The Nervous System Flashcards
What is the nervous system
- A specialised network of cells in the human body
- It is our primary internal communication system
What are the two main functions of the 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 are the two divisions of the Human Nervous System
Central Nervous System (CNS)
Peripheral Nervous System (PNS)
What are the two subdivisions in the Central nervous system
Brain- All conscious and most unconscious processing
Spinal cord- Recieves and transmits information from the brain and body
What is the importance of the brain (3)
- It is the centre of all conscious awareness
- The brains outer layer, the cerebral cortex, is highly developed in humans and it is what distinguishes us from other species
- The brain is also divided into two hemispheres
What is the importance of the Spinal Chord (3)
- An extension of the brain
- Responsible for reflex actions –>The spinal cord controls some reflexes without involving the brain
- Passes messages to and from the brain and connects nerves to the PNS
reflex action-Pulling ur hand away when in contact with something hot
Name the two sub divisions of the PNS
Autonomic and somatic nervous systems
What is the Autonomic Nervous System (ANS)?
There are 5 things it governs
- An involuntary system
- Governs vital functions in the body such as breathing, heart rate digestion sexual arousal and stress response
What is the somatic nervous system?
- Voluntary system
- Controls muscle movement and recieves information from sensory receptors
Are there any further divisions of the ANS and if so name them
- Yes, the Sympathetic and Parasympathetic
- They work in parallel
What is the role of the Parasympathetic nervous system (3)
- Decreases bodily activities
- Activates in rest
- The role is to relax the body, and return us to our ‘normal’ resting state. Consequently, the parasympathetic nervous system slows down our heart rate and breathing rate, and reduces our blood pressure. Furthermore, any functions that were previously slowed down during a fight or flight reaction are started again.
Q1- Describe two or more functions of the peripheral nervous system (4 marks) (3)
- PNS-Responsible for transmitting messages to and from the CNS
- SNS- Responsible for transmitting information from sense organs to the CNSand transmitting information from the CNS to effectors such as muscles
- ANS- Responsible for transmitting information to and from internal bodily organs
additional information: the sympathetic nervous system works alongside the endocrine system to bring about physiological arousal in the fight or flight response.
The parasympathetic nervous system works alongside the endocrine system to return the body to its resting state in the rest and digest responses.
How thick is the cerebral cortex
2mm-4mm thick
Name the 4 divisons of the cerebrum
Frontal lobe-The closest thing pointing to you
Temporal-Located below the frontal
Parietal-Located behind the frontal lobe
Occipital-Located furthest away from the frontal lobe
What does the Cerebellum do (3)
It controls a person’s
1. Motor skills
2. Balance
3. Coordinates muscles- which allows precise movements.
What does the diencephalon do (3)
- Works with the endocrine system to release hormones- contains the thalamus
- relays sensory and motor signals to the cerebral cortex
- regulates circadian rhythms- Sleep cycle
It also contains the hypothalamus
What does the brain stem do
Motor and sensory neurons travel through the brain stem allowing impulses to pass between brain and spinal cord.
Regulates automatic functions e.g. heart rate, breathing and swallowing
What is considered a spinal cord injury?
A fracture, or a tear of the spinal cord
an injury to it can have a serious impact on how your body functions.
What are the two types of spinal chord injurys?
Complete and incomplete. A doctor must examine you to determine which type of injury you have.
What are the symptoms of complete spinal cord injury
Total loss of feeling, movement, and bodily function below the level of the injury
What are the symptoms of incomplete spinal cord injury
Some feeling, movement, or function below the level of the injury
What is the Peripheral Nervous System (PNS)
- Body wide network of messenger neurons
- Delivers instructions to the body from the CNS
- Sensory neurons Send information to the CNS
- Motor neurons send information away from the CNS (to the rest of the body
What does the sympathetic system do (3)
- Works alongside the endocrine system to bring about physiological arousal in the fight or flight response
- Increases heart rate sweat breathing rate
dilates pupils - Inhibits digestion
