Exam #6

What are the two types of cholinergic receptors? Which one is fast and which is slow?

-Muscarinic; Nicotinic -Muscarinic: Slow -Nicotinic: Rapid

What kind of receptors are taste receptors?

Chemoreceptors

What is the main purpose of the "knee-jerk" or patellar reflex?

Helps maintain an upright posture

What is the function of the Pons?

Helps regular rate and depth of breathing, as well as relays nerve impulses to and from medulla oblongata and cerebellum.

What is the all-or-none response?

If a neuron responds at all, it responds completely

Sympathetic division is fight or flight, parasympathetic is rest and digest so which one is active if you are being chased by a bear?

Sympathetic

A spinal nerve is the union of the ventral and dorsal roots.

That is the definition...

The iris?

is the pigmented (colored) portion of the eye.

What are the 3 parts of the brain stem?

-Midbrain -Pons -Medulla Oblongata

Compare A-delta fibers and C fibers.

-A-delta fibers conduct impulses rapidly, they are associated with sharp pain and are well localized -C-fibers conduct impulses slowly, they are associated with aching pain, difficult to pinpoint

What is the difference between absolute refractory and relative refractory periods?

-Absolute: Time when threshold stimulus does not start another action potential -Relative: Time when stronger threshold stimulus can start another action potential

Know the difference between afferent and efferent.

-Afferent: Are sensory nerves -Efferent: Are Motor nerves

What information do the ascending tracts of the spinal cord carry? Descending tracks?

-Ascending tracts: conduct sensory impulses to the brain -Descending tracts: conduct motor impulses from the brain to motor neurons reaching muscles and glands.

Know the 3 structural classifications of neurons and what they mean. (unipolar, bipolar, and multipolar). Which is most prominent in the CNS?

-Bipolar: Tro processes, eyes, ears, nose -Unipolar: one process, ganglia -Multipolar: many processes, most neurons of the CNS

What are the 2 divisions of the nervous system and what is included in each?

-Central nervous system: Brain, and spinal cord -Peripheral nervous System: Nerves, cranial nerves, and spinal nerves

What is the cerebrum and what are the main parts? (Slide #21)

-Cerebrum is the two hemispheres of the brain - corpus callosum - convolutions - sulci - longitudinal fissure - transverse fissure

What are the 5 main receptor types and what do they respond to?

-Chemoreceptors: respond to changes in chemical concentrations -Pain receptors(nociceptors): Respond to tissue damage -Thermoreceptors; respond to changes in temperature -Mechanoreceptors: respond to mechanical forces -Photoreceptors: respond to light

What neurotransmitter do cholinergic fibers release? Adrenergic?

-Cholinergic: Acetylcholine -Adrenergic: Release norepinephrine

What are the three parts of the labyrinths of the inner ear and what are their functions?

-Cochlea: function in hearing -Semicircular canals: functions in equilibrium -Vestibule: functions in equilibrium

What is convergence? Divergence?

-Convergence: neuron receives input from several neurons -Divergence: One neuron sends impulses to several neurons

What are EPSPs and IPSPs and how do they relate to summation?

-Excitatory postsynaptic potential: depolarizes membrane of neuron, action potential becomes more likely -Inhibitory postsynaptic potential: hyperpolarizes membrane of the neuron, action potential becomes less likely

What are the 4 main association areas and what is their function?

-Frontal Lobe Association Areas: concentrating, planning, complex problem solving -Temporal Lobe Association Areas: interpret complex sensory experiences, store memories of visual scenes, music, and complex patterns -Parietal Lobe Association Areas: Understand speech, choose words to express thought -Occipital Lobe Association Areas: Analyze and combine visual images with other sensory experiences.

What are the main differences between general and special senses?

-General senses: are widely distributed throughout the body, skin, various organs and parts -Special senses: Specialized receptors confined to structures in the head, eyes and ears

What are neuronal pools?

-Groups of interneurons that make synaptic connections with each other, each pool receives input from other neurons, each pool generates output to other neurons.

Functions of the cerebrum?

-Interpret impulses Initiate voluntary movements -Store information as memory -Retrieving stored information -Reasoning -Seat of intelligence and personality

What are the main functions of the brain?

