practice midsem exam Flashcards
1
Q
The Project and Association function of the Temporal lobe of the brain
are:
(a) Primary Sensory, Premotor with alertness and temperament.
(b) Visual, Cognitive with interpretation of sensory stimuli.
(c) Visual, Cognitive with interpretation of sensory stimuli.
(d) Auditory, Interpretive and long-term memory and thinking
A
(d) Auditory, Interpretive and long-term memory and thinking
2
Q
The caudal lobe of the cerebellum is responsible for:
(a) Synergy and coordination.
(b) Synergy and muscle tone.
(c) Muscle tone and posture.
(d) Muscle tone and coordination.
A
(a) Synergy and coordination.
3
Q
- Compared to plasma, cerebrospinal fluid (CSF) has:
(a) Lower sodium and glucose and higher protein and potassium.
(b) Lower sodium and chloride and higher protein and glucose.
(c) Lower potassium and glucose and higher magnesium and chloride
(d) Lower potassium and calcium and higher magnesium and protein.
A
(c) Lower potassium and glucose and higher magnesium and chloride
4
Q
The structure in the eye responsible for the greatest refraction of light is:
(a) Cornea.
(b) Aqueous humor.
(c) Lens.
(d) Vitreous humor.
A
(a) Cornea.
5
Q
The function of the Macula utriculi is to monitor:
(a) The rate of movement of the head and linear acceleration.
(b) The position of the head and changes in direction
(c) The position of the head and linear acceleration.
(d) The rate of movement of the head and changes in direction.
A
(c) The position of the head and linear acceleration.
6
Q
Extrapyramidal motor tracts are defined as:
(a) Multi-synaptic tracts for fine motor control
(b) Mono-or bi-synaptic for locomotion
(c) Multi-synaptic tracts UMNs throughout brain
(d) Mono-or bi-synaptic for fine motor control.
A
(c) Multi-synaptic tracts UMNs throughout brain
7
Q
Dysfunction of the thalamus is characterised by:
(a) Hyperaesthesia, confusion and emotional instability.
(b) Hyperaesthesia, convulsions and emotional instability.
(c) Allodynia, confusion and emotional instability.
(d) Allodynia, confusion and personality changes.
A
(a) Hyperaesthesia, confusion and emotional instability.
8
Q
Central auditory pathways pass through the following structures:
(a) Trapezoid body, rostral colliculus, medial geniculate nucleus, auditory cortex.
(b) Trapezoid body, caudal colliculus, medial geniculate nucleus, auditory cortex.
(c) Trapezoid body, caudal colliculus, lateral geniculate nucleus, auditory cortex.
(d) Trapezoid body, caudal colliculus, medial geniculate nucleus, reticular formation.
A
(b) Trapezoid body, caudal colliculus, medial geniculate nucleus, auditory cortex.
9
Q
- Which of the following statements regarding Golgi Tendon Organs is FALSE?
(a) Golgi tendon organs are located in the muscular tendinous junctions
(b) Golgi tendon organs provide sensory information regarding muscle stretch
(c) Golgi tendon organs are innervated by Ib sensory afferents
(d) Golgi tendon organs provide sensory information regarding muscle tension.
A
(b) Golgi tendon organs provide sensory information regarding muscle stretch
10
Q
- A GABA agonist should cause:
(a) increased action potentials as sodium channels are opened.
(b) an inhibitory effect due to the opening of chloride channels.
(c) the release of adrenaline, which will trigger sympathetic nervous system responses.
(d) the propagation of the signal through the neuromuscular junction.
A
(b) an inhibitory effect due to the opening of chloride channels.
11
Q
When an adrenergic beta receptor on the bronchiole smooth muscle is activated, what is the response?
(a) Vasoconstriction.
(b) Smooth muscle relaxation and bronchiole dilation.
(c) Bronchiole constriction and coughing.
(d) Decreased blood pressure.
A
(b) Smooth muscle relaxation and bronchiole dilation.
12
Q
Nicotinic cholinergic receptors function to:
(a) contract gastro-intestinal muscle therefore aiding digestion.
(b) open sodium channels following their direct activation via acetylcholine.
(c) increase the force of contraction of cardiac muscle.
(d) open potassium channels in the neuromuscular junction causing skeletal muscle contraction.
A
(b) open sodium channels following their direct activation via acetylcholine.
13
Q
A reduction in the sensitivity of hearing can occur due to:
(a) Cilia movement causing cation channels to open and potassium moving in to hyperpolarise the neurons
(b) Tympanic membrane displacement in response to sound waves
(c) Contraction of the tensor tympani muscle dampening the ossicle chain
(d) Damage to cranial nerve II.
A
(c) Contraction of the tensor tympani muscle dampening the ossicle chain
14
Q
In an eye that is longer than normal, how is the image focussed incorrectly?
(a) Light is not bent enough, leading to the image being focussed beyond the retina
(b) The image is split into two focal points, creating blurred vision at all distances
(c) Light transmission is obscured
(d) Light rays from distant objects are focussed in front of the retina
A
(d) Light rays from distant objects are focussed in front of the retina
15
Q
Afferent sensory information is conveyed from the muscles to the CNS through which of the following tracts?
