Video Summaries Flashcards
The nervous system
- consists of two types of cells: neurons and glial cells
Neurons
- communicate info within the nervous system
Glial cells
- provide neurons with structural support, insulation, And nutrients
Structure of a neuron
- May vary in size and shape, but I’ll have one or more dendrites a cell body( soma) and an axon
Dendrites
- receive information from a presematic neuron
Cell body
- contains nucleus, mitochondria, and other elements essential for cell survival
Axon
- transmits info to a postsynaptic cell
Synapse
- Small space between presynaptic cells axon and receptor on a postsynaptic cell
Mylien
- some axons are insulated by this
+ Speeds up conduction
Multiple sclerosis
- destruction of mylien that insulates axons in the brain and spinal cord caused by a malfunctioning immune system
- symptoms very depending on location of damage
- impaired coordination and vision, pain, fatigue, slurred, speech, tremor
Neurotransmitters
+ chemicals that transmit information from presynaptic neurons to the adjacent Post-Synaptic neuron
+ Many have excitatory or inhibitory effects depending on the type of a post-synaptic cell and others are primarily one or the other
Excitatory
- released into the synapse is likely that an action potential will occur in a post- synaptic cell
Inhibitory
+ release into synapse decreases the likelihood that an AP will occur in a postsynaptic cell
Inhibitory
+ release into synapse decreases the likelihood that an AP will occur in a postsynaptic cell
Action potential
- electrical impulse that travel the length of cells axon and is responsible for the release of neurotransmitters into the synapse
- occurs when there is sufficient stimulation from a pre-synaptic neuron
-All or nothing
+ Always occurs at the same frequency
Dopamine
+ movement, learning, mood, sleep, and the reinforcement effects of drugs
Abnormal levels of dopamine
- Parkinson’s disease, Huntington’s disease, tourette’s disorder, ADHD, depression, and schizophrenia
Dopamine hypothesis
+ original: schizophrenia is due to excessive or hyperactivity of dopamine receptors
+ Revision: positive symptoms are due to dopamine hyperactivity in the subcortical regions of the brain
- negative symptoms are due to hypoactivity and cortical regions of the brain, especially the prefrontal cortex
Acetylcholine
- voluntary movements: controls contractions of the skeletal muscles
- regulate smooth and cardiac muscles
- arousal, attention, and memory
Low acetylcholine
- in hippocampus linked to early memory loss associated with Alzheimer’s
Cholinetarse inhibitors
- reduce the breakdown of ACH
- temporarily reverse or slow down memory loss or other cognitive impairments associated with people who have mild to moderate Alzheimer’s
Glutamate
- primarily excitatory
- movement, emotions, learning, and memory
- involved in long-term potentiation which is essential for the formation of long-term memory
Long-Term potentiation
,- essential for the formation of long-term memories
- rapid and or high frequency stimulation cause an increase in efficiency and strength of a synaptic transmission
Excessive glutamate
- glutamate induced excitotoxicity causes cell damage or death believed to contribute to brain damage associated with stroke, seizures, TBI, or several neurogenitive disorders like Alzheimer’s and Huntington’s disease
Norepinephrine
- arousal, sleep, learning, attention, mood and memory
- abnormal levels equal ADHD, mania and depression
Catecholamine hypothesis
- some forms of depression are caused by a deficiency
- mania is caused by excessive norepinephrine
Catecholamine hypothesis
- some forms of depression are caused by a deficiency
- mania is caused by excessive norepinephrine
Serotonin
Inhibitory
asleep, sex, aggression, mood, hunger, pain, and body temp
Low levels of serotonin
in certain areas of the brain have been linked to depression, increased risk for suicide, bulimia nervosa, obsessive-compulsive disorder, and migraine headaches.
Excessive serotonin
- anorexia nervosa have higher-than-normal brain levels of serotonin that cause anxiety and obsessive thinking and that food restriction lowers serotonin levels which alleviates these symptoms
Pplhigher-than-normal blood levels of serotonin have been found in individuals with autism spectrum disorder and individuals with chronic schizophrenia who also have enlarged cerebral ventricles and/or cerebral atrophy.
