The Brain and Autonomic Nervous System Flashcards
1
Q
What is not stored in the brain and must have a constant supply?
A
Glucose
2
Q
Brain-related symptoms are always the first of hypoglycemia (low blood sugar) what are some of the symptoms?
A
lightheadedness, dizziness, irritability, headache.
3
Q
The brain gets its blood supply carrying glucose and oxygen from what?
A
The bilateral common carotid arteries and bilateral vertebral arteries.
4
Q
Blood returns to the lungs from the brain via the?
A
bilateral internal jugular veins
5
Q
What is the Blood-brain barrier?
A
prevents the passage of many substances from the blood into brain tissue
6
Q
What is the Blood-brain barrier (BBB) Comprised mostly of? And what do they do?
A
astrocytes which protects the brain from many harmful substances.
7
Q
What crosses the BBB quickly?
A
A few water-soluble substances, such as glucose lipid-soluble substances, such oxygen, carbon dioxide, alcohol, & most anesthetic agents
8
Q
What crosses the BBB more slowly
A
Creatinine, Urea, and most ions
9
Q
What doesn’t cross the BBB at all?
A
Some substances, such as proteins and antibiotics
10
Q
How is the BBB broken down
A
trauma, inflammation, and certain toxins
11
Q
Can all drugs pass into the BBB?
A
no, Certain drugs cannot pass, making it difficult to treat some diseases and infections.
12
Q
What are the names of the 3 layers of connective tissue-protective covering of the brain? (The cranial meninges)
A
Dura mater, arachnoid mater, pia mater
13
Q
What is the Dura mater? And what is it surrounded by?
A
the superficial layer of The cranial meninges made of dense irregular CT. epidural space.
14
Q
What is the arachnoid mater?
A
the middle layer of the cranial meninges
15
Q
What is the pia mater?
A
One of the cranial meninges that is the innermost layer made of a thin, transparent layer of CT that adheres to the brain and spinal cord.
16
Q
What is the epidural space?
A
a layer of fat and connective tissue between the dura mater and the internal wall of the vertebral canal
17
Q
Does the arachnoid mater have a blood supply?
A
No
18
Q
What is the subdural space
A
the space between the arachnoid mater and the dura mater
19
Q
Does the pia mater have any blood supply
A
contains many blood vessels that supply oxygen and nutrients to the brain and spinal cord
Blood vessels are sheathed by pia mater as they penetrate the brain from the surface inward
20
Q
What is the subarachnoid space?
A
the space between the arachnoid mater and pia mater
21
Q
What are the parts of the brain are separated by three extensions of the dura mater called?
A
Falx cerebri, Falx cerebelli, and Tentorium cerebelli
22
Q
What is the Falx cerebri?
A
separates the left & right hemispheres of the brain
23
Q
What is the Falx cerebelli?
A
separates the two hemispheres of the cerebellum
24
Q
What is the Tentorium cerebelli?
A
separates the cerebrum from the cerebellum
25
What is Cerebrospinal Fluid (CSF)?
Clear colorless liquid that protects the CNS against harmful chemicals and physical damage. Also carries oxygen, glucose and other needed chemicals.
26
Where is Cerebrospinal Fluid produced
choroid plexuses found in the ventricles of the brain.
27
What is the Choroid Plexus?
a network of capillaries and blood vessels inside the ventricles that produce CSF.
28
What are Ventricles?
cavities within the brain that contain large amounts of CSF
29
Where is the Lateral Ventricle located?
Surrounded by the genu of the corpus callosum
30
Where is the Third Ventricle located?
inferior to the corpus callosum
31
Where is the Fourth Ventricle located?
between the pons and the cerebellum
32
What is the Cerebral Aqueduct?
CSF-filled channel through the midbrain of the brainstem that connects the 3rd & 4th ventricles to each other.
33
What is the Medulla Oblongata?
most inferior part of the brain stem. Contains the ascending sensory and descending motor tracts.
34
What are Pyramids
wo lateral, external bulges formed by the two largest motor tracts.
35
What is Decussation of the pyramids?
the pyramids cross within the medulla oblongata taking most of the motor axons with it.