(a) Dorsal column tract.
(b) Lateral corticospinal tract.
(c) Spinothalamic tract.
(d) Spinocerebellar tract.
A
(d) Spinocerebellar tract.
16
Q
The movement of trunk, neck and shoulder muscles is controlled by which of the following pathways?
(a) Lateral corticospinal tract.
(b) Corticobulbar tract.
(c) Spinocerebellar tract.
(d) Anterior corticospinal tract.
A
(d) Anterior corticospinal tract.
17
Q
Which of the following sensory pathways does NOT pass through the thalamus?
(a) Proprioception.
(b) Olfactory.
(c) Vestibular.
(d) Visual.
A
(b) Olfactory.
18
Q
What type of receptor senses when the skin is stretching?
(a) Merkel nerve endings
(b) Meissner corpuscles
(c) Pacinian corpuscles.
(d) Ruffini endings
A
(d) Ruffini endings
19
Q
If we apply a drug to the eye which blocks the action of acetylcholine (e.g. atropine), what occurs to the pupil size?
(a) The sympathetic innervation is blocked, resulting in pupil dilation.
(b) The parasympathetic innervation is blocked, resulting in pupil dilation.
(c) The sympathetic innervation is blocked, resulting in pupil constriction.
(d) The parasympathetic innervation is blocked, resulting in pupil constriction.
A
(b) The parasympathetic innervation is blocked, resulting in pupil dilation.
20
Q
What happens when light photons reach the retina?
(a) The concentration of cyclic GMP inside the cell decreases, sodium channels close, hyperpolarising the photoreceptor membrane.
(b) The concentration of cyclic GMP inside the cell increases, sodium channels close, depolarising the photoreceptor membrane.
(c) The concentration of cyclic GMP inside the cell decreases, sodium channels close, depolarising the photoreceptor membrane.
(d) The concentration of cyclic GMP inside the cell increases, sodium channels close, hyperpolarising the photoreceptor membrane
A
(a) The concentration of cyclic GMP inside the cell decreases, sodium channels close, hyperpolarising the photoreceptor membrane.
21
Q
In which part of the central nervous system is the respiratory centre located?
(a) Brainstem.
(b) Hypothalamus.
(c) Limbic lobe.
(d) Cerebral cortex.
A
(a) Brainstem.
22
Q
Which of the following would cause the lens of the eye to tense?
(a) Bright light.
(b) Eye is focussed on an object close to the animal.
(c) Relaxation of the zonule fibres.
(d) Relaxation of the ciliary muscles.
A
(d) Relaxation of the ciliary muscles.
23
Q
Peripheral sensitisation occurs as a consequence of tissue trauma and inflammation, and results in hyperalgesia at the site of injury. Intracellular components are released from damaged cells, inflammatory cells, nerve terminals, and nerve fibres – this increases the sensitivity of peripheral nociceptors. Inflammation produces a “sensitising soup” of chemical mediators. Direct tissue damage causes the release of:
(a) Histamine.
(b) Substance P.
(c) Bradykinin.
(d) Cytokines
A
(c) Bradykinin.
24
Q
The Project and Association function of the Parietal lobe of the brain are:
(a) Primary Sensory, Premotor with alertness and temperament.
(b) Primary Sensory, Cognitive with interpretation of sensory stimuli.
(c) Primary motor, Premotor, with interpretation of sensory stimuli.
(a) Primary motor, Premotor, with intellect and personality.
A
(b) Primary Sensory, Cognitive with interpretation of sensory stimuli.
25
The rostral lobe of the cerebellum is responsible for:
(a) Synergy and coordination.
(b) Synergy and muscle tone.
(c) Muscle tone and posture.
(d) Muscle tone and coordination.
(c) Muscle tone and posture.
26
Compared to cerebrospinal fluid (CSF), plasma has:
(a) Lower sodium and glucose and higher protein and potassium.
(b) Lower sodium and chloride and higher protein and glucose.
(c) Lower potassium and glucose and higher magnesium and chloride.
(d) Lower potassium and calcium and higher magnesium and protein.
(b) Lower sodium and chloride and higher protein and glucose.
27
The function of the crista ampullaris is to monitor:
(a) The position of the head and linear acceleration.
(b) The position of the head and changes in direction
(c) The rate of movement of the head and linear acceleration.
(d) The rate of movement of the head and changes in direction.
(d) The rate of movement of the head and changes in direction.
28
Pyramidal motor tracts are defined as:
(a) Multisynaptic tracts for fine motor control.
(b) Mono-or bi-synaptic for locomotion
(c) Multisynaptic tracts UMNs throughout brain
(d) Mono-or bi-synaptic for fine motor control
(d) Mono-or bi-synaptic for fine motor control
29
Which important structures need to be avoided when performing surgery at the base of the ear?
(a) Superficial temporal artery, Chorda tympani and the parotid salivary gland.
(b) Rostral auricular artery, Chorda tympani and the parotid salivary gland.
