The Nervous System Flashcards
(214 cards)
1
Q
What is the Nervous System?
A
The body’s communication network that transmits and processes information between the brain and other body parts.
2
Q
Define:
Central Nervous System
A
The body’s coordinating center for mechanical and chemical actions; it consists of the brain and spinal cord that integrates and coordinates sensory and motor functions.
3
Q
What is the function of the brain?
A
The brain serves as the control center of the nervous system, responsible for perception, thought, emotion, and bodily functions.
4
Q
Explain the role of the spinal cord.
A
The spinal cord is a long, thin, tubular bundle of nerves that extends from the brainstem down the back and serves as a pathway for nerve impulses between the brain and the body.
5
Q
Fill in the Blank:
The ______________ Nervous System is the network of nerves outside the central nervous system that connects the brain and spinal cord to the rest of the body.
A
The Peripheral Nervous System is the network of nerves outside the central nervous system that connects the brain and spinal cord to the rest of the body.
6
Q
True or False…
The Somatic Nervous System controls involuntary movements and sensory information from the body’s external environment.
A
False; the Somatic Nervous System controls VOLUNTARY movements and sensory information.
7
Q
Define:
Sensory (Afferent)
A
Sensory or afferent relates to the senses or perception, such as touch, taste, smell, sight, and hearing.
8
Q
What is the Motor (Efferent) function?
A
Motor or efferent relates to movement or muscle control, responsible for executing voluntary and involuntary actions.
9
Q
Explain the role of the Autonomic Nervous System.
A
The Autonomic Nervous System is responsible for regulating involuntary bodily functions such as heart rate, digestion, and respiratory rate.
10
Q
What is the function of the Sympathetic part of the Autonomic Nervous System?
A
The Sympathetic part prepares the body for fight or flight responses during stress or danger.
11
Q
Define:
Parasympathetic
A
Parasympathetic is the part of the autonomic nervous system that helps the body to rest and recover by conserving energy and promoting digestion and relaxation.
12
Q
What are Neurons?
A
Neurons are the functional units of the nervous system that conduct nerve impulses when a threshold is reached.
13
Q
What are Dendrites?
A
Dendrites are branch-like extensions of a neuron that receive signals from other neurons or sensory receptors.
14
Q
Define:
Neuron Cell Body
A
The Cell Body is the central part of a neuron that contains the nucleus and other organelles, functioning as the control center of the cell.
15
Q
What is the function of an Axon?
A
An Axon is a long, slender projection of a neuron that carries nerve impulses away from the cell body, serving as the communication highway of the nervous system.
16
Q
Explain the role of Schwann Cells.
A
Schwann Cells are specialized cells that wrap around and provide insulation to axons in the peripheral nervous system, resembling protective sheaths for efficient signal transmission.
17
Q
What is a Myelin Sheath?
A
A Myelin Sheath is a fatty, insulating layer surrounding certain axons that speeds up the transmission of nerve impulses, functioning like an electrical wire insulation for efficient signal conduction.
18
Q
Fill in the blank:
The part of the autonomic nervous system that prepares the body for fight or flight responses during stress or danger is the _______.
A
The part of the autonomic nervous system that prepares the body for fight or flight responses during stress or danger is the sympathetic
19
Q
True or False…
The parasympathetic part of the autonomic nervous system helps the body to rest, recover, and promotes digestion and relaxation.
A
True
20
Q
Define:
Neurons
A
Neurons are the functional units of the nervous system that conduct nerve impulses when a threshold is reached.
21
Q
What are the three main parts of a neuron?
A
- Dendrites
- Cell Body
- Axon
22
Q
Define:
Dendrites
A
Dendrites are branch-like extensions of a neuron that receive signals from other neurons or sensory receptors.
23
Q
Fill in the blank:
The _______ is the central part of a neuron that contains the nucleus and other organelles, functioning as the control center of the cell.
A
The cell body is the central part of a neuron that contains the nucleus and other organelles, functioning as the control center of the cell.
24
Q
Define:
Axon
A
An axon is a long, slender projection of a neuron that carries nerve impulses away from the cell body, serving as the communication highway of the nervous system.
25
What is the function of a Schwann Cell?
A Schwann Cell is a specialized cell that wraps around and provides insulation to axons in the peripheral nervous system, resembling protective sheaths for efficient signal transmission.
26
# **Fill in the blank:**
The _______ is a fatty, insulating layer surrounding certain axons that speeds up the transmission of nerve impulses.
The *myelin sheath* is a fatty, insulating layer surrounding certain axons that speeds up the transmission of nerve impulses.