36
What does the Medulla Oblongata contain and control?
cardiovascular center- controlling rate and force of heartbeat as well as the diameter of blood vessels.
medullary rhythmic area of the respiratory center- controlling the rhythm and rate of breathing.
reflexes such as vomiting, coughing, and sneezing.
37
What cranial nerves emerge from the medulla oblongata
Vestibulocochlear (CN VIII) cochlear branch
Glossopharyngeal (CN IX)
Vagus (CN X)
Accessory Nerve (CN XI)
Hypoglossal (CN XII)
38
What does the Vestibulocochlear (CN VIII) cochlear branch nerve control?
sensory and motor associated with hearing (cochlear branches)
39
What does the nerve Glossopharyngeal (CN IX) control?
sensory and motor control taste, swallowing, and salivation
40
What does the nerve Vagus (CN X) control?
sensory and motor associated with voice production, digestive secretions, taste, and slowing of heart rate
41
What does the Accessory Nerve (CN XI) nerve control?
motor swallowing and shoulder shrug (spinal portion)
42
What does the Hypoglossal (CN XII) nerve control?
motor tongue movement and swallowing
43
Where is the pons located? And what does it do?
superior to the medulla and anterior to the cerebellum
Helps control breathing with the pneumotaxic and apneustic areas.
44
What are the Cranial Nerves emerging from the pons?
Trigeminal (CN V),
Abducens (CN VI),
Facial (VII),
Vestibulocochlear (CN VIII) vestibular branch:
45
What does the Trigeminal (CN V) nerve control?
sensory and motor-sensory from the head and face, motor for chewing (mastication)
46
What does the Abducens (CN VI) nerve control?
motor eyeball movement
47
What does the Facial (VII) nerve control?
motor and sensory associated with sensory for taste and motor for saliva secretion, tears, and facial expression
48
What does the Vestibulocochlear (CN VIII) vestibular branch: nerve control?
sensory and motor associated with balance and equilibrium
49
Where is the midbrain located?
directly superior to the pons
50
What are the Cerebral peduncles?
the anterior part of the midbrain containing axons of the sensory and motor tracts.
51
What is the Tectum?
posterior part of the midbrain divided into the corpora quadrigemina
52
What are the two parts of the corpora quadrigemina called?
Superior Colliculi and Inferior Colliculi
53
What is the Superior Colliculi?
two superior elevations that are reflex centers controlling movements of the eyes, head, and neck in response to visual and other stimuli.
54
What is the Inferior Colliculi?
two inferior elevations that are reflex centers for movements of the head and truck in response to auditory stimuli.
55
What is the Cerebral Aqueduct?
CSF-filled channel between the tectum & the cerebral peduncles that connects the 3rd & 4th ventricles to each other.
56
What are the Cranial Nerves emerging from Midbrain?
Oculomotor (III) and
| Trochlear (IV)
57
What does the Oculomotor (III) nerve control?
motor movements of the ipsilateral eyeball, constriction of the pupil, changes in lens shape.
58
What does the Trochlear (IV) nerve control?
motor movements of the ipsilateral eyeball
59
Where is the cerebellum located?
Posterior and inferior to the cerebrum, posterior to the occipital lobe.
60
What are the main structures of the cerebellum?
cerebellar hemispheres on the left and right
Vermis: the raised structure along the median lineiii
Arbor vitae: highly branched, internal white matter
61
What are the 5 roles of the cerebellum?
monitors intentions for movementii
monitors actual movementiii
compares the command signals
sends out corrective signals
summary: important in learning and performing coordinated, highly skilled movements.
62
What is the function of the cerebellum?
compares intended movements with what is actually happening to coordinate and smooth out complex, skilled movements. Also regulates balance and posture.
63
Where is the Diencephalon located?
Extends from the brain stem to the cerebrum?
64
What other structures does the diencephalon include?
thalamus, hypothalamus, epithalamus, and subthalamus
65
What does the thalamus do?
Relays sensory input to the cerebral cortex, provides crude perception of touch, pressure, pain, and temperature. Also contributes to emotions, memory, cognition and awareness
66
Where is the Hypothalamus located and what does it do?
just inferior to the subthalamus.
