Unit 4 lecture Flashcards
1
Q
How many neurons does our nervous system contain?
A
85 billion neurons
2
Q
How many synapses (contacts with other neurons) does each neuron have?
A
10 thousand contacts (synapses)
3
Q
What are the three major functions of the nervous system?
A
- Sensory function (afferent neurons)
- Integrative functions (interneurons)
- Motor functions (efferent neurons)
4
Q
Describe sensory functions
A
- Information goe to the brain and spinal cord via cranial and spinal nerves
- Contains afferent neurons
- Anything going to the brain is afferent
- This regards any senses
5
Q
Describe integrative function
A
- Integrates sensory information by analyzing and storing it
- Interneurons are the integrating neurons
- They recognize the sense (feel of car keys) and then connect it with what it is (recognizing that they are actually car keys)
6
Q
Describe motor functions
A
- Contains efferent neurons
- Go from the brain to the rest of the body sending out signals
- Know that they are car keys from the integrative function and the motor functions tells your hands to put the keys in the ignition
7
Q
What is the Nervous system broken up into?
A
- Somatic Nervous system deals with the body and movement
- Autonomic Nervous system deals with automatic movements and actions like blood pressure and standing up
- Sympathetic: Fight or flight
- Parasympathetic: Rest and digest
8
Q
What are two cell neuronal tissue types:
A
- Nerve cells (neurons)
- Involved in the generation and interpretation of ‘electrical signals’
- Exciting cells
- Glial cells (Neuroglia)
- Support neuronal cell activity
- 10 times more plentiful than neurons
- Making sure you have the right amount of sodium and potassium
- No excitation just support exciting cells (neurons)
9
Q
What are the functions of glial cells?
A
- Insulate
- Support
- Nourish neurons
10
Q
What are the glial cells that wrap themselves around neurons?
A
Schwann cells that insulate neurons
11
Q
What are some functions of neurons?
A
- Process information
- Sense environmental and internal changes
- Ex. Its hot in here, this exercise is painful (aka. lactic acid build up)
- Communicate changes to other neurons
- Command body responses
12
Q
What are the four major anatomical features of a neuron?
A
- Dendrites
- Cell Body
- Axon
- In the picture, it is mylonated
- Can be long (meter long) or short (in the brain)
- Synapses
- Signals presynaptic terminal to release neurotransmitters
13
Q
Define resting potential
A
The resting potential is relatively steady voltage across the membrane
14
Q
What do graded voltage do?
A
They have changes occur in response to sensory stimuli or synaptic inputs that they will send action potentials
15
Q
What does it mean all or nothing?
A
Action potentials are transient, “all or none” changes in the voltage which allow transmission of information
16
Q
What is the brain and what does it do?
A
- Control center of the human body
- Center of intelligence, behavior, memory, and emotion
- Coordinates activity of skeletal muscles
- Influences activity of visceral organs and glands
17
Q
What is the brain composed of?
A
- 85-100 billion neurons and even more neuroglia
18
Q
How does the brain act as a processing center?
A
- Interpretation of sensory information is based on path traveled and destination in the brain
- It sends actions and recieves sensations on the correct paths
19
Q
What happens to the brain when we learn and develop new skills?
A
- Plasticity: anatomical changes in the brain; new synapses form and new pattern of activity develops; also neurogenesis (new neurons)
20
Q
What are the four major parts of the brain?
A
- Cerebrum
- Cerebellum (small, hind brain)
- Diencephalon
- Thalamus (gate keeper)
- Hypothalamus
- Epithalamus
- Brain Stem
- Pons
- Medulla oblongata
- Midbrain
21
Q
What are the 2 cerebral hemisohere’s specialties?
A
Right: Music, face recognition, visual imagery, spatial abilities
Left: Language, logic, reason
22
Q
What are the five lobes in the brain?
A
- Frontal
- Parietal
- Temporal
- Occipital
- Insula
23
Q
What are the functions of the frontal lobe?
