Nerves Part 1 and 2 Flashcards
(83 cards)
1
Q
Central Nervous System (CNS)
A
composed of the brain and the spinal cord
2
Q
Peripheral Nervous System (PNS)
A
composed of the nerves that connect the brain or spinal cord with the body muscles, glands, and sense organs
3
Q
Somatic Nervous System (Voluntary control of movements)
A
- afferent neurons bring signals from peripheral receptors to the CNS
- Efferent Neurons bring signals from the CNS to the skeletal muscle fibres
4
Q
Autonomic Nervous System - Involuntary (Smooth and Cardiac)
A
- Contains sensory neurons from visceral organs and motor neurons that convey impulses from the CNS to smooth muscle tissue, cardiac muscle tissue, and glands
- This system works with endocrine system to maintain homeostasis
5
Q
Enteric nervous system (Part of ANS)
A
Neurons that regulate gastrointestinal system
6
Q
Functions of the Nervous System (Sensory Function)
A
Sensory receptors detect internal and external stimuli
Information is carried to brain and spinal cord through cranial and spinal nerves
7
Q
Functions of the Nervous System (Integrative Function)
A
Integrates sensory information by analyzing and storing some of it
and by making decisions for appropriate responses (a.k.a. integration)
8
Q
Functions of the Nervous System (Motor Function)
A
Elicitation of motor response in response to integrated sensory
information
Activates effectors (muscles and/or glands)
9
Q
Neurons
A
Possess electrical excitability
3 parts
1. Cell Body
2. Dendrites
3. Axon
10
Q
Neurons (Cell Body)
A
Contains nucleus, cytoplasm & typical organelles
11
Q
Neurons (Dendrites)
A
The receiving or input parts of the neuron
Usually short with many branches
12
Q
Neurons (Axons)
A
- Conducts nerve impulses
- Nerve impulses arise at the
axon hillock - Some have axon collaterals
- Terminate at axon terminals
- Axon terminals form
Synapses with other neurons
or effector cells
13
Q
3 Structural Classification
A
- Multipolar
- Bipolar
- Unipolar
14
Q
Functional Classification
A
- Sensory (afferent) neurons
- Motor (efferent) neurons
- Interneurons (associtation neurons)
15
Q
Sensory (afferent neurons)
A
- unipolar/bipolar
- sensory receptors (input) at distal end
- action potential conveyed through cranial or spinal nerves
16
Q
Motor (efferent neurons)
A
- multipolar
- convey action potential to effectors (muscles and glands)
17
Q
Interneurons (Association neurons)
A
- Multipolar
- Within CNS between sensory and motor neurons
- Integrate/process incoming sensory information
- activate appropriate motor neurons to elicit a response
18
Q
Neuroglia (Neuron Helpers)
A
- smaller than neurons and at least 5 times as many
- they do not generate or conduct nerve impulses
19
Q
Neuroglia in the CNS
A
- astrocytes
- Oligodendrocytes
- Microglia
- Ependymal cells
20
Q
Neuroglia in the PNS
A
- Schwann Cells
- Satellite cells
21
Q
Astrocytes (CNS)
A
- protect Neurons from harmful substances
- Maintain proper chemical environment for nerve impulse generation
- play a role in learning and memory
- Help form the blood-brain barrier
22
Q
Oligodendrocytes (CNS)
A
- Produce/maintain myelin sheath around several adjacent neurons
23
Q
Microglia (CNS)
A
- Protect CNS from disease: engulf invading microbes
- Clear away debris of dead cells in damaged nerve tissue
24
Q
Ependymal Cells (CNS)
A
- line ventricles of the brain and central canal of the spinal cord
- form a cerebrospinal fluid and assist in circulation
25
Schwann Cells (PNS)
- produce and maintain myelin sheath around a single axon of a neuron
- participate in regeneration of PNS axons
26
Satellite cells (PNS)
- Support neurons in PNS ganglia
- Regulate exchange of materials between neurons and interstitial fluid
27
Myelin Sheath
- many-layered covering composed of lipid and protein
- protects axon, like insulation of an electrical wire
- Increase the speed of nerve impulse conduction
- up to 100 layers
28
Nodes of Ranvier
- gaps in the myelin sheath
29
Resting Membrane Potential
- 70 mv
30
Spinal Cord
- Runs from the foramen magnum to 2nd
lumbar vertebrae
- Suspended within the vertebral canal
- Extends from the medulla oblongata and (part of the brain stem) to the upper border of L2 (the conus medullaris)
31
Spinal Meninges
- Three meninges (meninx = singular),
* Cover the spinal cord.
* Continuous with the cranial meninges (protect the brain)
32
Cauda Equina
collection of spinal nerves that travel down the vertebral canal
33
Cervical Enlargement
neurons innervate upper limbs
34
Lumbar Enlargements
neurons innervate lower limbs
35
Dura Mater
Superficial
* Outer layer
* Tough, single-layered
membrane deep to the
epidural space.
36
Arachnoid Mater
* Middle layer of the
meninges
* Collagen and elastic fibers
resembles a spider's web.
37
Subarachnoid Space
* A space between the
arachnoid mater and pia
mater;
* Filled with cerebrospinal fluid
38
Pia Mater
* Delicate, transparent inner layer;
* Adheres to the surface of the
spinal cord.