-Interprets sensations -Determines perception -Stores memory -Reasoning -Makes decisions -Coordinates muscular movements -Regulates visceral activities -Determines personality

What is myelin? Which cells are responsible for creating myelin in the CNS and the PNS

-Is a lipid-protein which forms a myelin sheath on the outside on an axon -The cells responsible for creating myelin are called Schwann cells.

What is a nerve plexus? What do the brachial and the lumbosacral plexuses control?

-Nerve plexus: complex network formed by anterior branches of spinal nerves; fibers of various spinal nerves are sorted and recombined. -Brachial plexuses: controls motions of wrists, hands and arms -Lumbosacral plexuses: controls impulses and movement of legs, thighs, the leg, etc.

What is polarization? Depolarized? Hyperpolarized? Repolarized?

-Polarization: a more positive value -Depolarized: If membrane potential becomes less negative -Hyperpolarized: If membrane potential becomes more negative -Repolarized: reduce or remove the polarization of

What are the 2 divisions of the peripheral nervous system and what do they do?

-Sensory division: picks up sensory information and delivers it to the CNS -Motor Division: Carries information to muscles and glands

What are the 3 main functions of the nervous system?

-Sensory function -Integrative function -Motor Function

What are the 3 FUNCTIONAL classifications of neurons?

-Sensory neurons -Interneurons -Motor neurons

What are the main differences between slow wave sleep and REM sleep

-Slow Wave: Deep and restful, decreasing activity of reticular system, restful, dreamless, blood pressure and respiratory rate decrease, ranges from light to heavy. -REM: Paradoxical sleep, some areas of brain are active, heart and respiratory rates are irregular, and dreaming occurs

Know the difference between somatic and visceral.

-Somatic: Is for the skeletal muscles -Visceral: is for smooth muscle and glands

What are the 2 divisions of the motor division of the PNS and what does each do?

-Somatic: carries information to the skeletal muscle -Autonomic: Carries information to smooth muscle, cardiac muscle, and glands

What is the role of the thalamus and the role of the cerebral cortex with regards to pain?

-Thalamus allows person to be aware of pain -Cerebral cortex: judges intercity of pain and locates source of pain

What is the thalamus and what does it do? The hypothalamus?

-Thalamus: Gateway for sensory impulses heading to cerebral cortex, and receives all sensory impulses except for smell, and channels impulses to appropriate parts of cerebral cortex for interpretations. -Hypothalamus: Maintains homeostasis by regulating visceral activities, and links nervous and endocrine systems.

What is the dominant hemisphere of the brain responsible for? (Logical thought, analytical skills). The non-dominant hemisphere? (Emotion and intuition)

-The left hemisphere is dominant in most individuals. Dominant Hemisphere: speech, writing, reading, verbal skills, analytical skills, computational skills. -Nondominant hemisphere: nonverbal tasks, motor tasks, understanding and interpreting musical dn visual patterns, provides emotion and intuitive thought processes.

What is a synapse? How do neurotransmitters work during synaptic transmission?

-Where information is passed from one neuron to the next -Neurotransmitters are released when impulse reaches synaptic knob

What is white matter? Gray matter?

-White matter: Contains myelinated axons -Gray matter: Contains unmyelinated structures, ie, cell bodies, dendrites

Light through a convex lens will converge, light through a concave lens will diverge.

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How many pairs of spinal nerves are there?

31 pairs

What is perception?

A person's view of the stimulus; the way the brain interprets the information

What is the Frontal Eye field?

Above Broca's area, controls voluntary movements of eyes and eyelids

What are dermatomes?

An area of skin that the sensory nerve fibers of a particular spinal nerve innervate

What is Broca's area?

Anterior to primary motor cortex, usually in left hemisphere, controls muscles needed for speech.

What is a reflex arc and what are the 5 parts involved?

Automatic, subconscious responses to stimuli within or outside the body -Receptor - Sensory neuron - interneuron -Motor Neuron -Effector

What type of information does the ventral root carry?

Axons of motor neurons

What type of information does the dorsal root carry?

