath
Inner part of cerebral hemisphere -medulla
The cerebral medulla is __in colour and contains __part of the neurons .
White
Axon
What gives the inner layer (cerebral medulla ) an opaque white appearance ?
The fibres of the tract are covered with MYELIN SHEATH becoz the axon part of neuron is found here .
The CEREBRUM wraps around a structure called -
Thalamus
Thalamus is a major ______ centre for __and _____.
Coordinating
Sensory signaling
Motor signaling
Location of hypothalamus -
At the base of thalamus
The hypothalamus contains a number of centres which control __and ___.
Body temp
Urge for eating and drinking
The hypothalamus contains a number of ___cells .
Neurosecretory cells
What do neurosecretory cells secrete and where are they located ?
They secrete hormones called -HYPOTHALAMIC hormones
Location -hypothalamus
Which parts of the brain form the LIMBIC system /LYMBIC lobe ?
Inner parts of cerebral hemispheres + group of associated deep structures ( AMYGDALA and HIPPOCAMPUS )
____along with _____is involved in the regulation of sexual behaviour , expression of emotional reactions and motivation .
LIMBIC lobe / LIMBIC system
Hypothalamus
Function of LIMBIC lobe -
Along with hypothalamus , it is involved in the
1) regulation of sexual behaviour
2) expression of emotional reactions ( excitement ,pleasure ,rage and fear )
3) motivation
The midbrain is located between __and ___.
Thalamus /hypothalamus of FOREBRAIN
Pons of HINDBRAIN
A ___ called ____passes through the midbrain .
Canal
Cerebral aqueduct
The __portion of midbrain consists of 4 round swellings .
Dorsal
The dorsal portion of midbrain consists of -
Corpora qadrigemina (4 round swellings /lobes)
Te hindbrain comprises -
Pons
Cerebellum
Medulla oblongata
___consists of fibre tracts that interconnect diff regions of brain .
Pons
____has very convoluted surfaces in order to provide additional pace for many more NEURONS .
Cerebellum
The _____of the brain is connected to the SPINAL CORD .
Medulla
The medulla contains centres which control -
Respiration
Cardiovascular reflexes
Gastric secretions
_____major regions make up the BRAIN STEM . Name -
3
Mid-brain
Pons
Medulla oblongata
_____forms the connections btw brain and spinal cord .
Brain stem
Tree -like structure -arbour vitae is present in -
Cerebellum - becoz of extreme convolutions
Function of brain stem -
Connects brain and spinal cord
The entire process of response to touching a hot object ,etc, to a _____stimulation occurs involuntarily .
Peripheral nervous system
The process that occurs without any conscious effort or thought and requires the involvement of a part of the CNS is called -
Reflex action
The reflex pathway comprises at least _____and ______ appropriately arranged in a series .
1 afferent neuron (receptor )
1 efferent neuron ( effector /excitor )
The afferent neuron ( in a reflex pathway ) receives signals from a ____and transmits the impulse via a ________into the _____.
Sensory organ
Dorsal nerve root
CNS( at the level of spinal cord )
Dorsal root ganglia is involved in -
Afferent pathway of reflex arc
Transmits impulse from afferent neuron to the CNS (only spinal cord)
The part of CNS involved in REFLEX ACTION is -
Spinal cord ( only ) (Brain not involved )
The efferent neuron carries signals from __to the ____.
CNS
Effector
The stimulus and response forms a reflex arc . Example-
Knee jerk reflex
In the reflex arc , the effector can be a -
Motor end plate
What is interneuron ?
Central nodes of neural circuits enabling communication btw SENSORY and MOTOR NEURONS and the CNS .they play a vital role in reflexes .
The sensory organs can detect all types of changes in the environment and sent appropriate signals to the _____ . Signals are then sent to diff parts/centres of the brain .
CNS
The nose contains ____receptors which are specialised for receiving the sense of smell and called _____.
Mucus -coated
Olfactory receptors
the olfactory receptors are made up of ___that consists of ____kinds of cels .
Olfactory epithelium
3
The neurons of the olfactory epithelium extend from the outside environment directly into _____ called _____.
A pair of BROAD BEAN—SIZED organs
Olfactory BULB
The olfactory bulbs are the extensions of the _____.
Brain’s LIMBIC system
Both __and ____detect DISSOLVED CHEMICALS .
Nose
Tongue
The chemical senses of ___and __ are functionally similar and interrelated .
Guttation (taste )
Olfactory (smell)
The tongue detects taste through ___containing ______.
Taste buds
Gustatory receptors
The olfactory epithelium extends from the outside environment directly into a pair of broad bean -sized a organs ,called ____, which are extensions of the ______.
Olfactory bulb
Brain’s LIMBIC system
Our paired eyes are located in sockets of the skull called -
Orbits
The adult human eye is nearly a ____structure .
Spherical
The wall of the eye is compose of _____layers . Name -
3
Sclera -outer
Choroid -middle
Retina- inner
The external layer of eye is composed of ____tissue and is called the ____.
Dense connective tissue
Sclera
The middle layer of the eye , choroid , contains _____and looks ___in colour .