Contains the mamillary bodies, infundibulum, and median eminence (encircles the infundibulum)
Controls and integrates the autonomic nervous system and pituitary gland
Regulates emotional and behavioral patterns
Body temperature, eating and drinking behavior
Maintains waking state and established sleeping patterns
67
Where is the Subthalamus located and what does it do?
just posterior to the hypothalamus
Help control body movements
68
Where is the Epithalamus located and what does it do?
superior and posterior to the thalamus
Contains the pineal gland (endocrine) which secretes melatonin (thought to promote sleepiness).
69
where is the cerebrum located? And what does it contain?
Supported on top of the diencephalon
cerebral cortex
70
What is the cerebral cortex?
the outer layer of gray matter of the cerebrum)
Made up of sucli, gyri, and fissures.
71
how many hemispheres does the cerebrum have?
two, called bilateral hemispheres.
72
What are the names of the cerebrum lobes?
frontal, parietal occipital, temporal
73
Where is the frontal lobe located? And what are its functions?
anterior most lobe
Chiefly concerned with voluntary motor functions, motivation, foresight, planning, memory, mood, emotion, social judgement, and aggression.
74
What is the Precentral Gyrus? What does it do?
the posterior most gyrus of the frontal lobe.
The somato-motor center of the cerebral cortex
Voluntary motor impulses begin here
Located anterior to the central sulcus
75
Where is the parietal lobe located? And what are its functions?
divided from the frontal lobe by the central sulcus
Concerned with sensory reception and the integration of somatosensory, taste, and some visual information.
76
What is the Postcentral Gyrus? What does it do?
The anterior-most gyrus of the parietal lobe.
The somatosensory center of the cerebral cortex
All nerve impulses from perceived somatic sensations have their CNS destination here.
Located posterior to the central sulcus
77
Where is the occipital lobe located? And what are its functions?
The posterior-most lobe. Separated from the parietal lobe at the parieto-occipital sulcus.
The principal visual center of the brain.
78
What is the Temporal Lobe? And what are its functions?
lateral, horizontal lobe. Divided from the parietal lobe by the lateral sulcus.
Concerned with hearing, smell, learning, memory, visual recognition, and emotional behavior.
79
What is an Insula?
A small mass of cortex deep to the deep to the lateral sulcus.
Not accessible to study in living people because of its location.
Thought to play a role in understanding spoken language, the sense of taste, and in integrating information from visceral receptors.
80
What are commissural tracts?
The cerebrum’s white matter is divided into tracts of neurons that allow communication throughout the brain.
The two cerebral hemispheres communicate with each via masses of white matter in the cerebrum
81
Name the two commissural tracts. And where they are located.
Corpus Callosum: the largest commissural tract.
Anterior & Posterior Commissures: smaller masses of white matter tracts located anterior and posterior to the corpus callosum.
82
What are projection tracts?
allow different vertical levels of the brain (brainstem, diencephalon, cerebrum) to communicate with each other and the spinal cord.
83
What are motor tracts?
Carry impulses from the cerebral cortex to the spinal cord and sensory tracts carry impulses from the spinal cord or brainstem to the thalamus or cerebrum.
84
What are association tracts?
allow different regions of the same cerebral hemisphere to communicate with other.
Association tracts link perceptual and memory regions of the brain so a person can identify a sensation.
85
What is the Basal Nuclei (aka ganglia) and what does it contain?
inferior masses of cerebral gray matter buried deep in the white matter lateral to the bilateral thalamus.
Receives information from the substantia nigra of the midbrain and the motor area of the cerebral cortex.
Contains the caudatenucleus, putamen, and globus pallidus.
86
What is the lentiform Nucleus?
globus pallidus and putamen together
87
What is the Corpus Striatum?
Lentiform nucleus and caudate nucleus together
88
What are the 4 roles of the Basal Nuclei?
programs habitual or automatic movements
Inhibits motor neurons that are intrinsically active
Damage results in abnormal rigidity, flailing of the limbs (ballismus), and/or tremors.
Functions to coordinate gross automatic muscle movements and regulate muscle tone
89
What are Automatic movements?
movements that happen without your approval, but can be stopped if you wish (i.e. arm swing while walking or laughing at a joke)
90
What are Habitual movements?
highly practiced movements that require little cognitive thought
91
What is cognition?
refers to mental processes such as awareness, perception, thinking, knowledge, and memory.
