The nervous system and the endocrine system Flashcards
explain what the nervous system is
- consists of the central nervous system and the peripheral nervous system. Communicates using electrical signals
- is a specialist network of cells in the human body and is our primary internal communication system
- it is based on electrical and chemical signals (whereas the endocrine system is based on hormones)
explain what the central nervous system is
- consist of the brain and the spinal cord and is the origin of all complex commands and decisions
- the brain is the centre of all conscious awareness. The brains outer layer- the cerebral cortex- is only 3mm think and covers the brain
- the brain is divided into two hemispheres
- the spinal cord 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
explain what the peripheral nervous system is
- sends information to the CNS from the outside world, and transmits messages from the CNS to muscles and glands in the body
- transmits messages via neurons to and from the central nervous system
- is subdivided into the automatic nervous system which governs vital functions in the body like breathing, heart rate, digestion, sexual arousal and stress response. AND somatic nervous system which governs muscle movement and receives information from sensory receptors
explain what the somatic nervous system is
transmits information from the receptor cells in the sense organs to the CNS. it also receives information from the CNS that directs muscles to act
explain what the automatic nervous system is
Transmits information to and from internal bodily organs. it is ‘automatic’ as the system operates involuntary. It has two main divisions: the sympathetic and parasympathetic nervous systems
what are the two main functions of the nervous system
- to collect, process and reapond to information in the environment
- to go-ordinate the working of different organs and cells in the body
the nervous system is subdivided into two subsystems
- what are these?
- central nervous system
- peripheral nervous system
explain the role of glands and hormones in the endocrine system
- various glands in the body, such as the thyroid gland produce hormones. Hormones are secreted in the bloodstream and affect any cell in the body that has a receptor for that particular hormone
- most hormones affect cells in more than one body organ leading to many diverse and powerful responses. E.G. the thyroid gland produces thyroxine which affects cells in the heart and increases metabolic rate. this effects growth rates
what is the key endocrine gland
- the pituitary gland which is located in the brain
- it is often called the master gland because it controls the release of hormones from all the other glands in the body
Explain the role of Endocrine and ANS working together in flight or fight
- if you get scared your hypothalamus activates the pituitary gland and this triggers activity in the sympathetic branch of the automatic nervous system
- the ANS changes from its normal resting state (the parasympathetic state) to the physiologically aroused sympathetic state
explain the role of adrenaline in the endocrine and ANS working together in fight or flight
- this is a stress hormone
- is released from the adrenal mendulla - part of the adrenal gland into the bloodstream
- triggers physiological changes in the body like increased heart rate which creates the physiological arousal needed for the flight of fight response
explain the immediate and automatic part of the endocrine and ANS job in flight or fight
- happens instantly as a threat is detected
- is an acute response and an automatic reaction in the body
- feelings that come with fight or flight can make you feel sick
explain the parasympathetic action involved in the Endocrine and ANS job with fight or flight
- once the threat has passed, the parasympathetic nervous system returns the body to its resting state.
- works in opposition to the sympathetic nervous system- its actions are antagonistic to the sympathetic nervous system
- it acts as a brake and reduces the activities of the body that were increased by the actions of the sympathetic branch
- sometimes referred to as rest and digest response
