EDUCATION PERFECT Keeping Internal Balance - The Autonomic System Module 5 PT 1 Flashcards
Define autonomic functions
Body function that is not normally under conscious or voluntary control.
Define dysautonomias
dysfunctions of the autonomic nervous system
What are the systems that allow the brain to control who we are
- Skeletal Muscles
- Visceral (internal) muscle and tissues
- Hormonal Tissue and glands
How does the Somatic Nervous System help us
Through skeletal muscles.
Where nerves run to a specific muscle or muscle group. This allows for precise, point-to-point (i.e., brain output very precisely controls specific muscle targets), and fast control of skeletal muscles of our limbs and joints
How does the Autonomic Nervous System help us
Through visceral (internal) muscle and tissues.
Where nerves run (generally) to a number of target tissues or organs. This allows for diffuse (i.e., brain output now runs to control many structures simultaneously), integrative (i.e., brain output now coordinates activity across many structures), and medium to long-term control of tissues, glands and smooth muscles
How does the Endocrine System help us
Through hormonal tissues and glands.
Where nerves don’t run to the target tissues or organs. Instead, they either release hormones or control the release of hormones into the blood. These hormones are then transported to affect target tissues and organs (the ones which have receptors for these hormones). This is still for either tissue-specific or diffuse, integrative, and long-term control of tissues, glands and organs.
Of the three systems which two systems control autonomic function?
Autonomic Nervous System and Endocrine System
How do ANS and Endocrine systems achieve homeostasis and allow activity differently?
the ANS is the pathway used to produce direct and relatively rapid neural control of internal organs, in contrast to the slower and longer-term control obtained by using hormones.
What does ANS do
The ANS mediates relatively rapid responses using direct nerve control of peripheral structures.
ANS responses are specific/general to a target tissue but widespread/concentrated across the body.
Specific
Widespread
Can the ANS be supplemented by the actions of hormones? What does this result in?
The actions of the ANS can also be supplemented by the action of hormones which PRODUCE typically SLOW AND DIFFUSE EFFECTS and multiple tissues and organs might be affected.
What are the features of the ANS in the regulation of the internal state for activity and homeostasis?
- Pervasive neural network
- Effects can occur routinely and automatically without volitional control
- Effects are initiated in anticipation of a perturbation
- linked to and coordinated with the somatic NS
What does Pervasive mean?
widespread in where it acts
Define volitional
conscious
Define Perturbation
Distrubance
Give an example of how ANS is linked to and coordinated with the somatic NS
During exercise heart rate and respiratory rate increase, blood supply is diverted from the gut and from the bladder to the exercising muscle and so on - coordinating ANS control of internal organs with Somatic NS control of the exercising and other body muscles and limbs.
List the advantages of ANS control of autonomic function
- Produces a relatively fast body response to perturbation
- Coordinates activity across wide regions across the body
- Has the capacity to be flexible in the types of responses that it produces
- Acts on structures with intrinsic activity
How does the ANS produce a relatively fast body response to perturbation
Direct neural control of organs / tissues (vs nerves acting through hormones in the Endocrine system)
How does the ANS coordinates activity across wide regions across the body, give EXAMPLES
–Glands (eg salivary, pineal, sweat)
–Smooth muscle (eg vascular, reproductive, urinary bladder, bronchi, piloerector)
–Heart (sino-atrial node, ventricles)
–Eye (accommodation, pupil)
–Sex organs
How does the ANS have the capacity to be flexible in the types of responses that it produces?
– It has two motor divisions in most organs/tissues with opposing effects in most organs/tissues
– It can release more than one neurotransmitter at targets, with more than one receptor for each transmitter, increasing the type of responses it can produce
- Modulator chemicals are also released from many terminals at the same time or in addition to transmitter
– It receives continuous sensory feedback to carefully modulate and refine the control of the targets
Explain how the ANS acts on structures with intrinsic activity.
It regulates the activity of tissues and organs that have their own inherent activity.
Give an example of how the ANS acts on structures with intrinsic activity.
FOR EXAMPLE, if you remove ANS nerves from the heart, it will continue to beat, though you won’t be able to readily regulate the heart rate. This is in contrast to tissue such as skeletal muscle, which is regulated by the somatic nervous system. Without input from the somatic nervous system, the skeletal muscle will have no activity – it won’t contract!
Define the three components in ANS loop
(1) a motor (efferent) arm, under (2) high-level integrative control, with (3) sensory (afferent) feedback.
What are the peripheral components of the ANS
- Efferent (motor) arm
- Afferent (sensory) arm
What are the Efferent (motor) arms of the ANS
A set of motor nerve pathways running TO control body structures
What are the Afferent (Sensory) arms of the ANS
A set of sensory nerve pathways running back FROM body structures to provide feedback information.
What are the divisions that the autonomic nervous system efferent motor arm is divided into?
The Sympathetic, Parasympathetic Nervous Systems AND enteric nervous system
What is the enteric nervous system?
A system of neurons functions solely to control the function of the gastrointestinal tract and is confined to the GI tract.
Can the enteric nervous system act independently of the sympathetic and parasympathetic nervous systems
YES, although it may be influenced by them.
Does the afferent (sensory) arm have individual motor arms?
NO, the afferent arm has no such sympathetic / parasympathetic / enteric divisions.
How does the afferent (sensory) motor provide feedback?
Through both the Sympathetic and Parasympathetic Nervous Systems.
How is feedback provided?
This feedback goes to the ANS neurons’ cell bodies in the spinal cord, to neuronal groups in the brain stem that act as controllers to the ANS neurons, and to the hypothalamus, located directly above the midbrain of the brainstem, which acts as an integrator for autonomic functions, as we will see later
Where are the ANS neuron’s cell bodies at the first stage of afferent feedback?
First it goes to the ANS neurons’ cell bodies in spinal cord
Where are the neuronal groups at the second stage of afferent feedback and what does it do?
Neuronal groups in the brain stem that act as controllers to the ANS neurons
Where are the neuronal groups at the third stage of afferent feedback
Hypothalamus, located directly above the midbrain of the brainstem
Where is the hypothalamus
Directly above the midbrain of the brainstem
The functions of the sympathetic nervous system
Rest, Recover & Relax
The functions of parasympathetic nervous system
Fight, Flight or Fright
What input does the adrenal medulla receive?
Only sympathetic input
Do blood vessels in the body have parasympathetic innervation?
Most blood vessels in the body do not have parasympathetic innervation
The Sympathetic division allows the ________, while the Parasympathetic division helps ________ energy stores.
conduct of the activity, recuperate and build up energy stores
