Exam Flashcards
What is a ganglion?
A ganglion (plural: ganglia) is a collection of neuronal cell bodies located outside of the central nervous system
Where are ganglia located?
Outside of the CNS (in the PNS)
What ganglia is located in the CNS as an exception
The basal ganglia
What are the 3 layers of connective tissue surrounding a nerve?
Epineurium
* Contains the major blood vessels
Perineurium
* Contains bundles of axons known as fascicles
* Usually many fascicles per nerve
Endoneurium
* Connective tissue surrounding axon(s)
What are the different types of peripheral nerves and their functions?
Sensory nerves
* Each dorsal root of the spinal cord has a dorsal root ganglia
* Dorsal root ganglia contain the cell bodies of the sensory neurones and relay information from the body to the CNS about touch, pain and temp.
Autonomic nerves
Autonomic nerves regulate involuntary bodily functions, like heart rate, digestion, and breathing.
They are further divided into:
Sympathetic Nerves (activates the “fight or flight” response)
Parasympathetic Nerves (promotes “rest and digest” functions)
Enteric Nerves (controls the digestive tract functions independently).
Name all the cranial nerves
Oh, Oh, Oh, Touching Tits And Feeling Virgin Girls’ Vaginas – Ah, Heaven
Olfactory (I)
Optic (II)
Oculomotor (III)
Trochlear (IV)
Trigeminal (V)
Abducens (VI)
Facial (VII)
Vestibulocochlear (VIII)
Glossopharyngeal (IX)
Vagus (X)
Accessory (XI)
Hypoglossal (XII)
Function of cranial nerve I
- Olfactory nerve
- Smell
Function of cranial nerve II
- Optic nerve
- Vision
Function of cranial nerve III
- Oculomotor nerve
Eye movement and pupil constriction
Function of cranial nerve IV
- Trochlear nerve
- 1 eye muscle – Superior oblique
Function of cranial nerve V
- Trigeminal nerve
- facial sensation
- Muscles of mastication
Function of cranial nerve VI
- Abducens nerve
- 1 eye muscle – Lateral rectus
Function of cranial nerve VII
- Facial nerve
- Facial expression
- Taste to anterior 2/3 of tongue
Cranial nerve VIII
- Vestibulocochlear nerve
hearing and balance
Cranial nerve IX
- Glossopharyngeal nerve
taste to rest of tounge, swallowing
Cranial nerve X
- Vagus nerve
- Taste to remainder of oral cavity
- Parasympathetic supply to most internal organs
Cranial nerve XI
- Accessory nerve
shoulder and neck movement
Cranial nerve XII
- Hypoglossal nerve
- Muscles of the tongue
Which of the cranial nerves contain sensory, motor or both fibres
Some Say Marry Money But My Brother Says Big Brains Matter More
What are the general role of the subtypes of motor and sensory nerves in the cranial nerves
Sensory types can be:
Somatic sensory – sensation from the body.
Special sensory – senses like vision, hearing, balance and taste
Visceral sensory – sensation from the internal organs
Motor types can be:
Somatic motor - Control voluntary muscle movements, like moving the eyes, tongue, and face.
Branchial arch motor – skeletal muscle that arises from the branchial arches
Visceromotor – parasympathetic supply to much of the body
Divisions of the autonomic nervous system (ANS)
- Sympathetic nervous system
- Parasympathetic nervous system
What are the structures that the autonomic motor efferents act on?
Autonomics act on smooth and cardiac muscle
Gut muscles
Arterial muscle
Pupil muscles
Heart muscle
What are the structures that the somatic motor efferents act on?
Somatic primarily acts on skeletal muscle
Differences between the motor efferent of the somatic and autonomic nervous system
Target Muscles
Somatic: Controls skeletal muscle (voluntary movements).
Autonomic: Controls smooth muscle, cardiac muscle, and glands (involuntary functions).
Control
Somatic: Voluntary.
Autonomic: Involuntary.
Neural Pathway
Somatic: Single neuron from CNS to muscle.
Autonomic: Two-neuron chain (preganglionic and postganglionic).
Neurotransmitters
Somatic: Acetylcholine
Autonomic: Acetylcholine (parasympathetic) or norepinephrine (sympathetic).
Effect on Target Tissues
Somatic: muscle contraction (always excitatory)
Autonomic: Excitation or inhibition, depending on the receptor type and organ.
Which neurotransmitters are used in the SNS and PNS
PNS:
pre and post - Acetylcholine.
SNS
Pre ganglionic - Acetylcholine
Post ganglionic - Adrenaline
What are the two main plexus of the enteric nervous system and their functions?
Myenteric Plexus (Auerbach’s Plexus):
controlling motility.
Submucosal Plexus (Meissner’s Plexus):
regulates blood flow, secretions, and absorption.
