nervous system Flashcards
What are the three primary functions of the nervous system?
-Collects information about what is going on inside and outside your body through sensory receptors and send it to the spinal cord or brain
-interprets the info it receives
-Sends a response to different parts of the body
What are neurons?
specialized cells that send electrical signals which cause sensations, movement, and thoughts
How many neurons are in the body?
billions
Soma?
the cell body of a neuron that contains its nucleus. Together, they maintain the cell and keep the neuron functioning
Dendrites?
they stretch out from the cell like the branches of a tree. Dendrites receive chemical messages from other neurons
Axon?
A thin nerve fiber that conducts electrical signals
Axon terminal?
Fires electrical signals across a gap between nerve cells called a synapse
Neurotransmitter
Moves across the synapse and attaches to receptors on the dendrites of a nearby neuron
What are the parts of a neuron?
soma, dendrites, axon, axon terminal, neurotransmitter
What are messages between neurons called?
Impluses
The space between neurons is called
synapse
What is a sensory neuron?
they collect information from inside and outside the body and send it to the brain and spinal cord
What is an interneuron?
Messengers that transmit information between the motor and sensory neurons
What are motor neurons?
They send information between organs, muscles and glands, and are responsible for controlling muscles
What are the two main systems the brain is divided into?
CNS (central nervous system) and PNS (peripheral nervous system)
The CNS is divided into two parts:
brain and spinal cord
The main function of the CNS:
to receive and process all the information from the body
The function of the PNS:
to carry out all functions of the CNS
Cerebrum:
a large wrinkled structure that sits at the top of the brain
Cerebral cortex
a 3 millimeter thick layer of tissue that covers the brain’s hemispheres
Frontal lobe
Movement, problem solving, concentration, thinking, behavior, personality, and mood
Temporal lobe
Language, hearing, memory, learning
Parietal lobe
Integrates sensory information and processes spatial information
Occipital lobe
Visual processing center
Corpus callosum
200 million densely packed nerve cells that link the two hemispheres of the brain
Cerebellum
Located at the back of the brain below the cerebrum. It controls functions such as body movement, balance and posture
Brainstem
Responsible for the body’s most basic involuntary functions, such as breathing and circulating blood
Amygdala:
emotion
Hippocampus:
memory
Hypothalamus:
maintaining homeostasis (hunger, thirst, temperature, etc.)
Thalamus:
sends sensory information to the cerebral cortex
Motor Area?
Controls voluntary movements
Sensory Area?
Skin sensations
Broca’s area
speech control
Wernicke’s area
Language comprehension
Parasympathetic:
Helps to maintain normal body functions (Undoing the fight or flight response after a threat has passed)
Sympathetic:
Responds to stress and is responsible for the body’s fight or flight response
What makes a reflex different from any other type of movement?
There is no input from the brain. The signal goes directly in and out of the spinal cord
Two parts of autonomic>
Sympathetic, parasympathetic
What are the four parts of the limbic system?
Amygdala, hippocampus, hypothalamus, thalamus
Autonomic:
automatic movements (involuntary)
Somatic:
voluntary movements (Eg. walking, chicken dance, etc.)
What are the two parts of the PNS
somatic, autonomic
Give two examples of reflexes:
Removing hand from something hot, dilation of your pupils
What is Parkinson’s?
Parkinson’s is a progressive disorder that affects the nervous system. Symptoms gradually get worse.
What causes Parkinson’s?
Advancing age which causes a loss of brain cells which causes Parkinson’s.
Symptoms of parkinson’s
-Tremors
-People experience tremors in around 80% of Parkinson’s cases
-Stiffness
-There are two types of stiffness, lead-pipe and cogwheel. Lead-pipe is rigidness by itself and cogwheel is when rigidness is combined with tremors
-Unstable posture
-The rigidness can cause a hunched back or bad posture
-Other motor symptoms
-Blinking less often, cramped or small handwriting, trouble swallowing, etc.
Treatment or cure for Parkinson’s?
Levodopa is the leading treatment for Parkinson’s disease. Levodopa is absorbed by the nerve cells in the brain, where it is transformed into chemical dopamine. This is used to help the brain transmit messages between different parts of the brain, and to aid the neurological system in regaining control of motions. There is no cure.
