Dot Point 1 Flashcards
What are the three main functions of the nervous system?
Receive information
Process information
Coordinate a response
What are the two main divisions of the nervous system?
Central Nervous System (CNS)
Peripheral Nervous System (PNS)
What structures make up the CNS?
The brain and spinal cord
What is the function of the brain?
It processes information and directs actions throughout the body.
What is the function of the spinal cord?
Receives sensory information from the body and sends it to the brain.
Receives motor information from the brain and sends it to muscles, organs, and glands.
Allows for spinal reflex
What happens if the spinal cord is injured?
The brain will not receive sensory information, and motor control below the injury site will be lost, leading to paralysis.
What does the Peripheral Nervous System (PNS) include?
All parts of the nervous system outside the brain and spinal cord.
What are the two main functions of the PNS?
Communicate sensory information from the body to the CNS.
Communicate motor information from the CNS to the body’s muscles, organs, and glands.
What are the two subdivisions of the PNS?
The Somatic Nervous System (SNS) and the Autonomic Nervous System (ANS).
What are the functions of the Somatic Nervous System?
It controls voluntary movement and transmits sensory information to the CNS.
What are the two types of neurons in the PNS, and what do they do?
Sensory (afferent) neurons: Transmit sensory information to the CNS.
Motor (efferent) neurons: Transmit motor information from the CNS to muscles.
What is an acronym to remember the functions of sensory and motor neurons?
SAME – Sensory Afferent, Motor Efferent.
What does the Autonomic Nervous System (ANS) control?
Involuntary functions of muscles, internal organs, and glands (e.g., heart rate, digestion, perspiration).
What are the two subdivisions of the ANS?
The Sympathetic Nervous System and the Parasympathetic Nervous System.
What is the function of the Sympathetic Nervous System?
It prepares the body for emergencies by triggering the fight-flight-freeze response.
What are some physiological changes caused by the Sympathetic Nervous System?
Increased heartrate
Increases respiration
Dilates pupils
Slows digestion
Releases stress hormones (adrenaline, noradrenaline, cortisol)
What are the negative effects of cortisol?
Weakened immune system – Increased vulnerability to illness and slower wound healing.
Weight gain – Increased appetite and fat storage, particularly around the abdomen.
Sleep disturbances – High cortisol levels can interfere with sleep patterns, leading to insomnia.
Mood disorders – Linked to anxiety, depression, and irritability.
What are the two main functions of the Parasympathetic Nervous System?
Restores the body to a calm state after sympathetic activation.
Maintains homeostasis by regulating normal bodily functions (e.g., digestion).
Which nervous system is dominant most of the time?
The Parasympathetic Nervous System, as it controls everyday bodily functions.
How do the Sympathetic and Parasympathetic Nervous Systems interact?
They affect the same organs but in opposite ways (e.g., one increases heart rate, the other decreases it).
What is a conscious response to sensory stimuli?
A voluntary reaction that occurs with awareness (e.g., putting on a jacket when it’s cold).
What is an unconscious response to sensory stimuli?
An automatic reaction that occurs without awareness (e.g., heart beating faster when stressed).
Which nervous system controls conscious responses and which nervous system controls unconscious responses?
Conscious responses: Somatic Nervous System
Unconscious responses: Autonomic Nervous System
What is the spinal reflex?
An unconscious and automatic response to a stimuli, without the use of the brain to allow a faster reaction time.
What are the steps of the spinal reflex?
- Sensory neurons detect harmful stimuli and send a message via the afferent pathway to the spinal cord.
- Interneurons in the spinal cord process the message and trigger a reflex response.
- Motor neurons send a response via the efferent pathway to the muscles, causing movement.
- The brain receives sensory information after the reflex occurs, leading to a conscious response.
What is an example of a spinal reflex?
Pulling your hand away from a hot frying pan before feeling pain.