A
- Reasoning
- Planning
- Part of speech and movement
- Emotions
- Problem solving
24
Q
What are the functions of the parietal lobe?
A
- Preception of stimuli related to touch
- Pressure
- Temperature
- Pain
25
What are the functions of the Temporal lobe?
* Preception and recognition of auditory stimuli and memory
26
What are the functions of the occipital lobe?
* Many aspects of vision
27
What are the functions of the insula lobe?
* Integrates autonomic information
* Associated to visceral function
28
Define and differentiate beteen fissure and sulcus
Fissure and sulcus are invaginations in the brain however..
- Fissure is larger like inbetween the two hemispheres
- Sulcus is smaller like between lobes
29
How is the cerebrum organized? What does it contain?
Contains
* Foldings
* Gyri (gyrus)
* Sulci (sulcus)
* Fissures (deep envaginations including both gyri and sulci)
* Gray matter (cerebral cortex)
* Cell bodies/neurons that are the processing centers
* White matter (Cerebral white matter)
* Axons and pathways
* Important gyri, sulci, and fissures
* Longitudinal fissure
* Central sulcus
* Lateral cerebral sulcus
* Transverse fissure
30
How is the cerebellum organized?
* 2 Cerebrall hemisphere
* Cerebellar cortex
* Gray matter
* Contains the neurons
* Arbor Vitae
* White matter
* Contains the tracts
* Recieves the plan for movements
* Comparator of movements
* Partly in charge of posture and center of gravity
* Alcohol impairs the cerebrellum
31
What are the meninges?
Connective tissue coverings that surround the brain and spinal cord
32
What are the meninges functions?
* Protects underlying neural tissues
* Anchors the brain in cranial cavity and spinal cord in vertebral cavity
33
What are the three layers of the meninges?
* Dura mater
* Subdural space
* Arachnoid mater
* Subarachnoid space
* Pia mater
\*\*Villi pick up cereberal fluid
34
Discuss the dura mater
* Most superficial layer
* Outer layer fuses with periosteum of skull (not fused around the spinal cord)
* Inner later folds into parts of cranial cavity forming sinuses
* Major dural folds
* Falx cerebri
* Falx cerebelli
* Tentorium cerebelli
35
Look at the flow chart of the CSF
36
What do ependymal cells do regarding CSF?
CFS diffuses through the ependymal cells on a ventricle
37
What are functions of the Cerebrospinal fluid (CSF)?
* Cushioning and shock absorption
* Chemical protection
* Exchange nutrients and wastes
38
Discuss the blood brain barrier
* Protective mechanism that maintains stable environment for the brain
* Capillaries of the brain are the least permeable of any capillaties in the body
* Neuroglial cells pack them together tightly
* Capillaties are selective partly due to presence of astrocytes (a type of neuroglia)
39
What are the four major parts of the brain?
* Cerebrum
* Cerebellum
* Diencephalon
* Thalamus
* Hypothalamus
* Epithalamus
* Brain stem
* Pons
* Medulla oblongata
* Midbrain
40
What are the functional areas of the cerebral cortex (gray matter)?
- Sensory areas
- Motor areas
- Association areas
41
What is the location and function of the primary motor area on the cerebrum?
Location: precentral gyrus in frontal lobe
Function: voluntary activation of skeletal muscles. Very simple movements
42
What is the location and function of the premotor area (motor association area)?
Location: anterior to primary motor area is the frontal lobe
Function: communicates with primary motor area and thalamus to coordinate complex learned movements
43
What is the location and function of the primary somatosensory area?
Location: post central gyrus in parietal lobe
Function: receives sensory impules from sensory receptors responding to touch, temperature and proprioception. The actual perception of the touch which is sent to be processed in the associative areas.
44
Discuss the motor and sensory outputs for body parts on the weird cortex image
45
What is the location and function of the primary visual area?
