Chapter 8-The Nervous System Flashcards
What nervous system includes the brain and the spinal cord, which are both encased in bone for protection?
Central nervous system
What nervous system consists of the nerves that branch from the brain and spinal cord?
Peripheral nervous system
What is the principal organ of the nervous system?
Brain
What is a thick bundle of nerve fibers located within the spinal cavity?
Spinal cord
What are the 31 pair of nerves that transmit nerve signals to and from the rest of the body?
Spinal nerves
What are the 12 pair of nerves that branch directly from the brain stem and transmit nerve signals to and from the eyes, ears, mouth, face, and scalp?
Cranial nerves
The spinal cord and brain are covered by a triple layer of protective tissues known as the:
Meninges
A clear fluid called _________ circulates through the fibers of the arachnoid, serving to cushion the brain when you bump your head.
Cerebrospinal fluid
The brain and spinal cord are both made of two basic kinds of cells:
Glial cells
Neurons
What cell of the brain and spinal cord supports and insulates nerve tissue?
Glial cells
What cell of the brain and spinal cord are the actual nerve cells?
Neurons
The __________ of each neuron contains a nucleus and most of the nerve cell’s cytoplasm.
Cell body
What is a short, branched extension of the cell that receives nerve impulses from other neurons and conducts them toward the cell body?
Dendrite
What is a neuron’s long extension which relays nerve impulses from the cell body to other neurons?
Axon
What is found within the brain and spinal cord and consists of the cell bodies of neurons and is gray because the cell bodies lack myelin?
Gray matter
What is a white, specialized covering?
Myelin
The _______ of a brain and spinal cord is composed of axons and glial cells that are white because of their myelin content?
White matter
What is a mass of cell bodies?
Ganglion
Some ganglia are grouped together to form a large nerve mass called a:
Plexus
A group of cell bodies in the brain or spinal cord are known as a:
Nerve center
Neurons that transmit information to the central nervous system from the sense of sight, hearing, taste, touch, and smell, as well as those that transmit pain signals are known as:
Sensory neurons
Neurons that relay signals from the central nervous system to the other parts of the body are known as:
Motor neurons
What are only found in the central nervous system and relay signals between neurons or groups of neurons, and are responsible for the processing of information by the brain?
Interneurons
What are the tightly sealed capillary walls that protect the central nervous system from being permanently damaged every time you get sick?
Blood-brain barrier
What disease can occur when invading microorganisms enter the nerve tissue and infect the meninges?
Meningitis
In severe cases, the pressure on the brain impairs its functioning, causing the patient to become delirious or slip into a ________, a state of prolonged unconsciousness.
Coma
What serious disease that attacks the spinal cord is caused by a virus which enters the motor neurons of the spinal cord and destroys them?
Poliomyelitis
What nervous system consists of nerves?
Peripheral nervous system
What are bundles of nerve fibers branching from the brain and spinal cord and connecting the central nervous system to the extremities of the body?
Nerves
How many pairs of cranial nerves (branching directly from the brain) are there?
12
How many pairs of spinal nerves (connected to the brain by way of the spinal cord) are there?
31
Most nerves contain both sensory and motor fibers and thus are known as:
Mixed nerves
What carry impulses from light, taste, sound, touch, and pain from other parts of the body to the spinal cord and brain for analysis?
Sensory nerve fibers
What carry impulses from the brain and spinal cord to produce action in muscles and organs?
Motor nerve fibers
What is a biologist who studies the nervous system?
Neurobiologist
What is a bundle of axons branching from the brain and spinal cord and connecting the central nervous system to the extremities of the body?
Nerve
What is the part of the peripheral nervous system that controls the heart and other internal organs?
Autonomic nervous system
Each organ or gland must be turned on and off at specific times; what two parts of the autonomic nervous system are responsible for this and are controlled by the hypothalamus of the brain?
Sympathetic division
Parasympathetic division
The axons that extend from the nerve cell bodies in peripheral nerves are surrounded by special glial cells called:
Schwann cells
What is a disease of the brain and spinal cord and usually strikes adults, and occurs when the body’s immune system attacks the glial cells that provide myelin sheaths for nerve cell axons?