Many blood vessels
Bluish
In which part of eyeball ,is the CHOROID layer thin and thick ?
Thin -over the posterior 2/3rds of the eyeball
Thick - anterior part
The choroid layer becomes _____in the anterior part to form the ____.
Thick
Ciliary body
The ___itself continues forward to form the IRIS .
Ciliary body( extension of choroid )
The iris is a ____and ____structure .
Pigmented
Opaque
The visible coloured portion of the eye is -
Iris
The eyeball contains a transparent crystalline LEN which is held in place by _____ .
LIGAMENTS ( suspensions ligaments -attached to CILIARY BODY )
The CILIARY BODY continues to form what all ?
1) it itself continues to form -IRIS
2) forms ligaments ( which hold the lens in place )
In front of the ____ , the aperture surrounded by iris is called the ____.
Lens
Pupil
The DIAMETER of the PUPIL is regulated by the ______.
Muscle fibres of iris
becoz iris surrounds pupil
The inner layer is RETINA and i contains __layers of _____.
3
Neural cells
Name the 3 layers of NEURAL CELLS in the retina -
Innermost -GANGLION cells
Middle -BIPOLAR cells
Outermost -PHOTORECEPTOR cells
There are ____types of photoreceptors , namely ____and ____ .
2
Rods
Cones
The __cells contains the LIGHT -SENSITIVE PROTEINS called ____.
PHOTORECEPTOR cells ( rods and cones ) Photopigments
The ____and __visions are functions of cones .
Daylight (photopic ) vision
Colour vision
The __vision is the function of the RODs .
Twilight ( scotopic )
The rods contain a ____protein called the _____.
Purplish-red
RHODOPSIN
____ is also called visual purple and contains a derivative of _____.
Rhodopsin
Vit a
In the human eye , there are ___types of cones .
3
The cones possess their own characteristic photopigments that respond to __, __and __lights .
Red
Green
Blue
The sensation of diff colours are produced by various combinations of _____.
Cones and their photopigments
When all the types of cones ( red ,green, blue ) are stimulated equally , sensation of ___is produced .
White light
The OPTIC nerves leave the eye and the ______enter it at a point medial to and slightly above the posterior pole of the eyeball .
Retinal blood vessels
______are not present in the blind spot .
PHOTORECEPTOR cells
Location of blind spot -
A point medial to and slightly above the posterior pole of the eyeball .
Where the optic nerves leave te eye and retinal blood vessels enter it .
At the posterior pole of the eye lateral to the blind spot , there is _____ with a ______.
A yellowish pigmented spot called -MACULA LUTEA
Central pit - FOVEA
The __isa. Thinned out portion of the retina where only cones are ____.
Fovea ( fovea centralis )
Densely paced
The point where the visual acuity ( resolution ) is the greatest -
Fovea (fovea centralis )- thinned out portion of retina (central pit of te macula lutea )
Location of macula lutea (yellowish pigmented spot )-
At the posterior pole of the eye , lateral to the blind spot .
The space btw __and __is called AQUEOUS CHAMBER .
Cornea
Lens
The space btw ____and ____is called VITREOUS chamber .
Lens
Retina
The space btw the cornea and lens contains _____fluid called ____.
Thin watery
Aqueous humor
The space btw the lens and retina is filled with ____ called_____.
Transparent gel
Vitreous humor
The light rays in the visible wavelength focused on the retina through the ____and _____ generate potentials ( IMPULSES) in __and ____ .
Cornea
Lens
Rods
Cones
The photosensitive compounds ( photopigments ) in the eye are composed of __and _____.
Opsin
Retinal
Opsin is a ______.
Protein
Photopigment of cones
( similar to rhodopsin of rods )
Retinal is a _____.
An aldehyde of vit A
Difference btw rhodopsin and retinal -
Rhodopsin - protein in the rods ( photopigment )
Retinal - an aldehyde of vit A which is contained in rhodopsin
RHODOPSIN photopigment CONTAINS RETINAL
Light induces dissociation of the ____ from ______ .
Retinal
Opsin
Light induces dissociation of the retinal from opsin resulting in -
Changes in the structure of OPSIN
What produces a signal that generates action potentials in the ganglion cells through the bipolar cells ?
Or describe the mechanism of vision -
1) light induces dissociation of retinal from opsin resulting in changes in the structure of opsin .
2) this causes membrane permeability changes
3) as a result , potential diff are generated in the PHOTORECEPTOR cells .
4) this produces a signal that generates action potentials in the GANGLION CELLS through the BIPOLAR cells .
The action potentials generated in the ____through ____ are transmitted by the _____ to the ____of the brain .
Ganglion cells
Bipolar cells
Optic nerve
Visual CORTEX
In which region are the neural impulses analysed and the image formed on the retina is recognised based on earlier memory and experience .
Visual cortex of brain
What is the arrangement of white and grey matter in the spinal cord ?
Opposite to that in the brain
White matter - outside ( axons - myelin sheath -white)
Grey matter -centre - ( cell body and dendrites - NISSL’S granules -grey )
The ears perform ____sensory functions . Name -
2
Hearing
Maintenance of body balance
Anatomically , thee ear can be divided into _______ major sections .
