Organization/Nerve umpulses
Name and describe the function of the nervous system's 3 overlapping functions.
1. A sensory receptor monitors changes inside/outside the body (called stimuli) and sends this information to the CNS in the form of sensory input.
2. The Integration Center (brain) processes the sensory input and decides on an action.
3. A cause/effect is produced by activating muscles/glands (effectors) via motor output.
What is the body of the neuron?
The part of the neuron that contains the nucleus and most cell organelles.
What are glial cells?
This is the name for the protective and supportive cells in the nervous tissue.
What is a reflex?
A reflex is a rapid, predictable, and involuntary response to a stimuli.
The PNS consists of...?
All parts of the nervous system outside the CNS, mainly the spinal nerves and cranial nerves.
What is an axon?
This long projection sends information away from the neuron’s body.
What are sensory neurons?
These neurons carry signals from sensory organs like the eyes and skin to the nervous system.
What is resting potential?
The state when the inside of a cell is negative, and the outside is positive.
How do the neurons get back to the resting state?
Voltage-gated K⁺ channels open, allowing K⁺ ions to exit the cell. This efflux of K⁺ restores the membrane potential back toward the negative resting state.
What occurs at the synapse?
An impulse is transmitted from on neuron to another.
What are interneurons?
These neurons are found in the brain and spinal cord, relaying signals between sensory and motor neurons.
What is action potential?
The state when the charges inside and outside the cell reverse during an impulse.
What are neuroglia (glial cells)? What is the function of the microglia and where can it be found?
Neuroglia - supporting cells in the CNS/PNS that support/insulate/protect neurons.
What are dendrites?
These projections receive nerve signals and transfer them to the neuron's body.
What are motor neurons?
These neurons send signals to muscle or effector cells to produce a response.
What are the five components of a reflex arc and describe each one.
Receptor – Respond to stimulus
Sensory Neuron – Carry impulse to CNS
Interneuron – Integration center (brain) – decide on action
Motor neuron – Carry impulse to effector
Effector – Muscle/gland stimulated to produce response
please describe the process of the nerve impulse including the names of the ions, channels
When a stimulus reaches the neuron, it triggers voltage-gated Na⁺ channels to open in a localized region of the membrane. Na⁺ ions rush into the cell due to the concentration gradient and the attraction to the negatively charged interior.
What is produced within the axon terminals?
neurotransmitters
What is relaying signals from sensory neurons to motor neurons?
interneurons in the nervous system
These axons conduct information more rapidly. Name the type of the axon and the compartments through which the signals is transmitted.
Myelinated axons. through nodes of Ranvier.