Nervous System l Flashcards
(84 cards)
1
Q
Overview: What is the nervous system?
A
The master controlling and communicating system of the body. It regulates organ function during normal homeostasis, and facilitates the body’s response to emergency situations
2
Q
Overview: How does the Nervous system communicate?
A
Its cells (neurons) communicate via electrical and chemical signals, which are rapid and specific, and usually cause and instant response
3
Q
Overview: What are the two parts the nervous system is functionally divided into?
A
- The CNS (central nervous system: control centre)
- The PNS (peripheral nervous system: connects CNS to rest of the body)
4
Q
What are the 4 main regions of the brain?
A
- Cerebral Hemispheres (left and right - contain frontal, parietal, temporal lobe which contains amygdala and occipital lobes within)
- Cerebellum (contains posterior lobe, anterior lobe, and flocconodular lobe)
- Diencephalon (*contains epithalamus, thalamus, hypothalamus, subthalamus**)
- Brain stem (mid-brain, pons, medulla oblongata)
5
Q
For exam on slideshows: What do the cerebral hemispheres contain?
A
- Cerebral cortex
- Cerebral white matter
- Basal nuclei
6
Q
For exam on slideshows: What does the Diencephalon contain?
A
Thalamus, Hypothalamus
7
Q
For exam on slideshows: What does the brain stem contain?
A
Mid brain, Pons, Medulla Oblongata
8
Q
For exam on slideshows: What does the cerebellum contain?
A
The cerebellum No further elaboration
9
Q
What is the collective name for the cerebral hemispheres of the brain?
A
The cerebrum
10
Q
What is the largest portion of the brain?
A
The cerebrum
11
Q
What is the cerebrum covered in?
A
Convolutions
12
Q
What are the elevations and grooves called in the cerebral convolutions?
A
- Elevations called gyri (gyrus singular)
- Grooves called sulci (sulcus singular)
- Made primarily of grey matter (some white matter):
13
Q
What do the convolutions on the cerebrum achieve?
A
A greater surface area = a larger number of neurons to fit inside the thin cortical layer of the cerebrum
14
Q
What are the larger grooves that separate portions of the brain called?
A
Fissures. Made up of both grey and white matter
15
Q
What are the functions of grey and white matter in the brain?
A
Grey Matter: Densely populated with dendrites and cell bodies (for processing and decision making)
White Matter: Lipid rich white axons travel through (“communication cables”)**
16
Q
What is the corpus callosum?
A
A large bundle of nerve fibres (axons) that connects the left and right cerebral hemispheres of the brain. It’s a major pathway for communication and information transfer between the two hemispheres, allowing them to work together. (no notes on this on the slides)
Made up of white matter.
17
Q
What are the four lobes of the cerebral hemispheres? How is each hemisphere divided into these lobes?
A
- Frontal
- Parietal
- Temporal
- Occipital
These lobes are separated via fissures/sulci.
18
Q
Where are each of the four cerebral lobes located in relation to the brain?
A
- Frontal lobe - located posterior to the forehead
- Parietal lobe - located posterior to the frontal lobe
- Temporal lobe - located inside the skull near the ears
- Occipital - The most posterior part of the brain
19
Q
What is the role of the prefrontal cortex (cerebrum - frontal lobe)?
A
- Goal orientated behaviour (e.g ability to concentrate)
- Short term/recall memory
- The elaboration of though
- The inhibition of the limbic areas of the CNS
20
Q
What is the role of the parietal lobe (cerebrum)?
A
(two functional regions: sensation and perception)
- Receives sensory input and then integrates and interprets it.
- Constructs a spatial coordinate system to represent the world around us (e.g feel a smooth round object with your fingers and sensory integration allows you to recognise it as a ball).
21
Q
What is the role of the temporal lobe (cerebrum)?
A
Primary auditory cortex (Wernicke’s area), responsible for reception, understanding and interpretation of speech, linked closely with hearing.
Memory consolidation and olfaction (smell)
22
Q
What is the role of the occipital lobe (cerebrum)?
