Autonomic Nervous System and Basic Endocrinology

Question 1

The afferent nervous system is composed of______________

Answer 1

Sensory Neurons

Question 2

The efferent nervous system is composed of the ______________ and ______________

Answer 2

Autonomic NS and Somatic NS

Question 3

What is the function of the Autonomic Nervous System?

Answer 3

Maintenance of homeostasis

Question 4

Most autonomic signals are ____________ consciously and not under ________ control

Answer 4

Not perceived

Voluntary control

Question 5

Autonomic nerves consist of 2 neurons, the ____________ and ___________ neurons synapse in ganglia

Answer 5

Pre-ganglionic and Post-ganglionic

Question 6

What are the advantages of a 2 neuron chains in the ANS?

Answer 6

• 1 Pre-ganglionic neuron can synapse onto many postganglionic neurons
• 1 Pre-ganglionic neuron can synapse onto both excitatory and inhibitory neurons
• Information from sensory axons can act before reaching the CNS

Question 7

Sympathetic nerves have a _____ preganglionic neuron and a _____ postganglionic neuron.

Answer 7

Short

Long

Question 8

Sympathetic nerves exit the CNS in the _______ and _______ regions of the spine

Answer 8

Thoracic and Lumbar regions

Question 9

Due to the short length of the ___________ neuron, the ganglia of the sympathetic nerves form a body close to the spinal cord called the _______________

Answer 9

Pre-ganglionic

Sympathetic trunk

Question 10

What does the sympathetic trunk allow sympathetic neurons to do?

Answer 10

“Talk” to each other

Question 11

Parasympathetic nerves have ______ preganglionic neurons and _____ postganglionic neurons

Answer 11

Long

Short

Question 12

Parasympathetic nerves exit the ______ and _______ region of the spine

Answer 12

Brain

Sacral

Question 13

Parasympathetic and Sympathetic nerves generally exert _________ effect on an organ

Answer 13

An opposite

Question 14

Sympathetic stimulation causes heart rate and cardiac output to ________.

Answer 14

Increase

Question 15

In the presence of noradrenaline the contractility of the ventricle ______ which causes cardiac output to ______.

Answer 15

Increase, Increase

Question 16

What are the effects of increased Sympathetic NS activation?

Answer 16

Increased Heart Rate and CO
Constriction of arteriole and venous smooth muscle
Dilation of pupils
Relaxation of smooth muscle in the airways
Breakdown of Glycogen and Fat stores
Increased sweating

Question 17

Discuss the redistribution of blood flow when the Sympathetic NS is activated.

Answer 17

• At rest 15-20% of blood flow goes to the skeletal muscles
• When sympathetics are stimulated blood vessels in the skeletal muscles dilate
• The blood vessels in the kidney, stomach, intestines and liver constrict
• This causes 80-85% of blood flow to go to the skeletal muscles during activity

Question 18

Sympathetic NS activity stimulates the __________ to release ________ into the blood which reinforces sympathetic actions.

Answer 18

Adrenal Medulla

Adrenaline

Question 19

Do the Parasympathetic and Sympathetic nervous systems always have opposite effects?

Answer 19

No, for example in the salivary glands they both stimulate secretion of saliva

Question 20

What is the Dive reflex?

Answer 20

When the face is submerged in water, mechanoreceptors and thermoreceptors activate the parasympathetics resulting in pronounced Bradycardia (Abnormally slow HR)

Question 21

What is the Cold Shock response?

Answer 21

Submersion in cold water will stimulate cutaneous cold receptors to activate the sympathetic NS resulting in pronounced Tachycardia (Abnormally fast HR)

Question 22

With respect to the ANS, what is the function of the hypothalamus?

Answer 22

To integrate information it receives into a coherent pattern of autonomic responses

Question 23

What is the major neurotransmitter for all pre-ganglionic-post-ganglionic synapses?

Answer 23

Acetylcholine

Question 24

What does Cholinergic mean?

Answer 24

The neuron releases Acetylcholine at its synapse

Question 25

What does Adrenergic mean?

Answer 25

The neuron releases Noradrenaline at its synapse

Question 26

In sympathetic pathways, the pre-ganglionic neuron is ____________ and the post-ganglionic is ____________

Answer 26

Cholinergic | Adrenergic

Question 27

In sympathetic pathways sweat glands both the pre-ganglionic and post-ganglionic neurons are __________

Answer 27

Cholinergic

Question 28

In parasympathetic pathways the pre-ganglionic neuron is _________ and the post ganglionic neuron is __________

Answer 28

Cholinergic | Cholinergic

Question 29

Why is the effect of Acetylcholine short lived?

Answer 29

Acetylcholine is rapidly broken down by exctracellular Aceytlcholinesterases

Question 30

Why is the effect of Noradrenaline short lived?

Answer 30

Noradrenaline is rapidly reabsorbed by the sympathetic nerves

Question 31

What are catecholamines?

Answer 31

Substances derived from the amino acid tyrosine | i.e. Adrenaline, Noradrenaline

Question 32

Why are the effects of adreanline and noradrenline in the blood short lived?

