Unit 1; Organisation of the NS Flashcards
(28 cards)
What is psychobiology and its significance?
- Also known as biopsychology, biological psychology, behavioral neuroscience, and physiological psychology.
- Explains behavior in terms of biological mechanisms.
- Behavior is a reflection of nervous system activity.
How do the brain, behavior, and environment interact?
- Environment provides input.
- Brain processes input and produces behavior.
- Behavior influences the environment.
What is reductionism in psychobiology?
- Explains complex behaviors by reducing them to basic components
What were René Descartes’ contributions to psychobiology?
Proposed reflexes: automatic, involuntary behaviors.
Suggested the mind and body interact in the pineal gland (Cartesian dualism).
Believed mind controlled body by sending animal spirits down tubes that cause muscles and tendons(Disapproved by Luigi Galvani)
How did Luigi Galvani challenge Descartes’ views?
- discovered the electrical nature of nerve impulses
- showed that nerves and muscles function independently of the brain
- brain creates chain of command(brain-nerve-muscle)
What were Johannes Purkinje and Theodor Schwann’s contributions?
Purkinje: Described large nerve cells in the cerebellum (Purkinje cells).
Schwann: Identified myelin sheath around neurons.
What is phrenology, and how did it contribute to neuroscience?
Proposed by Joseph Gall: different brain areas control different functions.
Though largely invalid, it introduced the idea of cerebral localization
How did Phineas Gage’s case support cerebral localization? and John Baptiste Bouillaud?
Frontal lobe= responsible for higher-order functions eg planning, and intelligence
Frontal lobe damage changed his personality and behavior.
Demonstrated the role of the frontal lobe in behavior regulation
whats cerebral localisation?
different areas are specialized for specific functions
What are Brodmann areas?
- defined 52 cortical areas based on cellular structure
- each area corresponds to specific functions
Who help contribute to the discovery of individual neurons?
Camillo Golgi; develop silver staining technique
Santiago Ramon y Cajal; used the staining technique-> neurons= discrete,unitary entities
What is the function of synapses?
Charles Sherrrington- identified synapses as gaps between neurons
Nerons communicate using neurotransmitters
1st- acetylcholine(Henry dale 1990s)
What did Wilder Penfield’s research reveal about brain function?
Use light electrical stimulation to diff parts of cortex to see healthy parts + remove parts
awake-> no pain
stimuli to primary somatosensory cortex = tingling
stim to parts of temporal lobe= music, familiar voice, relive familiar events
What did patient H.M.’s case reveal about memory?
- removal of medial temporal lobes (including hippocampus) led to anterograde amnesia(only old, no new)
Demonstrated the hippocampus’ role in memory formation
no more seizure
What are the main functions of the nervous system?
- receives sensory input from receptors
- integrates information and produces responses via effectors (muscles, organs, glands)
Structure of neurons
- neurons: basic unit of the nervous system(and support cells (glia))
- Composed of a soma (cell body), dendrites, and an axon
- myelin sheath insulates axons to increase signal efficiency
What are the types of neurons based on function?
Afferent (sensory): Carry sensory input to CNS
Efferent (motor): Carry signals from CNS to muscles and organ
How is the nervous system divided?
CNS; Brain and spinal cord
-> PNS; Nerves outside the CNS
Somatic NS; Voluntary control and sensory perception
-> Autonomic NS; Involuntary control of internal organs
Sympathetic: Activates “fight or flight” response
Parasympathetic: Promotes relaxation and energy conservation
How do the sympathetic and parasympathetic systems affect the body?
- Sympathetic: Increases heart rate, dilates pupils, mobilizes energy
- Parasympathetic: Lowers heart rate, stimulates digestion, conserves energy
What are the protective structures of the CNS?
Meninges; 3 layer system, dura mater, arachnoid, pia mater
Between meninges cerbral spinal fluid acts as a shock absorber against trauma
Blood-brain-barrier; cells that make up the blood vessels in brain and spinal cord, tightly packed, prevents toxins
How do neurons integrate multiple inputs to decide whether to fire?
A neuron receives both excitatory and inhibitory signals from multiple sources
If the net effect of signals reaches the threshold, an action potential is triggered
What are the key differences between nerves and tracts?
Nerves: Found in the PNS, bundles of axons carrying sensory/motor signals.
Tracts: Found in the CNS, bundles of axons connecting different brain/spinal cord regions.
What are nuclei and ganglia in the nervous system?
Nuclei: Clusters of neuronal cell bodies in the CNS (e.g., hypothalamic nuclei).
Ganglia: Clusters of neuronal cell bodies in the PNS (e.g., dorsal root ganglia).
How do preganglionic and postganglionic neurons differ in the ANS?
Preganglionic neurons: Originate in the CNS and synapse onto postganglionic neurons.
Postganglionic neurons: Originate in the PNS and directly innervate target organs.
