Chapter 12 Flashcards
Nervous System (141 cards)
1
Q
Types of Functions of the nervous system
A
- sensory input functions
- integrative functions
- motor output functions
2
Q
what are sensory input functions
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Detection of sensations within and outside the body
3
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what are integrative functions
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“Decision-Making” processes
4
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what are motor functions
What do they do
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Stimulation of muscle cell contractions or gland secretions
5
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sensory input functions are performed by
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pns
6
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motor output functions are performed by
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pns
7
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integrative functions are performed by
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cns
8
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what is the brain (general)
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Soft, whitish-gray organ that resides in the cranial cavity; Consists of four divisions
9
Q
brain is composed of
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nervous tissue with some connective and modified epithelial tissue
10
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brain - internal cavities called
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ventricles
11
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brain - ventricles filled with
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cerebrospinal fluidw
12
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what does does csf stand for
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cerebrospinal fluid
13
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brain weighs
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Weighs between 1,250–1,450 g; slightly larger in males; Ratio of brain weight to body weight of females is equal to that of males
14
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during rest - how much of total blood flow goes to brain
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20%
15
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brain is made up of four divisions
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- cerebrum
- diencephalon
- cerebellum
- brainstem
16
Q
cerebrum made up of
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cerebral hemispheres
17
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cerebrum responsible for
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for higher mental functions, including learning, memory, personality, cognition (thinking), language, and conscience; major role in sensation and movement
18
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diencephalon composed of
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- large central thalamus
- posterior and superior epithalamus
- inferior subthalamus
- hypothalamus
19
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diencephalon responsible for
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processing, integrating, and relaying information; maintaining homeostasis of physiological variables, regulation of movement, biological rhythms
20
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cerebellum composed of
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hemispheres
21
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cerebellum responsible for
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Important in planning and coordination of movement, particularly for complex activities such as sports or playing an instrument
22
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brainstem connects
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brain and spinal cord
23
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brainstem responsible for
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basic involuntary processes such as rate and depth of breathing, mediates certain reflexes, monitors movement; integrates and relays information to other parts of the nervous system
24
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spinal cord begins at
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foramen magnum
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central canal of spinal cord filled with
csf
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what is foramen magnum
Where the spinal cord and the brain connect
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what is spinal cord
Long, tubular organ encased within the vertebral cavity
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csf of spinal cord is continuous with
csf of ventricles of the brain
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gray matter contains
unmylelinated axons
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white matter contains
myelinated axons
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Where is white matter and gray matter in the spinal cord
Gray matter is internal and tracts of white matter are superficial
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white matter and gray matter in the brain
Gray matter makes up the outer few millimeters and is scattered throughout in deeper portions;
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what is the cerebral cortex
outer layer of the cerebrum, composed of grey matter. About 2-4mm thick.
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what are the lobes of cerebral hemispheres
- frontal lobes
- parietal lobes
- temporal lobes
- occipital lobes
- insulas
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what is basal nuclei
Clusters of cells bodies buried in the cerebral hemispheres; Basal nuclei inhibit involuntary movement and initiate voluntary movement;
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what is the putamen
inhibit the globus pallidus to begin movement
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what are thewhat is the globus pallidus
prevents upper motor neurons from causing spontaneous, inappropriate muscle contractions;
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what is the caudate nucleus
inhibit the globus pallidus to begin movement
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basal nuclei composed of
- globus pallidus
- caudate nucleus
- putamen
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what are commisural fibers
Connect right and left cerebral hemispheres; largest of the four groups of fibers makes up the corpus callosum
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cerebral white matter made of
- commisural fibers
- projection fibers
- association fibers
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what are projection fibers
Connect cerebral cortex of one hemisphere with other areas of the hemisphere and other areas of the brain and spinal cord; form a radiating pattern called the Corona Radiata; condense to form V-shaped bands known as Internal Capsules
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what are association fibers
Restricted to a single hemisphere and connect gray matter of cortical gyri (area) with one another
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what are internal capsules
v shaped bands formed by projection fibers
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what is the limbic system
Found only in mammals; participates in memory, learning, emotion, and behavior; called the “visceral brain”
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what is conona radiata
radiating pattern formed by projection fibers
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main function of hippocampus
connected to a C-shaped ring
of white matter called the Fornix. Mainly
involved in memory, spatial navigation and learning.
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what is the hippocampus
Greek word for “seahorse”; connected to a C-shaped ring of white matter called the Fornix. Mainly involved in memory, spatial navigation and learning.
