Mairead - ANS Integration, Reflexes and Tone Flashcards

1
Q

What happens if an organ is innervated by both the sympathetic and parasympathetic division?
(2)

A

The divisions might have opposing effects e.g. in the heart

Or they might have complementary effects e.g. in reproduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which autonomic division are the arteries and veins innervated by?

A

Most are innervated by the sympathetic division

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is autonomic tone?

A

The resting level of spontaneous activity shown by the ANS neurons in the absence of stimuli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Write a note on the ANS and the heart
(4)

A

Has both sympathetic and parasympathetic innervation

The sympathetic increases heart function (HR and SV)

The parasympathetic decreases heart function (mostly just HR)

At rest both are active but parasympathetic is dominant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Write a note on the blood vessels and the ANS
(2)

A

Blood vessels are mainly innervated by sympathetic nerves

Control of blood flow and blood pressure by increasing/decreasing sympathetic tone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is integration?

A

Sensory receptors, sensory nerves, nervous interpretation, motor nerves and an effector all in a circuit called a reflex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

In the somatic NS, what does reflex speed depend on?
Giving examples (3)

A

The length of the circuit

Spinal reflexes are short and quick and have few synapses

Brain reflexes are long and slower and usually have many sensory inputs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

List the steps to a reflex arc
(5)

A
  1. Arrival of stimulus and activation of receptor
  2. Activation of a sensory neuron
  3. Information processing in CNS
  4. Activation of a motor neuron
  5. Response by effector
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Where can integration/information processing take place in the ANS?

A

In the ganglia

In the CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Give a specific type of ganglia where information processing can take place

A

Parasympathetic ganglia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Give some locations in the CNS where integration can take place.
Also give the type of integration that occurs.
(3)

A

In the spinal cord (subconscious)

In the brainstem (subconscious)

In the hypothalamus (both conscious and subconscious elements)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the blood pressure reflex called?

A

Baroreceptor reflex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What happens to the Baroreceptor reflex when the SNS activity increases and the PSNS activity decreases?

A

There is an increase in cardiac output and vasoconstriction which increases blood pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What happens to the Baroreceptor reflex when the PSNS activity increases and the SNS activity decreases?

A

There is a decrease in cardiac output and vasodilation which reduces blood pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Define negative feedback
(2)

A

A corrective mechanism that opposes or negates a variation from normal limits

A stimulus triggers a response, then the response reduces the strength of the stimulus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the main role of the hypothalamus?

A

It’s responsible for the maintenance of body internal environment -> maintenance of homeostasis by regulation of the ANS, the somatic NS and the endocrine system

17
Q

What balances does the hypothalamus control?
(5)

A

Body temperature
Blood pH
Electrolyte balance (Na+, K+, Ca++, PO4, etc)
Blood sugar
Blood gases

18
Q

Write a note on the sensory control of the hypothalamus
(2)

A

It has the integrative function of the spinal cord and the brainstem reflexes

It receives sensory information from many different systems

19
Q

Give five examples of places the hypothalamus receives sensory information from

A

The thalamus (all senses except smell synapse here)

The limbic system (thoughts)

The cerebral cortex

The blood flowing through the hypothalamus

CSF

20
Q

What three systems does the hypothalamus motor control involve?

A

ANS

Somatic NS

Endocrine System

21
Q

How does the hypothalamus react to decrease in body temperature?
(3)

A

ANS decreases blood flow to the skin

Somatic NS stimulates shivering, hair on skin rises

Endocrine system stimulates the release of thyroid hormone to increase metabolism

22
Q

Write a note on ANS reflexes

A

Reflexes are visceral and cranial or they include higher centres

There are some intra organ reflexes where there is no CNS involvement (fast and automatic)

23
Q

Write a note on the visceral and cranial nerve reflexes

A

They provide automatic responses that can be modified, facilitated or inhibited by higher centres e.g. eye reflexes that are activated by light or dark may also be triggered by some emotional states

24
Q

Give an example of an intra organ reflex

A

Control of movement of chyme from the stomach into the duodenum

25
Q

List the four higher centres

A

Cerebral cortex

Thalamus

Limbus

Hypothalamus

26
Q

List some of the reflex centres of the brainstem
(3)

A

Vasomotor centre

Respiratory centre

Cardiac centre

27
Q

What are the reflex centres of the brainstem modified by?

A

The higher centres

28
Q

Where are the sensory receptors responsible for blood pressure control?

A

They are found in the Baroreceptors of the large arteries e.g Aorta and Carotid

29
Q

Where does integration for blood pressure control take place?
(3)

A

The medulla oblongata of the brainstem in the:

Vasomotor centre

Cardiac accelerator

Cardiac inhibitory centres

30
Q

What are the effectors for blood pressure control?

A

The smooth muscle of the blood vessels, the SA node, the AV node and the cardiac muscle

31
Q

How does the blood pressure reflex respond to decreased blood pressure?
(3)

A

Increased sympathetic to heart and blood vessels

Decrease parasympathetic activation

Increases cardiac output and vascular resistance => increasing blood pressure

32
Q

How does the blood pressure reflex respond to increased blood pressure?
(3)

A

Barroreceptors stretched and sensory nerve alerts the medulla oblongata

Increased parasympathetic to the heart, decreases sympathetic to heart and arterioles

Decreases cardiac output, vasodilate => decrease blood pressure

33
Q

What are chemoreceptors?

A

Measure gas of the aortic blood and in medulla oblongata