Nervous System Flashcards
Nervous system
Made up of neurons; detect external and internal stimuli (sensory perception), coordinate movement, relay and process info., maintain basic physiological processes
Nerve nets
Simplest nervous systems; tons of neurons in the soma; no central processing area; common in radially symmetrical animals; Ex: echinoderms
Ganglia
Bundles of soma/cell bodies; neurons located at the cephalon ganglia and central nerve cords; common in bilaterally symmetric animals; Ex: platyhelminthes
Cephalic ganglia
Bundles of soma located near the head region of the animal
Cephalization
Concentration of ganglia at one end of the body
Ventral nerve cords
Interconnected; forms smth like a spine of nerves
Nerves
Bundles of axons; “cable management” and organized similarly to muscles; can be very long (butt to toes)
Where is the largest concentration of neurons located?
Brain
Where do brains originate from in vertebrates?
Dorsal, hollow nerve cord; convergently evolved in arthropods and molluscs
Central vs Peripheral Nervous System
CNS: includes brain, spinal cord, optic nerve and retina, olfactory nerve; information processing and transformation
PNS: includes most cranial nerves, sensory nerves, motor nerves, autonomic nerves, and ganglia; information gathering and body maintenance
Peripheral Nervous System
Sends and revives info. using afferent and efferent neurons; splits into Somatic and Autonomic Nervous Systems
Somatic Nervous System
Voluntary movement (moving skeletal muscles); sensory perception; part of the PNS
Autonomic Nervous System
Involuntary movement (churning of the stomach); physiological regulation (glands and hormones); split into Sympathetic Nervous System and Parasympathetic Nervous System; part of the PNS
Sympathetic Nervous System
In charge of “fight or flight” response (alarm/survival mode); adrenaline
Parasympathetic Nervous System
In charge of “rest and digest”; maintenance; getting ready for “fight or flight”
Afferent neurons
Sensory neurons; in skin
Efferent neurons
Motor neurons; in muscles
Central Nervous System
Processes information gathered by PNS; brain functions are laterialized
Brain Lateralization
Right hemisphere controls left side of the body; Left hemisphere controls right side of the body
What is the difference between white and grey matter?
White matter is myelated; white matter is light than gray matter
Frontal lobe
Decision making; judgement; personality; critical thinking
Temporal lobe
Auditory processing (hearing)
Cerebellum
Balance
Occipital lobe
Vision
Parietal lobe
Sensory processing; hunger
What happens when you damage your frontal lobe?
Change in personality
What happens when you damage your Broca’s area?
Difficulty w/ speech/language; can understood but cannot formulate sentences
What happens when you damage your hippocampus?
Inability to formulate new memories (retrograde amnesia)
Reflex arc
Involves both the CNS and PNS
Example of a reflex arc.
Get poked by a needle -> stimulus from afferent neuron in skin -> inter neuron in CNS -> efferent neuron -> pulls back arm
Interneuron
Connects the afferent neuron to the efferent neuron; present in the spinal cord and sends signal to brain
Reflex
Automatic, involuntary response to a stimulus
Your patient reports that they cannot move their right arm despite still having sensation in the right arm. Which part of their body might be damaged?
Afferent neurons in spine
Right arm biceps and triceps
Left parietal hemisphere
Left cerebellar cortex
Left parietal hemisphere