27
What is the Node of Ranvier?
The Node of Ranvier refers to the gaps in the myelin sheath along the axon where the axon membrane is exposed, allowing for faster propagation of nerve impulses.
28
What is the function of the Axon Terminal?
The Axon Terminal is the end of an axon that forms synapses with other neurons or effector cells, enabling the transmission of nerve impulses to target cells.
29
What is the primary role of Sensory (afferent) neurons?
Sensory (afferent) neurons relay information or stimuli received by sensory receptors about the internal and external environment to the central nervous system for processing.
30
How do Motor (efferent) neurons function in the nervous system?
Motor (efferent) neurons relay information to the effectors (the cell or organ that responds to the stimulus). Muscles, organs, and glands are classified as effectors as they produce responses.
31
What is the purpose of an Interneuron?
An Interneuron links neurons to other neurons, they are found only in the brain and spinal cord, and they integrate and interpret the sensory information and connect to outgoing motor neurons.
32
Explain the concept of a Reflex Arch.
A Reflex Arch is the simplest nerve pathway, which is involuntary and unconscious. It does not require coordination by the brain. It consists of a Receptor, sensory neuron, interneuron, motor neuron, and effector.
33
What is the Resting Potential in a neuron?
The Resting Potential refers to the voltage difference across the nerve cell membrane when it's not actively firing an action potential. It is usually around -70 millivolts
34
What is the meaning of depolarization?
Depolarization refers to the process during the firing of a neuron when the neuron's charge becomes less negative or even positive due to the influx of positively charged sodium ions.
35
# **Define:**
Action Potential
Action Potential is the change in electrical potential associated with the passage of an impulse along the membrane of a neuron. It's essentially the "firing" of the neuron.
36
What is Repolarization in the context of a neuron's activity?
Repolarization is the return of the cell membrane potential to resting potential after the peak of the action potential has been reached. It's mainly due to the outflow of positively charged potassium ions from the cell.
37
What is Hyperpolarization in a neuron's activity?
Hyperpolarization is the increase in the membrane potential of a cell relative to its normal resting potential. It makes the inside of the neuron more negative and is usually due to the outflow of potassium ions or the inflow of chloride ions.
38
What is the Refractory Period in a neuron's activity?
The Refractory Period is the time after an action potential during which the neuron is resistant to another action potential. It ensures the one-way transmission of nerve impulses.
39
What is the meaning of Saltatory Conduction?
Saltatory Conduction is the process by which nerve impulses jump from one Node of Ranvier to the next along a myelinated axon, significantly speeding up the propagation of the action potential.
40
# **Define:**
Synapse
A Synapse is the junction between two neurons or a neuron and an effector cell, where electrical or chemical signals are transmitted.
41
Describe the process and significance of repolarization during an action potential.
Repolarization is the process where the neuron returns to its resting membrane potential after an action potential. It's achieved by the opening of voltage-gated potassium channels and the outflow of potassium ions. This restores the negative charge inside the neuron, allowing it to potentially fire another action potential.
42
How do Glial Cells contribute to the function of the nervous system?
Glial cells support and protect neurons in the nervous system. They provide physical and nutritional support, participate in the immune response of the nervous system, produce and maintain the myelin sheath around axons, and regulate the extracellular fluid around neurons.
43
How does the myelin sheath contribute to the function of neurons?
The myelin sheath, produced by glial cells (Oligodendrocytes in the CNS and Schwann Cells in the PNS), wraps around the axon of neurons. It acts as an insulator and increases the speed of electrical signal transmission along the axon by allowing the action potential to jump between gaps in the myelin sheath, a process known as saltatory conduction.
44
How does the voltage-gated ion channel mechanism contribute to the "all or nothing" nature of an action potential?
Voltage-gated ion channels open when the membrane potential reaches a certain threshold. If the threshold is not reached, the channels remain closed, and no action potential is generated. However, once the threshold is reached, a full action potential is triggered regardless of the strength of the stimulus.
45
Describe the role of the sodium-potassium pump in the aftermath of an action potential. Why is it crucial for neuron function?
The sodium-potassium pump works to restore the resting membrane potential following an action potential by actively transporting three sodium ions out of the neuron for every two potassium ions it brings in. This helps maintain the electrochemical gradient necessary for the neuron to fire subsequent action potentials.
46
What would happen if a neuron's voltage-gated sodium channels failed to close during the action potential? How would this affect the neuron's ability to transmit signals?