(c) Caudal auricular artery, facial nerve and the parotid salivary gland.
(d) Deep temporal artery, facial nerve and the parotid salivary gland.
(c) Caudal auricular artery, facial nerve and the parotid salivary gland
30
Sympathetic stimulation of the adrenal medulla will cause:
(a) hyperaesthesiaed secretion of adrenaline from the pituitary gland.
(b) hyperaesthesiase of adrenaline from the post-synaptic neurons.
(c) the release of adrenaline from adrenal medulla cells and a broad-scale sympathetic response
(d) sodium channels to open and the signal to propagate faster between neurons
(c) the release of adrenaline from adrenal medulla cells and a broad-scale sympathetic response.
31
Nicotinic cholinergic receptors function to:
(a) contract gastro-intestinal muscle therefore aiding digestion.
(b) open sodium channels following their direct activation via acetylcholine.
(c) increase the force of contraction of cardiac muscle.
(d) open potassium channels in the neuromuscular junction causing skeletal muscle contraction.
(b) open sodium channels following their direct activation via acetylcholine
32
Alpha motor neurons are co-activated with gamma motor neurons because:
(a) contraction of the intrafusal muscle fibres contracts the muscle spindle which allows the afferent sensory neurons to function correctly.
(b) contraction of the extrafusal muscle fibres results in a stretch reflex which involves gamma motor neurons.
(c) the gamma motor neurons signal the muscle length and velocity of movement
(d) contraction of the extrafusal muscle fibres may result in the spindle losing sensitivity; therefore polar regions also contract to keep the equatorial region taut.
(d) contraction of the extrafusal muscle fibres may result in the spindle losing sensitivity; therefore polar regions also contract to keep the equatorial region taut.
33
Reduced spinal reflexes on the hind limbs may be due to:
(a) a neurotoxin targeting the upper motor neurons.
(b)vestibular disease
(c)a neurotoxin targeting the nicotinic cholinergic receptors
(d)sclerosis of the neurons in the motor cortex.
c)
This affects the junction between pre-ganglionic and post-ganglionic neurons, which are both LMNs. So this is the correct answer. Snake venom is an example of a neurotoxin that can act on the postsynaptic nicotinic receptor = LMN damage
34
Which of the following statements best describes the function of acetylcholine:
(a) This neurotransmitter acts on adrenergic receptors to activate sodium channels and cause the action potential to be propagated into the muscle fibre.
(b) This neurotransmitter acts on muscarinic receptors to constrict bronchiole smooth muscle fibres following parasympathetic stimulation.
(c) This neurotransmitter acts on cholinergic receptors to activate potassium channels.
(d)This neurotransmitter acts on adrenergic receptors in the heart to increase heart rate.
(b) This neurotransmitter acts on muscarinic receptors to constrict bronchiole smooth muscle fibres following parasympathetic stimulation.
35
Animals can be trained to behaviourally respond to a stimulus such as a tone. This is a method used when testing the hearing range of species. The process of learning this response can be best described as:
(a) operant conditioning using a positive reinforcer.
(b) sensitisation using positive reinforcement.
(c) negatively reinforced operant conditioning
(d) associative learning using an habituated response
a) operant conditioning using a positive reinforcer.
36
In which part of the central nervous system is the cardiovascular centre located?
(a) Brainstem
(b) Hypothalamus
(c) Limbic lobe
(d) Cerebral cortex.
(a) Brainstem
37
In an eye that is shorter than normal, how is the image focussed incorrectly?
(a) Light is not bent enough, leading to the image being focussed beyond the retina
(b) The image is split into two focal points, creating blurred vision at all distances -
(c) Light transmission is obscured -
(d) Light rays from distant objects are focussed in front of the retina
(a) Light is not bent enough, leading to the image being focussed beyond the retina
38
Which of the following is TRUE regarding photoreception?
(a) Rods are concerned with colour vision
(b) Rods have a large receptive field
(c) Cones have a large receptive field
(d) Cones are not concerned with colour vision.
(b) Rods have a large receptive field
39
The movement of limb muscles is controlled by which of the following pathways?
(a) Lateral corticospinal tract
(b) Corticobulbar tract
(c) Spinocerebellar tract
(d) Anterior corticospinal tract.
(a) Lateral corticospinal tract
40
Using dot points, describe the structure of the stereocilia or “hair cells”, and summarise the mechanism of hair cell activation in sensing sound.
- hair cells tethered together by proteins
- vibration causes hair cells to bend, once they bend towards longest cilium, protien causes K ion channels to open
- K rushes in, depolarizes cell
- all Ca channels to open
- Calcium enters the cell
- glutamate is released into synaptic cleft
- triggers afferent nerve
41
Damage to an upper motor neuron is characterized by:
(a) Hypertonia and exaggerated reflexes.
(b) Hypertonia and diminished reflexes.
(c) Hypotonia and exaggerated reflexes.
(d) Hypotonia and diminished reflexes.
(a) Hypertonia and exaggerated reflexes.
42
What are the functions of the cerebrospinal fluid (CSF)?
