#30

Question 1

What is blood pressure determined by?

Answer 1

Total blood volume, resistance and cardiac tension (force) production

Question 2

Homeostasis: sensors

Answer 2

something that constantly moitors specific external conditions to maintain a stable and balanced internal environment

Question 3

Homeostasis: integrator

Answer 3

component of a feedback loop that processes infornation from sensors to determine the necessary response to maintain a stable internal environment

Question 4

Homeostasis: effectors

Answer 4

Executing the necessary chages to adjust the variable

Question 5

Baroreceptors

Answer 5

mechanosensory neurons that monitor mean arterial blood pressure

Question 6

Where are baroreceptors located?

Answer 6

in the carotid sinus and aortic arch

Question 7

What do baroreceptoes monitor?

Answer 7

Blood pressure to the brain and systemic blood pressure

Question 8

How do baroreceptors sense change in blood pressure?

Answer 8

They respond to being stretched, High pressure increases the stretch and Low pressure decreases the stretch

Question 9

What is the effect the sympathetic nervous system has on BP?

Answer 9

SNS is “fight-or-flight” and releases norepinephrine to increase heart rate, stroke volume and peripheral vascular resistance.
promotes vasoconstriction
Resulting in increased blood pressure during

Question 10

What is the effect of the parasympathetic nervous system on bp?

Answer 10

PSNS “rest and digest”, releases acetycholine to reduce the excitability of the SA and AV nodes
promotes vasodilation to reduce heart rate and cardiac output leading to a decrease in blood pressure
Results in lower blood pressure

Question 11

What happens when basoreceptors are stretched from high pressure?

Answer 11

Decreases sympathetic (fight or flight) nervous system activity and increases parasympathetic (rest and digest) nervous system activity

Question 11

What would an increase in PNS activity do?

Answer 11

It would lower blood pressure because it lowers cardiac output and heart rate because ACh is released through the vagus nerve

Question 12

What does ACh do for the heartrate?

Answer 12

decreases heart rate by binding onto the SA node pacemaker cells causing them to fire more slowly which results in slower heart rate

Question 13

What happens when baroreceptors feel a decrease in stretch from low pressure?

Answer 13

Baroreceptor signalling would become reduced and therefore not block SNS activity, letting it run more active and therefore increase heart rate

Question 14

Afferent pathways

Answer 14

neural routes that transmit sensory information from peripheral receptors in body tissues/muscles/organs to the CNS

Question 15

Efferent pathways

Answer 15

neural route that conducts impulses away from the CNS toward peripheral effector organs like muscles and glands

Question 16

What are the afferent pathways involved in the baroreceptor reflex?

Answer 16

Cranial Nerve IX (Glossopharyngeal), Cranial Nerve X (Vagus)

Question 17

What are the efferent pathways involved in the baroreceptor reflex?

Answer 17

Cranial Nerve X (Vagus, Sympathetic fibers

Question 18

What do cardiovascular centres of the medulla do?

Answer 18

Control heart rate and force of contraction, diameter of systemic arterioles

Question 19

What are the effector organs of the baroreceptor reflex?

Answer 19

Heart and Systemic Arterioles

Question 20

What does the Adrenal Medulla do in the baroreceptor reflex?

Answer 20

Releases epinephrine and norepinphrin into the blood to increase cardiac output and vasoconstriction

Question 21

What are chemoreceptors?

Answer 21

specialized sensory cells that detect blood oxygen, carbon dioxide and pH levels and convert them into nerve impulses to maintain homeostasis

Question 22

What is PCO2?

Answer 22

The amount of carbon dioxide dissolved in blood plasma

Question 23

What do chemoreceptors do for cardiovascular regulation?

Answer 23

They help maintain arterial PO2, PCO2 and pH within normal ranges

Question 24

How are chemoreceptors stimulated?

Answer 24

by low oxygen (hypoxia), high carbon dioxide or low pH

Question 25

What does the chemoreceptor reflex do

Answer 25

Triggers increased hyperventilation to expel excess carbon dioxide and intake more oxygen Increased SNS activity to increase vasoconstriction and heart rate

Question 26

What is PO2?

Answer 26

Arterial partial pressure of oxygen, pressure of oxygen dissolved in the blood plasma

Question 27

Hypotension

Answer 27

low blood pressure (below 90/60mmHg)

Question 28

Hypertension

Answer 28

High blood pressure

Question 29

What is Erythropoietin (EPO)?

Answer 29

hormone produced by the kidneys that stimulates the bone marrow to create red blood cells

Question 30

Renin

Answer 30

Hormone released by the kidneys juxtaglomerular cells when blood pressure or renal blood flow drops

Question 31

Angiotensinogen

Answer 31

plasma protein produced by the liver

Question 32

What does renin do to angiotensinogen?

Answer 32

Converts angiotensinogen into angiotensin I

Question 33

Angiotensin I

Answer 33

inactive 10 amino acid peptide

Question 34

Angiotensin-Converting Enzyme (ACE)

Answer 34

converts the inactive angiotensin I into the active hormone Angiotensin II

Question 35

Angiotensin II

Answer 35

hormone that promotes vasoconstriction and triggers the release of aldosterone and ADH

Question 36

Aldosterone

Answer 36

hormone released by the adrenal cortex that causes kidneys to retain sodium and water, increasing total blood volume

Question 37

ADH

Answer 37

released by the posterior pituitary gland and promotes water retention by kidneys

Question 38

Angiotensin II reduces the sensitivity of ______ reflex to not counteract the RAAS response

Answer 38

baroreceptor

Question 39

Hypovolemic shock

Answer 39

Caused by a severe sudden loss of blood or fluis preventing the heart from pumping enough bloog to the body

Question 40

What does long term regulation of blood pressure involve?

Answer 40

Changes in blood volume

Question 41

What do blood volume changes must involve to maintain oxygen delivery at normal rates?

Answer 41

Changes to both plasma and RBC levels

Question 42

What do short term responses to blood loss involve?

Answer 42

Neural reflexes and the physiological ress response

Question 43

In the medium term, what can reductions to BP lead to?

Answer 43

decrease in CHP which leads to 'recall of fluid' from ISF

Question 44

In the long term, what can increase in ATii, ADH, aldosterone lead to?

Answer 44

increased fluid intake and retention, EPO will resotre RBCs