Nervous System Flashcards
(115 cards)
1
Q
Name the 2 main parts of the Nervous system and what each consists of.
A
Central Nervous System - Brain & Spinal cord
Peripheral Nervous system - Affector & effector neurones
2
Q
List the 3 parts of a neuron.
A
- Axon
- Cell body
- Dendrite(s)
3
Q
The axon carries information _____ from the cell body.
A
Away.
4
Q
Dendrites carry information ____ the cell body.
A
To.
5
Q
Name the 2 neuron types found in the spinal cord.
A
Ascending & Descending.
6
Q
What is the Vertebral foramen?
A
The vertical tunnel that runs through each vertebra.
7
Q
When the vertebrae are stacked on top of each other to form the spine, the vertebral foramen form the what?
A
Vertebral canal.
8
Q
Where is the spinal cord contained within?
A
Vertebral canal.
9
Q
True or false? Throughout its length, the spinal cord’s cross sectional appearance changes.
A
False. The spinal cord has a standard cross sectional appearance throughout its length.
10
Q
The outer section of the spinal cord is formed of white matter which consists of what?
A
It consists of axons of neurons that form ascending or descending pathways.
11
Q
The inner section of the spinal cord is formed from grey matter which consists of what?
A
The inner section is where cell bodies of neurons are located and is where synapses occur between these cell bodies, their dendrites and the axons of other neurons.
12
Q
Where do nerves from the body enter the spinal cord through?
A
Dorsal roots.
13
Q
What do nerves exit the spinal cord through?
A
Ventral horn (ventral root).
14
Q
Name the 2 divisions of the Peripheral Nervous system.
A
Somatic & Autonomic
15
Q
In the somatic nervous system where do descending motor tracts from the cerebral cortex mostly run?
A
In the lateral corticospinal tract.
16
Q
In the somatic nervous system where do sensory neurons carrying fine touch and proprioception from the limbs run?
A
In the dorsal columns.
17
Q
In the somatic nervous system where do sensory neurons carrying pain and temperature fibres run?
A
In the anterolateral fasciculus
18
Q
Where do autonomic nerves run?
A
Alongside the spinal cord in a collection of ganglia.
19
Q
At what vertebral level does the spinal cord end in adults?
A
L1
20
Q
At what vertebral level does the spinal cord end in children?
A
L3
21
Q
Nerves that travel to the CNS are called what?
A
Affector neurons.
22
Q
Nerves that travel from the CNS are called what?
A
Effector neurons.
23
Q
Which division of the PNS deals with the ‘subconscious’ control of our bodies (temperature control, secretions etc.)?
A
Autonomic Nervous system.
24
Q
The autonomic nervous system can be divided into what 2 systems?
A
Sympathetic & Parasympathetic systems.
25
True or false? The autonomic nervous system reaches its target via a single neuron.
False. The autonomic system has pre and post-ganglionic neurons.
26
Which section of the autonomic nervous system initiates the 'fight or flight' response?
The sympathetic nervous system.
27
Where are sympathetic cell bodies present?
In the thoracic and lumbar spinal cord segments.
28
Where do parasympathetic neurons arise from?
From the cranial nerves or from the lumbo-sacral spinal cord.
29
Which section of the autonomic nervous system initiates the 'rest and digest' response?
The parasympathetic nervous system.
30
Where are parasympathetic ganglia located?
Close to the target organ.
31
What does activation of the sympathetic nervous system do?
- Increases heart rate
- Causes vasoconstriction in the skin and viscera (including GI and kidneys)
- Reduces peristalsis
- Vasodilation occurs in the muscles and heart
- Sweat glands are stimulated to secrete sweat
- Adrenaline is secreted from the adrenal medulla
32
What does activation of the parasympathetic nervous system do?
- Decreases heart rate and force of contraction
- Causes vasodilation in the viscera (including GI and kidneys)
- Increases peristalsis
33
Which systems maintain homeostasis?
The autonomic and somatic nervous systems.
34
Which nervous system is responsible for conscious control?
The somatic nervous system.
35
What do somatic sensory nerves (afferent) detect?
Somatic sensory nerves (afferent) detect pain, temperature, touch and proprioception.
36
True or false? Somatic neurons do not synapse once they have left the CNS, they project directly to their target cell via a single neuron.
True.
37
Name the 2 types of somatic nerves and where they arise from.
- Spinal nerves that arise from the spinal cord.
| - Cranial nerves that arise directly from the brain.
38
Define Proprioception.
Location of the body in space, spacial awareness.
39
What do somatic efferent nerves innervate?