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the limbic system includes
- limbic lobe
- hippocampus
- amygdala
- diencephalon
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main function of fornix
primary white matter output tract of the limbic system
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what is the amygdala
Greek word for “almond”; anterior to the hippocampus; functions in behavioral expression of emotion, particularly fear
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main function of limbic lobe
participates in memory, learning,
emotion, and behaviour
Called the visceral brain
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where is the diencephalon
Found at the center of the brain;
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four components of the diencephalon
- thalamus
- posterior and superior epithalamus
- inferior subthalamus
- hypothalamus
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what is the thalamus
Consists of two large, egg-shaped masses of gray matter; Makes up about 80% of the diencephalon; Receive afferent fibers from cerebral cortex, cerebellum, basal nuclei, other structures of the limbic system, sensory system;
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what is the hypothalamus
(Size and location)
Anterior and inferior to the thalamus; weighs about 4 g; makes up less than 1% of brain mass
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functions of the hypothalamus
- Nuclei perform several functions vital to survival
- Receives sensory input from outside and within the body, such as level of light, blood pressure, body temperature, concentration of body fluids, blood glucose concentration
- Regulates sleep/wake cycle, causes thirst and hunger, adjusts body temperature
- “Boss” of the autonomic nervous system (A N S)
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what is the cerebellum
Posterior and inferior portion of the brain; composed of two Cerebellar Hemispheres connected by the vermis
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functions of cerebellum
Functions with cerebral cortex, basal nuclei, brainstem, and spinal cord to reduce motor error
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brainstem includes
Includes a superior midbrain, a middle pons, and an inferior medulla oblongata
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what is the brain stem responsible for
Control basic functions including maintenance of heart rate and breathing rhythm
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brainstem houses
a large group of connected nuclei called the Reticular Formation
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brainstem mediates ______ which...
Mediates Reflexes,
which are programmed, automatic responses to stimuli, and functions in movement, sensation, and maintaining alertness
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the brainstem includes
- superior midbrain
- middle pons
- inferior medulla oblongata
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what is reticular formation
large group of connected nucleiin the brainstem
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what is superior midbrain
Top part of the brain stem just below the diencephalon
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what is middle pons
middle part of the brainstem - between the midbrain and the medulla oblongata
handles unconscious movements and processes
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what is inferior medulla oblongata
bottom part of the brain stem - right below the pons
conscious thought and regulation of involuntary action
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what is the circadian rhythm
Spend a period of the 24-hour cycle awake and another period of the cycle asleep
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what is the circadian rhythm controlled by
hypothalamic Suprachiasmatic Nucleus (S C N)
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what is the hypothalamic suprachiasmatic nucleus
controls the circadian rhythm
- Food intake, movement, hormones, and most importantly, the level of light influence the rate of firing
- Process of sleep induction involves decreasing activity in brain areas that promote wakefulness
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being awake is mediated by ...
Lateral Hypothalamic Area
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the Lateral Hypothalamic Area mediates what
being awake
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what does the Lateral Hypothalamic Area secrete
orexin
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circadian rythem controlled by
by the hypothalamic Suprachiasmatic Nucleus (S C N)
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what is broca's area
In the frontal lobe; responsible for the production of language, including the planning and ordering of words with proper grammar and syntax
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process of sleep induction induction involves
decreasing activity in brain areas that promote wakefulness
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facial recognition is where
Right temporal cortex
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orexin deficiency may be cause of
narcolepsy
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what are the divisions of labour in cerebral lateralization
- emotional functions
- attention
- facial recognition
- language related recognition
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what is wernicke's area
In the temporal lobe; responsible for understanding language and linking a word with its correct symbolic meaning
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language related recognition is where
Includes ability to identify an object with its proper name; lateralized to the left temporal cortex
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what is cerebral lateralization
Cognitive functions are unequally represented in the right and left hemispheres; represents a division of labor, but is not absolute:
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where are emotional functions
left frontal cortex responsible for “positive” emotions, such as happiness; right frontal cortex responsible for “negative” emotions, such as anger
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what is aphasia
language deficit from damage to broca's area or wernicke's area
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attention is where
Right parietal cortex
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what is language
Ability to comprehend and produce words through speaking, writing, and/or signing, and to assign and recognize the symbolic meaning of a work correctly
- Involves syntax (arrangement of words and phrases to create sentences), grammar, and context
- Correct understanding also relies on cues such as tone, volume, and the speaker’s body language
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what is this - In the temporal lobe; responsible for understanding language and linking a word with its correct symbolic meaning
wernicke's area
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most language functions reside in
the left hemisphere in about 97% of people; damage to the language areas of the right hemisphere results in loss of emotional and tonal components of language
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damage to broca's area or wernicke's area results in
in a language deficit called aphasia
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what does it mean to learn
Acquiring new information that is observable as some sort of behavioral change
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what is declarative memory
Memory of things that are readily available to consciousness that could in principle be expressed aloud; such as a phone number or quote
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what is this - In the frontal lobe; responsible for the production of language, including the planning and ordering of words with proper grammar and syntax
