Lecture 5: Central Nervous System 1 Flashcards
CNS:
Brain & spinal cord
-> ____ division
-> ____ nervous system ->____ nervous system
->___ neurons ->___ nervous system
-> ___ muscles ->___ nervous system
-> __ muscles
-> ___ muscle
-> ___ glands
-> ___ glands
Efferent
Somatic autonomic
Motor sympathetic, parasympathetic
Skeletal smooth, cardiac, exocrine , endocrine
The central nervous system consists of the ___ and _____
Brain and spinal cord
The ____ nervous system consists if afferent and efferent neurons and their axons that are found outside the brain and spinal cord
Peripheral
The ___ nervous system- consists of the sympathetic and parasympathetic components
Autonomic
The 2 major types of cells in the central nervous system are ___ and ____
Neurons and glial cells
Neurons are the __ or ___
Glial cells play an important role in ___ and ___
Effectors or sensors
Protection and support
___-the business part of the nervous system : grey matter
Neurons
Various types of neurons- ___, ___, ____, ___
Function, morphology, phenotype, modality
________- Oligodendrocytes, astrocytes, microfilm, ependymal cells (CNS)
Schwann cells, satellite cells (PNS)
GLIAL CELLS
____- information arrives in the CNS
____- commands from the CNS exits to various parts of nervous system or other body systems
Afferent
Efferent
____- lie entirely within the CNS - are usually part of the intrinsic circuits
Inter neurons
_____- Long bundles of sensory and motor axons in the PNS
Nerves
Half of the cells in the brain are _____ and other half are neurons
Serve essentially as the _____ tissue of the brain
Important for maintaining the _____ composition of the extracellular environment surrounding neurons
Glial cells
Connective
Homeostatic
-
-
-
Astrocytes
Oligodendrocytes
Microglia
Ependymal cells
Type of glial cell that :
-physically support neurons in proper spatial relationships
-serve as a scaffold during fetal brain development
- form neural scar tissue
- Take up and degrade released neurotransmitters into raw materials for synthesis of more neurotransmitters by neurons
- take up excess K+ to help maintain proper-brain -ECF ion concentration and normal neural excitability
-enhance synapse formation and strengthen synaptic transmission
Astrocytes
Type of glial cell that:
Form myelin sheaths in CNS
Oligodendrocytes
Type of glial cell that play a role in defence of brain as phagocytes scavengers
Microglia
Type of glial cell that:
- line internal cavities of brain and spinal cord
Contribute to formation of cerebrospinal fluid
Serve as neural stem cells with the potential to form new neurons
Ependymal cells
The brain stem consists of ___, ___ and ___
Midbrain
Pons
Medulla
The brain is divided into 2 half’s, the ______ hemisphere and ______ hemisphere. Dividing the 2 is the ______
Left cerebral, right cerebral
Longitudinal fissure
The brain and spinal cord are protected by a 3 layer sheath- collectively referred to as the ____
Meninges
Meninges:
______: most fragile, inner most layer
____: middle membrane
____: tough outer most layer
These layers wrap and protect the ____
Pia mater
Arachnoid mater
Dura mater
CNS
Space between the arachnoid mater and the pia mater is called the ______, it is filled with ___ and contains ____ that supply the brain
Subarachnoid space
CSF
Blood vessels
Brain and spinal cord essentially float within a fluid filled space, this space is filled with____
Cerebrospinal fluid (csf)
The csf circulates through the ____ system
Ventricular
- Csf is produced by the ______ inside ventricles
- It circulates through the ___
- Exits 4th ventricle flows in the _____ space between the arachnoid mater and pia mater,
- Reabsorb from subarachnoid blood via the _____ villi
Choroid plexus
Ventricles
Subarchnoid
Arachnoid
Function of csf:
Buoyancy of csf reduces the ___ of brain = less ___ on blood vessels and nerves
Also provides protective ___; with a blow to the head the fluid absorbs some of the shock before he brain hits the skull.
Weight, pressure
Padding
Functions of CSF :
Csf creates a regulated _____ environment for the neurons.
Csf contains little ___ and no ___ cells
Extracellular
Protein
Blood
_____- when samples of csf test positive for the presence prof protein or blood cells , suggest infection
Spinal tap
The entire csf volume of about 125-15-mL is replaced about ___x a day
Problems with csf formation or reabsorption can lead to _____
3
Hydrocephalus
___ -functional barrier between interstitial fluid and the blood
Blood brain barrier (BBB)
The BBB limits passage of blood borne agents into the ___
CNS
BBB:
Selective permeability of brain capillaries protects brain from toxins and fluctuations in ___, ___ and _____ in the blood
Hormones
Ions
Neuroactive substances
The BBB consists of ____ cells of the brain capillaries.
Endothelial
Endothelial cells form tight junctions with each other that prevent _____ movement between endothelial cells
Solute
BBB:
Only possible exchange is through the _____ themselves
Endothelial cells
BBB:
Only _____ substances such as oxygen, C02, steroid hormones and alcohol that penetrate the cells
Lipid soluble
BBB;
____ molecules cannot cross BBB unless via a specific carrier
Water soluble
BBB:
Some areas of brain have a leaky BBB- ______ organs such as the neurohypophysis of the pituitary. This allows the brain to sense and respond to _____ occurring in the body
Circumventricular
Chemical changes
Neural tissue: metabolic needs:
_______:
- passes freely across BBB
-brain receives _____ of blood pumped by heart
- brain canno produce ___ in the absence of this.
