1. Bio. Perspectives (3) Flashcards
Neurons
Brain cells specialized in communication
Neuronal components
Soma Dendrites Axon Axon terminal Neurotransmitters (NT)
Glial cells
Astrocyte
Abundant, increases reliability of neuronal connections
Ogliodendrocytes
Promote new connections, produces myelin sheath around axons.
Neurons respond to NT by generating electrical activities.
No NT acting on neuron = resting potential.
Enough charge in neuron = action potential.
When at rest, there are positive and negative ions on both side of the neuron membrane.
During action potential, positive particles rapidly flow into axon.
After accumulating maximum positive charge, positive particles back out of axon.
Neurotransmission
Communication inside neurons are electrical but between neurons it’s chemical via NT.
NT binds with receptor sites at the next neuron
Then this process is halted by reuptake, and the NT go back to the axon terminal.
NT can be excitatory or inhibitory towards the nervous system depending on what it binds on.
List of NT:
Glutamate is excitatory
GABA is inhibitory
Acetylcholine (Ach) influences arousal, selective attention, sleep, and memory.
Monoamines:
Noradrenaline (Ne) and serotonin (5-HT) influence arousal.
Dopamine (DA) plays a role in responding to rewarding experiences.
Serotonin
Sleeping Eating Mood Impulse control Depression (under activity of 5-Ht)
Prozac increases serotonin
Dopamine (DA)
Movement Reward Pleasure Attention Learning
Deficiency = Parkinson’s disease
Overproduction = schizophrenia
Psychoactive drugs
Impact mood, arousal, behavior
By acting as agonists or antagonists for NT
Agonists: increase NT activity
Eg. Anti-depressants > increase activity of monoamines
Antagonists: decrease NT activity
Eg. Anti-psychotics > decrease DA activity
CNS
Forebrain Corpus callosum Hypothalamus Thalamus Cerebellum Brain stem
Central nervous system CNS
Cortex (4 lobes)
Basal ganglia: control movement and motor planning
Limbic system: thalamus, hypothalamus, amygdala, hippocampus
Cerebellum: controls balance and coordinated movements
Brain stem:
Midbrain > tracks visual stimuli and reflex triggered by sound
Pons > conveys information between cortex and cerebellum
Spinal cord: conveys info between brain and rest of body
Medulla > regulates breathing and heartbeats
Forebrain
Site of most cognitive functions of brain
Corpus callosum
Bundle of nerve Fibre which connects the cerebrum’s two hemispheres
Hypothalamus
Partly controls the body’s endocrine or hormone producing system
Thalamus
Areas that relay nerve impulses to cerebral cortex
Is on both sides of hemisphere
Cerebellum
Regulates balance and body control via muscle coordination.
Brain stem
Regulates involuntary functions as breathing and heart rate
Forebrain consists of cerebral cortex and other structures
Frontal lobe
Parietal lobe
Temporal lobe
Occipital lobe
Frontal lobe
Executive functioning
Body is mapped onto motor cortex
Prefrontal cortex: thinking, planning, language
Broca’s area: important for speech comprehension
Parietal lobe
Somatosensory cortex: touch, pain, temperature
Helps track object locations in space
Eg. Damage to right parietal lobe = contralateral neglect of left side of body and space.
Temporal lobe
Hearing, understanding language, storing autobiographical memory
Auditory cortex + Wernicke’s area : responsible for speech recognition
Occipital lobe
Specialized for vision
Sensory information enters brain and first goes to that sense’s Primary visual Cortex then to the Association cortex
Damaged primary visual cortex = cortical blindness
Damaged association cortex = visual agnosia
Peripheral Nervous System PNS
Somatic nervous system:
convey info between body and CNS, control and coordinate voluntary actions.
Autonomic nervous system:
Controls involuntary actions of internal organs and glands >
Sympathetic division: engaged in fight or flight
Parasympathetic division: control rest and digestion
Only either one is active at a time
