Unit 3 - Nervous & Endocrine Systems Flashcards
The nervous system controls these three types of cells via nerve impulses?
Neurons/ nerve cells
Muscle cells
Gland cells
The three major/general overlapping functions of the nervous system?
- Receives sensory input (uses sensory receptors to monitor changes (stimuli) in and outside the body)
- Integration (processes sensory input and makes “decisions” about what should be done)
- Sends out motor output (muscles respond by contracting and glands respond by secreting a chemical product (sweat, hormones, etc))
The major communication and controlling system of the body?
Nervous system
Nervous system vs. Endocrine system
- Means of communication and regulation?
- Transport of communication?
- Speed of communication?
- Duration of effects?
- NS: nerve impulses; ES: hormones
- NS: neurons/ nerve cells; ES: the blood
- NS: fast; ES: slow
- NS: short-lasting; ES: long-lasting
The two major divisions of the Nervous System?
Central nervous system (CNS)
Peripheral nervous system
(PNS)
CNS consists of?
Brain and spinal cord
PNS consists of?
Cranial nerves, spinal nerves and ganglia (clusters of cell bodies)
Divisions of the PNS?
Sensory/afferent division and Motor/efferent division
Sensory/afferent division of PNS consists of?
Neurons (in nerves) that convey impulses from sensory receptors to the CNS
The sensory/afferent division of the PNS includes these three sensory components?
General somatic sensory, special sensory, and visceral sensory
General somatic senses
Location?
Sensation?
Located throughout the body, mainly associated with receptors located in the skin and joint-related structures
Sensations include touch, pressure, pain, vibration, temperature, and proprioception
What is proprioception?
The sense of body position and movement that’s provided by receptors that detect stretch in joint-related structures (tendons, skeletal muscle, joint capsules)
Special senses
Location?
Sensation?
Located in the head
Sensations include vision, hearing, olfaction, and equilibrium (sense of balance related to receptors in the inner ear)
Visceral sensory?
Association?
Sensation?
Associated with internal organs
Sensations include pain, stretch (distension), nausea, and hunger
Motor/efferent division of PNS consists of?
Neurons (in nerves) that transmit impulses from the CNS to effectors (muscles and glands)
Two subdivisions of the motor/efferent division of PNS?
Somatic/voluntary motor and visceral/involuntary motor
Somatic motor/ voluntary nervous system provides for the stimulation of all ______?
Skeletal muscle (somatic effectors)
Visceral motor/ involuntary/ autonomic nervous system provides for the control of ______?
Cardiac muscle, smooth muscle, and glands (visceral effectors)
Subdivisions of the Involuntary/ autonomic/ visceral motor nervous system?
Parasympathetic division and sympathetic division
______ cells = _____ cells = Neuroglia
Supporting; Glial
Supporting cells
a. Support, _______ and protect neurons
b. Can or cannot produce nerve impulses?
c. More neurons or supporting cells in the body?
d. Can mitosis (cell division) occur?
a. Insulates
b. Cannot
c. Supporting cells
d. Yes (glial cells are capable of mitosis)
Found only in the CNS and they form myelin sheaths?
Oligodendrocytes
Found only in the CNS; the most abundant type of glial cell.
Help recycle ________, take up and release ____ to help maintain the proper _____ environment for for neurons, help form ______ between neurons, and may be involved with ______?
Astrocytes
Neurotransmitters; ions; ionic; synapses; memory
Found only in the PNS where they form myelin sheaths?
Schwann cells/ Neurolemmocytes
Electrical signals conducted by neurons are called _____ or ______?
Nerve impulses or action potentials
Neurons/ nerve cells
a. ______of neurons occur in the brain alone?
b. Lifespan of neurons?
c. Capable of mitosis?
d. Neurons cannot survive without _____?
a. Billions
b. Extreme longevity
c. Not capable of mitosis
d. Oxygen
Enlarged part of a neuron that contains the nucleus?
Cell body (soma)
The “receptive sites” of a neuron; receives signals from other neurons then conducts those signals toward the cell body?