If the voltage-gated sodium channels didn't close, the neuron would remain depolarized because sodium ions would continue to flow into the cell. This would prevent the neuron from repolarizing and entering the refractory period, effectively inhibiting the neuron's ability to transmit further action potentials.
47
Why is saltatory conduction faster than continuous conduction along an unmyelinated axon? How does this impact the overall efficiency of signal transmission?
Saltatory conduction is faster because it allows the action potential to jump from one node of Ranvier (gap in the myelin sheath) to the next, rather than traveling continuously along the entire length of the axon. This increases the speed of signal transmission and reduces the metabolic cost for the neuron, as less energy is required to restore the resting membrane potential.
48
What are synapses
Small spaces connecting neurons (between neurons and effectors) where neurotransmitters are released, allowing communication between neurons.
49
# **True or False...**
Terminal branches of one neuron may join with many different neurons.
True
50
What is the role of neurotransmitters in the nervous system?
Neurotransmitters are chemicals released from the end plates of axon terminals that diffuse across the synaptic cleft, bind to receptors, and depolarize dendrites on the postsynaptic neuron, facilitating communication between neurons.
51
What happens when the space between neurons increases?
Although the space is small (~20 nm), when it increases, diffusion across synapses becomes relatively slow, resulting in slower speed of transmission.
52
# **Fill in the blank:**
Acetylcholine is an _______ neurotransmitter
Acetylcholine is an *excitatory* neurotransmitter
53
How does acetylcholine work?
The neurotransmitter works by opening Na+ channels, found in most nerve cells. Once Na+ channels open, Na+ rush into postsynaptic neuron, resulting in depolarization → action potential → nerve impulse
54
# **Define:**
Cholinesterase and its function.
Cholinesterase is an enzyme released by the presynaptic membrane that destroys acetylcholine, allowing the Na+ channels to close and the neuron to enter a recovery stage.
55
What is the function of inhibitory neurotransmitters in the nervous system?
Inhibitory neurotransmitters make the postsynaptic membrane more permeable to K+, causing hyperpolarization and inhibiting action potentials.
56
# **Fill in the blank:**
Dopamine is a neurotransmitter that affects the brain synapse in control of _______, _______ and _______.
Dopamine is a neurotransmitter that affects the brain synapse in control of *body movement, reward, and most notably pleasure.*
57
# **Fill in the blank:**
Serotonin is a neurotransmitter that regulates _______, _______ and is involved in _______ control.
Serotonin is a neurotransmitter that regulates *temperature, sensory perception, and most notably mood control*
58
What are endorphins and their function in the nervous system?
Endorphins are neurotransmitters that act as natural painkillers in the brain synapses and affect emotional areas of the brain.
59
# **Fill in the blank:**
Norepinephrine is a neurotransmitter that complements the actions of _______, which readies the body to respond to danger or other stressful situations.
Norepinephrine is a neurotransmitter that complements the actions of *epinephrine* which readies the body to respond to danger or other stressful situations.
60
What are neurotoxins and their effect on the nervous system?
Neurotoxins like botulinum and tetanus are bacterial proteins that inhibit the release of essential neurotransmitters at nerve endings, disrupting the nervous system function.
61
# **Define:**
Summation
Summation is the effect in the postsynaptic neuron produced by the accumulation of neurotransmitters from two or more neurons.
62
Name the three protective layers surrounding the brain and spinal cord.
_The meninges_: dura mater (outer layer), arachnoid mater (middle layer), and pia mater (inner layer)
63
What is the function of cerebrospinal fluid in the nervous system?
Cerebrospinal fluid acts as a shock absorber and transport medium, carrying nutrients to and removing wastes from the central nervous system.
64
What is meningitis and how is it diagnosed?
Meningitis is inflammation of the meninges caused by a bacterial or viral infection. It can only be diagnosed by examining a sample of the fluid surrounding the brain and spinal cord.
65
# **Fill in the blank:**
The spinal cord consists of two types of nerve tissue: _______ & _______ matter.
The spinal cord consists of two types of nerve tissue: *grey & white* matter.
66
What is the function of the cerebrum in the brain?
The cerebrum acts as a major coordinating centre from which sensory information and motor actions originate.
67
# **Fill in the blank:**
The right hemisphere of the cerebrum is associated with _________ & _________, while the left hemisphere is linked to _______.
The right hemisphere of the cerebrum is associated with *visual patterns & spatial awareness* while the left hemisphere is linked to *verbal skills*
68
The hypothalamus in the brain plays a large role in maintaining the body's internal equilibrium. How does it connect the nervous and endocrine systems?