Axons of sensory neurons in the dorsal root ganglion

What are refractions?

Bending of light, occurs when light waves pass at an oblique angle into the mediums of different densities

What is the pupil and what does it respond to?

Black opening in the middle of the eye gets bigger and smaller in different amounts of light.

In general, what happens to the brain as we age?

Brain cells begin to die, brain shrinks 10%, by age 90 frontal cortex has lost half its neurons, memory fades, slower responses and reflexes, increased risk of falling, less sleep

What do the SPECIAL SOMATIC EFFERENT fibers do?

Carry motor impulses from brain to muscles used in chewing, swallowing, speaking, and forming facial expressions

What do the SPECIAL VISCERAL AFFERENT fibers do?

Carry sensory impulses to brain from olfactory (smell) and taste receptors

What did the SPECIAL SOMATIC AFFERENT fibers do?

Carry sensory impulses to the brain from receptors of sight, hearing, and equilibrium.

What is the dorsal root ganglion?

Cell bodies of sensory neurons whose axons conduct impulses inward from peripheral body parts.

What is cerebrospinal fluid and what is its function? What secretes it?

Cerebrospinal fluid helps maintain stable ion concentrations also is protective and has nutrients, it is secreted by Choroid plexus, it is a clear liquid that surrounds the brain and spinal cord

What is the reticular formation and what does it do? ("Alarm clock" for cortex)

Complex network of nerve fibers scattered throughout the brain stem. Filters incoming sensory information to arouse the cerebral cortex into a state of wakefulness.

What is the function of the medulla oblongata?

Conducts ascending and descending impulses between brain and spinal cord, also contains various non vital reflex control centers (coughing, sneezing, vomiting)

What are mixed nerves?

Contain both sensory and motor nerve fibers and motor nerve fibers: most nerves

What is the autonomic nervous system responsible for?

Controlings visceral activities, without conscious effort, as well as regulate smooth muscle, cardiac muscle, and glands.

What is resting membrane potential?

Inside is negative relative to the outside (-70mV=resting potential)

What is the cerebral cortex and what percentage of the neurons in the nervous system are located there?

Is a thin layer of gray matter that constitutes the outermost portion of cerebrum; it contains 75% of all neurons in the nervous system.

What is the auditory tube and what is its function?

It connects the middle ear to the throat, helps maintain equal pressure on both side of tympanic membrane

What is the limbic system?

It controls emotions, produces feelings, and interprets sensory impulses.

What is the function of the spinal cord?

It is a conduit for nerve impulses to and from the brain and center for spinal reflexes

What is the lacrimal apparatus? What is its function?

Lateral to the eye, secretes tears, which have an enzyme to reduce the chance of eye infections.

What is referred pain and why does it occur?

May occur due to sensory impulses from two regions following a common nerve pathway to brain

What are proprioceptors?

Mechanoreceptors, they send information to the spinal cord and CNS about body position and length and tension of muscles

What do Meissner's corpuscles detect? Pacinian corpuscles? Where are they found?

Meissner's corpuscles: detects fine touch, found on hairless portions of skin and lips -Pacinian corpuscles: Detect heavy pressure and vibrations, found in deeper subcutaneous tissues, tendons, and ligaments.

What are the meninges and what is their function?

Membrane surrounding the Central Nervous system (CNS), it also protects the CNS and is made of three layers - Dura Mater-outer layer and tough -Arachnoid mater- thin weblike -pia mater- inner, very thing

What is memory consolidation?

Memory consolidation is long term memory

What color are myelinated axons? Unmyelinated?

Myelinated: White Unmyelinated: Gray

What are the receptors for smell? What kind of receptors are they? How quickly does does the sense of smell adapt?

Olfactory receptors, they are also chemoreceptors, sense of smell drops by 50% within a second after stimulation

What type of receptors respond to temperatures above 113 deg f and below 50 deg f?

Pain receptor (free nerve endings)

The brain lacks what kind of receptors?

Pain receptors

What is the main purpose of the withdrawal reflex?

Prevents or limits tissue damage

What does the medulla oblongata regulate?