39
Spinal Cord Function
1. Carry sensory and motor
information
2. Spinal reflexes
40
Central Canal
Contains CSF
41
Grey Matter
Neuronal cell bodies, dendrites, unmyelinated axons,
axon terminals, and neuroglia.
42
White Matter
Myelinated Axons organized into white columns
43
Dorsal Horn
Posterior
- Sensory neurons cell body
- incoming signals
44
Ventral Horn
anterior
* Motor neuron cell bodies
* Outgoing signals
45
Lateral Horns
Only TSP and upper LSP contain cell bodies of ANS motor neurons which regulate activity of cardiac muscle, smooth muscle, and glands)
46
Roots
Two bundles of axons connect each
spinal nerve to a segment of
the cord.
47
Dorsal Root
contains only sensory axons, which conduct
nerve impulses from sensory
receptors in the skin, muscles &
internal organs to the CNS.
48
Dorsal Root Ganglion
contains sensory neuron cell bodies
49
Ventral Root
contains axons of motor neurons, which conduct nerve impulses from the CNS to the
effectors.
50
The Brain (Protection)
- Meninges
* Blood-Brain Barrier
(Astrocytes)
* Cerebrospinal Fluid (CSF)
51
Meninges (Layers)
3 Layers
1. Pia Mater (Deep)
2. Arachnoid Mater
3. Dura Mater (Superificial)
52
Meninges (Functions)
Functions:
i. Cover and protect the CNS
ii. Protect blood vessels
iii. Contain cerebrospinal fluid
iv. Form compartments in the skull
53
Blood - Brain Barrier (BBB)
Capillaries restrict the passage of substances from the bloodstream into the brain’s extracellular fluid
Astrocytes surround the endothelial cells and are essential to the BBB
BBB protects brain from harmful substances and pathogens
54
Cerebrospinal Fluid
Clear & colourless liquid
* Carries oxygen, glucose, and other chemicals to neurons
and neuroglia, removes their wastes
55
Ventricles
4 Cavities all connected
56
Choroid Plexus
contains ependymal cells that PRODUCE
CEREBROSPINAL FLUID
1. Flowing from the 1st to 4th ventricle
2. CSF flows into the central canal of the spinal cord
3. Into the subarachnoid space around the surface of the brain and
spinal cord
57
Diencephalon
thalamus, hypothalamus, pineal gland
58
Brain Stem
medulla oblongata, pons, midbrain
59
Thalamus (Diencephalon)
- processing station for sensory info
- focusing attention by filtering out sensory distractions
60
Hypothalamus (Diencephalon)
- Master command center for neural and hormone coordination
- Behaviours having to do with the preservation of the individual (ex. eating and drinking) and preservation of species (reproduction)
61
Pineal Gland (Diencephalon)
- regulates biological rhythms (ie. Sleep)
- the pineal gland secretes melatonin in low light that helps to promote sleep
- involved in producing dreams
62
Brainstem
- Connected directly with the spinal cord
- most primitive brain region, found in all animals
- regulating consciousness and sleep-wake cycles
63
Midbrain (Brainstem)
- releases dopamine effect on the basal nuclei (regulates muscle movements)
64
Pons (Brainstem)
- coordinating muscle movements
- relaying information between the cerebrum and the cerebellum
- regulating breathing
65
Medulla oblongata (Brainstem)
- controls breathing
- regulates heart contractions
- center for many reflexes
ex. coughing, sneezing, and vomiting
66
Cerebellum
Located at the base of the brain
- learning and controlling muscle movements
- fine motor control
- coordinating many muscle groups so movements are smooth (ex. walking and dancing)
67
Limbic System (Emotions)
Major role in our emotions and how they impact learning, memory, and social interactions
68
Limbic System Components
1. Olfactory bulb (smell is highly linked to memories)
2. Hippocampus (long term memory storage)
69
Outer Region (Cerebrum)
Cerebral Cortex
(an outer rim of grey matter)
70
Inner Region (Cerebrum)
- cerebral white matter
- cerebral grey matter nuclei
71
Longitudinal fissure (landmark)
divides the cerebrum into right and l;eft halves called cerebral hemispheres
72
Corpus Callosum
connects hemispheres (made of white matter)
73
4 Cerebrum Landmarks
1. Longitudinal Fissure
2. Corpus Callosum
3. Lateral Cerebral sulcus
4. Central Sulcus
74
5 Lobes of Cerebrum
1. Frontal Lobe - (Motor)
2. Parietal Lobe - (Sensory)
3. Temporal Lobe - (Auditory)
4. Occipital Lobe - (Visual)
5. Insula - perception of pain and gastric and bladder fullness (within lateral cerebral sulcus)
75
Central Sulcus
Separates the frontal and parietal lobes
76
Precentral gyrus
anterior to the central sulcus
77
Postcentral gyrus
Posterior to the central sulcus (motor cortex)
78
Postcentral gyrus
Posterior to the central sulcus (sensory cortex)
79
Frontal Lobe
Contains the motor cortex and premotor cortex
- Broca’s area is part of the frontal lobe that controls
muscles involved in speaking.
80
Parietal lobe
contains sensory cortex
81
Temporal lobe
contains the auditory cortex and associated areas that interpret sound
82
Occipital lobe
contains the visual cortex and associated areas that interpret visual stimuli
83
Insula
involved in perception of pain, gastric and bladder fullness