Multiple sclerosis
Permanent damage of multiple sclerosis leads to gradual __________, the inability of the muscles to move.
Paralysis
What is a wave of electrical activity that is propagated by fast-acting, voltage-sensing ion gates that quickly open and close, allowing sodium and potassium ions to briefly flow into and out of the cells?
Action potential
The axons of sensory neurons and Interneurons usually end at a ________, an enclosed junction between the axon of one neuron and the dendrites or cell body of another.
Synapse
When the action potential reaches the synapse, it causes a chemical known as a _________ to be released into the synapse.
Neurotransmitter
What serious disease of the nervous system affects the patient’s control of posture and movement and is characterized by tremors and the stiffness of the limbs?
Parkinson’s disease
What is a quick, automatic response, and is the simplest act of the nervous system?
Reflex
The simplest nerve pathway is a ________, which may involve as few as two or three nerve cells.
Reflex arc
What are the three main parts f the brain?
Cerebrum
Cerebellum
Brain stem
What is the largest part of the brain and is the physical organ that helps you in the areas of consciousness, memory, voluntary actions, thinking, and intelligence?
Cerebrum
The cerebrum consists of two halves called the:
Right hemisphere
Left hemisphere
The two hemispheres of the cerebrum communicate with each other through a mass of nerve fibers called the ________, located at the base of the cerebrum.
Corpus callosum
Much f the brain’s gray matter is located in the ________, the outer layer of the cerebrum.
Cerebral cortex
A physician who specializes in disorders of the nervous system is called a:
Neurologist
The convulsions of each of the cerebral hemispheres are divided by shallow grooves into various regions, __________, that correspond to the major bones of the cranium.
Lobes
What is the rear portion of the frontal lobe of the brain that controls the voluntary movement of the skeletal muscles?
Motor area
Damage to the cerebral motor area of the brain is known as:
Cerebral palsy
The two halves of the brain are split by the:
Longitudinal fissure
What are the four types of cerebral lobes?
Frontal lobes
Parietal lobes
Temporal lobes
Occipital lobes
What is the second largest brain region, lies behind the brain stem and just below the occipital lobe of the cerebrum, is divided into right and left hemispheres, and is highly convoluted?
Cerebellum
Most complex coordination is handled by the:
Cerebellum
What consists of the medulla oblongata, pons, and midbrain, and so located between the brain and spinal cord?
Brain stem
What is the lowest part of the brain stem, and contains nerve centers that monitor and regulate breathing, blood pressure, and other vital body functions?
Medulla oblongata
What part of the brain stem is located just above the medulla oblongata, and links the cerebrum with the cerebellum?
Pons
What part of the brain stem lies above the pons, and helps to coordinate the movements of both eyes, adjust the pupils in response to light, and operate the lens muscles to focus the eyes on the object of your attention?
Midbrain
What part of the brain is the “master switch” of the cerebrum, and is responsible for “switching on” the cerebral cortex to bring you to consciousness, and “shutting down” the cerebral cortex, causing you to sleep; and if it is damaged, a person would slip into a coma, and it also keeps your body balanced and upright when you aren’t moving?
Reticular formation
A number of complex brain structures lie clustered around the brain stem at the core of the brain, surrounded by the cerebrum; these structures collectively are referred to as the ________. This system is involved in coordinating the activity of the different parts of the brain and also seem important in generating and regulating emotions and desires.
Limbic system
What part of the brain that is a structure of the limbic system is at the uppermost end of the brain stem and acts as a switchboard, routing evacuation signals from the reticular formation and sensory impulses from various parts of the body to the appropriate areas of the cerebral cortex?
Thalamus
What part of the brain and limbic system is located just below the thalamus, and is the control unit for your body’s autonomic system, endocrine system, and is responsible for the physical effects of emotions?
Hypothalamus
Some biologists have suggested that the behavior of a person is determined by hi environment, not by his mind; what is this philosophy?
Behaviorism
The mind and the physical ______ are not the same.