Location: medial portion of occipital lobe
Function: nervous signals traveling along the optic nerve provide information about color, shape, and movement of visual stimuli
-Recieves info directly from the optic nerve
46
What is the location and function of the visual association area?
Location: occipital lobe, anterior to the primary visual area
Function: receives sensory impulses from the primary visual area for recognition of visual stimuli (visual memory)
47
What is the location and function of the primary auditory area?
location: superior portion of temporal lobe
Function: receives impuleses arising from the vestibulocochlear nerve which provide info on the basic characteristics of sound (pitch, rhythm, loudness)
48
What is the location and function of the auditory association area?
Location: temporal lobe, inferior and posterior to the primary auditory area; typically found on left temporal lobe only
Function: interpretation and recognition of sound; determines if sound is speech, music, or a noise
49
What is the location and function of the wernike's area?
- Part of the auditory association area
- Location: temporal lobe, posterior to primary auditory area on left lobe (usually)
Function: interprets the meaning of speech (translates words into thoughts)
50
What is the location and function of the broca's area?
- A part of the motor speech area
- Location: frontal lobe - usually left side
- Function: controls the activity of muscles of the vocal cords to facilitate speech
51
What is aphasia, what is the common cause, and what are two types of it?
* Acquired communication disorder that impairs a person's ability to process language but does not affect intelligence
* Most common cause is stroke
* Two common types:
* Broca's aphasia ('non-fluent aphasia')
* Mainly noises and moans
* Wernicke's aphasia ('fluent aphasia')
* Disconnected speech and thoughts
52
What are basal (ganglia) nuclei and what are their functions?
The basal nuclei are center of cell bodies deep in the cortex (gray matter).
- Help initiate and terminate movements
- Suppress unwanted movements
- Regulate muscle tone
- Control subconscious contractions of skeletal muscles
53
What is cerebral white matter and what is it responsible for?
Myelinated axons that are bond into large tracts
-White matter is responsible for communication between cerebral areas and between cerebral areas and other parts of the brain
54
What do Association tracts in cerebral white matter do?
Association tracts contain axons that conduct nerve impulses between gyri in the same hemisphere
55
What do commissural tracts of cerebral white matter do?
Commissural tracts conduct nerve impulses between corresponding gyri from one hemisphere to another
-Largest one: corpus callosum
56
What do the projection tracts of the cerebral white matter do?
Projection tracts convey impulses to lower parts of the CNS (thalamus, brain stem. or spinal cord) or visa versa
57
What is the corpus callosum and what is it in charge of?
The corpus callosum is one of the three important groups of commissural tracts (the other two being the anterior and posterior commissures) - it is a thick band of axons that connects corresponding areas of the two hempispheres
58
Hemisphereic lateralization
- Brain is almost symmetrical on right and left sides and share performance of many functions
- Each hemisphere specializes in performing certain unique functions
- Lateralization seems less pronounced in female
- When cut the right brain controls the left side of the body and visa versa
59
What are the unique parts about the left and right hemisphere?
- In most people, the left hemisphere is more important for reasoning, numerical and scientific skills, spoken and written language, and the ability to use and understand sign language
- Conversely, the right hemisphere is more specialized for musical and artistic awareness; spatial and pattern perception; recognition of faces and emotional content of language; discrimination of different smells; and generating mental images of sight, sound, touch, and taste
60
Define nucleus
a cluster of neuronal cell bodies in the CNS
61
Define ganglion (ganglia)
A cluster of neuronal cell bodies in the PNS
62
Define tract
a bundle of axons in the CNS
63
Define nerve
a bundle of axons in the PNS
64
What are the three structures of the diencephalon
65
Discuss the thalamus
* "Gate keeper" allowing selective things to come in: Keen's son's fortnite game sounds
* Relay station for sensory and motor information
* Crude interpretation of touch, temperature, pain, pressure
* Forms walls of 3rd ventricle
* Organized into 7 groups of nuclei (clusters of cell bodies in CNS)
66
How does the thalamus play a role in writing?
