nervous system Flashcards
(107 cards)
1
Q
the nervous system is divided into
A
central nervous system and peripheral nervous system
2
Q
what makes up the CNS
A
brain and spinal cord
3
Q
does the CNS or PNS further divide?
A
PNS
4
Q
PNS divides into what two sections?
A
Sensory (afferent) and motor (efferent)
5
Q
sensory (afferent)
A
sends impulses from the senses to the CNS
6
Q
motor (efferent)
A
sends impulses from the CNS to the muscles and glands
7
Q
is afferent or efferent further divided into two more sections? and what are these two sections called?
A
efferent; autonomic nervous system and somatic nervous system
8
Q
autonomic nervous system
A
involuntary muscle control
9
Q
somatic nervous system
A
voluntary muscle control
10
Q
is the autonomic NS or the somatic NS divided into two more sections? and what are these two sections called?
A
autonomic; sympathetic and parasympathetic
11
Q
sympathetic
A
used in emergency situations (fight or flight)
12
Q
parasympathetic
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reduces sympathetic response and provides resting functions such as digestion and urination
13
Q
the nervous system works with what other system?
A
endocrine
14
Q
to do its job, the NS uses:
A
sensory inputs, integration, and response
15
Q
what does sensory input do?
A
detects changes (stimulii) inside and outside of the body
16
Q
what does integration do?
A
processes and interprets the info
17
Q
what does response do?
A
activation of muscles (motor output) or glands
18
Q
what are the two types of nerve cells?
A
neurons and neuroglia
19
Q
neurons
A
conduct impulses around the body, 10%
20
Q
neuroglia
A
“nerve glue”, support, insulate, and protect neurons, 90%
21
Q
the cell body contains what structures?
A
nucleus, cytoplasm, and organelles
22
Q
processes are divided into
A
dendrites and axons
23
Q
dendrites
A
brings impulses towards cell body
24
Q
axons
A
send impulses away from cell body
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neurons are classified by the number of ------ extending from the cell body
processes
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unipolar processes
one process
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bipolar process
two processes
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multipolar process
many processes
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neurons can be classified by their function; afferent, efferent, and interneurons
afferent neurons- carry impulses towards CNS
efferent neurons- carry impulses away from the CNS
interneurons- connect afferent and efferent neurons
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axons are wrapped in what
myelin
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what forms myelin
schwann cells that wrap themselves around the axon
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the outer layers of the schwann cells are called the
neurilemma
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myelin helps the nerve impulses to travel more quickly by jumping over the what
Nodes of Ranvier
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neuroglia cells are found in CNS and PNS. in the CNS, the four types are
astrocytes: support and anchor neurons to surrounding capillaries
microglia: provide immune response to CNS
ependymal: secrete and circulate cerebrospinal
oligodendrocytes: provide myelin insulation to neurons in CNS
35
neuroglia cells are found in CNS and PNS. in the PNS, the two types are
satellites: support and anchor neurons in the PNS
schwanns: provides myelin insulation to neurons in PNS
36
The brain and spinal cord are protected by 3 layers of connective tissue called the what?
meninges
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dura mater
thick, tough layer
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arachnoid membrane
thin, cobweb like layer
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pia mater
thin layer containing lots of blood vessels
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between the arachnoid layer and pia mater is the what
cerebrospinal fluid
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the CSF protects the ----- by preventing it from contacting the ------
brain; skull
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the CSF also maintains the ------ which controls homeostasis for the brain and prevents infection
blood-brain barrier
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the CSF is produced in spaces within the brain called
ventricles
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what are the four ventricles where CSF could be made
2 lateral ventricles, a third ventricle, and a fourth ventricle
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clusters of capillaries in the ventricles called ------ secrete CSF, which flows around the ventricles then is absorbed by -------
choroid plexuses; arachnoid granulation into the blood
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CSF is constantly being ----, -----, and ----
produced, circulated, and absorbed
47
what is largest part of the brain
cerebrum
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the cerebrum is divided into two parts, divided by a bundle of fibers called
corpus callosum
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the surface of cerebrum is covered in ridges called --- and grooves called ----, and deeper grooves called ---- that divide portions of the brain
gyri; sulci; fissures
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the brain has 3 major layers (from superficial to deep)
Cerebral cortex: "grey matter", made of cell bodies and dendrites
Cerebral medulla: "white matter", made of myelinated axons
Basal nuclei: islands of grey matter
51
the names of the four lobes of the cerebrum and where they get their names from
they are named for their parts; frontal lobe, parietal lobe, occipital lobe, temporal lobe
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frontal lobe
voluntary movements, reasoning and decision making, memory, ability to predict consequences of actions, planning, verbal communication- specifically broca's area
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what separates the frontal lobe from the parietal lobe
central sulcus
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parietal lobe
sensations, visual-spatial processing, body positions
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occipital lobe
visual processing- vision and memory of objects
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the frontal lobe is separated from the temporal lobes by what
lateral sulcus
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temporal lobes
memory, comprehension and pronunciation of words, sensations of smell and sound, emotional association of memories
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diencephalon contains what three sections?
thalamus, hypothalamus, pineal gland
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thalamus
relays sensory impulses to the cerebral cortex for processing and sorting
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hypothalamus
tiny portion of the brain inferior to the thalamus.