The hypothalamus's direct connection with the pituitary gland unites the nervous and endocrine systems.
69
# **Fill in the blank:**
The cerebellum, located in the hindbrain, controls _______, _______, and _______.
The cerebellum, located in the hindbrain, controls *limb movements, balance, and muscle tone*
70
The frontal lobe of the brain is responsible for _______, and its association areas are linked to _______, _______, _______, and _______.
The frontal lobe of the brain is responsible for *Motor control*, and its association areas are linked to *intellect, memory, emotions, and personality*
71
# **Define:**
Association areas (in the context of different parts of the brain)
Association areas in the brain are regions that aren't involved in the processing of sensory information or the control of motor functions. Instead, these areas are involved in more complex processes that integrate information from different parts of the brain to support higher cognitive functions.
72
# **True or False...**
The parietal lobe of the brain is associated with vision and interpretation of visual information.
False; the occipital lobe is associated with vision and interpretation of visual information.
73
What are MRI, CT, and PET scans used for?
They are non-invasive tools used to map human brain function and screen for diseases.
74
Explain the process of transmission in the nervous system.
- Action potential reaches presynaptic terminal
- Voltage-gated Ca2+ channels open
- Influx of Ca2+
- Synaptic vesicles fuse with membrane (exocytosis)
- Neurotransmitters released into synaptic cleft and diffuse to postsynaptic terminal
- Neurotransmitters bind to receptor on postsynaptic membrane
- If threshold is reached, action potential is initiated
- Neurotransmitter is broken down by specific enzymes in synaptic cleft.
75
What is the role of the "blood-brain barrier" in protecting the CNS?
The blood-brain barrier is a unique property of the blood vessels that vascularize the CNS. It allows them to tightly regulate the movement of ions, molecules, and cells between the blood and brain.
76
# **True or False...**
The spinal cord emerges from the skull through an opening called the foramen magnum.
True
77
# **Fill in the blank:**
The _______ root brings sensory information into the spinal cord, while the _______ root carries motor information from the spinal cord to the peripheral nervous system.
The *dorsal* root brings sensory information into the spinal cord, while the *ventral* root carries motor information from the spinal cord to the peripheral nervous system.; ventral
78
# **Fill in the blanks:**
The forebrain consists of the _______, _______, and _______.
The forebrain consists of the *cerebrum, hypothalamus, olfactory bulbs.*
79
What is the function of the thalamus in the brain?
The thalamus acts as a relay station for sensory information going to the cerebrum.
80
The midbrain, located just below the thalamus, acts as a relay centre for what type of reflexes?
Some eye and ear reflexes.
81
What is the role of the pons in the hindbrain?
The pons acts as a relay station for regions of the cerebellum and between the cerebellum and medulla.
82
What are the main functions of the medulla oblongata?
The medulla oblongata controls involuntary muscle action (like breathing, heart rate, etc.) and acts as the coordination centre for the autonomic nervous system.
83
# **Fill in the blank:**
The temporal lobe of the brain processes _______ information and its association areas are linked to _______ and _______.
The temporal lobe of the brain processes *auditory/sound/hearing (and some visual)* information and its association areas are linked to *visual and verbal memory, emotions, learning and interpretation of language*
84
# **Fill in the blank:**
The sensory areas of the parietal lobe are associated with _______ and _______ awareness.
The sensory areas of the parietal lobe are associated with *touch and temperature* awareness.
85
# **Fill in the blank:**
The lateral ventricle is one of many ventricles that produce and store _______.
The lateral ventricle is one of many ventricles that produce and store *cerebrospinal fluid*
86
What is the role of the olfactory bulbs in the brain?
The olfactory bulbs receive and interpret information about smell.
87
What are the three main parts of the hindbrain?
The cerebellum, pons, and medulla oblongata.
88
What is the function of the cerebellum?
The cerebellum controls limb movements, balance, and muscle tone.
88
What is the function of the cerebellum?
The cerebellum controls limb movements, balance, and muscle tone.
89
What are the main functions associated with the frontal lobe of the brain?
The frontal lobe is responsible for motor control (the movement of voluntary muscles). Its association areas are linked to intellect, memory, emotions, and personality.
90
What sensory and association areas are associated with the occipital lobe of the brain?
The sensory areas of the occipital lobe are associated with vision. Its association areas interpret visual information.
91
Where does cerebrospinal fluid circulate?
Cerebrospinal fluid circulates between the innermost and middle meninges and through the central canal of the spinal cord.
92
What are the functions of cerebrospinal fluid?