3
Outer ear
Middle ear
Inner ear
The outer ear consists of -
Pinna
External auditory Meatus ( canal)
The __collects the vibrations in the air which produce sound .
Pinna
The external auditory Meatus leads ____and extends up to the ____.
Inwards TYMPANIC MEMBRANE ( the eardrum )
There are ___ and _____ in the skin of PINNA and the MEATUS .
Very fine hairs
Wax secreting glands
The tympanic membrane (eardrum) is composed of ___tissues .
Connective
The tympanic membrane is covered with _____outside and _____inside .
Skin
Mucus membrane
The ____ ear contains 3 ossicles attached to one another in a ____ fashion .
Middle
Chain-like
Which ear ossicle is attached to the tympanic membrane ?
Malleus
The stapes is attached to the __ window of _____ .
Oval
Cochlea
Function of ear ossicles -
Inc the efficiency of transmission of sound waves to the inner ear .
An eustachean tube connects _____with the __.
Middle ear
Pharynx
__helps in equalising the pressure on either side of EARDRUM .
Eustacean tube
The inner ear is __filled is called _____ and consists of ___parts
Fluid
Labyrinth
2 - bony labyrinth , membranous labyrinth
The ___ labyrinth ( inner ear ) is a series of CHANNELS .
Bony
Inside the chambers of bony labyrinth lies ___which is surrounded by ___.
Membranous
Perilymph -fluid
__is filled with endolymph .
Membranous labyrinth ( it lies inside bony )
The coiled portion of labyrinth is called -
Cochlea
Which membranes divide the surrounding perilymph filled bony labyrinth into Scala vestibule and Scala tympani ?
The membranes constituting COCHLEA -
1) reissner’s membrane
2) basilar membrane
The space within cochlea called _____is filled with endolymph .
Scala media
What are the 3 divisions of cochlea ?
Scala - vestibuli -upper
Scala media - middle
Scala tympani -lower
The Scala vestibuli ends at the ___ .
Oval window ( where stapes ends )
Scala tympani terminates at the _____which opens to the _____.
Round window
Middle ear
(It is the lower part )
Where is Scala vestibuli located ?
At the base of the cochlea . It is the upper part
It ends at the oval window
The membranes inside the cochlea , the reissner’s and basilar divide the ______filled _____ into ____and ______.
Surrounding perilymph
Bony labyrinth
Upper scala vestibuli
Lower scala tympani
The _____is the structure located on the basilar membrane .
Organ of corti
The organ of corti contains _____ that act as _____.
Hair cells
Auditory receptors
The hair cells are present in rows on the ___side of the ____ .
Internal side
Organ of corti
The __end of the hair cells is in close contact with the _____.
Basal end
Afferent nerve fibres
A large number of processes called _____are projected from the __part of each hair cell .
Stereo cilia
Apical part
Above the rows of hair cells ( on the organ of corti )is a __membrane called _____.
Thin elastic membrane
Tectorial membrane
Describe the hair cells present on the inner side of ORGAN OF CORTI -
Basal end of hair cells - in contact with afferent nerve fibres
apical end - process called stereo cilia project from the apical end
Above the hair cells - tectorial membrane is present
Where is the vestibular apparatus located ?
Above the cochlea
The vestibular apparatus is composed of _____and _____.
3 semicircular canals
Otolith -( saccule and utricle )
______is the sensory part of saccule and utricle .
Macula
Each semicircular canal lies in a ___plane at ____to each other .
Different
Right angles
The ___are suspended in the perilymph of the _____ . ( in semicircular canals )
Membranous canals
Bony canals
The base of the semicircular canals is __and is called __.
Swollen
Ampulla
The ampulla contains a PROJECTING RIDGE called _____which has ____cells .
Crista ampullaris
Hair cells
The crista ampullaris has hair cells
The _and ____contain a projecting ridge called macula .
Saccule
Utricle
The __and _____are the specific receptors of the vestibular apparatus .
CRISTA(ampullaris)-(at the base of semicircular canal of vestibule)
MACULA -(part of otolith of vestibule)
What are crista and macula responsible for ?
Maintenance of balance of body and posture
How does the ear convert sound waves into neural signals which are processed by the brain ?
1) the external ear receives sound waves and directs them to eardrum
2) eardrum vibrates and these vibrations are transmitted to ear ossicles
3) the vibrations are passed through oval window onto fluid of cochlea
4) the vibrations generate waves in the lymph of cochlea .
5) the waves in lymph induce a RIPPLE in the BASILAR membrane
6) the movement of basilar membrane bend the hair cells , pressing them against the tectorial membrane .
7) nerve impulses are generated in the associated AFFERENT neurons
8) these impulses are transmitted by the afferent fibres to the AUDITORY CORTEX of the brain via auditory nerves
9) in the auditory cortex , impulses are analysed and sound recognised .
The inner ear is composed of -
2 parts -
1) cochlea
2) vestibular apparatus -semicircular canals + otolith
( whole of inner ear is divided into bony and membranous labyrinth )
The resting membrane potential =
The depolarised potential =
-60 to -75 mV
30 to 40 mV
