Central and peripheral nervous system
how does meninges protect the CNS
3 layers of connective tissue forming membranes that cover the surface of brain and spinal cord
what are the structures that protect the central nervous system
Bone, meninges, cerebrospinal fluid
what is the function of the sensory (Afferent) division and what does it divide into and the function of those
Carries signals from nerve endings to the CNS. it has two types, Somatic Sensory: carries signals from skin, bones, joints and muscle, visceral sensory: carries signals from internal organs
Sensory Nerve
Carry impulses to CNS and only contains sensory neurons an example is the auditory nerve which carries information (sound and balance) from the ear into the CNS
Alzheimer's disease causes sysmtopms
Caused by brain cell death and symptoms include reduced ability to take in and remember new information, impairments to reasoning, complex tasking, and exercising judgment, impaired visuospatial abilities, impaired speaking, reading and writing and changes in personality and behavior
causes of Parkinson's disease
Caused by low and falling dopamine levels and dopamine-generating cells (dopaminergic neurons) have died
Mixed Nerve
Contains fibers that carry impulses away and to the CNS so it contain both sensory and motor neurons, an example is the vagus nerve which controls the muscle for voice
what is the effect of the sympathetic nervous system and parasympathetic on the heart and why
S: Increases rate and strength of contraction, in order to get more blood circulating to muscles in order to move better, P: decreases rate and strength of contraction to conserve energy
what is the effect of the sympathetic nervous system and parasympathetic on the blood vessels and why? in general
S: blood vessels in things involved in strenuous activity dilate (skeletal muscle, heart, liver, lungs), blood vessels not involved in fight or flight activity constrict (kidney, stomach, intestines and skin), P: little effect on blood vessels in skin or internal organs and no effect on blood vessels in skeletal muscle
what is the effect of the sympathetic nervous system and parasympathetic on the salivary gland and why?
S: decrease secretion of saliva, P: increase in production of saliva
what is the effect of the sympathetic nervous system and parasympathetic on the intestines and why?
S: decreases movement, in order to redirect blood flow and energy to muscles, P: increases movement
what is the effect of the sympathetic nervous system and parasympathetic on the iris and why?
S: dilate, P:constrict
what is the effect of the sympathetic nervous system and parasympathetic on the lungs and why?
S: dilates bronchioles, P: constricts bronchioles
what is the effect of the sympathetic nervous system and parasympathetic on the adrenal medual and why?
S: increase hormone secretion (adrenaline and noradrenaline which intensify and prolong fight or flight response), P: no effect
what is the effect of the sympathetic nervous system and parasympathetic on the liver and why?
S: increases breakdown of glycogen and release of glucose, to increase energy for action, P: increases uptake of glucose and synthesis glycogen
what is the effect of the sympathetic nervous system and parasympathetic on the sweat gland and why?
S: increases sweat secretion, P: no effect
what is the effect of the sympathetic nervous system and parasympathetic on the uniary bladder and why?
S: relax muscles wall, P: constricts muscle of wall
how does cerebrospinal fluid protect the CNS
Shock absorber
Cell replacement therapy and the nervous system
Stem cells are undifferentiated cells that can differentiate into specialized cells which makes them ideal for producing replacement tissues for damaged cells in the nervous system, In regard to Parkinson's disease they replace dying neurons with healthy neuronal tissue, In pilot studies embryonic stem cells are transplanted into damaged areas and survived and grew and established connections with adjacent neurons
what are the division in the autonomic motor/divisions
Sympathetic division: prepares the body for action (fight or flight), Parasympathetic division: has a calming effect (peace maker)
describe the foldings in the cerebrum
The foldings produces round ridges (convolutions or gyri/gyrus), the convolutions are separated by either shallow down folds: sulci or deep down folds: fissures
what does a interneurones do, where is it located and what else is it called :)
The link sensory and motor neurones, located in the CNS. also called connector, association or relay neurones
Components of a simple spinal reflex arc and how the work together
The receptor is the end of sensory neuron or specialized cells associated with the end of a sensory neutron, which reacts to changes in external or internal environment by initiating a nerve impulse in the sensory neutron which carries impulses from receptors to CNS. The impulse then reaches at least 1 synapse where it passes either to a mother connector neutron or/then to a motor neuron which carries nerve impulses to an effector (muscle cells or secretory cells) which receives impulses and carry out appropriate responses
composition and location of white
White matter is myelinated fibers and is in the inside of the brain and outside of spinal cord.
