Neurophysiology Flashcards
What are three components of the brain?
Cerebrum (cortex), cerebellum, brain stem
What are purposes of Gyrus and Sulci
Increase surface area of brain, thus, allowing for greater concentration of neurons, as skull size cannot increase
What are the lobes of the cerebrum?
Frontal lobe, Temporal lobe, Parietal lobe, Occipital lobe, Insula lobe
State purpose of frontal lobe + symptoms of damage
Frontal lobe is responsible for higher cognitive function (executive thinking), and Motor function (voluntary movement)
If damaged: Weakness to one side of body, Inability to plan or problem solve, Impaired judgement, difficulty controlling emotion
What is purpose of temporal lobe + symptoms if damaged
Temporal lobe is responsible for processing auditory information, understanding language, memory encoding, face recognition, object recognition, and perception
If damaged: Difficulty understanding spoken words, difficulty with identification and categorisation of objects, difficulty learning and retaining new information, impaired memory
What is purpose of parietal lobe + symptoms if damaged
Responsible for integrating sensory information, including touch, temperature, pressure, and pain
If damaged: Patient may have difficulty finding way around new or familiar places, may disrupt a persons ability to understand spoken articular written language
What is purpose of Occipital lobe + symptoms if damaged
Responsible for vision perception, including colour, form, motion
If damaged: Vision impairments such as blindness or blindspots, visual distortions, and poor spatial analysis
What is purpose of Insula lobe (DEEP within cerebrum) + symptoms if damaged
Responsible for taste, processing our environment for movement. Contains vestibular link which is link between brain and inner ear which helps maintain balance and proprioception.
If damaged: Dizziness, feeling off-balance, feeling as if you are floating or world is spinning
What are main gyrus and sulci of cerebrum
The central sulcus, which seperates the primary motor cortex (pre-central gyrus) from the primary somatosensory cortex (post central gyrus)
What joins left and right side of brain
Corpus callosum - mediates information between left and right side
What is purpose of cerebellum + symptoms if damaged
Cerebellum is responsible for smooth and refined movements (voluntary movement) , including balance and coordinating eye movement
If damaged: Inability to judge distance, Inability to perform rapid alternating movements, Movement tremors, Staggering or wide base walking
What are parts of brain stem
Midbrain, pons, medulla oblongata (involuntary movements)
Purpose of midbrain?
Regulates eye movement, plays a role in motor movement and audio/visual processing - works with occipital lobe and cerebellum
Purpose of Pons?
Coordinates facial movement, hearing, and balance
Purpose of Medulla oblongata?
Assists in regulation of breathing, heart rhythms, BP, and swallowing
What are meninges of brain and spinal cord?
Three protective membranes that cover brain and spinal cord:
Dura mater (most superficial)
Arachnoid mater
Sub-arachnoid space (CSF flows in this space)
Pia mater
What are three regions of the brain
Forebrain (cerebrum and regions that run deeper), Midbrain (one part of brain stem), Hindbrain (cerebellum, pons, medulla oblongata)
What is contained in Diencephalon?
Epithalamus (links limbic system to other parts of brain), Thalamus (All information of body senses except smell are processed through thalamus before being interpreted by cortex- also plays a role in sleep, wakefullness, conciousness, learning and memory)
Hypothalamus (horemone production, maintain homeostasis)
What is anatomy at end of spinal cord
Conus medullaris (cone shaped structure at end of spinal cord), cauda equina (loosely packed collection of nerve roots), Filum terminale ( singular fibre entending from conus medullaris to sacrum)
What are two types of nerve roots
Ventral (motor/effector and are anterior), Dorsal (sensory/affector, and are posterior - contain ganglia)
Difference between CNS and PNS
CNS is brain and spinal cord and have neurons (conducting cells) and helping cells called glial cells (keep neurons healthy, give nutrients)
PNS is neurons outside brain and spinal cord. PNS has Ganlia (collection of neuron bodies), plexus, and sensory receptions (pick up info such as temp, touch, hearing, balance, chemical and light)
What are the glial cell types
Astrocytes (CNS), Oligodendrocytes (CNS- myelin sheath), Microglia (immune cell of CNS), Shwann cell (Myelin sheath of PNS), Satelite ( wrap bodies found in ganglia of PNS)
What is nerve structure
Nerve (surrounded by epineurium), Fascial (surrounded by perineurium), and axon (endoneurium covering)
What are two structures of PNS
Somatic NS - Voluntary movement, skeletal muscle movement only. Efferent motor nerves send signal from CNS to voluntarily contract muscle
Autonomic NS (involuntary movement)
Enteric NS - innervate the gut (smooth muscle only)
Sympathetic NS - innervates “fight or flight” response (smooth and cardiac muscle)
Parasympathetic NS - Recovery from “fight or flight” response (smooth and cardiac only, return body to homeostasis)
What are types of general sensory receptors
Thermoreceptors- Detect temp stimuli
Noiciceptors- Detect pain stimuli
Mechanoreceptors - Touch, pressure, vibration
Baroreceptors - Detect BP
Proprioception - detect change in body position (conscious and unconscious)
What is receptor transduction
Refers to the conversion of energy from stimulus to an action potential.
E.G. energy in form of mechanical information resulting from stimulus causes mechanical-gates Na+ ion channels to open, depolarising membrane, sending AP down sensory fibre
What are receptive fields
A receptive field is an area of skin surface that is monitored by a single touch receptor - smaller field size allows much finer discrimination
What is receptor adaptation (and two types)
Refers to receptors actually stopping signalling when faced with constant stimulus
Slowly adapting- responds to signals considered to be a threat
Rapidly adapting - responds to situations considered not to be a threat (stops signalling after sending initial signal
Name the 4 sensory pathways
- Posterior column-medial lemniscus
- Spinothalamic
- Spinocerebellar
- Trigemino-thalamic
Describe posterior column-medial lemniscus sensory pathway
Spinal tract: Fasciculus Gracillis and fasciculus cuneatus
Decussion region: medulla
Order of neurons: 3
Info conducted: Touch, pressure, vibration, proprioception (conscious)
Describe spinothalamic sensory pathway
Spinal tract: lateral spinothalamic and anterior spinothalamic
Decussion region: spinal segment
Order of neurons: 3
Info conducted: Pain, temp, tickle, and itch
Describe spinocerebellar sensory pathway
Spinal tract: anterior spinocerebellar and posterior spinocerebellar
Decussion region: No decussation
Order of neurons: 2
Info conducted: unconscious proprioception
Trigemino-thalamic
Spinal tract: Ventral trigemino-thalamic, dorsal trigemino-thalamic
Decussion region: Medulla or pons
Order of neurons: 3
Info conducted: Specific to face- pressure, vibration, pain, temp, tickle, itch