(a) Nutritional, temperature regulation, signalling and protection against percussion.
(b) Chemical, regulatory, a nutritional buffer and protection against percussion.
(c) Reduces pressure, regulatory, a chemical buffer and protection against percussion.
(d) Nutritional, regulatory, a chemical buffer and protection against percussion.
(d) Nutritional, regulatory, a chemical buffer and protection against percussion.
43
Iridic granules are:
(a) Vascular outgrowths in ungulates.
(b) To support the tapetum nigrum in carnivores.
(c) Remnants of development occasionally see in the eye.
(d) Adaptions in carnivores to night vision
(a) Vascular outgrowths in ungulates.
44
Important structures associated with the middle ear in dogs are:
(a) The internal carotid artery, glossal branches of the vagus nerve and the parasympathetic nerve supply to the inner ear.x
(b) Chorda tympani, sympathetic fibres for the eye and the tympanic the efferent motor neuron response.
(c) The malleus, parasympathetic supply to the eye and the chorda tympani.
(d) The auditory tube, the malleus and the internal carotid artery.
(b) Chorda tympani, sympathetic fibres for the eye and the tympanic the efferent motor neuron response.
45
An upper motor neuron disorder may manifest as spinal hyperreflexia because:
(a) there is a lesion in the motor cortex causing disinhibition of the lower motor pathways.
(b) the signal has been prevented from crossing the neuromuscular junction.
(c) the afferent neurons have been demyelinated
(d) the alpha motor neurons are not functioning
(a) there is a lesion in the motor cortex causing disinhibition of the lower motor pathways.
46
The paw pinch test should, in a normal patient, cause:
(a) activation of the ipsilateral muscle fibres only via the efferent motor neuron response.
(b) activation of the muscle spindle alpha motor neurons.
(c) release of adrenaline causing muscle contraction.
(d) co-activation of the ipsilateral and contralateral muscle fibres to pull the limb away from the stimulus.
(d) co-activation of the ipsilateral and contralateral muscle fibres to pull the limb away from the stimulus.
47
Striking the patellar of a patient should result in:
(a) contraction of the hamstring muscles via the efferent motor neuron response.
(b) activation of the muscle spindle alpha motor neurons.
(c) release of noradrenaline causing muscle contraction.
(d) activation of the quadriceps as a response to stretch afferent action potentials.
(d) activation of the quadriceps as a response to stretch afferent action potentials.
48
Sensitisation of an associative learning pathway occurs by:
(a) propagating the signal faster by opening potassium channels more quickly.
(b) phosphorylating potassium channels within the response pathway.
(c) causing the release of the serotonin from vesicles which activate sodium channels.mess
(d) releasing dopamine which activates potassium channels.
(b) phosphorylating potassium channels within the response pathway.
49
Which statement is most accurate regarding nociception:
(a) Circulating opioids cause inhibitory post-synaptic potentials in the cerebral cortex.
(b) Nociceptive A fibres are thickly myelinated and have a low response threshold.
(c) Pain is initially detected by low threshold free sensory nerve endings.
(d) Nociception involves A and C sensory nerves, spinothalamic pathway nerves, an endogenous analgesic pathway, and pathways to the cerebral cortex.
(d) Nociception involves A and C sensory nerves, spinothalamic pathway nerves, an endogenous analgesic pathway, and pathways to the cerebral cortex.
50
Alpha motor neurons are co-activated with gamma motor neurons because:
(a) contraction of the intrafusal muscle fibres contracts the muscle spindle which allows the afferent sensory neurons to function correctly.
(b) contraction of the extrafusal muscle fibres results in a stretch reflex which involves gamma motor neurons. - THIS ONE IS INCORRECT (ITS D)
(c) the gamma motor neurons signal the muscle length and velocity of movement
(d) contraction of the extrafusal muscle fibres may result in the spindle loosing sensitivity; therefore polar regions also contract to keep the equatorial region taut.
(d) contraction of the extrafusal muscle fibres may result in the spindle loosing sensitivity; therefore polar regions also contract to keep the equatorial region taut.
51
A local anaesthetic decreases the sensation of pain by:
(a) causing potassium channels to open resulting in nociceptor hyperpolarisation.
(b) causing the release of adrenaline and noradrenaline onto post-synaptic neurons.
(c) causing the release of opioids from pre-synaptic neurons.
(d) temporarily blocking sodium channels on the afferent sensory neurons.
(d) temporarily blocking sodium channels on the afferent sensory neurons.
52
Reduced spinal reflexes on the hind limbs may be due to:
(a) a neurotoxin targeting the upper motor neurons.
(b) vestibular disease.
(c) a neurotoxin targeting the nicotinic cholinergic receptors
(d) sclerosis of the neurons in the motor cortex
(c) a neurotoxin targeting the nicotinic cholinergic receptors
53
Shining a light directly on the eye causes the pupil to constrict. This is best described as:
(a) a sympathetic response to light due to activation of the photoreceptors.
(b) a parasympathetic response in the optic nerve.