It acts as a shock absorber and transport medium, carrying nutrients to and removing wastes from the CNS.
93
# **True or False...**
Meningitis is an inflammation of the meninges that can become life threatening when the infection spreads to underlying brain tissue.
True
94
What is the role of the cerebrum in the brain?
The cerebrum is the largest part of the brain and its two hemispheres act as major coordinating centres from which sensory information and motor actions originate.
95
# **Fill in the blank:**
The right hemisphere of the cerebrum is associated with ________, while the left hemisphere is linked to ________.
The right hemisphere of the cerebrum is associated with *visual patterns/spatial awareness* while the left hemisphere is linked to *verbal skills.*
96
# **Fill in the blank:**
The surface of the cerebrum, known as the ________, is composed of grey matter and has many ________ that increase its surface area.
The surface of the cerebrum, known as the *cerebral cortex* is composed of grey matter and has many *fissures (folds or “sulci”)* that increase its surface area.
97
What role does the hypothalamus play in maintaining the body's internal equilibrium?
The hypothalamus plays a large role in maintaining homeostasis by regulating hormones, body temperature and food & fluid intake.
98
Which part of the brain is responsible for controlling limb movements, balance, and muscle tone?
The cerebellum
99
Non-invasive tools like MRI, CT and PET scans can be used for what purposes in studying the human brain?
These tools can be used to map human brain function and screen for diseases.
100
What is the role of the medulla oblongata in the nervous system?
The medulla oblongata is the connection between the central and peripheral nervous system. It controls involuntary muscle actions such as breathing and heart rate and is the coordination center for the autonomic nervous system.
101
What are the functions of the pons in the brain?
The pons acts as a relay station for regions of the cerebellum and between the cerebellum and the medulla.
102
What is the function of the thalamus in the brain?
The thalamus serves as a relay station for sensory information going to the cerebrum.
103
What is serotonin involved in regulating?
Serotonin regulates temperature and sensory perception, and is also involved in mood control.
104
What are the potential effects of excessive and inadequate production of dopamine?
_Excessive Production:_ linked to schizophrenia,
_Inadequate Production:_ linked to Parkinson’s disease
105
# **Fill in the blank:**
The _________ is a region of the brain that receives and interprets information about smell.
The olfactory bulbs is a region of the brain that receives and interprets information about smell.
106
What is the function of the Temporal Lobe?
The Temporal Lobe processes sound/hearing (and some visual) information. Its association areas are linked to visual and verbal memory, emotions, learning, and interpretation of language.
107
What is the function of the Parietal Lobe in the brain?
The Parietal Lobe's sensory areas are associated with touch and temperature awareness. Its association areas have been linked to emotions and interpreting language.
108
What is the function of norepinephrine in the nervous system?
Norepinephrine is used by the brain and some autonomic neurons and complements the actions of the hormone epinephrine, which readies the body to respond to danger or other stressful situations.
109
What are the potential effects of excessive and inadequate production of norepinephrine?
**Excessive Production:** associated with high blood pressure, anxiety, and insomnia
**Inadaquate Production:** can cause hunger cravings and feelings of exhaustion
110
What is the role of the frontal lobe in the brain?
The frontal lobe is responsible for motor control (the movement of voluntary muscles). Its association areas are linked to intellect, memory, emotions, and personality.
111
What are neurotoxins and what is their effect on the nervous system?
Neurotoxins like botulinum and tetanus are bacterial proteins that are exocytosed into nerve endings where they inhibit the release of essential neurotransmitters.
112
What is the function of the occipital lobe in the brain?
The occipital lobe's sensory areas are associated with vision. Its association areas interpret visual information.
113
# **Fill in the blank:**
Cerebrospinal fluid circulates between innermost and middle meninges and through the central canal of the _______.
Cerebrospinal fluid circulates between innermost and middle meninges and through the central canal of the *spinal cord.*
114
What role does the cerebellum play in the nervous system?
The cerebellum controls limb movements, balance, and muscle tone.
115
What is meningitis and how can it be diagnosed?
Meningitis is inflammation of the meninges caused by a bacterial or viral infection. It becomes life threatening when the infection spreads to the underlying brain tissue. It can only be diagnosed by examining a sample of the fluid surrounding the brain and spinal cord.
116
What is the function of the lateral ventricle in the brain?
The lateral ventricle is one of many ventricles that produce and store cerebrospinal fluid.
117
What is the cerebrum and what role does it play in the brain?
The cerebrum is the largest part of the brain. It has two hemispheres that act as major coordinating centers from which sensory information and motor actions originate.