Somatic efferent neurons innervate skeletal muscle.
40
Define Spinal nerves.
Spinal nerves are the peripheral nerves that carry axons of neurons of the somatic and autonomic nervous systems to and from the spinal cord.
41
Where does a spinal root leave the spinal cord and what is the exception?
A spinal root leaves the spinal cord below each vertebra (T1, T2 etc) except in the cervical region where they exit superior to the vertebrae.
42
How many spinal roots are there?
31.
43
Where are dorsal and ventral roots present?
A dorsal and ventral root is present at each segment or vertebral level (plus one at theoretical C8).
44
True or false? Dorsal roots (posterior roots) are usually afferent.
True. Dorsal roots are usually afferent,carrying information from the periphery to the CNS.
45
Where do dorsal and ventral roots unite and what do they become?
They unite a small distance from the spinal cord to form a mixed segmental spinal nerve which may continue to a nerve plexus or become a single peripheral nerve.
46
Which spinal nerves is the lumbar plexus made up of?
The lumbar plexus is made up of spinal nerves arising from the spinal cord below vertebrae T12-L5.
47
True or false? The ventral roots (anterior roots) are usually efferent.
The ventral roots are usually efferent, carrying information from the CNS to the periphery in somatic motor and autonomic neurons.
48
After spinal roots leave the spinal cord and form spinal nerves they may blend with nerves from other spinal levels to form what?
A plexus.
49
Dermatomes and Myotomes are representative of what?
The distribution of somatic nerves.
50
Each spinal nerve supplies and is supplied by a distinct area of skin called what?
A dermatome.
51
Each spinal nerve supplies and is supplied by a group of muscles called what?
A myotome.
52
Why is it clinically useful that each spinal nerve supplies and is supplied by a distinct area of skin or group of muscles?
Clinically this can be very useful as the location of spinal lesions or damage can be ascertained from loss of sensation or motor function in distinct areas.
53
Which spinal nerves innervate most of the muscles and dermatomes of the thigh and leg?
The Sciatic and Femoral nerves.
54
Which nerve is a motor to muscles of the posterior thigh (the hamstrings that act to flex the knee)?
The Sciatic nerve.
55
Which nerve is a sensory afferent nerve from the skin over the lateral side of the leg and skin on the sole and dorsum of foot?
The Sciatic nerve.
56
Which nerve is a motor to muscles of the anterior thigh (the quadriceps that act to extend the knee)?
The Femoral nerve.
57
Which nerve is a sensory afferent nerve from the anterior thigh and medial leg?
The Femoral nerve.
58
How many cranial nerves are there?
12.
59
How do cranial nerves differ from spinal nerves?
Cranial nerves don't have a dermatomal or myotomal distribution.
60
True or false? Each cranial nerves serves a different function in the head and neck.
True.
61
The cranial nerves supply 'special senses', what are they?
- Sight
- Taste
- Hearing
- Smell
- Balance
62
What is the CN I Olfactory nerve's function?
Afferent from nasal mucosa, carries information related to smell.
63
What is the CN II Optic nerve's function?
Afferent for vision from retina.
64
What is the CN III Oculomotor nerve's functions?
- Controls movements of the eye and some control of the eyelids
- Motor to pupil constrictors
65
What is the CN IV Trochlear nerve's function?
Motor to one muscle that moves the eye.
66
What is the CN V Trigeminal nerve's functions?
- Afferent from surface of face
| - Motor efferent to muscles of mastication
67
What is the CN VI Abducent nerves's function?
Motor efferent to one muscle of the eye.
68
What is the CN VII Facial nerve's functions?
- Taste from anterior tongue and palate
- Motor efferent to muscle of facial expression
- Motor efferent to glands that secrete saliva
69
What is the CN VIII Vestibulocochlear nerve's functions?
- Hearing from cochlear of ear
| - Balance from vestibular apparatus of ear
70
What is the CN IX Glossopharyngeal nerve's functions?
- Taste from posterior tongue
- Motor efferent to help with swallowing
- Afferent sensation from external ear
- Secretomotor to one saliva gland
- Afferent sensation from carotid body and sinus
71
What is the CN X Vagus nerve's functions?
- Motor to muscles of pharynx, larynx and palate
- Parasympathetic innervation of smooth muscle in trachea, bronchi, GI tract and cardiac muscle
- Afferent sensation from GI tract, heart and airways
72
What is the CN XI Accessory nerve's functions?
- Motor to soft palate.
- Motor to pharynx.
- Motor to two big muscles in the neck
73
What is the CN XII Hypoglossal nerve's function?