(c) a sympathetic response acting ciliary smooth muscles causing them to constrict
(d) a parasympathetic reflex in response to light activating photoreceptors
(d) a parasympathetic reflex in response to light activating photoreceptors
54
Vestibular disease can result in a head tilt, circling, loss of balance and equilibrium. Which, of the following, best explains these symptoms:
(a) demyelination of the lower motor neurons.
(b) an autoimmune disease targeting ion channel proteins.
(c) an inflammatory disease targeting the brainstem.
(d) a neurodegenerative disorder of the cortex.
(c) an inflammatory disease targeting the brainstem.
55
Which of the following is NOT required to hear a stimulus at a particular frequency?
(a) Functional afferent nerves that are sensitive to that frequency.
(b) Enough glutamate to propagate the signal onto the auditory nerve.
(c) Functioning stereocilia.
(d) A functioning tensor tympanic muscle
(d) A functioning tensor tympanic muscle
56
neural tube comes from
ectoderm; rostral and caudal neuropore
57
telencephalon
cerebrum
58
diencephalon
thalamus and hypothalamus
59
metenchephalon
pons and cerebellum
60
myelencephalon
medulla oblongata
61
frontal lobe function and projection fiber and association fiber
personality
projection: primary motor
association: premotor (alertness, intellect, temperament, personality)
62
parietal lobe function and projection fiber and association fiber
sensation/feeling
projection; primary sensory
assoication: cognitive (recognition and interpretation of sensory stimuli)
63
occipital lobe function and projection fiber and association fiber
vision
projection: visual
association: cognitive
64
temporal lobe function and projection fiber and association fiber
hearing/ balance
projection: auditory
association: interpretive; long term memory and thinking
65
within organ of corti along basilar membrane; diff parts of membrane are for different frequencies:
high frequency at base (near oval window)
low frequency at top (helicotrema)
66
cerebellum does not initiate movement, instead;
it monitors movement
67
cerebellum control is
ipsilateral
68
cerebellum lobes
rostral= muscle tone and posture
caudal= synergy and coordination
flocculonodular = balance and equilibrium
69
dysfunction of thalamus
loss of consciousness, emotional instability, confusion, aneasthetsia and hyperaesthesia
70
dysfunction of cerebellum
ataxia, nystagmus, paradoxical head tilt, base wide stance, hypertonia, hypermetria
71
maters and spaces out to in
which contains CSF
periosteum
epidural space
dura mater
subdural space
arachnoid mater
subarachnoid space (contains CSF)
pia mater
72
where is CSF produced
in choroid plexus of lateral ventricle and in roof of 3rd and 4th ventricles
less produced by arterioles of the subarachnoid space
73
CSF compared to plasma
CSF has higher NA CL Mg
and lower glucose, K, Ca, protein
74
describe arteries of brain
- internal carotid artery (dog)
- basilar artery (dog)
- maxillary artery (ruminant, cat, pig)
- vertebral artery (ruminant, cat, pig)
goes to
circle of willis goes to
paired rostral, middle, caudal cerebral arteries
paired caudal, rostral cerebellar arteries
75
how the eye refracts light
cornea
aqueous humor
lens
vitreous humor
76
layers of retina
optic nerve fibers
ganglion cell layer
inner plexiform layer
inner nuclear layer (bipolar, horizontal and amacrine cells)
outer plexiform layer
outer nucleaar layer (photoreceptor cells ie rods and cones)
pigment layer
choroid
77
layers of cornea
- anterior epithelium (stratified squamous) (continuous with conjunctiva)
- bowman's membrane , thin, aka anterior limiting membrane
- substansia propria (continuous w sclera) thick area of collagen
- descemets membrane, thick, aka, posterior limiting membrane
- posterior epithelium (thin squamous)
78
4 functions of vascular tunic
- provides vascular support
- holds lens
- produce aqueous humor
- controls size of pupil
79
4 functions of eyelid
- tear dispersal
- protection
- remove stimuli & facilitate sleeping
- optics and nutrition
80
fibrous tunic
sclera and cornea
81
vascular tunic
choroid, iris, ciliary body and processes
82
nervous tunic
optic disc, retina, ora serrata
83
3 cell types in retina
neurons
pigment epithelial cells
neuron support cells
84
types of neurons in the retina
- photoreceptor cells (rods and cones)
- afferent neurons (fibers into optic nerve)
- integrating neurons (between the top two, includes bipolar, horizontal and amacrine cells)
85
melanocytes
pigment cells in choroid and iris, they absorb light
86
periorobita
around the orbit
its a cone
apex is at optic nerve
base is at rim of eye (where eye inserts on eyelids)
sympathetic innervation
87
muscle spindle stretch reflex
a) initial stimulus
b) where do afferent/ efferent impulses enter and exit
c) excitatory and inhibitory path
d) neurotransmitters
a) type 1a neuron send sensory stimuli onto spinal cord and synpases with interneuron
b) afferent enter dorsal horn
efferent enter ventral horn
c) excitatory; interneuron synpases w alpha motor neuron which sends excitatory impulse to muscle and causes contraction
inhibitory; interneuron goes to other motor neurons innervating antagonist muscle, prevents contraction
d) excitatory: glutamate, aspartate, substance P
inhibitory; GABA, glycine
88
type 1a
type 1b
type 2
alpha motor
gamma motor
1a) muscle spindle primary, sensory; fires quickly, and responds to a change in length