118
How do the two hemispheres of the cerebrum communicate?
Communication between the two hemispheres occurs via the corpus callosum.
119
# **True or False...**
The right hemisphere of the cerebrum is associated with visual patterns and spatial awareness, while the left hemisphere is linked to verbal skills.
True
120
How does the structure of the cerebrum support its functions?
The surface of the cerebrum, the cerebral cortex, is composed of grey matter and has many fissures (folds or “sulci”). These sulci increase the surface area, allowing for greater cognitive and motor functions.
121
What role does the Thalamus play in the brain?
The Thalamus acts as a relay station for sensory information going to the cerebrum.
122
Where can you find the midbrain? What are its responsibilities?
The midbrain lies just below the thalamus and acts as a relay centre for some eye and ear reflexes.
123
What is the role of the Pons in the brain?
The Pons acts as a relay station for regions of the cerebellum and between the cerebellum and medulla.
124
# **True or False...**
The medulla oblongata controls involuntary muscle action and acts as the coordination centre for the autonomic nervous system.
True
125
What kind of information does the Temporal Lobe process?
The Temporal Lobe processes sound/hearing and some visual information. Its association areas are linked to visual and verbal memory, emotions, learning, and interpretation of language.
126
What is associated with the sensory areas of the Parietal Lobe?
The sensory areas of the Parietal Lobe are associated with touch and temperature awareness. Its association areas have been linked to emotions and interpreting language.
127
What tools can be used to map human brain function and screen for diseases?
MRI, CT, and PET scans are non-invasive tools that can be used to map human brain function and screen for diseases.
128
Explain the concept of summation in the context of the nervous system.
Summation is the effect in the post-synaptic neuron produced by accumulation of neurotransmitters from two or more neurons.
129
Explain the role of the olfactory bulbs in the brain.
The olfactory bulbs receive and interpret information about smell.
130
# **Define:**
A ________ is a bundle of fibers made up of neurons
A *nerve* is a bundle of fibers made up of neurons
131
What is the primary function of the Peripheral Nervous System?
It gathers sensory information and relays it to muscles and glands for a voluntary (somatic) or involuntary (autonomic) response.
132
# **True or False...**
Both the somatic and autonomic systems consist of sensory and motor neurons.
True; however, the somatic system senses and responds to external stimuli, while the autonomic system responds to internal stimuli.
133
What are the primary functions of the Somatic System?
- Communicates information about the external environment to the Central Nervous System
- Sends messages back to skeletal muscles
- Control is usually voluntary, but some involuntary reflexes are included.
134
# **Fill in the Blank:**
The Somatic System is composed of ___ pairs of cranial nerves and ___ pairs of spinal nerves.
The Somatic System is composed of *12* pairs of cranial nerves and *31* pairs of spinal nerves.
135
What functions are controlled by the cranial nerves?
Vision, hearing & balance, taste & smell, facial & tongue movements, and the muscles of the head and neck.
136
What is the primary role of spinal nerves in the Somatic System?
They operate the skeletal actions that we consciously make to cope with our surroundings (e.g., putting on sunglasses).
137
What are the key functions of the Autonomic System?
- Brings information about the body’s internal environment to the CNS
- Responds to maintain homeostasis (involuntarily)
- Controls smooth muscle, cardiac muscle, the internal organs, and glands.
138
What are the two groups of motor neurons used by the Autonomic System to stimulate target effectors?
Preganglionic neurons and postganglionic neurons.
139
What are the roles of the sympathetic and parasympathetic systems?
The sympathetic system prepares the body for stress (fight or flight), while the parasympathetic system aims to restore the body to normal (rest and digest).
140
What are some organs innervated by the Vagus Nerve?
The heart, bronchi of the lungs, liver, pancreas, and the digestive tract.
141
# **True or False...**
The sympathetic system stimulates tear production.
False; the sympathetic system inhibits tear production, while the parasympathetic system stimulates it.
142
# **Fill in the Blank:**
The sympathetic system ___________ the pupils, while the parasympathetic system ___________ them.
The sympathetic system dilates the pupils, while the parasympathetic system constricts them.
143
In response to stress, does the sympathetic system increase or decrease heart rate?
It increases (speeds up) heart rate.
144
Which nervous system increases activity of the stomach and pancreas: sympathetic or parasympathetic?
The parasympathetic system increases the activity of the stomach and pancreas.
145
# **True or False...**
The sympathetic nervous system stimulates the gallbladder to release bile.
False; the parasympathetic nervous system stimulates the gallbladder to release bile.