Dendrites
Singular process of a neuron that transmits impulses away from the cell body and towards dendrites of another neuron?
Axon
A long axon is called?
Nerve fiber
These provide axons with structural support and aid in the transport of beneficial substances to and from the cell body (axonal transport)?
Microtubules
Some viruses can use axonal transport to move up and down the length of neurons, namely _____ and ______?
The rabies virus and the herpes zoster virus
Axons with larger diameters ___________ faster than those with smaller diameters?
Conduct impulses
When nerve impulses reach the axon terminals, they stimulate the release of __________ from _________ that are located within the terminals?
Neurotransmitters; synaptic vesicles
Junction where the axon terminals meet with another neuron?
Synapse
The neuron that transmits impulses toward the synapse?
Presynaptic neuron
The second neuron on the other side of the synaptic cleft that is controlled by the first neuron?
Postsynaptic neuron
Neuron-neuron synapse that occur between the axon terminals of the presynaptic neuron and the dendrites of the postsynaptic neuron is called a _________ synapse?
Axodendritic synapse
Synapses that occur between axon terminals of presynaptic neurons and cell bodies of postsynaptic neurons are called?
Axosomatic synapses
Many nerve fibers/ axons in the PNS and CNS are covered with a fatty, white, lipoprotein wrapping called ______?
Myelin sheath
Myelin insulates axons and thereby _______________ down their length?
Increases the speed of impulse conduction
Axons that have myelin sheaths conduct impulses __________ than those that do not?
More efficiently and much faster
An autoimmune disease that involves the gradual progressive destruction of myelin sheaths that surround the axons in the CNS?
Subsequently, the person may exhibit what problems?
Multiple sclerosis
Sensory and/or muscular problems
Can neurons go through mitosis?
They have no appreciable capacity for mitosis
Axon regeneration can only occur if the ______ of the injured neuron survives?
Cell body
Since no glial cells in the CNS can form regeneration tubes to guide axon sprouts, there is very little _____________ after injury to the spinal cord or brain?
Axonal regeneration
Structural classification is based on the _________ that extends directly from the cell body?
Number of processes (dendrites and axon)
The three structural types of neurons?
Unipolar, bipolar, and multipolar
Structurally, over 99% of neurons are ________ neurons?
Multipolar (many dendrites and one axon)
Functional classification of neurons is based on __________?
The direction nerve impulses travel relative to the CNS
The three functional classes of neurons?
Sensory/ Afferent neurons
Motor/ Efferent neurons
Interneurons/ Association neurons
These neurons transmit impulses towards the CNS from sensory receptors?
Sensory/Afferent neurons
Neurons that convey impulses away from the CNS to effector organs (muscles and glands)?
Motor/Efferent neurons
Motor neurons form synapses with muscle cells and gland cells, thereby enabling them to promote ______ or _______?
Muscular contraction or glandular secretion
Somatic motor neurons transmit signals to _____?
Skeletal muscle
Visceral motor neurons transmit signals to ____, ______, and ________?
Smooth muscle, cardiac muscle and glands
Neurons that lie between sensory and motor neurons; only located in the CNS; responsible for the complexity of the nervous system?
Interneurons/ Association neurons
Functionally, over 99% of neurons are _________?
Association neurons/ interneurons
Rapid, automatic motor responses to stimuli?
Reflexes
Ex: constriction of pupils when the eyes are exposed to bright light, jerking your hand away when you touch something hot
Reflexes that regulate the activity of smooth muscle, cardiac muscle, the heart and glands?
Autonomic/Visceral reflexes
Ex: pupillary reflex, salivary reflex
Reflexes that stimulate skeletal muscle?
Somatic reflexes
Ex: patellar/knee jerk
Reflexes over neural pathways are called ______?
Reflex arcs
All reflex arcs include these five components?
- a sensory receptor
- a sensory/afferent neuron
- an integration center in the CNS
- a motor/efferent neuron
- an effector organ (muscle or gland)
The integration center in the CNS may consist of the ________ of a sensory neuron with a motor neuron OR may involve one or many __________ between a sensory neuron with a motor neuron?