1b) sensory, Golgi tendon organs, senses tension in tendon
2) muscle spindle secondary, slower, provides sensory input regarding the amount the muscle has stretched
alpha motor: extrafusal, faster, cause muscle contraction
gamma motor; intrafusal, slower, associated w muscle spindle, monitors extrafusal
89
reflex arc
- receptor
- sensory neuron
- synapse in CNS (interneuron)
- motor neuron
- target organ
90
pain pathway
1) Transduction: nociception initially detected by sensory neurons which are free nerve endings
2) Transmission: carriage of electrical impulses from nociceptor to spinal cord
3) Modulation: occurs in spinal cord or brain, modulated by neurotransmitters and receptors, either excitatory (glutamate, aspartate, substance P or inhibitory ( GABA, glycine, exogenous opioids, analgesics
4) Projection: project up to thalamus by spinothalamic tract (medial and lateral components)
5) Perception: processing, recognition and integration in brain
91
pain and temp if damaged what is released
a) mast cells
b) mast cells and traumatized skin cells
c) stressed skin cells
d) sensory afferents
e) cholinergic efferents
a) histamine
b) prostaglandins
c) bradykinin, H+, K+
d) substance P
e) Acetyclcholine
92
mechanism of hair cell activation
- The stereocilia on hair cells are tethered together by proteins, vibration causes steriocilia to bend towards the tallest cilium
- opens K ion channels
- K rushes in
- K goes in, depolarizes inner part of cell
- depolarization --> opens Ca channels
- Ca goes in cell
- glutamate released from inner cell to synaptic cleft
- triggers afferent nerve
93
how dog fixates/ how they gauge distance
- cornea
- lens
- retina:
- pigment epithelium (light absorbed), rods and cones
- optic nerve travels in periorbita, through optic canal
- optic chiasma (decussates)
- lateral geniculate body
- occipital lobe
- fixate using stereopsis
94
head tilt
- utricle and saccule have a macula with an otilith membrane
- on otolith membrane is otolith
- when tilt, otolith slides, crushes macula in direction of gravity
- depolarize and hyperpolarize steriocilia
- pattern integrated by brain to tell you where head is
95
head rotation
semicircular canal; 3 parts, 1 H, 2 V
at base is hair cells called ampulla
when you rotate endolymph lags, presses on capula in opposite direction of head movement
96
vestibulospinal tract
afferent; vestibular to brain
lateral: ipsilateral, posture
medial; bilateral, synpases w CN and controls face and neck mm
97
descending pyramidal tract
corticospinal tract
- efferent, from brain to muscles
- lateral: 90%, limbs, decussate in medulla
- anterior; trunk, decussate in spinal cord
corticobulbar tract
- efferent from brain to head and face
-synapse with
CN to face and neck muscle
98
ascending pyrimidal tract
spinalcerebellar tract
- afferent
- muscle to brain
- through medulla --> cerebellum --> thalamus --> motor cortex
99
dorsal column tract
afferent
fine touch, vibration, proprioception
nerve 1) from receptors to medulla, synapse
nerve 2) interneuron, decussates at medulla, goes to thalamus, synapse
nerve 3) to cerebral cortex
100
spinothalamic tract
afferent
pain, temp, itch
nerve 1) to spinal cord, synapse w nerve 2
nerve 2) interneuron, decussate at the grey matter of spinal cord, goes to thalamus, synapse
nerve 3) to cerebral cortex
101
tectospinal tract
rostral and caudal colliculi in tectum for involuntary, audio and visual reflex
rostral= visual
caudal= audio
unconscious processing:
spinovisual reflex
spinoauditory reflex
102
CN 1 pathway
cranial nerve 1
- nasal cavity
- cribiform plate
- olfactory bulb
- medial and lateral olfactory tracts
- pyriform lobe
103
CN 8 pathway
cranial nerve 8
- internal acoustic meatus
- medial geniculate body
- trapezoid body
- temporal lobe
104
function of auditory ossicles
tympanic membrane vibrates malleus
malleus vibrates incus
incus vibrates stapes
stapes vibrates oval window
105
what happens after stapes vibrates oval window
causes vibration of perilymph up scala vestibuli pushes basilar membrane down
goes through helicotrema down scala tympani, pushes basilar membrane up
releases pressure and round window
then within scala media is organ or corti, within that is hair cells which are activated
106
muscles that control the auditory ossicles
tensor tympani CN V-3 (mandibular)
stapedius (CN7)
they contract ossicle to reduce amplification of soundwave
107
3 cartilages around ear
auricular cartilage= pinna
annular cartilage= external aduitory meatus
scutiform cartilage
108
crista ampularis
change in direction
rate of change of head movement
109
macula utriculi;
position of head
linear acceleration
110
4 things to be aware of at base of ear during surgery
parotid salivary gland
facial nerve
caudal auricular artery
superficial temporal artery
111
3 structures in middle ear
I1:chorda tympani
2: tympanic nerve
3: sympathetic innervation to the eye
112
bony labyrinth has ____
membranous labyrinth has ____
perilymph
enodlymph
113
auditory tube goes from
supported by what
function
tympanic cavity to nasopharynx,
supported by tympanic bones and cartilaginous troph
equalizes pressure and gland secretion
114
pupil dilation is
sympathetic control
use atripine to block parasymp control to dilate pupil
115
pacini corpuscles
vibration
116
meissner corpuscles
touch and flutter
117
ruffini endings
skin stretch
118
root hair plexus nerves
hair deflection
119
merkel nerve endings
light pressure
120
List the functions of the thalamus.