What are the actions of the parasympathetic nervous system?
rest and digest
decrease heart rate
constrict pupils
* Increase digestion and repair functions
* Increase bladder contraction
* Increase immune system function
reduces blood pressure
What are the actions of the sympathetic nervous system?
fight or flight
Increase heart rate
increase blood pressure
* Dilate the pupils
* Slow digestion
* Release sugar into the blood stream
sweating
* Reduces bladder contraction
* Depresses immune system function
What sections of the spine do the Sympathetic nervous system and Parasympathetic nervous system arise from
SNS: Arises from the thoracic and lumbar regions of the spinal cord, specifically from T1 to L2
PSNS: Arises from the cranial nerves
Cranial Nerves: III (Oculomotor), VII (Facial), IX (Glossopharyngeal), and X (Vagus).
and S2-4 sacral segments
What occurs in a crossed cord reflex?
a stimulus on one side of the body causes a response on the same side but also the opposite side.
the left bicep is activated.
What would happen in the right tricep and bicep.
Left Bicep: activated
Right Tricep: slight activation to stabilize the right arm.
Right Bicep: Inhibition (relaxation)
pretty much the right side is inhibited and relaxes
Striking the right bicep tendon will cause what to the left bicep
inhibit it, relaxes
What is an example of a polysynaptic reflex?
Pupillary light reflexes. The pupils of the eye will constrict or dilate according to light levels
Withdrawal reflex. touch something hot, back away.
What receptors influence postural reflexes?
- Proprioceptors in the muscles and joints
- Cutaneous receptors in the skin
- Vestibular receptors in the ear
- Visual receptors in the retina of the eye
- Auditory receptors in the ear
What is the difference between short and long latency reflexes?
Short Latency Reflexes
Occur rapidly (20-45 milliseconds).
Allow for rapid responses to postural changes.
Example: Patellar reflex.
Long Latency Reflexes
Take longer (50-100 milliseconds or more).
Allow for more integrated responses to postural changes.
Example: Withdrawal reflex.
What pathways and systems are utilized for short latency and long latency reflexes?
Short latency reflexes:
Utilise spinal cord pathways, including monosynaptic muscle stretch and polysynaptic crossed cord reflexes
Long latency reflexes:
Utilise brainstem pathways, the vestibular system, visual system and proprioceptive system
Free nerve endings may respond to what type of stimuli?
- Pressure
- Chemicals
- Temperature
What is the difference between exteroceptors and interceptors and examples?
Exteroceptors transduce information from the external environment
* Light for vision
* Pressure for touch
Interoceptors transduce information from the internal environment
* Stretch receptors from the gut
* Blood pressure receptors in the aorta
What are the 6 eye muscles attaching to the sclera
Medial, lateral, superior, inferior rectus
Superior and inferior oblique
What are free nerve endings commonly associated with?
Pain sensation (nociception)
What are the primary actions of each of the eye muscles
Lateral rectus
Abduction
Medial rectus
Adduction
Superior rectus
Elevation
Inferior rectus
Depression
Superior oblique
Intorsion
Inferior oblique
Extorsion
What are the function differences between rods and cones?
Rods:
Responsible for vision in low light (scotopic vision)
Highly sensitive to light.
Do not detect colour
Detect motion
Cones:
Detect colour (red, green, blue)
Clarity of vision
Where are cones and rods more densely located, and what do they do?
Cones: More cones in the macula, fewer in the peripheral retina
* Better at clarity of vision and colour
* Not so good detecting motion and low light vision
Rods: Fewer rods on the macula, more rods in the peripheral retina
* Better at detecting motion and low light vision
* Not so good at clarity of vision and colour
What are the names of the ossicles of the middle ear
- Malleus, incus and stapes
What are the names of the muscles in the inner ear and their functions
- Cochlear
- vibration into electrical impulses
- Vestibular apparatus
- Turning head movements into electrical impulses
Semicircular canals
* Detect rotational movement of the head in different planes
What movements are detected by each of the semicircular canals
- Anterior – detects forward rotations of the head
- Posterior – detects backward movements of the head
- Horizontal – detects side to side rotations
What movements are detected by the Utricle and Saccule
- Utricle:
- Detects anterior-posterior and lateral linear movements
- Saccule:
- Detects anterior-posterior and vertical linear movements
What is the process of sound travelling through the ear?
Sound Waves Enter through the ear canal.
Vibration of the tympanic membrane.
Ossicle Movement of Malleus, incus, and stapes amplify sound.
Stapes pushes on the oval window.
Fluid waves stimulate hair cells in the cochlea.
Auditory Nerve Carries electrical signals to the brain.
Brain interprets signals as sound.
Know the cranial nerves contributing to taste
- Facial nerve (VII)
- supplies taste to the anterior two thirds of the tongue
- Glossopharyngeal (IX)
- supplies taste to the rest of the tongue
- Vagus (X)
- Supplies taste to the rest of the oral cavity
What are the three types of hearing loss?
Conductive Hearing Loss: Sound waves blocked; causes: earwax, fluid, eardrum/ossicle damage.
Sensorineural Hearing Loss: Inner ear (cochlea) or auditory nerve damage; causes: aging, noise, genetics, diseases.
Mixed Hearing Loss: Combination of both types.
What are the 5 basic types of taste
Sweet, salty, sour, bitter, umami (savoury)
How is each taste detected by the tongue?
- Sweet sensitive taste buds detect the presence of glucose or other sweet substances like fructose or aspartame
- Salt taste buds detect the presence of sodium ions
- Sour taste buds detect the presence of hydrogen ions, i.e. acidity
- Bitter detect a number of different bitter tasting molecules
- Umami (Savory) taste buds detect L-glutamate, often found in meat