Direct synapse; association neurons/interneurons
Relative to the CNS, many reflexes only involve the ________? But some do involve the brain such as the ________ reflex?
Spinal cord; photopupillary reflex
How can you classify reflexes?
According to how many synapses occur on the integration center (CNS)
This type of reflex involves the direct synapse of a sensory neuron with a motor neuron?
Ex: the knee-jerk reflex
Monosynaptic reflex (Help maintain balance and posture)
This reflex involves one or more association neurons in the CNS that are positioned between the incoming sensory neuron and outgoing motor neuron?
Polysynaptic reflex
If reflexes are exaggerated, distorted, or absent _________ are indicated?
Nervous system disorders
Clusters of neuron cell bodies located in the CNS; are grey in color because there is not much myelin present?
Nuclei (singular = nucleus)
Clusters of neuron cell bodies in the PNS?
Ganglia (singular = ganglion)
Bundle of nerve fibers/axons on the CNS; myelinated so they are white in color?
Tract
Bundle of nerve fibers/ axons in the PNS; myelinated therefore they are white in color?
Nerve
Portion of CNS containing little myelin?
Grey matter
Portion of CNS containing a large amount of myelin?
White matter
The four major regions/ subdivisions of the brain?
Cerebrum, diencephalon, brain stem, and cerebellum
Cerebrum consists of?
Left and right cerebral hemispheres
Ridges on the surface of cerebral hemispheres?
Gyri (singular = gurus)
Grooves on surface of cerebrum include _____ and ______?
Sulci (singular = sulcus)
and Fissures
The fissure that separates the left and right hemispheres?
Longitudinal
Four main lobes of each cerebral hemisphere?
Frontal, parietal, temporal, occipital
Groove that separates the frontal lobe from the parietal lobe?
Central sulcus
Groove that separates the temporal lobe from the the frontal and parietal lobes?
Lateral sulcus
Ridge immediately in front of the central sulcus; is in the posterior part of the frontal lobe?
Precentral sulcus
Ridge immediately behind the central sulcus; in the anterior part of the parietal lobe?
Postcentral gyrus
The outer layer of gray matter of the cerebrum that contains billions of cell bodies of associated neurons; the “executive suite” and the home of the “conscious mind”?
Cerebral cortex
What are the functions of the billions of neurons in the cerebral cortex?
Speech, memory, logic, consciousness, interpretation of sensations, and willful control of skeletal muscles
Name the three kinds of functional areas that are recognized on the cerebral cortex?
Sensory areas, association areas, and motor areas
Sensory areas of the cerebral cortex provide for?
Conscious awareness of sensations
Association areas of the cerebral cortex process?
Diverse information to enable purposeful action
Motor areas of the cerebral cortex control?
Voluntary motor functions (control skeletal muscle)
This area is located on the postcentral gyrus of the parietal lobe of the cerebral hemisphere; receives information concerned with the general somatic senses (touch, pressure, pain, temperature, vibration, and proprioception)
Primary somatosensory cortex
The sensory information that reaches the primary somatosensory cortex does so via nerve fibers of the _______ tract (located in the brain and spinal cord)?
Spinothalamic tract
The neurons of the primary somatosensory cortex are capable of processing incoming sensory information and identifying __________?
The precise area of the body being stimulated
The pathway of general somatic sensory info to the cortex is _________ on nature?
Contralateral (right hemisphere receives somatic sensory information from the left side of the body and the left hemisphere recovers info from the right side of the body)
Damage to the primary somatosensory cortex causes deficits in the consciousness of ________?
General somatic sensations
Name the three kinds of functional areas that are recognized on the cerebral cortex?
Sensory areas, association areas, and motor areas
Association areas of the cerebral cortex process?
Diverse information to enable purposeful action
Motor areas of the cerebral cortex control?