146
What effect does the sympathetic system have on the kidneys, stomach, and pancreas?
The sympathetic system inhibits activity in these organs.
147
Does the sympathetic or parasympathetic system decrease intestinal activity?
The sympathetic system decreases intestinal activity, while the parasympathetic system increases it.
148
# **True or False...**
The sympathetic system releases the bladder sphincter
True; the sympathetic system releases the bladder sphincter, while the parasympathetic system constricts it.
149
Which system causes skin vasodilation: sympathetic or parasympathetic?
The sympathetic system causes skin vasodilation, while the parasympathetic system causes skin vasoconstriction.
150
What is the role of the sympathetic system during times of stress?
The sympathetic system prepares the body for a "fight or flight" response. This includes inhibiting tear production, dilating pupils and air passages, speeding up the heart, stimulating the liver to release glucose, inhibiting activity of kidneys, stomach, and pancreas, decreasing intestinal activity, releasing bladder sphincter, and causing skin vasodilation.
151
What is the role of the parasympathetic system during periods of rest?
The parasympathetic system restores the body to a "rest and digest" state. This includes stimulating tear production, constricting pupils and bronchioles, slowing the heart, stimulating the gallbladder to release bile, increasing activity of stomach and pancreas, increasing intestinal activity, constricting the bladder sphincter, and causing skin vasoconstriction.
152
What is the connection of the human brain to the outside world?
The senses
153
What detects stimuli in the human body?
Sensory receptors
154
What happens when an electrochemical impulses arrive at the cerebral cortex?
Sensation occurs
155
What is the process called? I filters out repeated, insignificant signals?
Sensory adaptation
156
What do photoreceptors detect?
Light
157
What do chemoreceptors detect?
Chemical signals
158
What do mechanoreceptors detect?
Varying forms of pressure
159
What do thermoreceptors detect?
Differences between hot and cold temperatures
160
What is the function of the sclera in the human eye?
It is the outer most layer of the eye, responsible for the “white of the eye,” and acts as a tough, protective tissue 
161
What is the function of the cornea in the human eye?
It is the transparent part of the sclera that refracts/bends light into the eye, protects the eye, and is a vascular, but has pain receptors 
162
What is the function of the choroid layer in the human eye?
It is the middle layer of the eye that absorbs light to the back of the eye, contains blood vessels to supply oxygen, and nutrients to the retina, and prevents light scattering
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What is the function of the iris in the human eye?
It is the pigmented tissue surrounding the pupil that controls the amount of light entering the eye
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What is the function of the pupil in the human eye?
It is the hole located in the centre of the iris that allows light to strike the retina and changes size, depending on the amount of light
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What is the function of the aqueous humour in the human eye?
It maintains cornea shape and supplies nutrients and oxygen to the cornea, lens and surrounding cells
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What is the function of the vitreous humour in the human eye?
It is a jelly like substance that provides the shape of the eyeball
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What is the function of the lens in the human eye
It is a transparent, a vascular part of the eye used for focusing, with ciliary muscles and suspensory ligaments changing its shape to focus light on the retina
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What is the function of the ciliary body in the human eye?
It is the innermost layer of the eye that contains photo receptors, is stimulated by light, and sends sensory information to the occipital lobes through the optic nerves 
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What is the function of the fovea in the human?
It is a tiny depression in the centre of the right now packed with cones that provides the sharpest vision
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What is the function of rods in the human eye?
They are used for dim, light and peripheral vision, are concentrated on the edges of the retina, and contain a light absorbing pigment called rhodopsin
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What is the function of cones in the human eye?
They are used to find details in colour version, are concentrated in the fovea, and undergoes splitting reaction using light with pigment called photopsins
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What is photoreception?
It is the process by which organisms detect and respond to light stimuli, converting visual information into electrical signals that can be processed by the nervous system.
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What is the order of light entering the eye?
Aqueous humor, pupil, lens, vitreous humor, retina
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What is the order of light in the retina?
Rods and/or cones, bipolar cells, ganglion cells, nerve fibers, optic nerve, brain (thalamus, occipital lobe)
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What is the blindspot in the human eye?
It is located on the optic disc, does not have any photoreceptors, and therefore cannot detect light
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What is the optic chiasma?
It is the place where optic nerves cross, located right below the hypothalamus, and is involved in the brains interpretation of images
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What is binocular vision?
It is vision with to forward facing eyes with overlapping fields of view that allow for good depth perception
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What is monocular vision?
It is vision with two sideways facing eyes, used separately, allowing for increase field of view, but limited depth perception
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What is 20/20 vision
It is the ability of most young people to see a size of a 20 letter from a distance of 20 feet
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What is myopia?
