The Nervous System Flashcards
What is the nervous system?
It is a specialised network of cells in the human body and is our primary internal communication system. It has two main functions:
- to collect process and respond to information in the environment
- to coordinate the working of different organs and cells in the body
It is divided into the central nervous system and the peripheral nervous system
What is the central nervous system?
Consists of the brain and the spinal cord and is the origin of all complex commands and decisions. It passes messages to and from the brain and connects nerves to the PNS.
What is the Cerebral cortex?
The centre of all conscious awareness. It is the outer layer of the brain. The cerebral cortex is highly developed in humans and is what distinguishes human mental functions to those from animals. It is divided into two hemispheres
Spinal cord
An extension of the brain. It is responsible for reflex actions such as pulling your hand away from a hot plate. It passes messages to and from the brain and connects nerves to the PNS
Peripheral nervous system
Sends information to the CNS from the outside world and transmits messages from the CNS to muscles and glands in the body. It does this via millions of neurons (nerve cells) and is divided into the ANS and SNS.
Somatic nervous system
Transmits information from receptor cells in the sense organs to the
CNS. It also receives information from the CNS that direct muscles to contract. Controls muscle movement and receives information from sensory receptors.
Autonomic nervous system
Transmits information to and from internal bodily organs. It is
‘autonomic’ as the system operated involuntarily. It has two main divisions: the sympathetic and parasympathetic nervous systems.
Governs vital functions of the body such as breathing, heart rate, digestion, sexual arousal, and stress responses.
Parasympathetic nervous system
A division of the ANS which controls the relaxed state (rest and
Putheri digest), conserving resources and promoting digestion and
metabolism. The parasympathetic branch works in the opposition to
the sympathetic branch of the ANS. One or other is active at any time (work antagonistally)
Sympathetic nervous system
A division of the ANS which activates internal organs for vigorous activities and emergencies, such as the fight or flight response. consists of nerves that control, for example, increased heart rate
state/
and breathing, and decreased digestive activity.
branch works in opposition to the parasympathetic branch of the ANS
the nervous system diagram
The brain
Centre of all conscious awareness. The cerebral cortex is the outer layer of the brain and is what distinguishes human mental functions from those of animals. It is divided into two hemispheres left and right. Each hemisphere has 4 lobes: frontal, parietal, occipital and temporal.
Autonomic nervous system description.
This governs vital functions in the body such as breathing, heart rate, digestion, sexual arousal and stress responses - involuntary effect (done without conscious effort)
It is subdivided into two:
The sympathetic nervous system - it activates internal organs and increases bodily activities. (Flight or flight )
The parasympathetic nervous system - it relaxes internal organs and decreases bodily activities.
rest and digest
The somatic nervous system description
This transmits information from receptor cells in the sense organs to the central nervous system. It receives information from the central nervous system that directs muscles to act
- voluntary effect.