- Major relay and integration centre for sensation (besides smell)
- Regulation of motor activities
- Distributes information
- Alerts cortex
- Limbic and hypothalamic connections
121
Briefly describe the differences between upper motor neurons and lower motor neurons.
UMNs:
- Cell bodies : Higher motor brain centres
- Axons: CNS confined
- Functions: Initiate voluntary movement, posture
- Lesion: hypereflexia, hypertonia, spastic paralysis
LMNs:
- cell bodies: spinal cord dorsal horn
- axons: peripheral muscles
- functions: somatic (pyrimidal and extrapyrimidal)
- lesions: hyporeflexia, hypotonia, flaccid paralysis
122
Briefly describe the functions of the hypothalamus
Rostral- homeostasis, parasympathetic command centre
Caudal- stress and initiates rage, sympathetic command centre
Pituitary- ADH, oxytocin and inhibitory factor synthesis and release
123
UMN VS LMS
U found in cerebral cortex and brainstem
L found in brain stem and spinal cord
U located near CNS
L located near muscles
U impulses from brain, synapse w L
L impulses from U towards muscle
U lesion: spasticity, hypertonia, hyperreflexuia
L: flaccid paralysis, hypotonia, hyporeflexia
124
Which of the following is NOT a function of the vascular tunic?
(a) Vascular support of adjacent tissues.
(b) Suspect the lens and regulate its curvature.
(c) Production of vitreous humor.
(d) Adjust pupil size.
(c) Production of vitreous humor.
125
Dysfunction of the cerebellum is characterised by:
(a) Hypermetria, nystagmus, ataxia, hypotonus.
(b) Hypermetria, nystagmus, ataxia, hypertonus.
(c) Hypometria, nystagmus, ataxia, hypertonus.
(d) Hypometria, nystagmus, ataxia, paradoxical head tilt.
(b) Hypermetria, nystagmus, ataxia, hypertonus.
126
Central conscious visual pathways pass through the following structures:
(a) Optic chiasma, rostral colliculus, medial geniculate nucleus, occipital cortex.
(b) Optic chiasma, rostral colliculus, lateral geniculate nucleus, occipital cortex.
(c) Optic chiasma, optic radiation, lateral geniculate nucleus, occipital cortex.
(d) Optic chiasma, lateral geniculate nucleus, optic radiation, occipital cortex.
(d) Optic chiasma, lateral geniculate nucleus, optic radiation, occipital cortex.
127
What type of receptor senses when the skin is touched lightly, and adapt rapidly?
(a) Merkel nerve endings.
(b) Meissner corpuscles.
(c) Pacini corpuscles.
(d) Ruffini endings.
(b) Meissner corpuscles.
128
When an adrenergic beta receptor on the heart is activated, what is the response?
(a) Vasoconstriction.
(b) Decreased contractility in the atria.
(c) Increased heart rate.
(d) Decreased contractility in the atria and ventricles.
(c) Increased heart rate.
129
If we apply a drug to the eye which blocks the action of acetylcholine (e.g. atropine), what occurs to the pupil size?
(a) The sympathetic innervation is blocked, resulting in pupil dilation.
(b) The parasympathetic innervation is blocked, resulting in pupil dilation.
(c) The sympathetic innervation is blocked, resulting in pupil constriction.
(d) The parasympathetic innervation is blocked, resulting in pupil constriction.
(b) The parasympathetic innervation is blocked, resulting in pupil dilation.
130
Light entering the eye travels towards the retina, passing through layers of nerves until it reaches the pigment epithelium. What happens when light photons reach the photoreceptors in rods?
(a) The concentration of cyclic GMP increases, opening sodium channels, depolarising the cell membrane.
(b) The concentration of cyclic GMP increases, closing sodium channels, hyperpolarising the cell membrane.
(c) The concentration of cyclic GMP decreases, opening sodium channels, depolarising the cell membrane.
(d) The concentration of cyclic GMP decreases, closing sodium channels, hyperpolarising the cell membrane.
(d) The concentration of cyclic GMP decreases, closing sodium channels, hyperpolarising the cell membrane.
131
Which part of the cortex is involved in the comprehension of language?
(a) Hypothalamus.
(b) Limbic system.
(c) Frontal lobe.
(d) Wernicke’s area.
(d) Wernicke’s area.