Motor to muscles of tongue.
74
What is the left hemisphere of the brains function?
The left hemisphere controls logic, numbers and language. It processes the sensory and motor pathways for the right side of the body.
75
What is the right hemisphere of the brains function?
The right hemisphere is involved with creativity, imagination and rhythm and processes the sensory and motor pathways of the left side of the body.
76
What are the 2 hemispheres of the brain joined by?
A neural bridge of nerve fibres known as the corpus callosum.
77
What parts of the brain are found within the Forebrain?
- Cerebrum
- Thalamus
- Hypothalamus
78
What parts of the brain are found within the Hindbrain?
- Cerebellum
- Pons
- Medulla
79
What parts of the brain are found within the Brainstem?
- Midbrain
- Pons
- Medulla
80
Which part of the brain does the reticular formation run through?
The brainstem.
81
What does the reticular formation control?
Consciousness.
82
True or false? The brainstem has a similar structure to that of the rest of the brain.
False. The brainstem is a structurally distinct area of the brain.
83
What does the medulla control?
The medulla controls very basic functions such as breathing and heart-rate.
84
What does the pons control?
The pons has indistinct roles in consciousness and posture.
85
What does the midbrain control?
Eye movements and auditory systems.
86
Describe the structure of the cerebellum.
The cerebellum consists of two mounds of folded tissue posterior to the brainstem to which it is connected by three peduncles (bands of neurons resembling a stalk) of neural tissue.
87
What are the functions of the cerebellum?
The cerebellum is concerned mainly with motor functions. It also plays a vital role in motor learning as all motor skills are stored in cerebellar memory.
88
What inputs does the cerebellum recieve?
It receives inputs from ascending sensory pathways from the body and descending motor pathways from the cerebrum and other information from the brainstem.
89
What area is the midbrain located in?
The midbrain.
90
Why are the components of the brainstem grouped together?
This is a structural grouping as these three areas form part of the brain that is structurally very distinct from the forebrain or the cerebellum.
91
What happens when information is processed by the cerebellum?
The cerebellum modifies movements to make them appropriate to our surroundings.
92
Define the function of the thalamus?
The thalamus is a relay point where all inputs to the cerebrum synapse before ascending to the cerebral cortex.
93
What is the main function of the hypothalamus?
Homeostasis.
94
Most of the volume of the cerebral hemispheres consist of which type of matter?
White matter.
95
Which matter of the cerebral hemispheres contains the cell bodies of neurons?
Grey matter.
96
Which matter of the cerebral hemispheres contains the axons of neurons?
White matter.
97
Where does grey matter exist in the brain?
On the surface of the hemispheres.
98
What are the functions of the cerebral cortex?
- Intelligence
- Personality
- Interpretation of Sensory Impulses
- Motor Function
- Planning and Organisation
- Touch Sensation
99
Why is the surface of the cerebrum highly folded or convoluted?
The convolutions of the surface of the hemispheres increases their surface area therefore increasing the amount of grey matter that is present.
100
Define Sulci.
Infoldings of the brain. They are often used to demarcate (mark the boundary of) different functional areas.
101
Define Gyri.
Sticky out bits between sulci. These are areas of functional grey matter. Adjacent gyri may have very different functions.
102
What are the functions of the Frontal lobe?
Integrated brain functions such as planning. Also involved in the appreciation of emotional responses.
103
What are the functions of the Parietal lobe?
Movement, orientation and some recognition.
104
What are the functions of the Occipital lobe?
Mainly involved with the visual cortex.
105
What are the functions of the Temporal lobe?
Integrating sound and speech, forming memories.
106
What are the functions of the Pre central gyrus?
Movement.
107
What are the functions of the Post central gyrus?
Somatosensory inputs (touch, pain, temperature and proprioception).
108
Name the layer of tissue that physically separates the CNS from the rest of the body.
Meninges.
109
Within the meninges what fluid is the CNS bathed in?
Cerebro-Spinal Fluid (CSF).
110
What cushions the brain and protects it from damage?
The combination of the meninges and CSF.
111
What produces Cerebro-Spinal Fluid?
Choroid plexus (specialised epithelium).
112
How does CSF differ from plasma?
CSF has a higher concentration of Na, Cl and Mg but has a lower concentration of cells, proteins and other ions.
113
Where is CSF reabsorbed into the venous circulation?
At specialised points called arachnoid granulations.
114
What is the name for cavities within the brain?
Ventricles.
115
What links ventricles within the brain?
Passageways called aqueducts.
