Autonomic and Endocrine Systems Flashcards
What are the Two Classifications of Motor(Efferent) Neurons?
Somatic and Autonomic Motor Neurons
Are Somatic Motor Neruons under Voluntary or Involuntary Control?
Voluntary
What do Somatic Motor Neurons Innervate?
Skeletal Muscles under cerebrocortical control
What are the Two Classifications of Autonomic Motor Neurons?
Sympathetic and Parasympathetic
Are Autonomic Motor Neurons under Voluntary or Involuntary control?
Involuntary
Where does the Autonomic System recieve its Sensory Input from?
Mainly Interoceptors (Internal sensing)
The Autonomic System is Controlled by what?
Limbic system, hypothalamus, brainstem and spinal cord
How many Neurons are part of an Autonomic Pathway from the Spinal Cord?
Two
In the Autonomic System, are Pre-Ganglionic Nerves Myelinated?
Yes
In the Autonomic System, are Post-Ganglionic Nerves Myelinated?
No
What do Autonomic Motor Neurons Innervate?
Cardiac Muscle, Smooth Muscle and Glands
When an Action Potential reaches an Axon Terminal of a Neuron, what happens?
Voltage gated Ca2+ channels open, causing an influx of Ca2+ ions into the axon terminal
What does an Influx of Ca2+ Ions cause in the Pre-Synaptic Neuron?
Vesicles containing neurotransmitters to fuse with the plasma membrane, releasing the neurotransmitters into the synaptic cleft
What do the Neurotransmitters released from the Pre-Synaptic Neuron bind to?
Ligand gated Na+ channels in the post-synaptic neuron
What does the Binding of Neurotransmitters onto Ligand Gated Na+ Channels in the Post-Synaptic Neuron cause?
An influx of Na+ into the post-synaptic neuron, causing the depolarisation of the cell membrane and the creation of an action potential in the post-synaptic neuron
What is another name for the Alarm Response?
The “Fight or Flight” response
What happens to our Cardiovascular System during the Alarm Response?
Heart rate, heart contraction force and blood pressure increase
Blood vessels (especially in skin) constrict
Blood sugar level also increases
What happens to our Eyes during the Alarm Response?
Pupils dilate
What happens within our Digestive system during the Alarm Response?
Salivation and other digestive activities decrease to conserve energy
What happens within our Lungs during the Alarm Response?
Bronchi dilate to increase capacity for oxygen gas exchange
What happens to the Skin during the Alarm Response?
Arrector pili muscles contract and sweat secretion increases from sweat glands
What happens to our Cardiovascular System during the Relaxation Response?
Heart rate and force of heart contraction decrease
Peripheral blood vessels dilate
What happens to our Eyes during the Relaxation Response?
Pupils contract
What happens within our Digestive System during the Relaxation Response?
Salivation and other digestive activities increase
What happens within our Lungs during the Relaxation Response?
Constriction of Bronchi
Responses associated with Exercise, Emotion and Excitement are under the ___ Division
Responses associated with Exercise, Emotion and Excitement are under the Sympathetic Division
Responses associated with Repletion, Rest and Relaxation are under the ___ Division
Responses associated with Repletion, Rest and Relaxation are under the Parasympathetic Division
What Neurotransmitter do both Sympathetic and Parasympathetic Pre-Ganglionic Neurons use?
Acetylcholine
What Neurotransmitter do Most Sympathetic Post-Ganglionic Neurons use?
Norepinephrine
What Neurotransmitter do Sympathetic Post-Ganglionic Neurons innervating Sweat Glands use?
Acetylcholine
What Neurotransmitter do Parasympathetic Post-Ganglionic Neurons use?
Acetylcholine
Is the Sympathetic system always active?
Yes, just turned up and down when needed
What is Raynaud Disease?
The sympathetic system’s inability to deactivate quickly after being stimulated by cold temperatures, resulting in chronic vasoconstriction, causing fingers and toes to become ischemic (lack of blood) and turn white
What does the Hypothalamus control?
Internal organs via autonomic nervous system and pituitary gland
Behavioural patterns, circadian rhythms and sleep/wake cycles
Body temperature
Eating and drinking behaviour
What are the Main Organs in the Endocrine System?
The hypothalamus, pituitary gland and adrenal glands
Endocrine Hormone Target Cells are typically Near or Far from the Endocrine Cell?
