XI Chap 21 Neural Control & Coordination Flashcards
________________ is the process through which 2 or more organs interact and complement the functions of one another
Coordination
Physical exercises is an example of coordination. T or F?
True
Functions of muscles, lungs, heart, blood vessels, kidney and other organs are coordinated while performing physical activity. T or F?
True
The __________ system and the __________ system jointly coordinate and integrate all activities of the organs.
neural, endocrine
Neural system provides an organised network of __________ for quick coordination
point-to-point connections
Endocrine system provides chemical integration through __________
hormones
Neural system of ALL animals is composed of neurons. T or F?
True
__________ are highly specialised cells which can detect, receive and transmit different kinds of stimuli.
Neurons
Neural organisation is very __________ (simple / complex) in lower invertebrates.
very simple
In Hydra, neural system is composed of __________
a network of neurons
Neural system is better organised in insects than lower invertebrates, where a __________ is present along with __________ and __________
brain, ganglia, neural tissues
Human neural system is divided into 2 parts:
CNS (central)
PNS (peripheral)
CNS includes the __________ and the __________
brain, spinal cord
CNS is the site of __________
information processing and control
PNS comprises of ALL the nerves in the body associated with CNS. T or F?
True
Nerve fibres of PNS are of 2 types:
afferent, efferent
Afferent vs efferent fibres
Afferent - impluses from tissues/organs to CNS
Efferent - regulatory impulses from CNS to peripheral tissues/organs
PNS is divided into 2 divisions:
somatic neural system
autonomic neural system
Somatic neural system vs Autonomic neural system?
Somatic - relays impulses from CNS to skeletal muscles
Autonomic - impulses from CNS to involuntary organs and smooth muscles
Autonomic neural system is further classified into:
sympathetic neural system
parasympathetic neural system
Visceral nervous system is part of __________ nervous system (central / peripheral)
peripheral
Visceral nervous system comprises of:
the whole complex of nerves, fibres, ganglia and plexuses by which impulses travel from CNS to viscera and from viscera to CNS
Neuron is a microscopic structure composed of 3 parts:
cell body, dendrites, axon
Cell body of neuron contains cytoplasm with __________ and certain granular bodies called __________
typical cell organelles, Nissl’s granules
Dendrites?
Short fibres
branch repeatedly
project out of cell body
also contain Nissl’s granules
Dendrite fibres transmit impulses towards the __________
cell body
Axon?
long fibre,
distal end of which is branched
Each axon terminates as a ____-like structure called __________ which posesses __________
bulb, synaptic knob, neurotransmitters
Neurotransmitters?
Synaptic vesicles containing chemicals at terminal end of axon
Axons transmit nerve impulses __________ (toward/away) from cell body
to a __________ or __________
away,
synapse,
neuro-muscular junction
Based on the number of axon and dendrites, neurons are divided into _____ (how many?) types. They are:
3;
multipolar - 1 axon, >=2 dendrites - found in cerebral cortex
bipolar - 1 axon, 1 dendrite - found in retina of eye
unipolar - 1 axon only - found in embryonic stage
There are 2 types of axons:
Explain
myelinated - enveloped which Schwann cells which form a myelin sheath
Non-myelinated - enclosed by Schwann cell that does NOT form a myelin sheath
Gaps between 2 adjacent myelin sheaths are called __________
nodes of Ranvier
Myelinated nerve fibres are found in __________ and __________ nerves
spinal, cranial
Unmyelinated nerve fibres are commonly found in __________ and __________
autonomous and somatic neural systems
Neurons are excitable cells because __________
their membranes are in a polarised state
Different types of ion channels are present on the neural membrane that are selectively permeable to different ions. T or F?
True
When a neuron is not conducting any impulse it is __________
resting
Axonal membrane of neuron is more permeable to __________ ions and nearly impermeable to __________ ions
K+, Na+
Axonal membrane is impermeable to __________
negatively charged proteins present in the axoplasm
The axoplasm inside the axon contains high concentration of __________ and low concentration of __________
high - K+, negatively charged proteins
low - Na+
The fluid outside the axon contains high concentration of __________ and low concentration of __________
high - Na+
low - K+
The ionic gradients across the resting axonal membrane are maintained by __________
active transport of ions / sodium - potassium pump
Sodium-potassium pump transports __________ outwards for __________ into the cell
3 Na+
2K+
Outer surface of the membrane possesses a __________ charge while the inner surface possesses a __________ charge and therefore is polarised.
positive, negative
What is resting potential?