Voluntary motor functions (control skeletal muscle)
This area is located on the postcentral gyrus of the parietal lobe of the cerebral hemisphere; receives information concerned with the general somatic senses (touch, pressure, pain, temperature, vibration, and proprioception)
Primary somatosensory cortex
The sensory information that reaches the primary somatosensory cortex does so via nerve fibers of the _______ tract (located in the brain and spinal cord)?
Spinothalamic tract
The neurons of the primary somatosensory cortex are capable of processing incoming sensory information and identifying __________?
The precise area of the body being stimulated
The pathway of general somatic sensory info to the cortex is _________ on nature?
Contralateral (right hemisphere receives somatic sensory information from the left side of the body and the left hemisphere recovers info from the right side of the body)
Damage to the primary somatosensory cortex causes deficits in the consciousness of ________?
General somatic sensations
This area is located in the occipital lobe; receives visual information that originates on the _____ of the eye; if this area is destroyed, _________ results?
Primary visual cortex
Retina
Blindness
This area is located in the temporal lobe; provides for conscious awareness of sound; receive signals that originate in the ______ of the inner ear?
Primary auditory cortex
Cochlea
This area occupies much of the frontal lobe?
Prefrontal cortex
(Associated with thinking, reasoning, judgement, problem solving, emotions, reasoning, remembering and recalling information, social skills, understanding and abstract conceptualization)
This area is located on the precentral gyrus of the frontal lobe; provides for conscious control of ______?
Primary motor cortex
Skeletal muscles
Axons (nerve fibers) extending from the neuron cell bodies in the primary motor area form a major voluntary motor tract named the ___________ tract?
Pyramidal/corticospinal tract
The body is represented spatially on the primary motor cortex of each hemisphere meaning?
The neurons that control hand movement are in one part of the primary motor cortex and those that control the foot are in another place and so on
The left hemisphere has greater involvement with?
Language abilities, math and logic
The right hemisphere is more involved with?
Emotion and artistic and musical skills
Underlies the cerebral cortex and makes up most of the interior of the cerebrum; is composed of?
Cerebral white matter;
Myelinated fiber tracts
The most important myelinated tract of the brain? What is its purpose?
Corpus callosum; connects the two cerebral hemispheres allowing them to communicate and act as a whole
A group of nuclei located deep within the cerebrum; also known as “islands of grey matter”?
Basal ganglia - help regulate skeletal muscle activity at the subconscious level
Specific members of the basal ganglia?
Caudate nucleus, putamen, and globus pallidus
Disorders of the basal nuclei result in ________? Two such disorders are?
Dyskinesia (problems with movement)
Huntington’s disease and Parkinson’s disease
Parkinson’s disease actually involves both certain basal ganglia and a nucleus in the midbrain called the _________?
Substantia nigra
Parkinson’s disease results from degeneration of the neuron cell bodies in the substantia nigra that produce the neurotransmitter _________?
Dopamine
A ventricle is a space/chamber that contains _________?
Cerebrospinal fluid (CSF)
The three main parts of the diencephalon?
Thalamus, hypothalamus, pineal gland
The thalamus and hypothalamus form the borders of the ________?
Third ventricle
Contains about a dozen nuclei, each of which sends axons to particular portions of the cerebral cortex; the “gateway” to the cerebral cortex?
Thalamus
All sensory impulses except for those associated with olfaction/smell pass through the ______ before each in the cortex?
Thalamus
Is located below the thalamus and above the pituitary gland/hypophysis?
Hypothalamus
The pituitary gland/ hypophysis hangs from the floor of the hypothalamus by a slender stalk called _______?
Infundibulum
Hypothalamus
- Has rounded bumps named _________ bulge from its floor
- Has ___ nuclei
- Directs activity of the _____
- Regulates _______
- Is involved in the control of _________
- Is an important component to the _____ system
- Is involved with ______ and _______
- Helps regulate sleep wake cycles in conjunction with the ________
- Controls the _______ and regulates much of the ________ system
- Mammillary bodies
- 12
- autonomic nervous system
- Body temperature
- Emotional responses
- Limbic system
- Thirst and hunger
- Pineal gland
- Pituitary gland; endocrine system
The hypothalamus makes these three hormones?
