The Nervous System And The Edocrine System Flashcards
(16 cards)
What is the nervous system and how does it differ from the endocrine system?
The nervous system is a specialised 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.
What are the two main functions of the nervous system?
• They collect, process and respond to information in the environment.
• To coordinate the working of the different organs and cells in the body.
What are the two subsystems of the nervous system?
The nervous system is divided into two subsystems: the central nervous system and the peripheral nervous system.
What does the central nervous system (CNS) consist of?
The central nervous system (CNS) consists of the brain and the spinal cord.
What is the spinal cord and what does it do?
• The spinal cord: This 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.
What is the brain and what distinguishes it in humans?
• The brain: This is the center of all conscious awareness.
• The brain’s outer layer, the cerebral cortex, is only 3mm thick and covers the brain like an orange peel.
• The brain is highly developed in humans and is what distinguishes our higher mental functions from those of other animals.
What is the function of the peripheral nervous system (PNS)?
The peripheral nervous system passes messages, via millions of neurons (nerve cells), to and from the central nervous system.
How is the peripheral nervous system subdivided?
The peripheral nervous system is further subdivided into:
• The somatic nervous system
• The autonomic nervous system
What does the somatic nervous system govern?
The somatic nervous system governs vital functions of the body such as breathing, heart rate, digestion, sexual arousal and stress response.
(It consists of the sympathetic nervous system and the parasympathetic nervous system – that are in balance to create a state of equilibrium called homeostasis)
What does the autonomic nervous system govern and receive?
The autonomic nervous system governs muscle movement and receives information from the sensory receptors.
What is the role and nature of the endocrine system?
• The endocrine system works alongside the nervous system to control vital functions in the body.
• The endocrine system acts more slowly than the nervous system but has very powerful widespread effects.
What do glands do in the endocrine system and how do hormones function?
• Various glands, such as the thyroid gland, produce hormones.
• Hormones are secreted into the bloodstream and may 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.
How do the endocrine system and autonomic nervous system work together in response to fear?
• When we are scared a part of our brain called the hypothalamus activates the pituitary gland (master gland that something is going on) and triggers activity in the sympathetic nervous system, a branch of the autonomic nervous system.
• The ANS changes from the normal resting state to a psychologically aroused state.
What does adrenaline do in the fight or flight response?
• Adrenaline: The stress hormone adrenaline is released from the adrenal medulla into the bloodstream.
• Adrenaline triggers psychological changes in the body which creates the arousal necessary for the fight or flight response.
What bodily changes occur during the fight or flight response?
• The response is immediate and automatic: this means that the sympathetic nervous system is activated and we experience things such as increased heart rate, constricted rectum, dilated pupils, saliva inhibition etc. that make us more ready to deal with a threat.
What happens after the threat passes in the fight or flight response?
• After the threat has passed the parasympathetic nervous system is activated so that the body can return to its resting state.
• This means things like the eyes constricting, rectum dilation, saliva production and digestion are stimulated.