Electrical potential difference across the resting plasma membrane of axon
When a stimulus is applied at a site A, it becomes freely permeable to ______ which leads to a rapid influx of _____
Na+, Na+
With influx of Na+ polarity at site on an axon is reversed i.e. outer surface is __________ charged and inner side becomes __________ charged
negatively, positively
When polarity of the axonal membrane is reversed it is known as __________
depolarised
Define action potential / nerve impulse
Electrical potential difference across the plasma membrane at site where stimulus is applied, Na+ influx and depolarisation occurs
At site of stimulus (say “A”), current flows on inner surface from __________ to __________ and on outer surface from __________ to __________
(say site immediately ahead is “B”)
inner: A to B
outer: B to A
Stimulus-induced permeability to Na+ is extremely __________ (permanent / short-lived)
short-lived
Stimulus-induced permeability to Na+ is quickly followed by rise in permeability to __________
K+
Within fraction of a second, K+ diffuses __________ (inside/outside) the membrane and restores the resting potential at the site of excitation
outside
A nerve impulse is transmitted from one neuron to another through junctions called __________
synapses
A synapse is formed by the membranes of __________ and __________
pre-synaptic neuron
post-synaptic neuron
Pre- and post-synaptic neurons are always separated by a gap called synaptic cleft. T or F?
False, may or may not be separated by synaptic cleft
What are the 2 types of synapses?
- electrical
2. chemical
Electrical vs. chemical synapse?
- Membranes of pre- and post are in very close proximity in electrical; separated by fluid-filled synaptic cleft in chemical
- current flows directly from one neuron to another (similar to impulse conduction along single axon); chemicals called neurotransmitters involved in impulse transmission
- electrical impulse transmission is faster than chemical
- electrical synapses are rare-r in our system than chemical
Axon terminals contain vesicles filled with __________
neurotransmitters
In a chemical synapse:
When an impulse arrives at axon terminal, it stimulates…
movement of synaptic vesicles towards membrane => vesicles fuse with plasma membrane => release neurotransmitters into synaptic cleft => neurotransmitters bind to specific receptors on post-synaptic membrane => ion channels open => generate new potential in post-synaptic neuron
New potential developed in a chemical synapse may be __________ or __________
excitory, inhibitory
__________ is the central information processing organ of our body and acts as the ‘command and control system’
brain
Brain controls:
voluntary movements, balance, functioning of vital involuntary organs (lungs/hearts/kidneys) thermoregulation hunger and thirst circadian (24-hour) rhythms, activities of several endocrine glands, human behaviour, processing of vision, hearing, speech, memory, intelligence, emotions and thoughts
Inside skull, brain is covered by __________
cranial meninges
Cranial meninges consist of 3 layers:
outer layer - dura mater
middle layer - arachnoid (very thin)
inner - pia mater (in contact with brain tissue)
Brain can be divided into 3 major parts:
forebrain,
midbrain,
hindbrain
Forebrain consists of __________ , __________ and __________
cerebrum, thalamus, hypothalamus
__________ forms the major part of the human brain
Cerebrum
A __________ divides the cerebrum longitudinally into 2 haves termed as __________ and __________
deep cleft, left and right cerebral hemispheres
The cerebral hemispheres are connected by a tract of nerve fibres called __________
corpus callosum
Layer of cells which covers the cerebral hemisphere is called __________ and is thrown into __________
cerebral cortex, prominent folds
Cerebral cortex is referred to as __________
grey matter (due to greyish appearance)
__________ are concentrated in the cerebral cortex giving it the grey colour
neuron cell bodies
Cerebral cortex contains __________, __________ and __________ areas
motor, sensory, association
What are association areas?
large regions
neither clearly sensory nor motor in function
responsible for complex functions like intersensory associations, memory and communication
Fibres of the tracts are covered with __________ which constitute the __________ part of the cerebral hemisphere
mylein sheath, inner
Fibres of tracts give an opaque white appearance to the cerebral layer and hence is called __________
white matter
Cerebrum wraps around a structure called __________
thalamus
Thalamus is a major coordinating centre for __________ and __________ signaling
sensory, motor
l
Hypothalamus contains several groups of neurosecretory cells, which secrete hormones called __________
hypothalamic hormones
Inner parts of the cerebral hemispheres and a group of associated deep structures (amygdala, hippocampus, etc) form a complex structure called __________ or __________
limbic lobe, limbic system
Along with hypothalamus, limbic lobe is involved in regulation of __________ , __________ and __________
sexual behavior, expression of emotional reactions, motivation
Midbrain is located between the __________ of the forebrain and the __________ of the hindbrain
hypothalamus/thalamus,
pons
A canal called __________ passes through the midbrain
cerebral aqueduct
Hindbrain comprises __________, __________ and __________
pons, cerebellum, medulla
Medulla is aka __________
medulla oblongata
Pons consists of __________ that interconnect different regions of the brain
fibre tracts
__________ has very convoluted surface in order to provide the additional space for many more neurons
Cerebellum
Medulla contains centres which control __________, __________ and __________
respiration, cardiovascular reflexes, gastric secretions
Define reflex action?