broca's area
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what is short term memory
Stored for several minutes
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what is memory
Information is encoded and stored in neural circuitry and is retrievable at will
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nondeclarative memory aka
skills memory
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what is long term memory
More permanent form of storage for days, weeks, or even a lifetime
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declarative memory aka
fact memory
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what is nondeclarative memory
Includes skills and associations that are largely unconscious; such as how to enter a phone number on a phone
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short term memory aka
working memory
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some information is transferred into long-term memory by _________ but much is forgotten and the process is often flawed, resulting in incorrect memories
consolidation
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what are cranial meninges
Made primarily of dense irregular connective tissue
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how does Cranial meninges protect the brain
Set of three protective membranes that surround the brain
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what is immediate memory
Stored for a few seconds; important in conversation, reading, and daily tasks
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how does Cerebrospinal fluid protect the brain
Protective fluid that bathes the brain and fills its cavities
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inside the skull there are features which add protection
- cranial meninges
- cerbrospinal fluid
-blood brain barrier
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how does Blood brain barrier protect the brain
Prevents many substances in the blood from gaining access to brain cells
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arachnoid aka
arachnoid mater
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dura aka
dura mater
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where is arachnoid
middle layer of cranial meninges
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pia aka
pia mater
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blood brain barrier cells are unique how
- They have more tight junctions than cells of most capillaries
- They limit endocytosis and exocytosis
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what is dura
Outermost layer; thickest and toughest - of cranial meninges
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what is blood brain barrier
Consists of simple squamous epithelial (endothelial) cells of the blood capillaries in the brain, their basal laminae, and foot processes of astrocytes; cells are unique
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elaborate bbb - They limit endocytosis and exocytosis
Endothelial cells of the blood brain barrier have a very limited ability to perform these processes compared to other capillary cells
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what does bbb stand for
blood brain barrier
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________, _______ molecules are effectively prevented from crossing in significant amounts; does prevent many toxins and organisms from crossing, but also prevents many therapeutic drugs, such as most antibiotics, from entering the brain
large, polar
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where is pia
innermost layer of cranial meninges
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elaborate bbb - They have more tight junctions than cells of most capillaries
Tight junctions are cell-cell junctions that prevent water and other substances from passing through the spaces between cells
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plasma membrane of bbb -
generally freely permeable to certain substances, such as water, oxygen, carbon dioxide, and nonpolar, lipid-based compounds
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capillaries in most organs and tissues ...
are somewhat leaky and allow many substances to move from the blood to the E C F (and vice versa)
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tiniest blood vessels in the body
capillaries
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where is bbb
Blood brain barrier isn’t around the brain; it’s within the brain and not in one distinct location, but is found throughout the entire brain
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substances with channels or carriers, such as glucose, amino acids, and ions, also cross bbb __________
easily
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spinal cord has two roles:
- relay station
- processing station
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what do capillaries do
the tiniest blood vessels in the body; they deliver oxygen and nutrients to the body’s cells and remove any wastes produced by the cells
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brain capillaries are specialized to do what
specialized to only allow selected substances to enter the E C F, so they act as a “barrier”
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elaborate spinal cord- relay station
Only means by which the brain can communicate with most of the body below the head and neck; receives outgoing stimuli from the brain and sends them to the rest of the body; receives incoming stimuli from the body and sends them to the brain
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elaborate spinal cord processing station
Does some integration and processing functions; certain activities called Spinal Reflexes, can be carried out by the spinal cord alone, without influence from the brain
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what are spinal reflexes
activities carried out by the spinal cord alone, without influence from the brain
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spinal meninges include
Dura, Arachnoid, and Pia Mater;
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spinal reflexes do not need
influence from the brain
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what are the three spaces of the spinal cord
- epidural space
- subdural space
- subarachnoid space
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what is an actual space of the spinal cord
space that exists under normal conditions
subarachnoid space - between the arachnoid and pia; filled with a very thin layer of CSF; area inferior to the base of the spinal cord contains a larger volume of CSF; useful for CSF sampling if needed
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what is a potential space of the spinal cord
spaces that only exist under certain conditions
subdural space - normally the dura and arachnoid adhere to each other
epidural space - between the meningeal dura and the walls of the vertebrae; filled with veins and adipose tissue that cushions and protects the spinal cord
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the epidural space is actual or potential
actual
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thesubdural space is actual or potential
potential
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the subarachnoid space is actual or potential
actual
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what is the epidural space
Between the meningeal dura and the walls of the vertebrae; filled with veins and adipose tissue that cushions and protects the spinal cord
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what is the subdural space
Potential space; normally the dura and arachnoid adhere to each other
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what is the subarachnoid space
Between the arachnoid and pia; filled with a very thin layer of C S F; area inferior to the base of the spinal cord contains a larger volume of C S F; useful for C S F sampling if needed