92
What percent of our brain consists of cognitive areas?
75%
93
How are most of what’s known of the cognitive functions of different areas was obtained?
by studying people who’ve had injuries or lesions to specific areas.
94
Lesions of the Parietal lobe cause?
people to be unaware of objects or limbs of their own body contralaterally.
95
Lesions of the temporal lobe cause?
agnosia: The inability to recognize, identify, or name familiar objects.
96
What is Prosopagnosia?
The person can’t remember familiar faces or their own face in the mirror.
97
Lesions of the frontal lobe cause?
changes in personality.
98
The frontal lobe integrates information from?
the sensory and motor regions of the cortex.
99
What is amnesia?`
a defect in declarative memory (the ability to describe past events)
100
Hippocampus: important to?
Memory forming
`
does not do short term memory but it relayes it to the cerebral cortex
101
Difference between the temporal lobe and frontal when it comes to memory.
The temporal lobe stores memories of faces and familiar objects while the frontal lobe stores memories of our plans and social roles
102
What is Anterograde Amnesia?
nability to store new information
caused by lesions of the hippocampus
103
What is Retrograde amnesia?
Inability to recall things that took place prior to the injury
caused by lesions of the cerebral cortex
104
The expression of our emotions is controlled by the?
the prefrontal cortex (the deeper portion of the frontal lobes cortex).
105
Our feelings and emotional memories take place deeper in the brain’s tissue
hypothalamus and amygdala
106
where we decide the appropriate way to express those emotions and feelings
prefrontal cortex
107
What is the Amygdala
part of the limbic system that causes us to jump back from a frightening stimulus or miss someone you love.
108
Where is Wernicke Area and what does it do?
posterior to the lateral sulcus usually in the left hemisphere
Responsible for the recognition of spoken & written language.
Formulates words and phrases based on learned rules of grammar and transmits a plan for speech to the Broca Area
109
Where is Broca's Area and what does it do?
located in the posterior/inferior portion of the frontal lobe ipsilateral to Wernicke’s Area.
Generates a motor program for the muscles of the larynx, tongue, cheeks, and lips to produce speech.
transmits this program to the primary motor cortex (precentral gyrus), which executes it.
110
The emotional aspect of language is controlled by?
the contralateral portions of the cortex that mirror the Wernicke & Broca area.
111
Where is the Affective language Area and what does it do?
opposite the Broca Area
creates emotion and intonation in speech
lesions cause flat, emotionless speech
112
concerned with recognizing the emotional content of another person’s speech.
Opposite the Wernicke Area is a cortical region
113
What is Aphasia?
any language deficit resulting from lesions of the Wernicke or Broca area.
114
What is Nonfluent Aphasia?
results from lesions in Broca’s area.
115
What is Fluent Aphasia?
results from lesions of Wernicke’s Area
Speaks normally but uses made-up words that make little sense to others.
Person also cannot comprehend written and spoken words.
116
What is Anomic Aphasia?
person can understand speech and speak normally but cannot understand written words or pictures.
117
What is the integrating center of the ANS
hypothalamus
118
The ANS regulates the activity of
smooth muscle, cardiac muscle, and certain glands.
119
the autonomic Nervous System includes
autonomic sensory neurons, integrating centers and autonomic motor neurons.
120
The ANS operates without conscious control and requires
constant sensory input from the visceral organs.
121
What are Autonomic Sensory Neurons?
bring sensory information from the organs to the CNS
122
What are Autonomic Motor Neurons?
bring autonomic motor responses from the CNS to the PNS.
123
The proximal motor neuron (preganglionic) is and
The distal motor neuron (postganglionic) is
myelinated
unmyelinated
124
The motor portion of the ANS has two major branches:
Sympathetic Division
Parasympathetic Division
125
All preganglionic Sympathetic neurons emerge from the
T1-L2 segments of the spinal cord and travel to the entire body after exiting the autonomic ganglion. It is therefore referred to as the thoracolumbar division.
126
All preganglionic Parasympathetic neurons emerge from the?
brainstem and S2-S4 spinal segments and travel to the entire body after emerging from the autonomic ganglion. It is therefore referred to as the craniosacral division.