Entire process of response to a peripheral nervous stimulation;
occurs involuntarily;
requires involvement of a part of CNS
Reflex pathway comprises of:
At least one afferent neuron (receptor) One efferent (effector/excitor) appropriately arranged in a series
__________ neuron receives signal from a sensory organ and transmits the impulse via a __________ into the CNS
Afferent, dorsal nerve root
__________ neuron carries signals from CNS to effector
Efferent
__________ and __________ forms a reflex arc
Stimulus, response
Sensory organs detect all types of changes in the environment and send appropriate signals to the __________ where all inputs are processed and analysed
CNS
Nose contains __________-coated receptors which are specialised for receiving the sense of smell and called __________
mucus, olfactory receptors
Olfactory receptors are made up of __________ that consists of __________ (how many?) kinds of cells
olfactory epithelium, 3
Olfactory bulb is a pair of __________-sized organs which are extensions of the __________
broad bean,
brain’s limbic system
Both __________ and __________ detect dissolved chemicals
nose, tongue
Chemical sense of gustation (taste) and olfactory (smell) are functionally similar and interrelated. T or F?
True
Tongue detects tastes through __________
taste buds
Taste buds contain __________ receptors
gustatory
Wall of eye ball is composed of __________ (how many?) layers.
They’re called?
3
sclera (external), choroid (middle), retina (inner)
Sclera is composed of __________ tissue
dense connective
Anterior portion of the sclera layer is called __________
cornea
Middle layer, choroid, contains many __________ and looks __________ in color
blood vessels, bluish
__________ is the visible coloured portion of the eye
Iris
Eyeball contains a transparent, crystalline __________ which is held in place by __________
lens,
ligaments attached to the ciliary body
Diameter of the pupil is regulated by the __________
muscle fibres of the iris
Retina (inner layer) consists of __________ (how many?) layers of neural cells. They are?
3
from inside to outside:
ganglion cells, bipolar cells, photoreceptor cells
The two types of photoreceptor cells are __________ and __________
rods, cones
Photoreceptor cells contain __________ called photopigments
light-sensitive proteins
Daylight is aka __________ vision and twilight is known as __________ vision
photopic, scotopic
Phototopic and colour vision are the functions of __________ and scotopic vision is the function of __________
cones, rods
Rods contain a __________ protein called __________ or __________ which contains a derivative of Vitamin __________
purplish-red protein, rhodopsin, visual purple, A
There are 3 types of cones in human eye:
red, green, blue
When red, green and blue cones are stimulated equally, a sensation of __________ light is produced
white
__________ leave the eye and the __________ enter it at a point medial to and slightly above the posterior pole of the eye ball.
Optic nerves, retinal blood vessels
Photoreceptor cells are not present in the region called the __________
blind spot
At the posterior pole of the eye, lateral to the blind spot, there is a yellowish pigmented spot called __________ with a central pit called the __________
macula lutea,
fovea
Fovea is a thinned-out portion of the retina where only the __________ are densely packed
cones
__________ is the point where the visual activity (resolution) is the greatest
Fovea
Space between cornea and the lens is __________
aqueous chamber
Aqueous chamber contains a thin, watery fluid called __________
aqueous humor
Space between the lens and retina is called the __________ chamber and is filled with a transparent gel called __________
vitreous chamber, vitreous humor
Vitreous humor vs. aqueous humor
Vitreous - transparent gel, between lens & retina
Aqueous - thin, watery, between cornea & lens
Light rays in visible wavelength focussed on the retina through the cornea and lens generate __________ in rods and cones
potentials (impulses)
Photosensitive compounds in the human eyes is composed of __________ and __________
opsin (a protein)
retinal (an aldehyde of vitamin A)
Light induces dissociation of the __________ from __________ resulting in changes in __________
retinal, opsin, structure of opsin
Changes in opsin causes __________ as a result of which potential differences are generated in photoreceptor cells
membrane permeability changes
The membrane permeability change and potential differences in photoreceptor cells produces a signal that generates action potentials in the __________ cells through the __________ cells
ganglion, bipolar
Action potentials (impulses) are transmitted by the __________ to the visual cortex area of the brain
optic nerves
The ears perform 2 sensory functions:
hearing,
maintenance of body balance
Ear can be divided into 3 major sections anatomically:
outer, middle, inner
Outer ear consists of __________ and __________
pinna, external auditory meatus(canal)
__________ collects the vibrations in the air which produce sound
Pinna
The external auditory meatus leads inwards and extends up to the __________
tympanic membrane (ear drum)
There are __________ and __________ in the skin of the pinna and meatus
very fine hairs,
wax-secreting glands
The tympanic membrane is composed of __________ tissues covered with __________ outside and with __________ inside
connective, skin, mucus membrane
Middle ear contains three __________ called __________, __________ and __________
ossicles, malleus, incus, stapes
Malleus, incus and pinna are attached to one another in a chain-like fashion. T or F?
