The Nervous System Flashcards
Homeostasis
Balance
All our systems work together to maintain a stable internal environmental for our cells to work optimally.
What is the function of the nervous system
- The nervous system and hormone system coordinate the functioning of all the systems in the body.
- Controls our movements, organs, glands, and blood vessels in response to information it receives from our sense organs collecting information from our internal and external environments.
In what 2 sections is the nervous system divided in?
Central- controls the brain and spinal cord
Peripheral- Somatic- controls the motor and sensory
neurons
- Autonomic - controls the sympathetic
(fight/flight) and parasympathetic (rest and
digest)
How is the brain protected?
Protected by the Cranium of the skull and 3 layers of membranes called meninges and Cerebrospinal fluid
How many lobes is the cerebrum divided into and what are their functions?
4
Frontal= reasoning, speech, problem-solving, and voluntary actions.
Parietal= movement, orientation, perception of stimuli
Temporal= auditory, memory, speech
Occipital= vision
What are the 2 other sections of the brain:
Cerebellum= coordination of movement, balance, and posture
Brain stem= 1. Medulla oblongata- heart rate, breathing,
blood pressure and cross-over.
2. Hypothalamus(ANS)- temperature
regulation, sleep-wake cycles, emotions, and
balance.
What are neurons?
Neurons are nerve cells specialized and adapted to carry stimuli. One nerve consists of millions of neurons. They’re receptors (in the skin/sense organs) that receive the stimulus and convert it to an electrical impulse that travels along the neuron in milliseconds.
What are the 2 types of neurons?
Motor and sensory neurons
What are the characteristics of motor neurons?
Structural: Functional:
1. Cell body in the CNS 1. Carry info from the CNS to the
2. Multipolar muscle
2. Voluntary movements and
responses
What are the characteristics of sensory neurons?
Structural: Functional:
1. Unipolar 1. Info from sense organ to
CNS
2. Cell body in the sense 2. Collect info about
environment
organs or ganglions.
What is the spinal cord?
A pathway for impulses traveling to and from the brain including sympathetic and parasympathetic impulses and integrates reflexes.
What is a reflex?
A quick, protective response that is automatic and does not involve the brain.
What is a reflex arc?
The path traveled by the impulse causes the reflex action.
Innate reflexes
Involuntary, controlled by the brain. Eg blinking, coughing, and sneezing
Acquired reflexes
Voluntary, controlled by the Medulla Oblongata. Eg reading, driving and catching a ball.
Autonomic Nervous System
Double innervation-Sympathetic nerves (adrenalin) stimulate the organs to prepare for action, Parasympathetic nerves slow the systems down.
Sympathetic (Adrenalin)
Increased: heart rate and breathing rate.
Pupil dilates
Decreased Peristalsis
Parasympathetic
Decreased: Heart rate and breathing rate.
Pupil constricts
Increased peristalsis
Epileptic seizure
Large numbers of neurons are activated and the body convulses followed by nausea and severe headaches.
Triggered by: flickering lights, hormone imbalances and chemicals including drugs.
Stroke
Blood doesn’t reach part of the brain or a blood vessel bursts. A lack of blood for 1-min can cause- a loss of vision and fainting. A lack of blood for 2-min can cause- brain damage, death of neurons and facial paralysis.
Parkinson’s
Neurodegenerative disease. Motor function is affected, and lack of dopamine, shuffling gait (walking), and depression.
Alzheimer’s disease
A neurodegenerative disease causes a lack of neurotransmitters affecting the front and temporal lobes. Which affects memory. Genetic and amyloid
Damage due to drugs
Stimulants - speed up the CNS
Depressants & analgesics - decrease the perception of pain
Hallucinogens - change a person’s perception of reality (eg, weed)
Damage due to alcohol
Alcohol is a neurotoxin. Short-term effects = decreased concentration, reflexes , coordination, and large amounts of vomiting.
Long-term effects = change in emotions , shrinking the frontal lobes and damaging the liver , heart , and pancreas, and can cause cancer.
