Nervous Flashcards
What does the Nervous System do?
Regulates/Controls all body processes + Maintains Homeostasis
The 2 main categories of the Nervous System
Peripheral Nervous System(PNS) and Central Nervous System(CNS)
What makes up the CNS
Brain + Spinal Cord
What makes up the PNS
All the nerves other than the Brain + Spinal Cord
What is the main characteristic of the Sympathetic Nervous System
A fight or flight response; in times of stress
increases heart rate, breathing, adrenaline, decreases digestion and thought processes
What is the main characteristic of the Parasympathetic Nervous System
“rest and digest”, in times of peace/calm
decreases adrenaline, heart rate, breathing, increases memory, thought processes, and digestion
What does the Cerebrum control
Voluntary activity, interprets sensory impulses, motor control, thinking, etc
What does the Cerebellum control
Balance + Motor Coordination
Homeostasis
What does the the Medulla control
Involuntary activity(heartbeat, breathing, blood flow, digestion, etc.)
What does the Hypothalamus control + what does it release
“Master gland”
Releases “releasing factors”(chemicals), controls the Pituitary Gland
What does the Pituitary gland do
releases hormones such as growth hormone, follicle stimulated hormone, etc.
What is the spinal cord
A hollow tube composed of nerve fibers that carry impulses to and from the brain
What is the functional unit of nerves called
Neurons(Nerve Cells)
What do Neurons do
detect stimuli and send impulse down neuron/nerves
What are the parts of a Neuron
Cell Body
Dendrites
Axon
Terminal Branches
Myelin Sheath
Synapse(technically not a part but still important to function)
What does the cell body of a Neuron do
Control activities of the neuron
What are Dendrites
Fibers that detect stimuli from environment + other neurons
What is the Axon
Carries messages from Cell body to Terminal Branches
What are the Terminal Branches
Branches that send the signal/message to the next neuron or muscle
What is the Myelin Sheath
A coating around the axon made of myelin cells
Prevents signal from shorting out & speeds up transmission
What are neurotransmitters
Chemicals that travel from neuron to neuron to send a message
Explain in detail how a signal travels thru a neuron
First, a chemical signal is picked up by a dendrite (branched to increase surface area), then the signal travels to the soma (nucleus body) and goes thru the axon. This signal is now electrical and the axon releases K+ ions and takes in Na+ for an electrical charge to form. Then, the axon terminal is reached where the signal is then chemical and thru exocytosis, chemicals are released, and travel thru the synapse and communicate with the next neuron.
what is the synapse
the gap junction between a axon terminal and the dendrites
What is a synapse
A gap/space between nerve cells(or between nerve and muscle)
1st neuron releases chemical called a neurotransmitter, converts into a electrical signal
How does a signal travel thru the myelin sheath
The signal jumps from sheath to sheath, causing the signal to travel at 330 miles per hour than 11 miles per hour without a myelin sheath
Where do drugs affect the nervous system
The synapses
How do signals travel into and between neurons
Diffusion, bind to receptors on the next neuron
Explain in detail how a stimulus is reacted upon by different neurons
First, sensory neurons, found everywhere in the body, communicate what the stimulus is with neurotransmitters to interneurons, (Part of the CNS), that report to the brain, via the spinal cord, and a signal comes back and a signal goes to the PNS to the motor neurons to create a response by relaxing or contracting skeletal muscle.
What are glial cells
They are cells that wrap around the axon of the neuron and also produce a myelin membrane around them
What are reflexes
a reaction to a stimulus without being thought about. The autonomic nervous system is responsible for this
Is it active transport or diffusion that powers the movement of neurotransmitters
it is diffusion
What is a reflex
A reaction to a stimulus that doesn’t require conscious thought
Does a reflex message go to the brain
No, it travels between the PNS and Spinal Cord(Spinal Reflex Arc)
What are the 3 types of neurons
Sensory Neuron, Interneuron, Motor Neuron
What does the Sensory Neuron do
Detects stimulus, sends to CNS or spinal cord
What does the Interneuron do
Acts as a relay between the Sensory neuron and the Motor Neuron
What does the Motor Neuron do
Sends message to Skeletal Muscle Effector(Muscle or Gland) which moves the muscles
What are the 6 steps of the reflex arc (path the signal travels)
- Stimulus is introduced
- Receptor detects stimulus
- Sensory Neuron carries impulse to spinal cord
- Interneuron
- Motor Neuron carries message to Effector
- Effector; controls muscle/moves the muscle
Explain the reflex arc and its components
- stimulus - a change in the surrounding environment
- Receptor - Detect change via the 5 senses
- Sensory neurons (PNS that communicates with CNS) - carries impulse to the spinal cord
- Interneurons (neurons of the CNS) - Located in the spinal cord between the sensory and motor neurons
- Motor Neuron (PNS) - carries message away from the spinal cord
- effector - muscle or gland connected to the motor neuron
How are the Nervous and Endocrine system connected
The endocrine system works with the Nervous system to regulate the human body to maintain homeostasis by releasing hormones from various glands.
What are the 3 parts of the brain
Forebrain, midbrain, and the hindbrain
What is the midbrain responsible for
Vision and hearing
What is the forebrain responsible for
learning, cognitive thinking, etc (voluntary action)
what is the hindbrain responsible for?
Involuntary action
