Chapter 3 - The Nervous System Flashcards
How are signals sent through the nervous system?
Via a series of neurons, which are connected by synapses.
What kind of signal travels down a neuron?
Electrical
What kind of signal travels over a synapse?
Chemical
Considering the way signals are sent aroud it, what kind of system is the nervous system?
Electrochemical.
What are the functions of neurons and synapses?
To connect sensory receptors to the central nervous system
To connect 1 part of the nervous system to another
To carry signals from the nervous system to organs or muscles.
How do neurons carry a signal?
When stimulated they transmit an electrical impulse.
What is an action potential?
An electrical impulse
What is the sensory threshold?
A threshold where any stimulus below that threshold will not be noticed.
If the threshold is raised then a person will be less sensitive to stimulus.
This threshold will reset over time.
What is Habituation?
The decrease in physiological response as the result of repeated exposure to a stimulus.
What does the endocrine system use to send signals around the body?
Hormone secretion into the bloodstream, which is controlled by neuronal signals.
Considering the way signals are sent in the endocrine system, what kind of system is it?
A neuro-hormonal system.
What are the advantages and disadvantages of the endocrine system regarding sending signals to the body?
Disadvantage:
It takes longer for signals to reach recpetors.
Advantages:
Many cells can recieve signals simultaneously.
Plays imprtant rols in homeostasis.
What is the peripheral nervous system and how is it subdivided?
The nerve trunks outside of the CNS.
What is the responsiblity of the somatic nervous system within the PNS?
Volunary movement and concious senses.
What is the responsibility of the enteric nervous system as part of the PNS?
Control of the gut.
What is the responsibility of the autonomic nervous system as part of the PNS.
Operation of internal organs and control of blood supply.
It is further divided into Sympathetic and Parasympathetic divisions.
What is the role of the sympathetic and parasympathetic divisions of the autonomin nervous sytem in the PNS?
Sympathetic - prepares body for action, eg. increases heart rate
Parasympathetic - restores the body, eg decreases heart rate.
What are the primary components of the central nervous system and what is it’s function?
The brain and the spinal cord.
To analyse sensory data.
Where is vision information processed?
In the visual cortex.
What are the physical components of the peripheral nervous system and what do they do?
Sensory nerves - pass sensory information to the CNS
Motor nerves - shortcut information directly to organs and muscles and are responsible for relexes.
Where are proprioreceptors found and what do they do?
They are found in muscles and they detect and relay precise information regarding the motion and position of body parts.
Where are mechanoreceptors found and what do they do?
The are foud in tendons and they send precise information regarding the tension on muscles and therefore are used to control the amount of force on body parts.