Regulates cardiac, vasomotor, and respiratory activities.

What are rods and cones and what are the pigments for each. What colors do the pigments in the cones respond to?

Rods: are long, thin projections, contain light sensitive pigment, 100 times more sensitive to light than cones, produces colorless vision, produce outline of objects, can rebuild Cones: Short blunt like projections, contain light sensitive pigment called erythrolabe, chlorolabe and cyanolabe, provide vision in bright light, produce sharp vision, if all three sets are stimulated we see white, if none of the sets of cones are stimulated we perceive black.

Be sure to know/understand the basic structure of a neuron.

See image in chapter 10 notes; page 4; slide 7

What layer or structure of the eye are the visual receptors found on?

The Retina

What is sensory adaptation?

The ability to ignore unimportant stimuli

What is the blind spot in the eye called?

The optic disc

What is projection?

The process in which the brain projects the sensation back to the apparent source, it allows a person to pinpoint the region of stimulation

What are "Nodes of Ranvier"? Saltatory conduction? What do they do?

They are narrow gaps in the myelin sheath. This exposes a small portion of the axon to allow for exchange of ions.

What is the function of the basal nuclei?

To control certain muscular activities, also produce dopamine

What is the function of the cerebellum?

Tree of life, integrates sensory information concerning position of body parts.

Compared to the original image, the image focused on the retina is _____________ ____________ and _______________ from left to right.

Upside down, and reversed

What are the ventricles and what is their function?

Ventricles are interconnected cavities within cerebral hemispheres and brainstem, filled with cerebrospinal fluid

What does the hypothalamus regulate?

Visceral functions, such as body temperature, hunger ,thirst , and water and electrolyte balance

Know the following regarding the cranial nerves:

a. 1-Olfactory-sensory for smell b. II-Optic-sensory for vision c. III-Oculomotor-Primarily motor for eye movement and focus d.IV-Trochlear - primarily motor for eye movement e. V-Trigeminal - Mixed nerve-ophthalmic, maxillary, and mandibular f. VI-Abducens - Primarily motor for eye movement g. VII-Facial- Mixed nerve for taste and motor for facial expression h. VIII-Vestibulocochlear-Sensory for equilibrium/balance and hearing I. IX-Glossopharyngeal - Mixed-sensory for tongue and tonsils, motor f salivary glands J. X-Vagus- Mixed-muscles of speech, parasympathetic functions k. XI-Accessory- primarily motor-skeletal muscles of cranial and spinal L. XII-Hypoglossal - primarily motor-muscles to the tongue

Define the following: Astrocytes, Oligodenrocytes, Microglia, ependyma

a. Astrocytes: Scar tissue, mop up excess ions, connect neurons to blood vessels b. Oligodendrocytes: Myelinating cell c. Microglia: Phagocytic cell D. ependyma: Ciliated, line central canal of spinal cord, line ventricles of brain

Define the following: Cell body, neurofibrils, nissl bodies, Dendrites, Axons, Axonal hillock, Collateral branches, Telodendria, Synaptic knob

a. Cell body: contains cytoplasm and various organelles. Sometimes referred to as a soma b. Neurofibrils: Fine cytoplasmic threads that extend from the cell body into the processes of neurons. They also provide support. c. Nissl bodies: Are membranous sacs that occur within the cytoplasm of nerve cells and have ribosomes attached to their surfaces. d. Dendrites: Short, highly branched structure which provide the main receptor surface of the neuron e. Axons: Arise from a slight elevation called the Axonal Hillock f. Axonal hillock: Specializes to conduct nerve impulses away from the cell body g. Collateral branches: When axons branch they are called... h. Telodendria: Near the end of the axon with many fine branches i. Synaptic knob: Which contact the receptive surface of another cell or a specialized ending.

Where are the cell bodies of the ventral root axons?

cell bodies are in the spinal cord.

What structure is responsible for changing the shape of the lens for focusing?

ciliary muscle

Know the pathway for sound waves to turn to sound:

collected in the auricle, through the EAM, causes the tympanic membrane to vibrate which causes the auditory ossicles to vibrate, vibrating the oval window which moves fluid in the inner ear.