Pressure of pencil, deciding what you need to pay attention do from the content youre writing, where the pencil is on the paper, the overall motor plan (the movement)
67
Where is the hypothalamus?
- Located inferior to the thalamus
- Contains roughly 12 nuclei in 4 major regions
68
What are the hypothalamus functions?
* Controls and integrates the activity of the autonomic nervous system and pituitary gland -\> controls HOMEOSTASIS
* Hypothalamus is the link between the nervous system and endocrine system
* Regulates body temperature, eating and drinking behavior, other biological drives
* Main control center for visceral functions
* Receives information from cerebrum and from brain stem and spinal cord
* Regulates emotions - pleasure, pain, aggression
* Regulates diurnal rhythms with help from pineal glad (melatonin)
69
Where is the epithalamus located and what are two structures within it?
* Located superior and posterior to the thalamus
* Pineal gland (melatonin) - contributes to setting the biological clock
* Habenular nuclei - emotional responses to odors (remembring childhood form the smell of thanksgiving turkey)
70
What does the cerebellum do?
* Receives input from proprioceptors in muscles and tendons about movement; sends signals to motor cortex to improve and coordinate movemnents
* Receives input from visual and equilibrium receptors and sens input to motor cortex to aid in regulation of posture and balance
71
What are the 3 regions of the brain stem?
- Midbrain
- Pons
- Medulla oblongata
- All regions contain both tracts and nuclei
72
What is the pons in the brain stem and what are two areas for respiratory control within this area?
- Bridge between the medulla oblongata, cerebellum and higher brain centers in the cerebral cortex
- Pontine nuclei - gray matter centers connecting the cerebral cortex and cerebellum -\> coordinate voluntary motor output
- Contains two areas for respiratory control:
1) Apneustic area: controls depth of breathing
2) Pneumotaxic area: controls rate of breathing
73
What is the Medulla Oblongata, what are its functions, and what does it contain?
* Connects the brain to the spinal cord
* Involves all nerve tracts that ascend sensory to or descnd (motor) from the brain; axons cross over from one side to the other of the brain stem
* Contains the cardiovascular center-control of heart rate and force, blood pressure
* Control of respiratory rhythmicity
* Control of vegetative functions: Swallowing, coughing, sneezing, and vomiting
74
Where is the Midbrain in the brainstem?
Located between the pons and the diencephalon
75
What does the midbrain contain regarding specific structures?
Specific structures:
- Superior Colliculi: reflexes for certain visula activites and movements of the head and trunk in response to visual stimuli
- Inferior colliculi: part of the auditory pathway and startle reflex
76
What does the midbrain contain?
The midbrain contains several other nuclei, including the darkly pigmented substantia nigra. Neurons that release dopamine, extending from the substantia nigra, help control subconscious muscle activities. The red nucleus helps control voluntary movements of the limbs
77
What controls movement in the brain?
* Primary motor area and premotor area of the cerebral cortex
* Basal (ganglia) nuclei
* Cerebellum
* Midbrain (substantia nigra and red nucleus)
78
What is the limbic system?
* Encircling the upper part of the brain stem and the corpus callosum is a ring of structures on the inner border of the cerebrum and floor of the diencephalon that constitutes the limbic system
79
What is the definition of the limbic system and what are its functions?
The limbic system is a functional system composed of parts of the cerebral cortex, diencephalon, and midbrain
- Emotional brain -\> plays a primary role in promoting a range of emotions, including pleasure, pain, docility, affection, fear, and anger
- Functions in memory together with parts of the cerebrum
- Connects motivation to action
80
What are the three main specific sturctures in the limbic system and what are their functions?