Gaba
- primarily inhibitory
- memory, mood, sleep, and motor control
Low levels of gaba
- anxiety, mania, insomnia, seizures, Parkinson’s and Huntington’s disease
- benzos enhance the effects of gaba
Endorphins
Inhibitory
- contribute to the feelings of pleasure and well-being
Help relieve pain
- produced by the pituitary gland and hypothalamus during strenuous exercise and produce the runner’s high
Agonist
- mimics or increases the effects of the neurotransmitter at receptors
Partial agonist
+ produces effects similar but weaker than the effects of the neurotransmitter at receptors
Inverse agonist
- produce effects that are opposite of the neurotransmitter at receptors
Antagonist
- produce no effects on their own, but block or reduce the effects of a neurotransmitter or agonist at receptor
Dopamine agonist
Used to treat Parkinson’s disease and exert their effects by mimicking the effects of dopamine at dopamine receptors
Buspirone
+ partial agonist serotonin receptors and is useful for treating anxiety
Some atypical antipsychotic
- act as inverse agonist at serotonin receptors
Psychotic drugs that blocked dopamine receptors
Antagonists
Myasthenia gravis
- autoimmune disorder in which antibodies destroy receptors for acetylcholine that neuromuscular junctions and thereby cause skeletal muscle fatigue and weakness
Naloxone
- has no response on its own but blocks receptors for heroin
Antagonist
Central nervous system
- Brain and spinal cord
Hindbrain
located directly above the spinal cord
+The most primitive part of the brain. It
medulla, pons and cerebellum
Mid brain
Connects the hind brain with forebrain and includes the reticular activating system and substantia nigra
Brain stem
- midbrain
- pons
- medulla
Forebrain
Aka cerebrum
It’s the largest and most complex region of the human brain and consists of subcortical and cortical structures
Spinal cord
- Comsists of 31 Pairs of spinal nerve that consist of bundles of axons, dendrites and cell bodies
- transmits sensory and motor information between the brain and the peripheral nervous system
+8 cervical, 12 thoracic, five lumbar, five sacral and one coccygeal
Effects of spinal cord injury
- depend on its location, whether an injury is complete or incomplete and whether It affects sensory or motor nerves motor nerves
Damage at the cervical level
- causes quadriplegia which is also known as tetraplegia and involves partial or complete loss of movement and or sensation in the arms, trunk and legs
Injury at thoracic or lumbar level
- paraplegia: partial or complete loss of movement and or sensation in the legs and all are part of the trunk
Peripheral nervous system
- translates transmits information between the central nervous system and the rest of the body and includes the somatic and autonomic nervous systems.
somatic nervous system
-transmits information from the body’s sensory receptors to the central nervous system and from the central nervous system to the skeletal muscles and it’s responsible for actions that are usually considered voluntary
Autonomic nervous system
- transmits information between the body’s smooth muscles of the organs and glands and the central nervous system. It’s responsible for activities that are usually considered involuntary, although some activities can be brought under voluntary control using biofeedback
- consists of the sympathetic and parasympathetic branches
Autonomic nervous system
- transmits information between the body’s smooth muscles of the organs and glands and the central nervous system. It’s responsible for activities that are usually considered involuntary, although some activities can be brought under voluntary control using biofeedback
- consists of the sympathetic and parasympathetic branches
Sympathetic branch
- mediates fight or flight response and energy output
Causes pupil dilation,Sweating and increase heart and respiration rates and inhibits digestion and sexual activity
Parasympathetic branch
- responsible for rest and relaxation and energy conservation
- And it causes the body to return to its pre-emergency state after a fight-or-flight response
Sympathetic and parasympathetic branches
- both active to some degree o some degree most of the time and work together cooperatively for some functions
General adoption syndrome
- frequently cited model regarding the body’s reaction to stress
-proposes that the body’s response to all types of stress is the same is mediated by the sympathetic and parasympathetic nervous systems and involves three stages
Alarm reaction stage
Resistance stage
Exhaustion stage
Alarm reaction stage
-the hypothalamus stimulates the pituitary gland to release ACTH, which in turn stimulates the adrenal medulla to release epinephrine and norepinephrine in the adrenal cortex to release cortisol.