what is deep inside the cerebrum*
additional grey matter called basal ganglia
Functions of the medulla oblongata
automatically adjusts body systems through its centres, cardiac centre: regulates the rate and force of heart beat, respiratory centre: controls rate and depth of breathing, vasomotor centre: regulates diameter of blood vessels, other centres: regulate reflexes of swallowing, sneezing, coughing and vomiting. centresmare influenced and controlled by higher centres in the brain like the hypothalamus
how does CSF support nervous system
brain is suspended inside cranium and floats in the CSF
what are tracts
bundles of nerve fibres in CNS
how does CFS protect the nervous system
by acting as a shock absorber between middle and inner layers of the meninges
what is the function of the Motor (Efferent/) division and what does it divide into and the function of those
carries signals from CNS to rest of body, it has two divisions, Somatic motor/division: allows voluntary movements of skeletal muscles, Autonomic motor/division: pcontrols involuntary activities of smooth muscle, cardiac muscle and certain gland, it divide into the parasympathetic division which has a calming effect and the sympathetic division which arouses the body for action
Motor nerves
carry impulses away from the CNS, it only contains motor neurons, as example is the trochlear nerve which rotates the eyeball
what does a sensory neurone do and what else is it called :)
carry messages from receptors to the CNS. also called receptors neurones
what does a motor neurone do and what else is it called :)
carry messages from the CNS to muscles and glands. also called effector neurones
what does CSF look like
clear, watery fluid containing few cells, glucose, protein, urea, salts
Functions of the corpus callosum
communication between the two cerebral hemispheres
Endocrine system functions
consists of ductless glands that secrete hormones directly into blood stream that target a tissue and alter its functioning in someway
cell body
contains nucleus and organelles that control the functioning of the cell
what is the corpus callosum composition and function
contains white matter that joins the two cerebral hemispheres
what is the Autonomic Divisions function
controls involuntary activities of smooth muscle, cardiac muscle and certain glands. This includes regulates heart rate, blood pressure, body tempretuere, digestion, release of energy, pupil diameter, air flow to the lungs, defecation and urination
Functions of a nervous system
detects changes in external and internal environment, receptors detect stimuli in enviornment. conveys nerve impulses from receptors to brain. analyses sensory input from various receptors, stores information about previous sensory input, integrates information. conveys nerve impulse from the brain along motor neurons to effectors to bring about a response
Functions of the cerebellum
exercises control over posture, balance and fine coordination of voluntary muscle movement (DOES NOT INITIATE MOVEMENT), but without it our movements would be spasmodic, jerky and uncontrolled
what are the 5 sections of the cerebral hemisphere and what divides it
fissures and sulci subdivide each cerebral hemisphere into, frontal lobes, temporal lobes, occipital lobes, Parietal lobe and the insula which is deep inside the brain
neurilemma
found around mylin sheath and is formed out of schwann cells, it helps repair injured fibres, is only in PNS
node rainier
gaps which occur at intervals along myelin sheath
composition and location of grey matter
grey matter is nerve cell bodies and unmyelinated fibers and is in the outside of brain and inside of the spinal cord.
ganglia
group of nerve cell bodies outside the brain or spianl cord, singular ganglion
ganglia
groups of nerve cells bodies
Functions of the hypothalamus
homeostasis, maintaining a constant environment for the cells, this includes, regulation of the autonomic nervous system, body temperature, food and water intake, patterns of waking and sleeping, concentration of the urinary bladder, emotional responses and the secretion of hormones and coordination of the endocrine system which includes controling metabolism, growth, reproduction and response to stress
functions of myline sheath
insulator, protects axon, speeds up movement of nerve impulses along axon
Functions of the cerebrum
involved in mental activities such as thinking, reasoning, learning, memory, intelligence and sense of responsibility, concerned with perception of senses and initiates control of voluntary muscle contraction
unipolar neuron structure
it has one extension that is an axon, the cell body is to one side of the axon, most sensory neurons that carry messages to spinal cord are unipolar
Structure of the spinal cord
it is a cylindrical structure of nervous tissue containing white matter on the outside and grey on the inside. In the middle of the cord in the central canal which contains CSF.
what encloses the spinal cord
it is enclosed in the vertebral canal, and inside the ring of bone there are the three minge layers, between the last layer and the bone is containing fat, connective tissue and blood vessels
what is the cerebrum
it is the biggest part of the brain and contains both grey and white matter. it is folded
the cerebrum has two sides called the...