A
Primary visual cortex, receives input from the retinas.
Involved in visual association, interpret and associate structures that you see.
23
Q
What are the main parts of the cerebral frontal lobe?
A
- The prefrontal Cortex (front)
- The primary motor cortex (posterior to prefrontal cortex)
- Broca’s speech area (? confusing)
24
Q
What is the role of the primary motor cortex (cerebrum - frontal lobe)?
A
For consciously moving our skeletal muscles - voluntary movements
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What is the role of broca's speech area (cerebrum - frontal lobe)?
Responsible for motor aspects of speech - facial muscle movement (lips, tongue, throat)
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Frontal lobe disorders: What is alexia and aphasia?
Difficulty recognising written words (alexia), and spoken words (aphasia). Can be caused by lesions in this region.
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Frontal lobe disorders: What can lesions in this area give rise to (other than alexia and aphasia)?
Failure to conform to social norms, ethical behaviour, emotional responses and morality may be altered
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Frontal lobe disorders: What can damage to the Broca's area cause?
Can interfere with the ability to use language (expressive aphasia)
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Frontal lobe disorders: What can damage to this area cause overall?
Personality change
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Parietal lobe disorders: What is alcalculia, apraxia, constructional apraxia, anosagnosia, agnosia and contralateral neglect ?
What other problems can occur from parietal lobe damage?
Alcalculia - Difficulty with maths
Apraxia - Difficulty with motor planning and complex movements- can have spatial disorientation
Constructional apraxia - difficulty making things
Anosagnosia - Denial of deficits
Agnosia - Disorders of object perception
Contralateral neglect - neglecting part of body or space (can impair many self care skills like washing/dressing)
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Occipital lobe disorders: What kind of disorders are generally associated with the occipital lobe?
Eye and vision related disorders
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Occipital lobe disorders: What is object agnosia?
Not recognizing objects by sight
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Occipital lobe disorders: What is colour agnosia?
The inability to process colours (dim or grey), or the inability to connect colours with their names
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Occipital lobe disorders: What is visual simultanagnosia?
See objects, but have an inability to relate them to each other (I.e see individual trees but not understand it's a forest)
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Occipital lobe disorders: NOTES for rest of disorders:
- Visual illusions (size form or movement) are inaccurate
- Visual hallucinations where the neurons in occipital lobe process signals that they are creating not the eye.
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Temporal lobe disorders:
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Temporal lobe disorders: NOTES
- 75% of focal seizures begin in the temporal lobe
- Disorders of severe anxiety, stress, panic including those relating to trauma
- Mental health related conditions affect the area specifically
- Memory linked sensory processing (amnesia)
37
The limbic lobe/system: What part of the brain is this usually linked to?
The cerebrum
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What is the limbic system responsible for?
Closely associated with memory and emotion.
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What structures make up the limbic system?
Many structures located within the cerebral cortex hemispheres and around the corpus callosum. These include:
- Limbic lobe
- Amygdala
- Fornix
- Hippocampus
- Olfactory bulb
- Portions of the thalamus + hypothalamus
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ANATOMY - Cerebral cortex (NOTES)
– outer or superficial layer of the cerebral hemispheres (2-4mm thick)
Contains the grey matter (densely populated with cell bodies and dendrites)
Speech, memory logical and emotional response, consciousness and interpretation of sensation and voluntary movement
Critical part of the brain for conscious control
Sensory information must reach cerebral cortex for conscious awareness and control of muscles originates in the cerebral cortex
41
Where is the limbic lobe/system located within the brain?
Parts of the cerebrum. It is a system of structures, many of which are in the cerebral hemispheres and surround the corpus callosum. Parts of the limbic system are cerebral and diecephalic.
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What is the primary function/s of the limbic system?
Associated with emotion, memory *and motivation*.
Involved in basic behavioural responses, visceral reaction to emotions, feeding behaviours, biological rhythms and sense of smell
This system is powerful and has a great influence on how we interpret our environment and experiences, such as whether or not something makes us happy.
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What parts of the brain make up the limbic system?
