Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

physiology module 2 > Reflexes > Flashcards

Reflexes Flashcards

(40 cards)

Start Studying
1
Q

Describe neural regulation of circulation, including various reflexes that influence it.

A

Nervous regulation of circulation involves
① redistributing blood to different areas of the body.
② increasing the heart’s pumping activity
③ providing rapid BP control
Only the SNS provides ANS circulatory control through the vasomotor center in the medulla (and pons)Which has vasoconstrictor fibers throughout circulation .These fibers secrete NE onto alpha fibers, causing vasoconstriction. The vasodilator area inhibits this mechanism and sensory area regulates both.

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

Nervous Regulation of Circulation

A

Local flow control locally
Nervous control for
Redistributing blood flow to different body areas
Increasing heart’s pumping activity
Providing rapid BP control
Regulated by autonomic nervous system (ANS)

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

Sympathetic

A

Circulation
Heart function

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

Parasympathetic

A

Heart Function
NOT circulation

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

Sympathetic Innervation
of Blood Vessels

A

Most tissues: all vessels except capillaries
Some tissues: precapillary sphincters & metarterioles
Innervation of small arteries/arterioles can increase resistance and decrease flow
Innervation of large vessels (veins) can decrease volume/affect heart pumping

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

Control by the CNS

A

Vasoconstrictor fibers (throughout circulation)
Especially kidneys, intestines, spleen
Not as much brain, skeletal muscle

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

Vasomotor Center

A

Medulla/lower pons
Parasympathetic impulses to heart (through vagus)
Sympathetic through spinal cord/PNS to all arteries, arterioles and veins

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

Vasoconstrictor area

A

SNS vasoconstrictor neurons throughout spinal cord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Vasodilator area

A

Inhibit vasoconstrictor area

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

Sensory area

A

Receives signals from vagus & glossopharyngeal nerves
Regultes vasoconstrictor & vasodilator areas

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

Vasomotor Tone

A

Continuous signals from vasoconstrictor area – sympathetic tone

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

Sympathetic (lateral)

A

Increases heart rate & contractility
Generally increase when vasoconstriction occurs
Generally decrease when vasoconstriction inhibited

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

Parasympathetic (medial)

A

Decreases heart rate (vagus nerve)

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

Higher nervous centers can influence vasomotor center

A

Pons
Midbrain
Diencephalon
Hypothalamus – powerful regulator
Cerebral cortex

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

Vasoconstrictor neurotransmitter

A

NE

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

Adrenal Medulla Innervation

A

Causes medulla to release Epi and NE
Generally cause vasoconstriction
In tissues with β2 receptors, cause vasodilation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

MAP can be increased by

Study These Flashcards
A

Constricting most arterioles
Increase TPR and therefore CO
Constricting large vessels
Increase venous return and therefore CO
Increasing HR and contractility
Increase CO
These can occur within seconds
Exercise/fright

18
Q

Constricting most arterioles

Study These Flashcards
A

Increase TPR and therefore CO

19
Q

Constricting large vessels

Study These Flashcards
A

Increase venous return and therefore CO
Increasing HR and contractility
Increase CO
These can occur within seconds
Exercise/fright

20
Q

Cardiovascular Reflexes & Responses

Study These Flashcards
A

Vasovagal syncope
Baroreceptor reflex
Ischemic response
Atrial & pulmonary artery reflexes
Bainbridge reflex

21
Q

Baroreceptor Reflex

Study These Flashcards
A

Important in short term BP regulation
Increase in BP stretches baroreceptors
Increases the number of impulses from carotid sinus increases which results in
Inhibition of the vasoconstrictor
Activation of the vagal center
Causes AP through afferent neurons
Hering’s and glossopharyngeal or vagus
Integrating center is vasomotor center in medulla
Baroreceptors respond to changes in arterial pressure
Carotid sinus baroreceptors respond to pressures between 60 and 180 mmHg
Baroreceptors reflex is most sensitive at a pressure of ~100mmHg
Maintains relatively constant pressure despite changes in body posture

22
Q

Moving from a supine to a standing position results in

Study These Flashcards
A

an increase in heart rate
an increase in total peripheral resistance
constriction of veins

23
Q

Baroreceptor Reflex Functions

Study These Flashcards
A

Oppose changes (increase or decrease) in BP, reducing daily fluctuations
Adapt, so not helpful in long-term regulation of BP