-responsible for autonomic processes such as body temp, metabolism, and blood volume
-controls hormones released by pituitary gland
-part of the limbic system which has to do with emotions, pleasure, pain, etc
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three sections of the brain stem
midbrain, pons, medulla oblongata
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midbrain
"mesencephalon"
-relays info to cerebrum
-controls body movement and posture
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pons
"bridge"
-almost completely made of "white matter" that links the cerebral cortex and cerebellum
-carries info from one side to another of the brain
-central control of breathing
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medulla oblongata
-located just above the spinal cord
-transmits impulses between spinal cord and brain
-controls blood pressure, heart rate, swallowing, and coughing
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cerebellum facts
-2nd largest part of the brain
-responsible for making movements more graceful and efficient
-"muscle memory"
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spinal cord facts
-extends from medulla oblongata to lumbar vertebrae
-covered in meninges for protection
-relays impulses between the peripheral nervous system and the brain through 31 pairs of spinal nerves
-has a cross section
67
spinal cord cross-section
-butterfly of grey matter surrounded by white matter
-dorsal horns receive impulses from afferent nerves, then pass the impulses through the ventral horns to the efferent nerves
-dorsal and ventral roots contain the nerve fibers and join together to form a 2-directional spinal nerve
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reflexes
preprogrammed responses, they pathway they take is called a reflex arc
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5 elements of a reflex arc
receptor, sensory neurons, integration, motor neurons, effector
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5 major types of sensory receptors
mechanoreceptors (touch), thermoreceptors (temp), nociceptors (pain receptors), chemoreceptors (chemicals), photoreceptors (light)
71
impulses produced in the skin are called ---- sensations. these sensations include ---, ---, ---, ---, and ---.
cutaneous; touch, heat, cold, pressure, and pain
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types of touch receptors
free nerve endings, Meissner's corpuscles, Merkel's disks, hair follicle receptors, Ruffini's corpuscles, Pacinian corpuscles
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Free nerve endings
sense pain, temp, touch, and pressure
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Meissner's corpuscles
encapsulated nerve endings found in hairless skin that detects light touch
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Merkel's disks
detects light touch and pressure within the epidermis
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hair follicle receptors
detect movement of hair
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Ruffini's corpuscles
detect deep pressure and stretching of skin
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Pacinian corpuscles
encapsulated nerve endings that detect deep pressure and vibrations
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touch is a ---- sense because it includes many types of ---- found all over the body.
general; receptors
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sight, hearing, smell, and taste are ---- senses because their receptors are ---- in ---- organs or in a small area (eye)
special; clustered; specialized
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the eye is covered with the ---, that meets the corners of the eye at the --- --- and the --- ---, and is lined with eyelashes
eyelid; medial commissure, lateral commissure
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conjunctiva
thin membrane that covers the surface of the eyeball and the inner layer of the eyelid. it secretes mucus to keep the eye moist/to lubricate it
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lacrimal apparatus
group of structures that also lubricate the eye
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lacrimal glands
above the eye constantly release tears to cleanse and moisten the eye. tears contain mucus, antibodies, and lysozyme. the tears drain into ducts called the lacrimal cuniculi, then into the lacrimal sac and finally into the nasal cavity through the nasolacrimal duct
85
the eye is comprised of 3 tissue layers:
sclarea, choroid, & retina
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sclarea
white of the eye; made of fibrous connective tissue; protects and shapes the eye
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choroid
pigmented, vascular membrane that includes the iris and pupil
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retina
contains photoreceptors that turn light energy into nerve impulses.
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cornea
made of thick, transparent tissue. it allows light into the eye
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iris
colored part of the eye, located behind the cornea. works with the pupil to regulate light entering the eye
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pupil
opening in the center of the iris through which light enters
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lens
semi-solid disc that directs light waves towards the retina. the lens is controlled by the ciliary muscles and suspensory ligaments. these both help bend/flatten the lens based on the distance of the image being viewed
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aqueous humor
fluid in front of the lens; nourishes the cornea
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vitreous humor
behind the lens; thick, jelly-like fluid that refracts light and fills the space between the lens and retina
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two types of photoreceptors
rods: distributed all over the retina. responsible for vision in low light; extremely sensitive
cones: concentrated in center of retina, responsible for detection of colors; less sensitive
96
in order to see an image, light passes through the eye and hits the --- --- --- (RPE) on the back of the eye. the light causes a --- change that begins an ---. this travels through the rods and cones, then --- ---, then --- --- before traveling to the brain via the optic nerve.
retinal pigment epithelium; molecular; impulse; bipolar neurons; ganglion cells
97
forea centralis
tiny pit that contains only cones so it is the point that provides the sharpest image
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blind spot
where there are no photoreceptor. (where the optic nerve meets the eye)
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myopia
near-sightedness
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hyperopia
far-sightedness
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the ear uses --- to accomplish collecting and transferring sound vibrations to the auditory nerve
mechanoreceptors
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auricle
collects sound waves that are then passed through the external auditory canal
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tympanic membrane
"eardrum", sound waves from the auricle vibrate this
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middle ear contains what three bones (ossicles)
malleus, incus, and stapes; these amplify the sounds waves to the inner ear through a membrane called the oval window
105
choclea
bony snail-shaped structure containing membranes filled with fluid (perilymph). the perilymph then vibrates the basilar membrane, which has tiny receptor cells attached to it. the hairs of the receptor cells move against the tectorial membrane, depolarizing the ends of the nerve cells and beginning an action potential. when the action potential is transferred through the auditory nerve, the brain registers these impulses as sounds
106
maculae
receptor cell found in the choclea that helps to maintain static equilibrium; provides info to keep our head upright
107
--- --- (hairs) of the maculae are embedded in a gel-like membrane with calcium salts called ---- resting on it
receptor cells; otoliths