- “Releasing” and “inhibiting” hormones (affect the activity of the anterior pituitary gland)
- Oxytocin (promotes uterine smooth muscle contractions)
- Antidiuretic hormone/ADH (promotes water conservation by kidney tubules *water FROM kidneys TO blood)
Secretes the hormone melatonin which has a influence on mood and also helps the sleep-wake cycle/rhythm?
Pineal gland
The uppermost part of the brain stem?
Midbrain
These nuclei produce and release dopamine to help regulate the basal nuclei?
Substantia nigra
A tiny canal that connects the third ventricle in the diencephalon to the forth ventricle?
Cerebral aqueduct
4 bumpy reflex related nuclei on dorsal surface of midbrain?
Corpora quadrigemina
Forms a bulge in the brain stem between the midbrain and the medulla oblongata?
Contains some centers involved with control of ________?
Dorsally, it is separated from the cerebellum by the ________?
Pons
Breathing
Fourth ventricle
Medulla oblongata
- Is the most _______ part of brain stem
- Gives rise to visceral/autonomic motor fibers/axons of the ________
- Contains nuclei called ______
- inferior
- Vagus nerve
- Centers
The three most important medullary centers?
- Cardiac center (controls the heart rate)
- vasomotor center (regulates blood pressure by controlling smooth muscle)
- medullary respiratory center (controls the rhythm and rate of breathing)
The area of the medulla oblongata where the fibers of the corticospinal/ pyramidal tract cross over to the oppsite side of the brain?
Decussation of the pyramids
The white matter located in the cerebellum is called?
Arbor vitae
Functionally the cerebellum provides for?
Subconscious control of skeletal muscle activity in relation to balance, equilibrium, coordination, and posture
The cerebellum is able to coordinate body movements because it receives?
- Info from the inner ear
- Info on body posting and movement from proprioceptors on joint related structures
- Info on muscle control from the cerebral cortex
Networks of neurons that function together even though widely scattered throughout the brain; name them?
Functional brain systems; limbic and reticular formation
The limbic system is involved with _____ and _______?
Emotion and memory
Name the four specific cerebral components of the limbic system?
Amygdala
Cingulate gyrus
Hippocampus
Fornix
The amygdala, cingulate gyrus, and hypothalamic components are related to _______ while the hippocampus is largely associated with _______?
Emotions; memories
Consists of components of the brain that control visceral responses such as changes in heart rate, blood pressure, and digestive activity?
Reticular formation
Much of the output from the Limbic system is relayed from ______ to the _______?
Hypothalamus to the reticular formation
It’s central core of clustered neurons is located in the brain stem?
Reticular formation
An aspect of the reticular formation consisting of neurons that send a continuous stream of impulses from the brain stem through the thalamus and to the cerebral cortex; is responsible for maintaining an alert _____ and _______?
Reticular activating system (RAS)
Cerebral cortex and consciousness
General anesthesia, alcohol, tranquilizers, and sleep-inducing drugs suppress the ____ and leads to loss of alertness and consciousness?
Knockout blows produce the same effect because they _____ the core of the RAS on the brain stem?
Severe injury to the RAS can result in _____?
RAS (reticular activating system)
Twist
Coma
Protection of the brain is provided by?
Bones
Meninges
Cerebrospinal fluid
The blood brain-barrier
Three connective tissue membranes that surround and protect the brain and spinal cord?
Meninges
Name the meningeal layers from outermost to innermost?
Dura mater
Arachnoid mater
Pia mater
The outermost and toughest of the meninges; ______- layered around the brain (called _______) and ______- layered around the spinal cord ( called ______)?
Dura mater
Double-layered (cranial dura mater)
Single-layered (spinal dura mater)
In the cranium, the _____ layer of the dura mater is attached to the internal surfaces of some bones while the _____layer is covering the brain?
Periosteal; meningeal
Blood-filled passages between the portions of the cranial dura mater that act as veins in that the receive deoxygenated blood?
Specific example: superior sagittal sinus
Dural sinuses
A cerebrospinal fluid filled space that lies deep to the arachnoid, between the arachnoid and pia mater?