- Limbic lobe
- Amygdala
- Fornix
- Hippocampus
- Olfactory bulb
- Portions of the thalamus
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What is the cerebral cortex?
The outer/superficial layer of the cerebral hemispheres (2-4mm thick)
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What does the cerebral cortex contain?
Grey matter + dendrites (*transmit information*)
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Cerebral cortex: Additional NOTES
Speech, memory logical and emotional response, consciousness and interpretation of sensation and voluntary movement
Critical part of the brain for conscious control
Sensory information must reach cerebral cortex for conscious awareness and control of muscles originates in the cerebral cortex
47
Where is the diencephalon located in the brain?
The diencephalon sits atop the Brain stem, and is surrounded by the cerebrum.
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Where is the third ventricle in the brain located?
The diencephalon (**first two lateral ventricles in the either side of the cerebrum, fourth in the hindbrain). The third ventricle is enclosed by the thalamus.
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What is the function of the diencephalon overall?
Relaying station for sensory impulses to the cerebral cortex. Relay for information from basal nuclei and cerebellum to the appropriate motor area
50
What are ventricles of the brain?
Cavities that produce and circular CSF (cerebral spinal fluid)
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What are the structures within the diencephalon?
Hypothalamus + pituitary gland, Thalamus, Epithalamus, Pineal gland (in the epithalamus), choroid plexus (in the epithalamus - creates CSF).
52
What is the function of the hypothalamus in the brain?
TO:
- Maintain a constant internal environment
- Implement behavioural patterns
- Autonomic nervous system function and endocrine function
- Regulate body temperature and emotions
53
What is the brain stem? What is its function?
The brain stem is the vital centre of the brain, and breathing/blood pressure is controlled in this area. Is a pathway for ascending and descending tracts. Many small grey matter areas – autonomic behaviours for survival
54
What are the parts of the brain stem?
- Midbrain (superior portion)
- Pons
- Medulla oblongata
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What are the structures of the midbrain (which is located within the brain stem)...?
- Corpora quadrigemina
- Cerebral aqueduct
- Cerebral peduncle
56
Where is the fourth ventricle of the brain located?
In the hindbrain/brainstem between cerebellum and brain stem
57
What is the function of the pons in the brainstem?
- Primarily transmitting information from the cerebellum to the brain stem between the two hemispheres
- Assisting the nuclei in the medulla oblongata to maintain respiratory function
58
What is the function of the medulla oblongata in the brain stem?
Reflex activities controlled in this area
Heart rate
Breathing
Blood pressure
Coughing
Sneezing
Vomiting
Most important area for basic life support!
- contains cranial nerves: each with a specific function
59
Where are the cranial nerves located in the brain (12)?
The first cranial (l) olfactory (smell) and second (ll) optic (sight) nerves originate in the cerebral hemispheres, whilst the other ten are located elsewhere:
(lll/lV): Oculometer and Trochlear nerves:
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What are the twelve cranial nerves in the brain? =
- Olfactory nerve (I):
- Optic nerve (II):
- Oculomotor nerve (III):
- Trochlear nerve (IV)
- Trigeminal nerve (V):
(VI): Abducens nerve
- Facial nerve (VII):
- Vestibulocochlear nerve (VIII):
- Glossopharyngeal nerve (IX):
- Vagus nerve (X):
- Accessory nerve or spinal accessory nerve (XI):
- Hypoglossal nerve (XII):
61
Where is the olfactory cranial nerve found in the brain? What is its function + number (of the twelve)
Olfactory nerve (I): Providing the sense of smell.
62
Where is the optic cranial nerve found in the brain? What is its function + number (of the twelve)
Optic nerve (II): Providing vision.
63
Where is the ocular/ocularmotor cranial nerve found in the brain? What is its function + number (of the twelve)
Oculomotor nerve (III): Opening and moving your eyes and adjusting pupil width.
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Where is the trochlear cranial nerve found in the brain? What is its function + number (of the twelve)
Trochlear nerve (IV): Looking down and moving your eyes toward your nose or away from it.
