Nervous System Regulation

Question 1

Local control of blood flow to tissue by which 2 theories?

Answer 1

Vasodilator and O2 Lack theories

Question 2

Characteristic of elastic arteries

Answer 2

Stretch and recoil every heartbeat to maintain pressure

Question 3

Characteristic of muscular arteries

Answer 3

Adjust diameter for blood pressure control, can regulate flow to parts of body

Question 4

Characteristic of arterioles

Answer 4

Control blood flow to tissue

Question 5

Characteristic of capillaries

Answer 5

serve tissues and are for local control of blood to tissue

Question 6

Venules? What do they do?

Answer 6

collect blood from capillaries

Question 7

Characteristic of veins?

Answer 7

Reservoir, transport to heart

Question 8

Autonomic Nervous System regulates locally or globally?

Has which 3 effects on the CVP system?

Answer 8

Globally

1) redistributes blood flow to different areas of body
2) affects HR
3) rapidly changes arterial blood pressure

Question 9

Which system has most influence in circulation regulation?

Which system assists in heart function regulation?

Answer 9

SNS is primary influence in circulation

PSNS assists in regulation of heart function

Question 10

Where do the SNS vasomotor nerves leave the body at?

Answer 10

T1-L2

Question 11

SNS innervates all vessels except which 3?

Answer 11

Capillaries, precapillary sphincters, metarterioles

Question 12

What happens to vessels of SNS innervation?

Answer 12

SNS –> vasoconstriction –> High BP

Question 13

SNS stimulation decreases vessel volume by what?

Answer 13

Vasoconstriction

Question 14

Define circulatory shock

Answer 14

Condition where blood vessels are not properly filled and blood cannot circulate normally

Question 15

What is hypovolemic shock?

Answer 15

Severe loss of blood/fluids that make the heart unable to pump blood to rest of the body

Question 16

What is vascular shock?

Answer 16

characterized by a normal blood volume, but extreme vasodilation, often related to a loss of vasomotor tone, resulting in poor circulation and a rapid drop in blood pressure

TOO MUCH VASODILATION

Question 17

What is cardiogenic shock?

Answer 17

heart suddenly can’t pump enough blood to meet your body’s needs. The condition is most often caused by a severe heart attack.

Question 18

What is the SNS affect on HR?

Answer 18

Increases heart rate to circulate fuel and oxygen to vital organs for activity and defense

Question 19

SNS affect on BP?

Answer 19

Increases blood pressure to get blood to the brain and vital organs

Question 20

SNS affect on blood loss?

Answer 20

Increases blood clotting ,which minimizes blood loss if wounded during defense such as fight/flight

due to vasoconstriction

Question 21

Vasoconstriction fibers distributed to all segments of circulation but largest to which 4 areas of the body and why?

Answer 21

Kidneys, intestines, spleen, and skin.

Want to vasoconstrict blood flow to areas not needed for flight or fight arousal period. Want to maximize effiency to other areas

Question 22

Where are SNS fibers for vasoconstriction less distributed to?

Answer 22

skeletal mm and brain

Question 23

Where is the vasomotor center located?

Answer 23

Medulla Oblongata

Question 24

3 areas of the vasomotor center include:

Answer 24

vasoconstrictor area, vasodilator area, sensory area

Question 25

What happens if normal vasoconstrictor tone is lost?

Answer 25

vasodilation, widening of vessels will occur. BP is not maintained and may drop

Question 26

SNS secretes what substance?

Answer 26

Norepinephrine

Question 27

Vasodilator area does what to the vasoconstrictor area?

Answer 27

Inhibits it.

Question 28

Which area helps control both vasoconstriction and vasodilation areas?

Answer 28

Sensory Areas

Question 29

Where are the sensory areas received?

Answer 29

Circulatory system via vagus and glossopharyngeal nerves

Question 30

Adrenal medulla is stimulated by blood vessels and then secrets what 2 substances?

Answer 30

Norepinephrine and epinephrine into blood system

Question 31

Epinephrine has what affect on some tissues?

Answer 31

vasodilation

Question 32

Cardiac center is located where and has what function?

Answer 32

Adjacent to vasomotor center. Adjusts HR and force of contraction to meet needs via the cardioaccelerator center and cardioinhibitory center

Question 33

What 2 centers does the cardiovascular center make up?

Answer 33

Cardiac center + vasomotor center

Question 34

Stimulation of vasomotor center has what affect on the cardiac center?

Answer 34

Stimulates cardiac centers Therefore Heart Function and Vascular Function controlled SIMULTANEOUSLY! - Increases in vasoconstriction with increase HR - Decreases in HR with decreases in vasodilation

Question 35

What response is considered most sensitive of nervous system responses?

Answer 35

Blood pressure Can increase x2 within 5-10 seconds

Question 36

Increase in Arterial Pressure result of simultaneous stimulation of what 2 things?

Answer 36

vasoconstriction and cardioacceleration

Question 37

Increases in Arterial Pressure have what 3 major changes?

Answer 37

Arterioles constrict, veins and other large vessels constrict, and SNS stimulation of heart occurs

Question 38

How does the body maintain normal arterial pressure?

Answer 38

Baroreceptors are in nearly every large artery of the neck and thorax are PRESSURE sensitive.

Question 39

barometer measures decline in MAP? What happens next?

Answer 39

Initiation of reflex vasoconstriction and increases cardiac output --> bp rise

Question 40

Standing up from a chair creates orthostatic hypotension, how does the body react when with the baroreceptors?

Answer 40

low BP fall will increase vasoconstriction and increase cardiac output so BP will rise for homeostasis.

Question 41

Functions of the baroreceptor function include 3 things:

Answer 41

Protects against acute changes in BP as a buffer system Minimizes variation in BP But is ineffective during prolonged pressure changes due to adaptability.

Question 42

Example of adaptability of a baroreceptor in hypertension?

Answer 42

Reset at higher set point due to prolonged period of HTN, limiting longterm response to higher perceived pressure

Question 43

Chemoreceptor is in contact with which blood ? What does it sense? What does it initiate?

Answer 43

Arterial blood Senses low O2 or high CO2 or H+ that results with drops in arterial pressure. Reflexive vaso/venoconstriction response

Question 44

What does the chemoreceptor increase?

Answer 44

cardiac output, heart rate, vasoconstriction

Question 45

Bainbridge reflex of the atria does what? What kind of receptor is it?

Answer 45

Receptor= stretch increases in arterial pressure increase in HR and strength of contraction to prevent blood from backing up.

Question 46

Low pressure receptor in the atria will do what?

Answer 46

Sense and minimize arterial pressure changes. If need be, it will initiate more fluid retention to increase pressure.

Question 47

Damage to atria can result in?

Answer 47

Damaged and less effective pressure receptors in atria.

Question 48

If CNS ischemia happens, what occurs?

Answer 48

STRONG REACTION OF VASOCONSTRICTOR AND CARDIOACCELERATOR CENTERS LARGE RISE IN ARTERIAL PRESSURE

Question 49

What are the steps of cerebral ischemic response?

Answer 49

1) large drop in BP 2) drop in cerebral blood flow 3) increases in CO2 and H+ 4) ACTIVATION OF VMC 5) increase sympathetic activity 6) increase in TPR, HR 7) restoration of BP

Question 50

As the SNS activates what happens to EDV and ESV levels?

Answer 50

ESV levels decrease and EDV increases

Question 51

Formula for cardiac output?

Answer 51

Stroke volume x heart rate