Subarachnoid space
The subarachnoid space surrounds the _____?
Entire CNS
Inflammation of the meninges caused by a bacterial or viral infection?
If the infection and inflammation spread to the brain, then the condition is called ____?
Meningitis
Encephalitis
Acquiring a sample of CSF from the portion of the subarachnoid space below the end of the spinal cord is called a ______ or _______?
Spinal tap or a lumbar puncture
Where is cerebrospinal fluid located?
In the ventricles of the brain, the central canal of the spinal cord, and the subarachnoid space
The main function of CSF?
To serve as a liquid cushion for the brain and spinal cord, helping to protect them from physical trauma
CSF is formed from the blood by _____?
Choroid plexuses (located in all four ventricles)
Circulation of CSF?
From the lateral ventricles through the interventricular foramen and into the third ventricle then passes through the cerebral aqueduct and into the forth ventricle and then goes into the subarachnoid space and then into the central canal. When the CSF leaves the subarachnoid space it releases into Dural sinuses (returning to blood)
A condition when something obstructs the drainage of CSF or if it is over produced, it begins to accumulate in the subarachnoid space and or ventricles exerting pressure on the brain?
Who is more susceptible to brain damage?
Hydrocephalus
Adults because the bones are fully fused exerting the pressure inward where newborns fontanelles are present allowing the skull to expand outward
Composed of the least permeable capillaries in the whole body; helps separate neurons of the brain from many potentially harmful substances in the bloodstream?
Blood-brain barrier
The blood-brain barrier is ineffective against ______ such as nicotine, alcohol, and anesthetics so these substances can reach and affect the brain?
Fat-soluble chemicals
The spinal cord extends from the __________ of the skull to the level of the __________ vertebra?
Medulla oblongata; 1st or 2nd lumbar vertebrae
Major functions of the spinal cord?
- via the spinal nerves, the spinal cord is involved in the sensory and motor innervation of all the body below the head
- provides a two way conduction pathway to and from the brain
- is a major reflex integration center
Immediately external to the spinal dura mater is the ______? It’s filled with?
Epidural space; fat and blood vessels
The spinal cord ends at the ______?
1st or 2nd lumbar vertebra
The ______ extends all the way down to the end of the vertebral column?
The ______ and ______ are accessible inferior to the spinal cord?
Meninges;
Subarachnoid space and cerebrospinal fluid
In a lumbar puncture (or spinal tap), a needle is inserted between the laminae of ___ or ______ and into the ________?
L3 and L4 or L4 and L5; subarachnoid space
There are ___ pairs of spinal nerves?
31
Because spinal nerves are not actually part of the spinal cord, spinal nerves are technically organs of the ____?
PNS
A collection of spinal nerve roots located below the spinal cord in the inferior part of the vertebral canal?
Cauda equina
Gray matter of the spinal cord
- In a cross section, looks like an _____ or a ____.
- The two posterior projections of gray matter are _______.
- The two anterior projections are the _______.
- The crossbar of the H is called ______.
- H or a butterfly
- Dorsal (posterior) gray horns
- Ventral (anterior) gray horns
- Gray commissure
The anterior/ventral gray horns contain the cell bodies of ______ whose axons extend away from the spinal cord (via ventral anterior roots) and to skeletal muscles (via spinal nerves) ?
Somatic motor neurons
Cell bodies of sensory neurons are located in enlarged areas on the dorsal root called ____?
Dorsal root ganglia
The cell bodies of somatic motor neurons are located in the ______?
Anterior (ventral) gray horns
A dorsal root is entirely _____ in nature and a ventral root is entirely _____ in nature the spinal nerve itself is ______.
Dorsal - sensory
Ventral- motor
Spinal nerve- mixed (both motor and sensory)
White matter of the spinal cord consists of ______?
Myelinated tracts
White matter is divided into these three sections of the spinal cord?
The posterior (dorsal) white column funiculus, the anterior (ventral) white column funiculus, lateral white column funiculus