127
The Parasympathetic Division utilizes the following cranial nerves:
Oculomotor (III),
Facial (VII),
Glossopharyngeal (IX), and Vagus (X)
128
What does the Oculomotor (III) nerve do?
narrows the pupil and thickens the lens
129
What does the Facial (VII) nerve do?
regulates the lacrimal glands, salivary glands, and nasal glands.
130
What does the Glossopharyngeal (IX) nerve do?
regulates other salivary glands
131
What does the Vagus (X) nerve do?
carries about 90% of all parasympathetic nerve fibers.
Regulates heart rate, respiratory rate, and swallowing
132
Where is the sympathetic ganglia
The site of synapses between pre- and postganglionic sympathetic neurons.
Divided into 2 groups
133
Where and what is Sympathetic Chain Ganglia?
lie in a vertical row on either side of the vertebral column from the base of the skull to the coccyx.
In general, postganglionic neurons from the sympathetic chain innervate the organs superior to the diaphragm.
134
Where and what is Prevertebral Ganglia?
lie anterior to the vertebral column close to the abdominal aorta and its branches.
In general, postganglionic neurons from the prevertebral ganglia innervate the organs inferior to the diaphragm.
135
What is the Parasympathetic Ganglia?
Preganglionic neurons synapse with postganglionic close to or actually within the effector organ it innervates.
136
What are Autonomic Plexuses?
Tangled networks of both sympathetic and parasympathetic neurons which lie along major arteries.
137
6 Major Plexuses
Cardiac Plexus: innervates the heart
Pulmonary Plexus: innervates the lungs
Celiac Plexus: digestion (stomach, pancreas, gall bladder, liver), diaphram, kidneys, testes, ovaries, and adrenal gland.
Superior Mesenteric Plexus: Small and large intestine (digestion)
Inferior Mesenteric Plexus: Large intestine (excretion)
Hypogastric Plexus: Pelvic viscera (uterus, ureters, etc.)
138
Postganglionic Neurons
After a preganglionic neuron of the sympathetic division reaches the sympathetic chain, it may or may not ascend or descend to another level before it synapses with a postganglionic neuron.
Parasympathetic preganglionic neurons synapse directly near or within the effector and therefore can only innervate that effector.
139
Physiological Effects of the ANS
Most body organs are innervated by both divisions of the ANS.
The divisions typically work in opposition of each other.
140
Organs that only have Sympathetic Innervation
Sweat Glands
Arrector pili muscles of hair follicles
Kidneys
Most blood vessels
Adrenal Medulla of the adrenal glands
141
Sympathetic responses
fight or flight
caused by physical and emotional distress
favors body functions that can support vigorous physical activity
reduces functions that favor the storage of energy, such as digestion.
142
fight or flight effects 8
1. .pupil dilation
2. Increase in heart rate, force of contraction, and blood pressure
3. Bronchial dilation allowing faster air movement in the lungs
4. Constriction of blood vessels that allow non-essential organs.Kidneys, gastrointestinal
5. Dilation of blood vessels that supply organs involved in exercise or fighting off danger.Skeletal muscles, cardiac muscle, liver, and fat tissue
6. Liver cells liberate stored sugar and fat cells liberate stored fat for energy
7. Glucose released from the liver
8. Digestion is inhibited
143
Which effects last longer sympathetic stimulation or parasympathetic stimulation.
sympathetic stimulation
144
Parasympathetic Responses 5
1. Salivation
2. Lacrimation
3. Urination
4. Digestion
5. Defecation
145
Autonomic Reflexes
Reflex arcs similar to somatic reflexes that are used to regulate blood pressure, respiratory rate, digestion, and excretion.
146
Cholinergic neurons
Cholinergic neurons are named so because they release the neurotransmitter acetylcholine (ACh).
147
Nicotinic receptors
found in the dendrites of sympathetic and parasympathetic postganglionic neurons
148
Muscarinic receptors
present in the post-synaptic membranes of all effectors of the parasympathetic nervous system.
149
Adrenergic neurons release the transmitter
norepinepherine
150
Most sympathetic post-ganglionic neurons are
adrenergic
151
Norepenephrine is removed from the synapse by either re-uptake by the presynaptic membrane or it is enzymatically deactivated by one of 2 enzymes
catechal-O-methytranserase (COMT)
monoamine oxidase (MAO)