Brain
Repeated or prolonged exposure to excessively loud sounds results in a form of partial or complete hearing loss known as:
Sensorineural deafness
What is a scientific measure of loudness?
Decibel
When a sleeper’s closed eyes show rapid eye movements as though he were watching the events of a dream, these periods are referred to as:
REM sleep
One of the most commonly abused drugs in the world today is:
Alcohol
What is a degeneration or inflammation of nerves?
Neuritis
What is condition characterized by pain in the lower back and the back of the thigh, and is caused by a pinching of the static nerve of the lower spinal cord?
Sciatica
The most common serious injury of the nervous system is _______, which is not caused by outside forces but by an internal blockage or rupture of a blood vessel in the brain; when this happens, certain brain areas are not supplied with blood, resulting in death.
Stroke
What is a period of paralysis of the central nervous system accompanied by a short period of unconsciousness?
Concussion
What is a loss of memory that could possibly result from a concussion?
Amnesia
What is a prolonged state of unconsciousness that may not be reversible, and can result from damage to the nervous system?
Coma
What disease is commonly known as lockjaw because severe spasms of the jaw muscles make it hard to open the mouth, and is caused by a type of bacterium that dwells naturally in the soil?
Tetanus
What is a mental disorder that is a disturbance of the brain caused by physical Illness elsewhere in the body?
Acute confusion
What mental disorder is the slow process of natural nerve cell loss that may become noticeable between the ages of 70 and 80?
Senile dementia
What mental disorder is caused by the death of brain cells because of a blockage in the arteries that restricts their blood supply?
Artiosclerotic dementia
What disease makes people become physically as well as intellectually disabled, forgetfulness, loss of coordination, and continuous repetition of a word or gesture are common; and eventually the loss of the ability to speak, write, and walk, and the loss of short-term and long-term memory?
Alzheimer’s disease
What is a common neurological disorder where neurons occasionally malfunction and begin to fire together over and over, disrupting ordinary cerebral processing and causing unconsciousness?
Epilepsy
Information from the outer world is obtained and relayed to the spinal cord or brain by living sensors known as:
Sensory receptors
Some neurons are designed to detect pressure or temperature changes, and are responsible for the __________, which include all the senses of your skin.
Somatic senses
What kind of sense includes sight, hearing, smell, taste, and balance, and is provided by a second group of neurons located in intricately designed sense organs?
Special senses
Special senses are provided by a second group of neurons located in intricately designed:
Sense organs
Each of the skin’s ____________ is a bare dendrite that reacts to a certain type of strong stimulus and some become activated when extremes of heat or cold cause your skin temperature to rise or fall to dangerous levels.
Pain receptors
The sensory receptors responsible for sensations of touch and pressure are __________; these receptors lie at different depths in the layers of your skin.
Mechanoreceptors
What kind of sensory receptors respond to temperature changes?
Thermoreceptors
What kind of receptors in your skin react to temperatures above normal body temperature?
Heat receptors
What kind of sensory receptors are sensitive to temperatures below normal body temperature?
Cold receptors
The senses of taste and smell are __________, which result from the stimulation of chemoreceptors on the tongue and in the nose.
Chemical senses
The chemical senses result from the stimulation of ________ on the tongue and in the nose.
Chemoreceptors
The organs responsible for the sense of taste are the ________, which are chemoreceptors on the back, sides, and front of the tongue that detect dissolved chemicals in the mouth.
Taste buds
Most flavors we taste are strongly affected by the _______, we smell.
Odors
The nose’s sensory receptors are located in the upper part of the nasal cavity and are connected to the brain by the:
Olfactory nerve
What is the taut membrane stretched across the canal of the ear like the surface of a drum, and the sound waves bounce against this, creating vibrations?
Eardrum
In the ear, the vibrations of the eardrum are relayed to the inner ear by means of three tiny bones called the:
Malleus
Incus
Stapes
The main component of the fluid-filled chamber in the ear is the _________, a coiled tube resembling a snail’s shell, and as the vibrations enter this, they create waves in the fluid, causing these nerves to wave.