* Cingulate gyrus - plays role in emotion
* Connecting to olfactory bulb to connect smell to emotion
* Hippocampus - involved in learning and memory
* Amygdala - involved in emotion and memory
* Involved in very intense love or hate
81
Discuss spinal cord gross anatomy and define plexus
* Mixed sensory/motor nerves exit the spinal cord segmentally
* Enlargements occur in regions where nerves supply limbs
* A plexus is a location lateral to the spinal cord where spibal nerves from different segments can rejoin
82
What are three distributions of spinal nerves?
* Cervical enlargement: at C4-T1: Nerves that exit here supply the shoulder girdle and upper limbs
* Lumbar enlargement: at T9-T12: Nerves that exit here supply the pelvis and lower limbs
* Cauda Equina: Extension of nerves exiting from end of spinal cord
83
Why does a cavity form that can be used to withdraw CSF in spinal taps?
Because the spinal cord proper ends at the leve L@ and the dura and arachnoid layers extend to S2, a cavity forms that can be used to withdraw CSF
84
How do the spinal meninges arrange?
CSF flows in subarachnoid space- same as cranial meninges
Dura mater is not attached to the bony vertebral column-creates epidural space
85
What is the cenral canal regarding internal anatomy of spinal cord (gray matter)?
Small opening in the center of SC; contains CSF
86
What is the Posterior horns regarding internal anatomy of spinal cord (gray matter)?
Cell bodies of somatic and visceral sensory neurons
87
What is the Gray Commisure regarding internal anatomy of spinal cord (gray matter)?
Connects posterior horns
88
What are the anterior horns regarding internal anatomy of spinal cord (gray matter)?
Cell bodies of somatic motor neurons
89
What are lateral horns regarding internal anatomy of spinal cord (gray matter)?
Cell bodies of visceral motor neurons; found only in thoracic, lumbar and sacral regions of spinal cord
90
Whhat are the posterior columns regarding internal anatomy of spinal cord (white matter)?
Sensory tracts (ascending)
91
What are the lateral columns regarding internal anatomy of spinal cord (white matter)?
Motor and sensory tracts
92
What are anterior columns regarding internal anatomy of spinal cord (white matter)?
Motor tracts (descending)
93
What is the anterior white commisure regarding internal anatomy of spinal cord (white matter)?
Connects white matter on the left and right side of spinal cord
94
What does the Dorsal root of the spinal cord do regarding input and output to the spinal cord?
Carries afferent (sensory) information
95
What are Dorsal root ganglion regarding input and output to the spinal cord?
Cluster of (sensory) cell bodies outside the CNS
96
What does the ventral root do regarding input and output to the spinal cord?
Carries motor (efferent) information from the anterior portion of the cord
97
What are spinal nerves regarding input and output to the spinal cord?
Joining of dorsal and ventral roots; only 2 cm long; are mixed nerves in that they contain both sensory and motor information. Thirty-one pairs of spinal nerves exit the cord
98
How do sensory and motor neurons go into and out of the spinal cord?
99
Look at a cross section of spinal cord within vertebra
100
look at the ascending and descending tracts
101
Define reflex
A rapid automatic response to a stimulus
102
Define reflex arc
The "wiring" of a particular reflex
103
Define innate reflex
Inborn
104
Define learned reflex
Reflex acquired through experience
105
What are the five components of a reflex arc
* Sensory receptor
* Sensory neuron
* Integrating center - may or may not include an interneuron
* Motor neuron
* Effector
106
What are the four ways to classify reflexes?
* Monosynaptic vs. polysynaptic
* Somatic vs. visceral
* Cranial vs. spinal
* Ipsilateral vs. contralateral
107
What are stretch reflexes? What is their purpose? What are they sensed by? What do they result in?
* Purpose is to prevent injury from over-stretching a muscle
* Results in contraction of the muscle that was stretched
* Stretch sensed by muscle spindle
* Monosynaptic, ipsilateral, spinal, somatic reflex
108
What is the anatomy of muscle spindles?
109
What are tendon reflexes? What is their purpose? What are they sensed by? What do they result in?