Far, endocrine hormones need to use bloodstream to reach target cells
Paracrine Hormone Target Cells are typically Near or Far from the Paracrine Cell?
Near, don’t typically need to use the bloodstream for hormone to reach target cell
What cells do Autocrine Hormones affect?
They affect the cell that secreted them
Hormones can either be ___ Soluble or ___ Soluble
Hormones can either be Lipid-Soluble or Water-Soluble
What do Lipid-Soluble Hormones require to pass through the Blood Stream?
Transport proteins
Can Lipid-Soluble Hormones diffuse directly through the Plasma Membrane?
Yes
Where do Lipid-Soluble Hormones typically Act?
In the nuclei of target cells, altering gene expression and therefore cell activity
Can Water-Soluble hormones diffuse through the Plasma Membrane?
No
After a Water-Soluble Hormone binds to a Receptor on the surface of a cell, what type of protein is activated?
G-protein
What does an Activated G-Protein activate?
Adenyl Cyclase
What does Activated Adenyl Cyclase do?
Converts ATP to cAMP, a second messenger
What does cAMP do?
Activates protein kinases, which can then phosphorylate other enzymes, causing reactions which induce physiological responses
cAMP is Deactivated by what?
Phosphodiesterase
How many different Hormones does the Hypothalamus secrete to control the Pituitary?
Nine
How many different Hormones does the Pituitary secrete to control Endocrine Organs?
Seven
What connects the Pituitary to the Hypothalamus?
Infundibulum
Which Blood Vessels connect the Hypothalamus and the Anterior Pituitary?
The Hypophyseal Portal Veins
What do the Hypothalamus and Pituitary Gland jointly Regulate?
Growth, Metabolism, Development and Homeostasis
In the Adrenal Medulla, Sympathetic Pre-Ganglionic Neurons innervate ___. These cells secrete ___ and ___ into the bloodstream
In the Adrenal Medulla, Sympathetic Pre-Ganglionic Neurons innervate Modified Post-Ganglionic Neurons (with no axons). These cells secrete Epinephrine and Norepinephrine into the bloodstream
What do Epinephrine and Norepinephrine do to the Alarm Response?
Maintain and enhance the alarm response
What Hormones are produced in the Adrenal Cortex?
Mineralocorticoids (e.g. Aldosterone) and Glucocorticoids (e.g. Cortisol)
What causes Mineralocorticoid Secretion from the Adrenal Cortex?
Increased K+ and angiotensin II in the blood
What causes Glucocorticoid Secretion from the Adrenal Cortex?
Adrenocorticotropic Hormone (ACTH) release from the pituitary gland, Stimulated by Corticotropin releasing hormone (CRH) from the Hypothalamus
What do Mineralocorticoids do?
Increase blood Na+ and water levels and decrease blood K+ levels, increasing blood volume and pressure
What do Glucocorticoids do?
Initiate a resistance reaction to stress, dampen inflammation and depress immune responses
In relation to Proteins (especially in muscle fibres), what does Cortisol do?
Induce the breakdown of proteins into amino acids for release into the bloodstream to aid tissue repair, new protein synthesis and ATP production
In relation to the Liver, what does Cortisol do?
Promotes Gluconeogenesis, raising glucose levels for ATP production
In terms of Adipose Tissue, what does Cortisol do?
Promotes triglyceride breakdown and fatty acids to be released into the blood to aid in tissue repair
In terms of Blood Vessels, what does Cortisol do?
Increases sensitivity of blood vessels to vasoconstriction hormones, increasing blood pressure
In terms of Inflammation, what does Cortisol do?
Limits inflammation to limit tissue damage done by white blood cells, which does also slow tissue repair and wound healing
In terms of the Immune System, what does Cortisol do?
It supresses some immune responses
In response to High Blood Cortisol Levels after the Removal Of The Stressor, the Pituitary Gland and Hypothalamus do what?
The pituitary gland stops secreting adrenocorticotropic hormone (ACTH) and the hypothalamus stops secreting corticotropin releasing hormone (CRH)
The Two Components of the Stress Response are…
- The Alarm Response (Immediate Sympathetic Nerve Activity and release of Epinephrine and Norepinephrine from the Adrenal Medulla)
- The Resistance Reaction (Slower and longer lasting hormone driven activity in the Adrenal Cortex, releasing Mineralocorticoids and Glucocorticoids)