132
Which of the following would cause the lens of the eye to relax?
(a) Bright light.
(b) Zonule fibres relaxed.
(c) Animal focussed on an object far away.
(d) Relaxation of the ciliary muscles.
(b) Zonule fibres relaxed.
133
The stereocilia are tethered together by proteins that open ion channels when the array is bent toward the tallest cilium, depolarising the membrane. Which ion enters hair cells after membrane depolarisation via voltage-gated channels?
(a) Calcium.
(b) Potassium.
(c) Sodium.
(d) Chloride.
(a) Calcium.
134
Peripheral sensitisation occurs as a consequence of tissue trauma and inflammation and decreases the pain threshold. Intracellular components are released from damaged cells, inflammatory cells, nerve terminals, and nerve fibres – this increases the sensitivity of peripheral nociceptors. Inflammation produces a “sensitising soup” of chemical mediators.
Which of the following substances sensitises the nociceptor endings?
(a) Histamine.
(b) Substance P.
(c) Bradykinin.
(d) Cytokines.
(c) Bradykinin.
135
Long-term sensitisation of a stimulus/response pathway helps to facilitate learning. Which of the following features is NOT involved in long-term sensitisation?
(a) Increased number of action potentials along motor neurons to carry out movement.
(b) Increased number of vesicles.
(c) Increased number of vesicle release sites.
(d) Increased number of pre-synaptic terminals.
(a) Increased number of action potentials along motor neurons to carry out movement.
136
In the parasympathetic nervous system, acetylcholine released from postganglionic neurons binds to which of the following receptors?
(a) Muscarinic type 1.
(b) Nicotinic type 2.
(c) Nicotinic type 1.
(d) β2-adrenergic receptor.
(a) Muscarinic type 1.
137
Horses with severe equine asthma aka “heaves” or recurrent airway obstruction exhibit prolonged contraction of abdominal muscles, associated with trying to force air out of the small airways. When stimulated, which of the following receptors induces bronchodilation in the lungs?
(a) Muscarinic type 1.
(b) α1-adrenergic receptors.
(c) Muscarinic type 3.
(d) β2-adrenergic receptors.
(d) β2-adrenergic receptors.
138
Which structure senses soundwave frequency?
Tympanic membrane
Incus
Stapes
Hair cells
Hair cells
139
Depending on the pre-synaptic neurotransmitter released and the post-synaptic receptor activated, the post-synaptic membrane can either be depolarised or hyperpolarised. Which of the following statements is FALSE?
Neurotransmitter binding to metabotropic receptors causes a conformational change in pore proteins
The action of metabotropic receptors is slower than ionotropic receptors
Neurotransmitter binding to metabotropic receptors causes a conformational change, activating a signal transduction pathway
An example of an ionotropic receptor is the nicotinic acetylcholine receptor
Neurotransmitter binding to metabotropic receptors causes a conformational change in pore proteins
140
Which of the following receptors respond to stretch and have a wide receptive field?
Meissner corpuscles
Ruffini endings
Merkel cells
Pacinian corpuscles
Ruffini endings
141
Which of the following receptors in the sympathetic system increases the heart rate when engaged?
Muscarinic type 1
Beta-2 adrenergic
Beta-1 adrenergic
Nicotinic
Muscarinic type 2
Beta-1 adrenergic
142
Which of the following statements regarding lower motor neurons is FALSE?
They contact skeletal muscle, leading to muscle contraction
They travel in the corticospinal tract
Their cell body is in the spinal cord
They synapse with upper motor neurons
They travel in the corticospinal tract
143
Binding of an odorant to an odorant receptor on olfactory cells results in which of the following?
Inflow of calcium
Inflow of chloride
Outflow of calcium
Outflow of calcium and sodium
Inflow of calcium
144
In a racehorse, which of the following receptors in the sympathetic system increases the production of sweat?
Muscarinic type 1
Beta-2 adrenergic
Alpha-1 adrenergic
Nicotinic
Muscarinic type 3
Muscarinic type 3
145
What happens when light photons reach the retina?
Potassium channels open
Potassium channels close
Calcium channels open
Sodium channels close
Sodium channels close
146
Which part of the central nervous system is the main integration centre for the autonomic nervous system?
Spinal cord
Brainstem
Hypothalamus
Limbic lobe
Hypothalamus
147
Which of the following receptors induces vasoconstriction of blood vessels in the skin when engaged?
Alpha adrenergic
Beta-2 adrenergic
Muscarinic type 1
Alpha adrenergic
148
Which of the following is NOT a function of the basal ganglia?
Cognitive function
Initiating movement
Voluntary motor control
Learning routine behaviours
Initiating movement
149
Which cranial nerve contains sensory neurons that contribute to the gag reflex?
Facial nerve (CN VII)
Glossopharyngeal nerve (CN IX)
Vagus nerve (CN X)
Hypoglossal nerve (CN XII)
Vagus nerve (CN X)
150
Which tract carries information from receptors for pain, temperature and itch?
spinothalamic tract
151
Which tract carries information from receptors for fine touch, vibration and proprioception
dorsal column tract