* Purpose is to prevent damage from development of too much tension in a muscle
* Result in inhibition of the muscle that is contracting
* Tension sensed by Golgi tendon organ
* Polysynaptic, ipsilateral, spinal, somatic reflex
110
What is the anatomy of golgi tendon organ?
111
What are flexor reflexes? What is their purpose? What are they sensed by? What do they result in?
* Purpose is to protect body part from further injury
* Results in flexion of affected limb
* Pain sensed by nociceptors (sometimes the threat of pain can stimulate the reflex)
* Polysynaptic, ipsilateral, spinal, somatic reflex
112
What are crossed extensor reflexes? What is their purpose? What are they sensed by? What do they result in?
* Purpose is to stabilize body position when a painful stimulus results in flexion of opposite limb
* Usually paired with flexor reflex
* Result is extension of opposite limb
* Pain sensed by nociceptors
* Polysynaptic, contralateral, spinal, somatic reflex
113
Look at the a cranial reflex charts
114
What is the nervous system broken up into?
The central nervous system (brain and spinal cord) and the peripheral nervous system (cranial and spinal nerves)
115
What is the peripheral nervous system broken up into?
* Enteric Nervous System
* Smooth Muscle, Glands of GI tract
* Somatic Nervous System
* Skeletal Muscles
* Autonomic Nervous System
* Smooth Muscle, Cardiac Muscle, Glands
116
What is the autonomic nervous system broken up into?
* Sympathetic Division
* Fight or flight response
* Parasympathetic Division
* Rest or digest
117
How does the central and peripheral nervous systems communicate?
118
Why do we need the Autonomic Nervous System?
- It operates without conscious control
- Operates via reflex arcs
- Is controlled by centers in the hypothalamus and brain stem
119
What are the differences between the somatic and autonomic nervous systems?
120
What does the somatic nervous system from spinal cord to muscle look like?
121
What does the Autonomic Nervous System look like from spinal cord on?
122
What are the main differences between the subdivisions of the Autonomic nervous system?
1. Sympathetic Division
1. "Fight of flight"
2. Prepares body for stress
2. Parasympathetic division
1. "Rest and digest"
2. Promotes digestion and storage of nutrients
123
What is the thoracolumbar regarding sympathetic nervous system?
Preganglionic neurons begin in the thoracic (T1) and lumbar (L2) regions of the spinal cord
124
Where are most ganglia located in the SNS?
Near the spinal cord
125
What is the first location of sns ganglia and what does it innervate?
Sympathetic trunk (chain) - paired ganglia near spinal cord, postganglionic neuron innervates visceral organs in thoracic cavity
126
What is the second location of SNS gangli and what does it innervate?
Prevertebral ganglia (collateral) - anterior to vertebral bodies, postganglionic neurons innervare abdominopelvic organs
127
What is the third location of SNS ganglia and what does it act as?
Adrenal medulla - acts as a modified sympathetic ganglion, postganglionic neurons are short and release norepginephrine (20%) and epinephrine (80%) into the blood stream
\*NE and epinephrine are called catecholamines
128
What are NE and epinephrine called?
Catecholamines
129
How many ganglia are in the sympathetic trunk? What are the prevertebral ganglia? What is the adrenal medulla ganglia?
3 cervical
11 thoracic
4 lumbar
4 sacral
Celiac
Superior mesenteric
Inferior mesenteric
Special case
130
Discuss neurotransmitters of the SNS
* Preganglionic neurons release ACh -\> binds to nicotinic cholinergic receptors on postganglionic cell body
* Postganglionic neurons release norepinepherine -\> binds to adrenergic receptors on effector cell
* Always excitatory
131
Discuss sweat glands (special case) in the SNS
* Preganglionic neurons release ACh
* Postganglionic neurons release ACh instead of NE at the effector tissue; ACh binds to muscarinic cholinergic receptors as sweat gland
132
Dicuss adrenal medulla (special case) in the SNS
* Preganglionic neurons release ACh
* Chromaffin cells act as postganglionic neurons and the adrenal medulla acts as a modified ganglion
* Chromaffin cells release Epinepherine and NE into the blood
133
When is NE a neurotransmitter?
