Central Nervous System Flashcards
Main axes on the brain
- dorsal =top of the brain
-ventral = bottom of the brain
Rostral-=front of the brain
-Claudual= back of the brain
Sectional planes of the brain
-horizontal=divides the brain into top and bottom
-coronal plane= divides the brain into front and back
-Sagittal= divides the brain into left and right
Afferent division of the nervous system
-inputs to the CNS from the peripheral system such and sensory and visual stimuli
Efferent division of the nervous system
-outputs from CNS to peripheral
-consistent of the somatic nervous systems and autonomic and stimuli from the digestive tract which are further divided
Meninges
-act as a protective barrier for the brain abb no d spinal cord shielding then from injury and providing support.they also contain the cerebrospinal fluid
-blood vessels cross the meninges supplying the brain with oxygen and nutrients and allowing the release of CO2 and waste products
Cerebrospinal fluid
- protects the brain. From injury
- helps remove waste products from the brain and provides nutrients to the nervous system.
-* ion composition
similar to blood plasma, but with higher chloride concentration and much lower protein
concentrations
Blood brain barrier
- surrounds the blood vessels and capillaries
-tight junctions between the walls of the blood vessels
-protects CNS from toxins and pathogens, but also hinders drug treatments. Harder from drugs to reach the brain
three main classification of the brain
-forebrain
-hindbrain
Midbrain
Forebrain
-includes cerebral cortex,basal ganglia,hippocampus,amygdala
Cerebral cortex
-outer layer of the brain involved in thinking,perceiving and decision-making
- made up of different regions such as the frontal lobe,parietal lobe,occipital lobe and temporal lobe
in the forebrain
Thalamus
-process and directs sensory signals to the cerebral cortex
Hypothalamus
- regulated homeostasis and controls autonomic nervous system and hormone secretion by the pituitary gland
basal ganglia
-regulates emotions
-controls voluntary movements such as walking
-associated with pathological conditions including Parkinsons disease,Huntington’s disease
hippocampus
- located in medial temporal lobe of cerebral hemispheres
-functions are learning,memory
amygdala
-small almond-shape structure adjacent to hippocampus at base of cerebral hemispheres
-fun actions are emotional behaviour and association of emotions with places/events
Brainstem (Midbrain & Hindbrain)
-Midbrain, Pons & Medulla oblongata (hindbrain)- contains -all axons that connect spinal cord to forebrain and cerebellum
midbrain
- direct control of eye movements
-involved in skeletal motor control
hinderbrain-cerebellum
-maintaining posture
-coordinating hand, eye and arm movements
-involved in cognitive functions
hindbrain-pons
-relays info from cerebral cortex to cerebellum
-dorsal portion contains structures involved in respiration,taste and sleep
hinderbrain-medulla
- involved in the control of blood pressure & respiration
-contains early components of auditory, taste and balancepathways - control of neck and facial muscles
spinal cord
-dorsal roots: sensory information
- ventral roots: motor axons and pre-ganglionic sympatheticand parasympathetic axon
motor control at the local level
- autonomic responses
-involves reflex generators
-brain stems for respiratory control and eye movements and spinal cord for stereotyped movements such as walking
motor control at the middle level
-initiation and coordination of movements
-brainstem, thalamus, basal ganglia, cerebellum & primary motor cortex
-fine movements,motor skill learning, coordination of movements
-automatic resposnes
what makes the human brain different to other primates
-ha the largest number of neurons than other primates but not structurally different or necessarily larger
effects ageing on the brain
- there is no loss of neuronal cells, however,neuron complexity and synaptic connections reduce=shinkage of the cortex
dementia
- the result of severe neuronal cell loss
- Amyloid plaques are abnormal clusters of beta-amyloid protein that accumulate between nerve cells in the brain. The accumulation of amyloid plaques is believed to disrupt communication between neurons and trigger an inflammatory response, contributing to neuronal damage and cell death.
-Neurofibrillary tangles consist of abnormal tau protein that forms twisted tangles inside neurons. Tau protein is crucial for maintaining the structure of neurons, and when it becomes abnormal, it leads to the breakdown of the neuronal transport system. This disrupts the normal functioning of neurons, contributes to cellular damage, and eventually results in cell death.
Alzheimers drugs
- targets the symptoms
-potential targets: amyloid plagues and tau tangles
-only five drugs approved
motor control at the higher level
-movement at conscious control
-Decision making and planning, motivation, learning and memory