- brain damage occurs if this is cut for about 5 or more mins
Oxygen
15%
ATP
Neural tissue: metabolic needs :
_____:
- brain responsible for about half of body’s consumption of this and the body does not store it well.
- ________ move this from plasma into brain interstitial fluid
-____ leads to confusion, unconsciousness and death
- brain damage if this is cut off for about 15 mins
Glucose
Membrane transporters
Hypoglycaemia
What brain component?
sensory perception
voluntary control of movement
Language
Personality traits
Sophisticated mental events such as thinking, memory, decision making, creativity, and self-consciousness
Cerebral cortex
What brain component?
Inhibition of muscle tone
Coordination of slow, sustained movements
Suppression of useless patterns of movement
Basal nuclei
What brain component?
Relay station for all synaptic input
Crude awareness of sensation
Some degree of consciousness
Role in motor control
Thalamus
What brain component?
Regulation of many homeostatic functions such as temperature control, third, urine output and food intake.
Important link between nervous and endocrine systems
Extensive involvement with emotional and basic
behavioural patterns
Role in sleep-wake cycle
Hypothalamus
What brain component?
Maintenance of balance
Enhancement of muscle tone
Coordination and planning on skilled voluntary muscle activity
Cerebellum
What brain component?
Origin of majority of peripheral cranial nerves
Cardiovascular, respiratory and digestive control cortex
Regulation of muscle reflexes involved with equilibrium and posture
Reception and integration of all synaptic input from spinal cord; arousal and activation of cerebral cortex
Role in sleep-wake cycle
Brain stem (midbrain, pons, medulla)
The cerebral cortex is __matter and the core is ___ matter
Grey, white
_____Comprised mainly of neuronal cells, dendrites and glial cells
Grey matter
Integration of neural input and initiation of neural output take place within _____
Grey matter
The _______ consists of bundles of myelinated nerve fibers that interconnect brain areas
White matter
The _______ is organized into six well defined layers also organized into vertically organized columns of cells
Cerebral cortex
Each hemisphere is divided into 4 lobes:
_____ lobes: receives and processes visual inputs
___ lobes: receives and process auditory inputs
___ lobes: receiving and processing of somatosensory input
___ lobes: voluntary motor activity, speaking and elaboration of thought
Occipital
Temporal
Parietal
Frontal
Occipital lobes receives and processes _____ inputs
Visual
Temporal lobes receives and processes ___ inputs
Auditory
Parietal lobes receiving and processing ____ input.
Somatosensory
Frontal lobes : voluntary _____, ____ and elaboration of ____
Motor activity
Speaking
Thought
______ detects the magnitude of blood flow in different regions of the brain. More blood flow = more active brain region.
(PET) POSITRON -EMISSION TOMOGRAPHY
Primmary auditory cortex receives topographic sensory fibres from the ___ of each ear, mapped by pitch
Cochlea
Temporal lobe contains the ____ and ___, important for episodic memory formation of recent events
What is hippocampus and amygdala important for?
Episodic memory formation of recent events
Each hemisphere receives out from both eyes via ____ and ____
Optic nerve and thalamus
Visual hemi-field projects onto ________
Primary visual cortex
______- area in front of the centra sulcus: plan and execute movements in coordination with the pre-motor cortex
Primary motor cortex
Primary motor cortex controls _________
Muscle/movements on opposite side of body
______- depicts the location and relative amount of motor cortex devoted to output to the muscles of each body part
Motor homunculus
_____- muscles of each body part are represented typographically
Motor homunculus
Extent of representation in the ________ is proportional to the precision and complexity of motor skills required
Motor cortex
Motor areas are adjacent to _______areas for same body regions, facilitating communication
Sensory
Projects to motor neurons that directly innervate _____ muscle
Skeletal
Executes ______ movements, by coordinated activation of multiple muscle groups
Muscle
____ encode force, direction and speed of movement
Neurons
_______ on each side controls muscles on opposite side of body-tracts originating in the cortex cross before continuing down spinal cord
Motor cortex
Primary motor cortex does not initiate ________. Associative structures process progressively more abstract info
Voluntary movement
_______- signals preparation for movement, informed of body’s position in relation to target, codes behavioural context/goals, correct and incorrect actions
Premotor cortex
_____- plays a preparatory role in programming complex sequences of movement, resounds to remembered movements, active during action and imagination of Action
Supplementary motor area
______- planning and organization of goal-directed behavioural, working memory and decision making
Prefrontal cortex
_____- sensations from receptors on the surface of the body, specialized for tough, pain, pressure, heat and cold
Somaesthetic sensation
_____- site for processing tough inputs and features
Primary somatosensation cortex
______- area posterior to central sulcus
- information acquired by PNS processing iOS relayed to the CNS and somatosensory cortex
Somatosensory cortex
________:
-each region receives somaesthetic and proprioceptive input from a specific area of the body
-the size of each body part indicates the relative proportion of the somatosensory cortex devoted to that area
Sensory homunculus
_______ integrates tough, vision and audition information in spatial context, part of dorsal stream
Associative parietal cortex
_______ receives information from opposite side of the body
Primary sensory cortex
The ___ detects simple awareness of sensation but doesn’t tell you where or intensity.
Thalamus
Motor, sensory and language areas account or only half of the total ______
Remaining areas are called ________
Cerebral cortex
Association areas
Association areas :
-_____ association cortex
-_____ association cortex
-_____ association cortex
Prefrontal
Parietal-temporal-occipital
Limbic