Answer 32

They are inactivated in the liver by catechol-O-methyltranferase

Question 33

What are adrenergic receptors?

Answer 33

Receptors specific to Noradrenaline and Adrenaline

Question 34

What effect do α1 - adrenergic receptors have?

Answer 34

They stimulate contraction of the smooth muscle in arterioles and veins

Question 35

What effect do α2 - adrenergic receptors have?

Answer 35

They inhibit the release of insulin from the endocrine pancreas

Question 36

What effect do β1 - adrenergic receptors have?

Answer 36

They stimulate an increase in heart rate and force of contraction

Question 37

What effect do β2 - adrenergic receptors have?

Answer 37

They stimulate the smooth muscle in the airways to relax. These receptors have a greater affinity for adrenaline than noradrenaline

Question 38

What are cholinergic receptors?

Answer 38

Receptors specific to Acetylcholine

Question 39

What is a Muscarinic Acetylcholine receptor?

Answer 39

- A receptor named after the agonist muscarine - Found on effector (target) cells innervated by the parasympathetic nerves - It can be blocked by atropine

Question 40

Whats is a Nicotinic Acetylcholine receptor?

Answer 40

- A receptor named after the agonist nicotine | - These receptors are found on post-ganglionic cell bodies and post-synaptic membranes of skeletal muscle cells

Question 41

Peptide hormones are stored in _________. They are _________ and so bind to receptors on the cell membrane.

Answer 41

Vesicles | Lipophobic

Question 42

Give some examples of Tyrosine derivative hormones

Answer 42

Adrenaline/Noradrenaline Dopamine Thyroxine

Question 43

The pituitary gland is also known as the ________

Answer 43

Hypophysis

Question 44

Nerves that can secrete hormones are called __________

Answer 44

Neuroendocrine cells

Question 45

The Posterior Pituitary is also called the

Answer 45

Neurohypophysis

Question 46

Explain how hormones are release from the Neurohypophysis

Answer 46

- Hormones are made in the hypothalamus' neuroendocrine cell bodies - The hormones are then stored in their axons in the neurohypohysis - Hormones are released into the blood in response to neural stimulation

Question 47

The Anterior Pituitary is also called the

Answer 47

Adenohypophysis

Question 48

How is the hypothalamus able to communicated with the Adenohypophysis?

Answer 48

It can send chemical signals via the Hypothalamo-pituiatry portal vessels

Question 49

What does GHRH stand for?

Answer 49

Growth Hormone Releasing Hormone

Question 50

What does CRH stand for?

Answer 50

Corticotropin Releasing Hormone, stimulates the release of ACTH

Question 51

What does TRH stand for?

Answer 51

Thyrotropin Releasing Hormone, stimulates secretion of Prolactin and TSH

Question 52

What does GnRH stand for?

Answer 52

Gondaltropin Releasing Hormone, stimulates the release of FSH and LH

Question 53

What does SS stand for?

Answer 53

Somatostatin, Inhibits the release of FSH and GH

Question 54

What does DA stand for?

Answer 54

Dopaminne, it inhibits the release of Prolactin

Question 55

Cortisol is released by the ___________ of the adrenal gland at a rate of about ___mg a day

Answer 55

Zona Reticularis | 10mg/day

Question 56

Under basal conditions, what is cortisols function?

Answer 56

Maintaining homeostasis of metabolic processes and fluid balance

Question 57

Explain how Cortisol is secreted under stressful conditions

Answer 57

1. The hypothalamus increases secretion of CRH 2. CRH goes to the Ant. Pit. causing it to release ACTH 3. ACTH goes to the Zona Reticularis portion of the Adrenal Gland's cortex and stimulates the secretion of Cortisol

Question 58

During stress what does Cortisol do?

Answer 58

Increase glucose and oxygen supply to the skeletal muscles, heart and brain Increases Muscle performance

Question 59

At the liver, cortisol causes an increase in _____________

Answer 59

Gluconeogenesis

Question 60

Cortisol prevents cells that aren't necessary from taking up _________ and __________

Answer 60

Amino Acid and Glucose

Question 61

By activating _________ cortisol increases the amount of free fatty acids that can be used and an alternative fuel

Answer 61

Lipolysis

Question 62

In order to conserve energy, cortisol suppresses __________, __________ and __________ functions

Answer 62

Immune, Digestive and Reproductive

Question 63

What is Cushing's Disease?

Answer 63

Overproduction of Cortisol

Question 64

Cushings Disease can be caused by:

Answer 64

1. Over-secretion of CRH by a hypothalamic tumour 2. Over-secretion of ACTH by a anterior pituitary tumour 3. Negative feedback issue, insensitivity to raised cortisol levels

Question 65

What are some of the effects Cushings disease?

Answer 65

Diabetes Mellitus Central Obesity Thinning of Skin and bruising Muscles

Question 66

How do you treat Cushings disease?

Answer 66

Removal of the tumour