It is a condition where an individual can see close objects, but not far ones, caused by the eyeball being “stretched” wider
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What is hyperopia?
It is a condition where an individual cannot see close objects, but can’t see far ones, caused by the eyeball being “stretched” longer
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What is astigmatism?
It is a condition where are the uneven shape of the cornea impairs the ability to focus light properly 
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What is a glaucoma?
It is a condition caused by improper drainage of aqueous humor, resulting in too much pressure with the eyeball, damaging blood vessels and causing cell deterioration 
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What is a detached retina?
It is a condition where the rotten apples away from the choroid resulting in sight loss, often due to injury or ageing
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What is macular degeneration?
It is a condition affecting the macula, and oval shaped pigmented area near the centre of the retina, causing slow or sudden painless loss of vision
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What are floaters?
They are clumps, specs, and strings of undissolved virtuous gel that cast a shadow on the retina
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What is strabismus?
It is a condition where the eye is misaligned, and turns either up, down, in, out, or at an oblique angle
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What are after images?
They are the result of fatigued rods and cones from prolonged exposure to colors, causing an imbalance in the information from different colour receptors and the perception of colour “after images”
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What are the two major sensory functions of the ear?
Hearing and balance (equilibrium)
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What is the function of the pinna in the ear?
It is the external part of the ear that funnels sound into the auditory canal
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What is the function of the auditory canal in the ear?
It is a line with cerbuminous glands and direct sound to the tympanic membrane (eardrum)
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What is the function of the tympanic membrane in the ear?
The tympanic membrane is the eardrum. It vibrates with sounds, causing the ossicles to vibrate
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What is the function of the ossicles in the ear?
They are three small bones which amplify and transmit vibrations to the fluid-filled cochlea
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What is the function of the Eustachian tube in the ear?
It is an air-filled tube that allows equalization of pressure in the middle ear
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What is the function of the semicircular canals in the ear?
They are fluid filled structures providing information about 3-D body movement and position
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What is the function of the cochlea in the ear?
Is a coiled tube that identify sounds, and convert them into nerve impulses
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What is the function of the vestibule in the ear?
It is a chamber at the base of the semicircular canals, that is important and balance. It contains the utricle and saccule (two small sacs that establish 2-D head position)
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What is the function of the auditory nerve in the ear?
Transmits messages to the brain
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What is the process of how we hear?
Sound waves are funnelled into the pinna, travel down the auditory canal, vibrate the tympanic membrane (eardrum), vibrate the ossicles, vibrate the oval window, transmit the pressure change through the cochlea, bend the hair, like receptors in the organ of Corti, stimulate the sensory nerves in the basilar membrane, and send a signal via the auditory nerve to the brain
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What are the two types of equilibrium?
2-D (static, positional, gravitational) and 3-D (dynamic, rotational) 
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What is 2-D equilibrium?
It is movement along one plane, maintained by the saccule and utricle of the vestibule
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What is 3-D equilibrium?
It is dynamic equilibrium that maintains balance, maintained by the 3 semicircular canals
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What is tinnitus?
It is a condition where puss and mucus move from the throat, through the Eustachian tube to fill the air filled space surrounding the ossicles, leading to temporary hearing loss
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What is an inner ear infection?
It is a condition where inflammation occurs in the semicircular canals, leading to nausea and loss of balance
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What is motion sickness?
It’s a condition thought to be caused by the movement of the fluid in the semi circular canals 
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What is vertigo?
It is a sensation of spinning or dizziness, causing symptoms, like lightheadedness, nausea, vomiting, headache, ringing of the ears. Is caused by inflammation of the semicircular canals and nerve that encodes head position, or fluid imbalance 
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What is the function of the skin sensory receptors?
They are responsible for detecting light touch, pressure, pain, and high/low temperatures
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What happens when odour particles bind to olfactory cells?
Ion channels open and action potential’s are triggered
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What are pheromones?
They are chemicals released by animals, including humans, responsible for mate recognition and attraction
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What is the relationship between the sense of smell and the sense of taste?
The sense of smell is closely linked with the sense of taste, with up to 90% of what we taste actually due to our sense of smell
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What are taste buds?
They are chemoreceptors on the tongue
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Why is taste believed to have evolved?
Taste is believed to have evolved as a mechanism for animals to avoid eating poisonous foods, which often taste bitter
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What are canker sores?
They are small sores that appear on the inside of the mouth, especially the cheeks, the inside of the lips, and the tongue