When it is released from the sympathetic nerve endings directly at target tissues (short lived effects)
134
What is NE a hormone?
When it is released from the adrenal gland into the blood stream (longer lasting effects)
135
Why is epinephrine a hormone?
Because it is release from the adrenal gland into the blood
136
What are adrenergic receptors and Alpha and Beta adrenergic receptors?
* Binds epinephrine (adrenaline) and norepinephrine (noradrenaline) at effector tissue
* Alpha adrenergic receptors - found in smooth muscle of ateriorles, bladder; results in constriction when activated
* Beta adrenergic receptors - foundin heart, bronchioles, live; cause an increase metabolism
137
WHat is the general goal of the SNS aswell as general function?
Function: "fight or flight"
Goal: to increase mental alertness, increase energy availability (glucose), and body's ability to handle a stressor
138
What are 7 specific responses to SNS?
* Mobilizes (break down) fuels
* Redistribution of blood flow
* Decrease urinary output and digestive functions
* Increase heart rate and blood pressure
* Increase activity of sweat glands
* Increase diameter of bronchioles (bronchodilation)
* Dilation of pupils
139
Describe oculomotor (III) cranial nerve
Mixed cranial nerve responsible for eye ball movement stimulates the lacrimal gland
140
Describe facial (VII) cranial nerve function
Mixed cranial nerve stimulates salvation
141
Describe glossopharngeal (IX) cranial nerve function
Mixed cranial nerve involved in swallowing and salivation
142
Describe vagus (X) cranial nerve function
Mixed cranial nerve; carries 80% OF PARASYMPATHETIC OUTFLOW TO HEART, AIRWAYS, LIVER, GALLBLADDER, STOMACH, SMALL INTESTINE AND PART OF LARGE INTESTINE
143
Describe the cranial portion of the parasympathetic nervous system
1. Preganglionic neurons found in pons of medulla
2. Information carried by 4 cranial nerves: III, VII, IX, X
3. 80% OF PSNS INFORMATION CARRIED BY VAGUS (X)
144
Describe the sacral portion of the parasympathetic nervous system
Preganglionic neurons in sacral region (S2-S4) exit via pelvic nerves
145
What are some PSNS ganglia?
146
What are the two cholinergic receptors of the PSNS and what do they both do?
Nicotinic and muscarinic receptors and they both resond to ACh
147
Where is the nicotinic receptor of the PSNS and what does it do?
Found on sympathetic and parasympathertic cell bodies and dendrites of postganglionic neurons (within the ganglion) - can only generate excitatory post-synaptic potentials (EPSP)
148
Where is the muscarinic receptor of the PSNS and what does it do?
Found on membrane of target tissues innervated by parasympathetic postganglionic axons -can generate both EPSP and inhibitory post-synaptic potentials (IPSP)
149
Look at a picture of cholinergic receptors (PSNS)
150
What is the general function of PSNS
"Rest and Digest"
Goal: promote digestion of food and the absorption of nutrients
Salivation
Lacrimation
Urination
Defecation
151
What are 6 specific respinses to PSNS
* Increased digestive enzyme/hormone secretion
* Increased smooth muscle activity of the GI tract
* Contriction of pupils for near vision
* Decreased heart rate, contractility, blood pressure
* Contraction of muscular wall of bladder and intestine; promotes urination/defecation
* Increased secretion of the lacrimal glands
152
Discuss Syncope
Syncope = fainting = vasovagal reaction
* Transient loss of consciousness resulting from an insufficient supply of oxygen to the brain
* Insufficient cerebral perfusion from hypotnesion because of failure of the ANS to maintain blood pressure
* Syncope can be avioded by laying down in supine position, elevating feet, contracting leg and arm muscles to bring more blood back to the heart and increase circulation of blood to the brain
153