These hormones cause an increase in heart and respiration rates, a rise in glucose levels, and other physical changes that provide the body with the energy. It needs to respond to the stressor with a fight or flight reaction
Resistance stage
- If the stressor continues, this stage begins
+ During this stage, the parasympathetic nervous system attempts to return some physiological functions to their normal level, but the stress hormone cortisol continues to circulate in an elevated level which helps the body maintain a high level of energy
Exhaustion stage
- If the stress starts effects are not resolved this stage begins
-The pituitary and adrenal glands lose their ability to maintain elevated hormone levels in physiological processes begin to break down.
Prolonged exposure to stress
suppression o is the hybrid which is located just above the spinal cord f the body’s immune system which causes an increase in the body’s susceptibility to infection
Partially due to chronically elevated levels of cortisol and other stress hormones
Medulla
Regulates vital autonomic nervous system, functions: respiration, heart rate, blood pressure and digestive processes as well as coughing, swallowing, sneezing and other reflexes
Damage to the medulla
- Brain injury, certain diseases and opioids and other drugs can disrupt the functioning of the medulla and result in death
Pons
+ connects the two halves of the cerebellum and the cerebellum to the forebrain
- helps coordinate movements on two sides of the body
- raousal sleep and the regulation of respiration by coordinating the transition between inhalation and exhalation
Cerebellum
- coordinates and sequences complex voluntary movements that are initiated in the motor cortex
+ Involved in posture and balance
- responsible for processing and storing procedural memories
Procedural memories
- walking, riding a bicycle and driving a car as well as other types of automatic behaviors such as reciting, the alphabet and multiplication tables
Damage to the cerebellum
- can cause ataxialack of muscle control, impaired balance and coordination, slurred speech and blurred or double vision
Reticular activating system
+ also known as the ascending reticular activating system
The network of neurons that extend from the medulla into the midbrain
- mediates behavioral arousal and consciousness control the sleep wake cycle and alerts the cerebral cortex to incoming sensory signals
Lesions on the Ras
Can cause a comatose state while directs electrical stimulation or stimulation by sensory input. Can awaken a sleeping person and cause an awake person to become more alert
Substantial niagra
- plays a role in reward seeking behaviors, drug addiction and through its connection to the basal ganglia motor control
Degeneration of dopamine producing cells in the substantia nigra
- contribute to the motor symptoms associated with Parkinson’s disease
- contribute to the slow movement, tremors,muscle rigidity and other motor symptoms
Subcortical structures
- hypothalamus
- thalamus
- Basil ganglia
- amygdala
-Hippocampus
Hypothalamus
- regulates the body’s homeostasis. (HR, BP, appetite, and thirst) Through effects on ANS and endocrine glands
- influence is development of secondary sex characteristics and sexual /reproductive behaviors by stimulating pituitary gland to release sex hormones
- regulates body’s response to stress by stimulating pituitary gland to release ACH
Suprachiasmatic nucleus
- Located in the hypothalamus
- control circadian rhythms (sleep wake cycle, body temperature, and hormones)
+ Bodies biological clock
Mammillary bodies
- attached to the hypothalamus
- memory
- damage interferes with ability to form new declarative memories
Declarative memories
- semantic memory
-Episotic memory
Thalamus
- The railway station for all senses but smell
- receives and transmits sensory information to appropriate areas of the cortex
- coordinates incoming sensory info with motor functions regulated by a basal ganglia, cerebellum, and motor cortex
Involved in memory
Damage to the thalamus and mammillary bodies
- korsakoff syndrome
- caused by a thiamine deficiency, drinking
- anterior grade amnesia, retrograde amnesia and confabulation
Basal ganglia
- caudate nucleus, putamen,and globus pallidus
- important role in initiating/coordinating voluntary movements, emotional processing and responses, procedural memory and habit forming, other aspects of cognition including attention, insight, planning, and prioritizing
+ Sensitive to rewards involved in reward-based associative learning
Damage to the basal ganglia
+ Huntington’s disease
+ Parkinson’s disease
+Tourette’s
+ Ocd
+ Adhd
+ Schizophrenia
Limbic system
- several structures involved in memory and emotion
+ Amigdala
Hippocampus
Amygdala
- emotional reactions, (especially fair and anger)
+ Attaches emotions to memory
- responsible for recognizing emotions in facial expressions
Damage the amygdala
- bilateral lesions and amygdala and temporal lobe in monkeys produces Kluver bucy syndrome