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Where is the trigeminal cranial nerve found in the brain? What is its function + number (of the twelve)
Trigeminal nerve (V): Providing sensations in your eyes, most of your face and inside your mouth. It also allows you to chew food.
66
Where is the abducens cranial nerve found in the brain? What is its function + number (of the twelve)
Abducens nerve (VI): Moving your eyes from left to right.
67
Where is the facial cranial nerve found in the brain? What is its function + number (of the twelve)
Facial nerve (VII): Controlling several facial muscles to make facial expressions and providing the sense of taste in part of your tongue.
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Where is the vestibulocochlear cranial nerve found in the brain? What is its function + number (of the twelve)
Vestibulocochlear nerve (VIII): Providing the sense of hearing and balance.
69
Where is the glossopharyngeal cranial nerve found in the brain? What is its function + number (of the twelve)
Glossopharyngeal nerve (IX): Providing taste sensations to part of your tongue and controlling muscles for swallowing. It also has parasympathetic nerve fibres that play a role in blood pressure regulation and saliva (spit) production.
70
Where is the vagus cranial nerve found in the brain? What is its function + number (of the twelve)
Vagus nerve (X): Regulating several automatic bodily processes, including your digestion, blood pressure, heart rate, breathing, mood, saliva production and more. It’s the main nerve of your parasympathetic nervous system.
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Where is the accessory/spinal accessory cranial nerve found in the brain? What is its function + number (of the twelve)
Accessory nerve or spinal accessory nerve (XI): Controlling shoulder and neck movement.
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Where is the hypoglossal cranial nerve found in the brain? What is its function + number (of the twelve)
Hypoglossal nerve (XII): Controlling tongue movement, which plays a role in speaking, eating and swallowing.
73
What is reticular formation?
A large network of neurons that extends the entire length of the brain stem
74
What is the RAS/Reticular activation system?
**A subset of the reticular formation. It is responsible for controlling arousal and wakefulnes, filtering incoming sensory information to decide what gets into your conscious awareness, and to maintain alertness and attention. **
- Anaesthetic agents affect this area
- Glasgow Coma Score (GCS) tests RAS indirectly
- Damage to this area can result in permanent unconsciousness (coma)
75
What does 'cerebellum' translate to?
'Little brain'- The shape of the cerebellum looks like a miniature brain
76
Where is the cerebellum located in the brain? What is it composed of?
Posterior and inferior to the occipital lobe of the cerebral hemispheres. It is composed of grey and white matter
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What are the two lobes of the cerebellum connected by?
The vermis
78
What does the outside of the cerebellum look like?
It is convoluted - much like the cerebral hemispheres of the brain. It is divied into two lobes, and connected by the vermis.
79
What is the function of the cerebellum?
- Responsible for reflexive, involuntary fine-tuning of motor control for precise activities
- Maintains balance and posture (extensive neural connections with the medulla and midbrain)
- Compared to an automatic pilot – continuously receiving feedback and adjusting – unless damaged
80
Cerebellum: ADDITIONAL NOTES:
Precise timing for skeletal muscle activity and controls our balance and equilibrium. Because of its activity, body movements are smooth and coordinated. It plays its role less well when it is sedated by alcohol.
If the cerebellum is damaged (for example, by a blow to the head, a tumour, or a stroke), movements become clumsy and disorganized—a condition called ataxia. Victims cannot keep their balance and may appear to be drunk because of
the loss of muscle coordination. They are no longer able to touch their finger to their nose with eyes closed—a feat that normal individuals accomplish easily.
81
What is the outer layer of the cerebellum called?
The cerebellar cortex
82
What are brain ventricles?
Four large fluid filled spaces within the brain
83
What is the location of the four ventricles in the brain?
1st/2nd: The 'lateral' ventricles are located one in each hemisphere of the cerebrum
3rd ventricle: Located inferior and medial to the lateral ventricles, is a thin, vertical pocket of fluid.
4th ventricle: A tiny, diamond shaped space where the cerebellum attached to the back of the brainstem. A slight extension of the central canal extending upwards from the spinal cord.
