Endocrine & Nervous Systems Flashcards
What are the 3 main functions of the nervous system?
Sensory input – monitoring events and changes inside and outside the body
Interpretation – analysing the data
Motor output – response to the incoming data
What are the 2 branches of the nervous system?
The central nervous system (CNS)
The peripheral nervous system (PNS)
What makes up the CNS?
Brain & Spinal cord
What is the role of an Afferent Nerve?
Sends incoming information about change to CNS
What is the role of an Efferent Nerve?
Sends outgoing information about a response
What two branches is the PNS split into?
Somatic Nervous System
Autonomic Nervous System
What is the role of the Somatic Nervous System?
This branch of the PNS is concerned with changes in the external environment. It senses movement, touch, pain, skin temperature etc. It is under our conscious control.
What is the role of the Autonomic Nervous System?
This branch of the PNS is concerned with changes in the internal environment. It senses hormonal status, functioning of internal organs, controls cardiac and smooth (involuntary) muscles and the endocrine glands that secrete hormones. The autonomic nervous system is not under our conscious control.
What is the role of Sympathetic Nerves in the efferent nerves of the autonomic nervous system?
Sympathetic nerves are responsible for increasing activity and play a vital role in the ‘fight or flight’ mechanism. They work by releasing a chemical known as a neurotransmitter from the nerve ending to bring about an associated response. For example, during times of stress, such as exercise, the neurotransmitters adrenaline and noradrenaline (also known as epinephrine and norepinephrine) are released
What changes do the Sympathetic Nerves in the efferent nerves of the autonomic nervous system bring about?
Increased heart rate
Increased breathing rate
More forceful contraction of the heart leading to increased stroke volume
Vasoconstriction of all arteries and arterioles in the body, which increases blood pressure
What is the role of Parasympathetic Nerves in the efferent nerves of the autonomic nervous system?
Parasympathetic nerves are stimulated to counteract the vasoconstriction of arteries at the working muscles. They are initiated with the increase in carbon dioxide which is a by-product of the increased oxygen utilisation at the active muscles. This increase causes the release of a neurotransmitter - acetylcholine, which has the opposite effect of adrenaline and noradrenaline. The process blocks the vasoconstriction response and actually dilates the arteries at the local working muscles allowing for more oxygen utilisation.
What is the role of Chemoreceptors?
Monitor the levels of many chemicals in the body
What is the role of Proprioceptors?
Detect excessive tension or contraction
What is the role of Baroreceptors?
Monitor BP
What is the role of Thermoreceptors?
Detect temperature changes
What 3 main parts make up a Neuron?
Axon
Cell Body
Dendrites