Nervous System Flashcards
Nervous System
Primary internal communication system.
Collects, processes and responds to the information from our environment
Divided into two subsystems: the central nervous system and the peripheral nervous system.
Central Nervous System (CNS)
Made up of the brain and the spinal cord
The brain lives in the cranium and it is the centre of all conscious awareness
The outer layer of the brain is called the cerebral cortex which is only 3mm thick
Because the brain is so highly developed, it distinguishes us from other animals
The spinal cord is the extension of the brain, passes information to and from the brain to the rest of the body and controls simple reflex actions such as removing your hands from a hot object.
Peripheral Nervous System (PNS)
PNS relays messages from the central nervous system to the rest of the body
It has two main component: somatic nervous system and autonomic nervous system
It also has sympathetic nervous system and parasympathetic nervous system
Somatic Nervous System (SNS)
Somatic nervous system maintains the communication between CNS and the outside word e.g. senses.
It is made up of sensory receptors (that carry information to the spinal cord and the brain) and motor pathways (that allow the brain to control movement)
They provide muscle response
Autonomic Nervous System (ANS)
The autonomic nervous system plays an important role in homeostasis
Homeostasis maintains internal processes like body temperature, heart rate and blood pressure.
The autonomic nervous system only has motor pathways
Sympathetic Nervous System (SPNS)
Usually involved in flight or fight response, it allows impulses to travel from the sympathetic nervous system to organs to help us prepare an action during an emergency. It results in an increase in heart and breathing rate.
parasympathetic nervous system
Parasympathetic Nervous System (PNS)
The PNS relaxes the body or returns to its normal state, by slowing down heart rate, breathing rate and reduces blood pressure and any processes which were slowed down like the digestive system would start again.
