BIO 01 - Nervous system Flashcards
(13 cards)
What is the nervous system divided in to?
Central nervous system (CNS) and peripheral nervous system (PNS)
What is the CNS composed of?
Brain and spinal cord
What is the PNS composed of?
Somatic and autonomic nervous system
What is the ANS composed of?
Sympathetic and parasympathetic nervous system
What is the function of CNS?
Consists of the brain and the spinal cord and is the origin of all complex commands and decisions
What is the function of PNS?
Sends information to the CNS from the outside world, and transmits messages from the CNS to muscles and glands in the body
What is the function of the nervous system?
Consists of the central nervous system and the peripheral nervous system. Communicates using electrical signals
Two main functions of nervous system:
- To collect, process and respond to information in the environment
- To coordinate the working of different organs and cells in the body
What is the brain? And what is its function?
- It is the centre of all conscious awareness
- The brain’s outerlayer, the cerebral cortex, is only 3mm thick and covers the brain like an orange peel covers an orange
- It is only found in mammals. The brain is highly developed in humans and is what distinguishes our higher mental functions from those of other animals
- Only a few living creatures (i.e. sponges, sea squirts, jellyfish) do not have a brain
Primary functions:
- Controls life functions
- Controls psychological processes
- Controls higher mental functions
What is the spinal cord? And what is its function?
- It is an extension of the brain
- It passes messages to and from the brain and connects nerves to the PNS
- It is also responsible for reflex actions such as pulling your hand away from a hot plate
Primary function:
- Transmits information to and from the brain
- Connects to the PNS
- Involved in reflex action
What is the function of the ANS?
- Controls and regulates involuntary actions/responses (i.e. automatic)
- Regulates the functions of our internal organs, such as the heart, stomach, lungs, and intestines.
- Transmits information to and from internal bodily organs
- Part of the peripheral nervous system and it also controls some of the muscles within the body.
- Governs vital functions in the body such as breathing, heart rate, digestion, sexual arousal and stress response
- It has two main divisions: the sympathetic and parasympathetic nervous system
What is the function of the SNS?
- Controls voluntary actions
- Regulates voluntary movement.
- Part of the peripheral nervous system connects the brain to the motor neurons such as those found in the skeletal muscles.
- We are in control of this system (voluntary), and we use it when we want to make our muscles move.
- Governs muscle movement and receives information from sensory receptors
- Transmits information from receptor cells in the sense organs to the CNS
- It also receives information from the CNS that directs muscles to act
What occurs when your body is in the sympathetic state?
- Increases heart rate
- Increases breathing rate
- Dilates pupils
- Inhibits digestion
- Inhibits saliva production
- Contracts rectum
What occurs when your body is in the parasympathetic state?
- Decreases heart rate
- Decreases breathing rate
- Constricts pupils
- Stimulates digestion
- Stimulates saliva production
- Relaxes rectum