left and right cerebral hemisphere
axon
long extension of cytoplasm away
peripheral nervous system nerves
motor nerves, sensory nerves, mixed
what is the structure of motor and connector neurones :)
multipolar nerone
types of nerve structure
multipolar neuron, bipolar neuron, unipolar neuron
is the brain involved in spinal reflects
no ,but whilst response occurring, impulses travel up spinal cord to brain and only after the response does the person become consciously aware of the situation, due to the fast speed of reflex and longer time taken for brain to be made aware
please draw the three types of neurones
ok!
bipolar neuron structure
one axon and one dendrite, both axon and dendrite may have multiple branches at their ends, in eye ear nose where they take impulses from receptors to other neurons
multipolar neuron structure
one axon, multiple dendrites extending from cell body, most motor and connector neuron
Functions of the spinal cord
provide a pathway for communication between muscles and glands and the brain, swell as integration of automatic protective reflexes
why the brain can't be involved in simple spinal arc
reflex occurs very quickly because its a protective mechanism that makes sure our bodies react quickly to situations to minimize damage to the body, If we waited for our brains to become aware of the situation and then take action we would damage our bodies allowing them to be exposed to the danger too long
one job of the hypothalamus is to regulate the automatic nervous system, this involves...
regulation of heart beat, blood pressure, secretion of digestive juices, movements of the alimentary canal, diameter of the eye pupil
Three types of functioning areas in the cerebral cortex
sensory areas: which interpret impulses from receptors, motor areas: control muscular movements, association areas: concerned with intellectual and emotional processes
dendrites
short extensions of cytoplasm of a nerve cell carry nerve impulses towards cell body
Functions of the cerebrospinal fluid
support, protection, transport
how does CSF help the nervous system with transport
takes nutrients to the cells of the brain and spinal cord and carries their wastes away, it circulates through cavities in the brain and through a canal in the center of the spinal cord.
structural and functional difference between central nervous system and peripheral nervous system
the CNS is the control center, brain and spinal cord. The PNS is nerve fibers that carry information to and from the CNS.
how does bone protect the CNS
the brain is protected by the cranium and the spinal cord protected by the vertebrae Cerebrospinal fluid • Shock absorber, cushions blows to the CNS
what regulates the autonomic division
the hypothalamu and medulla oblongata and it usual operates without conscious control
what is the cerebral cortex
the outer part of the cerebrum, composes of grey matter that is 2-4mm thick and contains 70% of all the neurons in the CNS
what is the function of the fat, connective tissue and blood vessels around the spinal cord
to act as padding and allow cord to bend when spine is bent
why is the cerebral cortex folded
to increase surface area
Functions of the meninges
to protect the central nervous system, it is the membranes covering the brain and spinal cord, it has three layers of connective tissue
symptoms of parkinson's disease
tremors, slow movement, stiff and inflexible muscles, impaired posture and balance, gait problems, reduced facial expression, cognitive impairment, anxiety and depression, sleep difficulties, loss of sense of smell, constipation, voice becomes quieter, swallowing problems, writing problems and vision difficulties
what are the three types of tracts in the white matter
type one:connect areas of cortex within same hemisphere, type two: carry impulses between left and right hemisphere, type three: connect cortex to other parts of the brain or spinal cord
what is the structure of a sensory neurone :)
unipolar neurone
common Nervous and endocrine system :)
whether working together or independently they co-ordinate and control the activities of all the body's cells
what enables messages to travel up and down the spinal cord
white matter is arranged into tracts, ascending tracts: sensory axons that carry sensory impulses upwards, towards the brain, descending tracts: contain motor axons that conduct motor impulses downwards, away from the brain
what is below the cerebral cortex
white matter, within this this the basal ganglia, this is part of the cerebrum
what is Myelin sheath and what are the types
white, fatty sheath that surrounds some nerve fibres, produced by schwann cells, myelinated fibres: neve fibres with myelin sheath, unmyelinated fibres : without schwann cells only in PNS so only nerve in PNS can be mylinated
please draw or recall the structural and functional divisions of the nervous system :)
you have the peripheral nervous system and the central nervous system. the CNS divided into the brain and spinal cord. The PNS divides into the sensory (afferent) division and the motor (efferent) division. The sensory division divides into the somatic sensory and the visceral sensory. The motor division divides into the somatic motor and autonomic motor. The autonomic motor divides into sympathetic division and the parasympathetic division.