Cochlea
The waving of the cells from the cochlea sends electrical messages into the __________, which carries them to the brain, where they are translated into meaningful sounds.
Auditory nerve
In the ear is an assembly of three, fluid-filled tubes called _________, which serve as balance receptors.
Semicircular canals
The inner ear receives vibrations from the jawbones; thus type of hearing is known as:
Bone conduction
Many people suffer from an ear condition known as _________, or ringing in the ears.
Tinnitus
Adults have some ten thousand taste buds, most of which are located in tiny projections called ________ on the tongue’s surface.
Papillae
What are a common problem among infants and children?
Ear infections
Ear infections occur when microbes from the throat travel up the _________ to the middle ear.
Eustachian tube
The eye, a very delicate organ, is protected from injury by what two things?
Socket
Eyelid
What is produced by lacrimal glands and are more than 90% water, and also contain electrolytes, which gives them the salty taste?
Tears
Tears are produced by tear glands, also known as ________, which are located under the upper eyelid on the side away from the nose.
Lacrimal glands
What are the set of six muscles attached to the eye that serve to move the eye?
Extrinsic muscles
What is the tough outer layer of tissue that provides protection and the supporting frame for the interior portion of the eye?
Sclera
What is the middle layer of the eye which includes the iris, the ciliary body, and the choroid?
Uvea
What is the innermost layer of the eye, and is itself composed of three main layers of cells?
Retina
What is the transparent portion of the eye that is the area through which light enters the eye?
Cornea
What is the largest portion of the uvea in the eye that is a layer of connective tissue rich in blood vessels, which provides most of the eye’s nourishment?
Choroid
The choroid becomes the _________, which is used to adjust the lens so that it will focus on objects at varying distances.
Ciliary body
The part of the uvea in front of the eye is the _________, which is a continuation of the ciliary body, and is the colored portion of the eye.
Iris
In the center of the iris in the eye is the ________, the opening through which light enters.
Pupil
What a the innermost layer of the eye, and is the delicate part of the eye and most important for vision, and with the choroid covers the rear 80% of the eye?
Retina
In the light-sensitive layer of the retina are two kinds f cells known as:
Rods
Cones
What is a small depression on the retina that is the area that produces the clearest vision?
Fovea
Processed signals are relayed to the visual centers of the brain via the ___________, which is a large bundle of individual nerves, each of which carries nerve impulses from a specific region of the retina to the brain.
Optic nerve
At the point on the retina where the optic nerve leaves the eyeball is a _________; at that point there are no light-sensitive cells to receive visual messages.
Blind spot
The substance in rod cells that absorbs light is called _________, which consists of a molecule derived from vitamin A yah is suspended in a protein framework.
Rhodopsin
The phenomenon where the image or picture of the object on the retina persists about a tenth of a second after the object is gone is called:
Persistence of vision
Between the cornea and the iris and lens is a space filled with a clear fluid called the ___________, which is produced from blood circulating in the ciliary body.
Aqueous humor
The part of the eye that focuses the rays of light which pass through it is called the:
Lens
The increase in the curvature of the lens to focus on nearby objects is called:
Accommodation
Between the lens and the rear of the eye is a space filled with _________, a transparent, jellylike substance that is about 98% water.
Vitreous humor
What condition results when the lens of the eye is in its relaxed state, and is too thick and convex to form a clear image on the retina, and is the ability to see only near objects clearly?
Nearsightedness
What is the condition where a person sees objects at a distance better than those that are nearby?
Farsightedness
What is eye focusing problem that usually results of an asymmetrically curved cornea, which causes light rays entering the eye to be bent incorrectly?
Astigmatism
When the eye’s lens become less elastic, it is difficult to focus on nearby objects; such a condition of farsightedness brought on by age is known as:
Presbyopia
People who cannot distinguish one or more of the primary colors of light are said to be:
Colorblind
What is the condition where some people’s eyes do not become adjusted to darkness, remaining almost totally blind in dimly lit places?
Night blindness
What is the condition in which the pressure of the fluid inside the eye becomes much higher than normal?
Glaucoma
