Topic 2: The ANS

Question 1

This directs the “flight or fight or freeze” response of the ANS

Answer 1

The Hypothalamus

Question 2

Monitors blood glucose levels, the body’s water content, Circadian rhythm regulates appetite, sleep and sexual behaviour as well as controlling body temperature.

Answer 2

The Hypothalamus

Question 3

The Hypothalamus also controls hormones released from the pituitary gland Including…

Answer 3

Oxytocin and Antidiuretic Hormone (ADH)

Question 4

Plays a role in uterine contractions during childbirth and breast feeding. its secretion can be caused by the sound of a baby crying.

Answer 4

Oxytocin

Question 5

This hormone is responsible for increasing water absorption in the collecting ducts of the kidney. It also increases arterial blood pressure.

Answer 5

Antidiuretic Hormone (ADH)

Question 6

The hypothalamus will release this hormone in the morning just before waking to increase blood glucose levels to counterbalance the potentially harmful effects of not eating or drinking while asleep

Answer 6

Cortisol

Question 7

What is the HPA Axis?

Answer 7

Hypothalamus, pituitary, and adrenal cortex alliance

Question 8

This hormone is released which has widespread actions which help restore homeostasis after stress.

Answer 8

Cortisol

Question 9

Partly responsible for for creating euphoria and pain inhibition. It works with epinephrine to create memories of short-term emotionally significant events (flash-bulb memories) to remember what to avoid in the future. (these memories can sometimes be inaccurate)

Answer 9

Cortisol

Question 10

The effects of chronic cortistol secretion:

Answer 10

Damage to cells in the hippocampus resulting in impairedorsosis

Question 11

Difference between short term stress response vs chronic stress response of the HPA axis:

Answer 11

Short term: arouses immunological memory for the invaders

Chronic: supresses the ability of the immune system to do its job

Question 12

The ANS (aka Visceral System) involves the

Answer 12

control of the heart, gland, and smooth muscles of the body. Since for the most part, it is not subject to voluntary control, it is also known as the involuntary system.

Question 13

The ANS works together with the ______ ______ to control the secretion of hormones and is itself controled by the hypothalamus. Its effects include secretions from the _______ ______

Answer 13

Endocrine System;

Exocrine Glands

Question 14

True or False: The ANS is an efferent system.

Answer 14

True

Motor Fibers make up the bulk of the ANS, although it does include afferent axons that carry information from the viscera

Question 15

The motor component of these reflexes may also involve the SNS for example salivating and vomitting.

Simple reflexes are completed entirely within the organ concerned, whereas more complex reflexes are controlled by the higher autonomic centres in the CNS, principally the hypthalamus.

Answer 15

examples of how the ANS effects often involve reflexes

Question 16

Comparison of ANS & SNS

Answer 16

Control:
SNS: Voluntary – ANS: Involuntary

Effectors:
SNS: Skeletal mm – ANS: Cardiac & Smooth mm; glands

of neurons in the motor pathway:
SNS: 1 LMN from CNS synapses directly with skeletal mm
ANS: 2 motor neurons in a series

Question 17

The ANS is divided into two divisions (on the basis of anatomical and functional differences) called

Answer 17

The Parasympathetic and Sympathetic

Question 18

T or F: most organs are innervated by fibres from both divisions and the influence is usually antagonistic

Answer 18

True; example: the PNS slows the heart while the SNS increase its rate and contractility

Question 19

T or F: The sympathetic nervous system is not only associated with “flight or fight” reactions but overall homeostasis as well being essential for maintaining the fundamental vital activities of an organ. It will always be active at a basal level(sympathetic tone)

Answer 19

True;

It becomes more active during times of stress and its action during the stress response comprise the flight or fight response.

Question 20

Where are parasympathetic nerve cell bodies located

Answer 20

Theyre located in different nuclei throughout the brain stem, as well as a few nuclei in the sacral region of the spinal cord. (sacrocranial division)

Question 21

In the medulla, the cranial nerves III, VII, IX, and X (3,7,9,10) form the

Answer 21

preganglionic parasympathetic fibers

Question 22

The preganglionic fiber from the medulla or spinal cord projects to ganglia very close to the target organ and makes a synapse. This nerve carries most of the PANS (parasympathetic) signals

Answer 22

CN X (vagus)

Question 23

The sympathetic nerve cell bodies of a preganglionic (presynaptic) neuron are always in the CNS within the ________.

Answer 23

Lateral horn.

Every preganglionic sympathetic neuron orginates at these levels. There are no exceptions, which is why the sympathetic division is also known as the thoracolumbar division of the ANS

Question 24

Paravertebral Ganglia (sympathetic trunk) are

Answer 24

paired chains of ganglia connected by nerve fibers that extend from the base of the skull to the Coccyx.

Question 25

Paravertebral Ganglia (pre-aortic ganglia)

Answer 25

Lie directly anterior to the vertebral column and
are cemented on the anterior aorta

2 celiac ganglia (solar plexus) are situated behind the stomach and supply the organs in the abdomen. Celiac plexus block is sometimes used to treat intractable pain from cancers such as pancreatic cancer.

Question 26

Preganglionic Fibres and The Adrenal Medullae

Answer 26

Preganglionic axons go directly to the adrenal medulla where synapse on cells releasing noradrenalin and adrenalin into the blood. Since every cell of the body can be affected by these hormones, this allows sympathetic access beyond those cells which have direct post ganglion sympathetic fibres innervating them

Question 27

Vasovagal Syncope =

Answer 27

Fainting

Question 28

A paroxysmal condition marked by a slow pulse, fall in blood pressure, and sometimes convulsions. It is though to be a sudden stimulation of the Vagus nerve mediated through baroceptors in the carotid sinus, the aortic arch, or the heart

Answer 28

Vasovagal Syncope

Question 29

A paroxysmal condition marked by a slow pulse, fall in blood pressure, and sometimes convulsions. It is though to be a sudden stimulation of the Vagus nerve mediated through baroceptors in the carotid sinus, the aortic arch, or the heart

Answer 29

Vasovagal Syncope

Information passed on to the higher centers like the hypothalamus results in simultaenous enhancement of PANS (vagal) tone and withdrawal of SYNS tone

Question 30

The two most common causes of Vasovagal Syncope

Answer 30

Orthostatic hypotension aka postural hypotension which is a drop in BP that occurs when a person who was sitting or lying down suddenly stands.

Postprandial hypotension, a drop in BP within one hour of eating a meal. In clinically stable, unmedicated elderly person, blood pressure decreases significantly after morning and noon meals. Such decreases do not occur in younger persons.

Question 31

Thought to be due to impaired baroreflex compensation for low BP. Splanchnic blood pooling during digestion and lower limb blood pooling in the lower limb on standing are the triggers.

Answer 31

Postprandial hypotension and postural hypotension

Question 32

Comes with rapid emptying of the urinary bladder. Typically these episodes follow lots of beer or while passing water in the middle of the night

Answer 32

Micturation Syncope

Question 33

The Stellate ganglion’s AKA and location

Answer 33

Cervicothoracic ganglion is a sympathetic ganglion of the paravertebral chain of ganglia located superior to the neck of the 1st rib

Question 34

May be cut in order to decrease the symptoms of exhibited by Raynaud’s phenomenon and hyperhydrosis of the hands

Answer 34

The Stellate ganglion