Nervous System Flashcards
An action that is performed as a response to a stimulus and without conscious thought
Reflex
Neutral pathway involved in a reflex action
Reflex arc
Nerve endings that respond to a stimulus from an internal or external environment
Receptor
Carries the message from the sensor to the CNS
Sensory neuron
A relay nerve in CNS (some reflects bypass the interneurons others go via 3 or 4 interneurons)
Interneuron
Brain and spinal cord
Central nervous system
Carries the message from the CNS to the muscle
Motor neuron
Contraction
Muscle fiber
What do reflexes do?
Maintain homeostasis
Carry out automatic actions
Maintain balance and posture
What are examples of maintaining homeostasis
Heart rate, blood pressure, breathing, digestion
Mechanical stimuli such as touch
Mechanoreceptors
Chemicals stimuli such as smell and taste
Chemoreceptors
Temperature change
Thermorecepters
Light, vision
Photoreceptors
Pain
Nociceptors
Sense of self. Body’s position without sight
Proprioceptors
What are the 6 receptor types
Mechanorecepters Chemoreceptors Thermorecepters Photoreceptors Nociceptors Propioceptors
A junction between neurons
Synapse
Chemical message passed from one neuron to another
Neurotransmitter
How many neurotransmitters are there
50 different types
Some will cause an action potential in the next cell
Excitatory
Some will suppress an action potential in the next cell
Inhibitory
Stimulates muscle contraction
Acetylcholine
Fight or flight response
Epinephrine/norepinephrine
Enhances mood and sleep
Serotonin
Increased attention and learning ability
Dopamine
Decrease perception of pain
Endorphins
Anxiety control
GABA
Which neurotransmitters are excitatory
Acetylcholine
Epinephrine/norepinephrine
Serotonin
Dopamine
Which neurotransmitters are inhibitory
Dopamine
Endorphins
GABA
The temporary inability to distinguish a particular odor after a prolonged exposure to that airborne compound
Olfactory fatigue
Your sense of smell
Olfactory
Fatigue to constant stimulation is a general feature of sensory systems
Stimulus adaptation
Takes sensory signal to the CNS (brain/spinal cord)
Sensory neuron
Takes signal from CNS to muscle or gland
Motor neuron
1 process extending from Soma
Unipolar
2 process extending from Soma
Bipolar
Several processes extending from Soma
Multipolar
Direction from the receptor to CNS
Afferent
Direction from CNS to effector
Efferent
The endings by which axons make synaptic contacts with other nerve cells
Axon terminals
A cell that wraps around the nerve fiber in the peripheral nervous system
Schwann cell
The insulating covering of an axon
Myelin sheath
The long threadlike part of a nerve cell along which impulses are conducted from the cell body to other cells
Axon
A short extension of a nerve cell
Soma
Primary motor cortex
Initiation of voluntary movement
Premotor cortex
Refinement of voluntary movement
Broca’s area
Facial neurons, speech
Wernickles area
Language comprehension
Prefrontal areas
Problem solving, emotion, complex thought
Brainstem (midbrain, pons, medulla oblongata)
Involuntary activities
Cerebellum
Balance, coordination
Motor areas
Voluntary movement
Sensory areas
Conscious awareness of sensation
Association areas
Gives meaning to the info the brain receives
Multimodal association
Uses multiple association areas to interpret information
Each hemisphere is
Concerned with the opposite side of the body
Somatic association
Processing of multisensory info
How many pair of nerves branch off the spinal cord
31
How many cervical
8
How many thoracic
12
How many lumbar
5
How many sacral
5
How many coccygeal
1
Gathered information from a stimulus
Sensory input
Responds by activating muscle and glands
Motor output
Receives, processes and sends info to and from the peripheral nervous system
Brain and spinal cord (CNS)
Cranial nerves and spinal nerves
Peripheral nervous system
Somatic skeletal nervous system
Muscle movements/reflexes
Autonomic nervous system
Controls involuntary functions
Sympathetic
Fight or flight
Parasympathetic
Rest and digest
Sympathetic division signs of arousal
Pupils dilate Salvation decreases Skin perspires Respiration increases Heart accelerates Digestion inhibits Adrenal glands secrete stress hormones
Parasympathetic Division signs of calming
Salvation increases Skin dries out Respiration decreases Heart slows Digestion activates Adrenal Glands decrease secretion of stress hormones