False,
malleus, incus and stapes - middle ear ossicles
Malleus is attached to the __________ and the stapes is attached to the __________
tympanic membrane,
oval window of the coclea
Ear ossicles increase the efficiency of …
transmission of sound waves to the inner waves
A __________ connects the middle ear cavity with the pharynx
Eustachian tube
An Eustachian tube helps in __________
equalising the pressures on either sides of the ear drum
Fluid-filled inner ear called __________ consists of two parts: __________ and __________
labyrinth, bony, membranous
__________ is a series of channels
Bony / membranous
Bony labyrinth
Inside the channels of the membrane labyrinth lies the bony labyrinth. T or F?
False, other way around
Membranous labyrinth is surrounded by a fluid called __________
perilymph
Membranous labyrinth is filled with a fluid called __________
endolymph
Coiled portion of the labyrinth is called __________
cochlea
The membranes constituting __________, __________ and __________ divide the surrounding perilymph filled bony labyrinth into __________ and __________
cochlea, the reissner’s, basilar
upper scala vestibuli
lower scala tympani
The space within cochlea is called __________ and is filled is __________
scala media, endolymph
At the base of the cochlea, the scala vestibuli ends at the __________ while the scala tympani terminates at the __________ which opens to the __________
oval window, round window, middle ear
What is the organ of corti?
structure located on the basilar membrane
contains hair cells as auditory receptors
Hair cells are present in the rows on the __________ side of the organ of corti
inner
The basal end of the hair cells of organ of corti are in close contact with the __________
afferent nerve fibres
A large number of processes called __________ are projected from the __________ part of each hair cell
stereo cilia, apical
Above the rows of the hair cells in the organ of corti is a thin elastic membrane called __________
tectorial membrane
Inner ear contains a complex system called __________ located above the cochlea
vestibular apparatus
Vestibular apparatus is composed of __________ and __________
3 semi-circular canals, otolith
Macula is the sensory part of the __________ and __________
saccule, utricle
Each semi-circular canal of the vestibular apparatus lies in the same plane at right angles to each other. T or F?
False, different planes
Membranous canals are suspended in the __________ of the bony canals.
perilymph
Base of the semi-circular canals is swollen and called __________
ampulla
Ampulla contains a projecting ridge called __________ which has __________ cells
crista ampullaris, hair
The saccule and utricle contain a projecting ridge called __________
macula
__________ and __________ are the specific receptors of the vestibular apparatus responsible for maintenance of balance of the body and posture
Crista, macula
The __________ receives sounds waves and directs them to the ear drum
external ear
The ear drum vibrates in response to sound waves and these vibrations are transmitted through the __________ to the __________
ear ossicles, oval window
Vibrations pass through the oval window on to the __________ where they generate waves in the __________
fluid of the cochlea, lymphs
The waves in the lymphs induce a ripple in the __________
basilar membrane
The ripple movements of the basilar membrane bend the __________, pressing them against the __________
hair cells, tectorial membrane
When hair cells press against the tectorial membrane, __________ are generated in the __________
nerve impulses, associated afferent neurons
Nerve impulses in the associated afferent neurons are transmitted by the afferent fibres via __________ to the __________ of the brain
auditory nerves, auditory cortex
__________ system coordinates and integrates functions as well as metabolic and homeostatic activities of all the organs
neural
The nerve impulse is conducted along the axon membrane in the form of a wave of __________ and __________
depolarisation, repolarisation
The __________ receives and integrates visual, tactile and auditory inputs
midbrain
The __________ integrates information received from the semicircular canals of the ear and the auditory system
cerebellum
Inside sclera is the middle layer, which is called the choroid. T or F?
True
__________ is influenced by gravity and movements, and helps us in maintaining balance of the body and posture
Vestibular apparatus