24
Q

Chemoreceptors

Study These Flashcards
A

Remember chemoreceptors located in carotid bodies and aorta?
Their activation also activates vasomotor center in medulla to increase sympathetic stimulation

25
CNS Ischemic Response
CNS Ischemic response is activated in response to cerebral ischemia Reduced cerebral blood flow causes CO2 buildup which stimulates vasomotor center thereby increasing arterial pressure
26
Atrial and Pulmonary Reflexes
Receptors in atria and pulmonary arteries minimize arterial pressure changes in response to changes in blood volume Increases in blood volume activate receptors Decrease ADH Increasing GFR Decrease Na reabsorption And H2O
27
Bainbridge Reflex
Prevents damming of blood in veins, atria, and pulmonary circulation Increase in atrial pressure increases heart rate Stretch of atria sends signals to VMC via vagal afferents to increase heart rate and contractility
28
Components of Blood
Plasma Cellular elements Red blood cells (RBCs)/erythrocytes White blood cells (WBCs)/leukocytes Platelets/thrombocytes
29
Plasma
Aqueous solution Proteins Enzymes Hormones Nutrients Ions Gases
30
Describe the basic composition of the fluid & cellular portions of blood.
The basic components of blood are : ①Plasma ↳ an aqueous solution with nutrients , gases , -Ions , and proteins (hormones 1- enzymes) ② cellular-elements RBCs ↳WBCS ↳Platelets : cell fragments
31
Requirements for RBC Production
Erythropoeitin Vitamin B12 Folic acid Iron Normal hemoglobin formation
32
Erythropoietin
Hormone released from kidney in response to low renal oxygenation (also produced in liver) Red cell production increases within 24 hours Erythropoietin life span is 4-12 hours Increase in red cell number in 5 days
33
Vitamin B12 & Folic Acid
Required for final maturation of RBCs Required for DNA synthesis
34
Vitamin B12
Dietary Sources: mostly animal proteins; especially high in fish Absorption: requires intrinsic factor, produced by the stomach Cells in the ileum contain intrinsic factor receptors Storage: liver (can store >3 years’ worth) Deficiency: due to lack of vitamin B12 in the diet or lack of absorption due to insufficient intrinsic factor
35
Folic Acid
Dietary Sources: liver; dark, leafy greens; other vegetables and fruits Storage: liver Deficiency: malnutrition; intestinal issues that prevent absorption
36
Iron
Necessary for oxygen to be able to bind to the hemoglobin (and other things in body) ~ 10% in food absorbed, few mg/day loss 1 mg/day males average menstruating women additional 14 mg/period loss duodenum and upper jejunum major site absorption Absorption enhanced by meat, Vitamin C, HCl Inhibited by carbonates, tannate (tea), oxalate (spinach, rhubarb), phosphates (vegetables) Excess iron is stored in liver Mechanism of absorption (throughout small intestine) Requires substance produced by liver into bile This is secreted into the duodenum It then binds to iron, created transferrin Intestinal cells contain receptors for transferrin, bringing the complex into the cell Transferrin is moved out of the cell and into the blood
37
Hemoglobin
Protein containing 4 hemoglobin chains, each of which contains: Globin chains Heme molecules Each contains one atom of iron, for a total of 4 iron atoms/hemoglobin Each atom of iron can bind on molecule of O2, for a total of 4 oxygen molecules/hemoglobin
38
Abnormal Hemoglobin
Generally inherited Sickle-cell anemia Thalassemia Others Genetic mutation results in abnormal protein with reduced function
39
Regulation of RBC Numbers
Balance between production and destruction ~ 1% produced/day ~ 1% destroyed/day Produced in bone marrow sternum, pelvis, vertebrae, ribs Life span ~100 days before starting to degrade and being ingested by macrophages in the spleen.
40
Describe the physical characteristics, production, function, and life span of red blood cells (erythrocytes).
Physical : flat , biconcave , nd nucleus or organelles 4 heme groups which bind to Oz v4 help of iron Production: from stem cells in bone marrow ↳ NEET ① erythropoei fin : hormone from kidney 9 in lack of Oz ② vitamin Biz: found in animals (protein ③ folic acid : liver ④ iron : needed for 02 → hemoglobin quit.C ⑤ hemoglobin : 4 heme groups binds 402s Function : transport Oz 1- Coz Life Span :3-4 months , recycled by spleen 100 days

physiology module 2 (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions