Mechanisms of reflex action on blood circulation presentation. Regulation of blood circulation
The movement of blood through the vessels. Causes of the movement of blood through the vessels. Blood pressure is the pressure of blood on the walls of blood vessels. The difference in pressure in the arteries and veins is the main reason for the continuous movement of blood through the vessels. The blood moves to the place of least pressure. The pressure is highest in the aorta, less in the large arteries, even less in the capillaries, and lowest in the veins.
The movement of blood through the vessels is possible due to the pressure difference at the beginning and at the end of the circle of blood circulation. Blood pressure in the aorta and large arteries is 110 120 mm Hg. (i.e. 110 120 mm Hg above atmospheric). In the arteries 6070 In the arterial and venous ends of the capillary - 3015, respectively. In the veins of the extremities 58 blood velocity: in the aorta (maximum) 0.5 m/s; in the hollow veins - 0.2 m / s; in capillaries (smallest) - 0.5 1.2 mm/s.
A person's blood pressure is measured using a mercury or spring sphygmomanometer in the brachial artery (blood pressure). Maximum (systolic) pressure - pressure during ventricular systole (110120 mmHg) Minimum (diastolic) pressure - pressure during ventricular diastole (6080 mmHg) Pulse pressure - difference between systolic and diastolic pressure .
Pressure little depends on gender, but changes with age. Scientists have empirically established a formula by which each person under 20 years old can calculate his normal pressure at rest. (People older than this age, this formula is not suitable). Upper blood pressure \u003d 1.7 x age + 83 Lower blood pressure \u003d 1.6 x age + 42 (BP is blood pressure, age is taken in whole years)
For 14 years, upper BP = 106.8 Lower BP = 64.4 BP = 106.8 / 64.4
Pressure fluctuations must change within certain limits. If the fluctuations exceed the norm, the vessels may not withstand, burst, which often leads to the death of the patient. Stroke is damage to the blood vessels of the brain. A heart attack is a lesion in a specific part of the heart muscle. After a heart attack, the affected area does not function, because. muscle tissue is replaced by scarred connective tissue that is unable to contract.
Hypertension - increase blood pressure An increase in blood pressure occurs with heavy physical exertion. With age, the elasticity of the walls of the arteries decreases, so the pressure in them becomes higher.
Hypotension is a decrease in blood pressure. A decrease is observed with large blood loss, severe injuries, poisoning, etc. Hypotension symptoms: weakness and fatigue; irritability; increased sensitivity to heat (in particular, poor health in the bath); feel better during physical activity; palpitations during physical exertion;
After physical activity! In a trained and healthy person, the upper pressure rises high, but the lower one does not! If the bottom also rises, then this indicates low dynamic activity.
Arterial pulse - rhythmic oscillations of the walls of the arteries as a result of blood entering the aorta during left ventricular systole. The pulse can be detected by touch where the arteries lie closer to the surface of the body: in the area radial artery the lower third of the forearm, in the superficial temporal artery and the dorsal artery of the foot.
Measuring the pulse on the radial artery (practical work in pairs) Let's make sure that at point A the pulse does not disappear, although the blood has stopped. Clamp the artery at point A. Clamp the artery at point B so that the blood flow stops. Let's close its walls and stop the pulse wave. Conclusion - To find out if the blood has stopped, you need to feel the pulse below the constriction.
The pulse rate (heart rate) allows you to judge the health of a person, the work of his heart. If the number of heartbeats after exercise increased by 1.3 times or less, then good indications; If more than 1.3 times - relatively mediocre indications (lack of movement, physical inactivity). Normally, cardiac activity after exercise should return to its original level in 2 minutes! If earlier - very good, later - mediocre, and if more than 3 minutes, then this indicates a poor physical condition.
Mosso experience. The amount of blood in the body can be redistributed. To prove this, let's get acquainted with experience. The Italian scientist Angelo Mosso put a man on top of a large but very sensitive scale so that the head and opposite halves of the body were strictly balanced. When the scientist asked the subject to solve a mathematical problem, did the scales lose balance? Why? (Blood rushes to the brain, as the activity of the brain is activated.) Where will the blood flow go if a person has lunch, does exercises? It is known that during sleep the amount of blood in the brain decreases by 40%. Why can't an agitated person sleep?
Municipal budgetary educational institution
"Kamenolomnenskaya secondary school»
Saksky district of the Republic of Crimea
MUNICIPAL STAGE
COMPETITION "TEACHER OF THE YEAR - 2017"
OPEN BIOLOGY LESSON
"BLOOD CIRCULATION REGULATION"
8th grade
Prepared and conducted
biology and chemistry teacher
MBOU "Kamenolomno secondary school"
Starodubtseva Antonina Mikhailovna
Quarry, 2016
annotation
The topic "Regulation of blood circulation" is studied in the section "Life support systems. Formation of a culture of health”. This lesson is the fourth in a series of lessons dedicated to the study of this section.
The content of this topic provides a natural scientific basis for understanding the need for health protection by schoolchildren, since Special attention here is given to the formation of specific knowledge about the functioning of cardio-vascular system. During the study of the topic, the basics are considered neurohumoral regulation blood circulation, influence of factors environment, a healthy lifestyle on the mechanisms of regulation of blood circulation.
This development may be useful for biology teachers working in the line of teaching materials "Spheres" (textbook “Biology. Person. Culture of Health" authors:L.N. Sukhorukova, V.S. Kuchmenko, T.A. Tsekhmistrenko - M., "Enlightenment", 2014).
Synopsis of a biology lesson on the topic "Regulation of blood circulation"
Goals
Educational: to form in students an idea of the nervous and humoral regulation of the blood supply to organs, the influence of parasympathetic and sympathetic nervous system on blood circulationinfluence physical activity and environmental factors on the cardiovascular system.
Developing: to develop interest in the subject, the ability of students to work in a group, to promote the formation of information competence in the process of working with educational literature and other sources of information.
Educational: nurturing the need for healthy way life, taking care of your health.
Planned results
Subject: students have an idea about the regulation of blood circulation, the influence of environmental factors on the work of the cardiovascular system.
Metasubject:
Personal UUD: determine the choice of individual educational needs; learn to communicate with peers, defend their point of view in the process of conversation;caring for one's own health.
Regulatory UUD: define the goal and draw up a plan for completing the task;evaluate the progress and results of the task; compare your answers with the standards and answers of classmates.
Cognitive UUD : learn how to perform tasks for independent acquisition and application of knowledge; establish causal relationships; put forward hypotheses and justify them; formulate problems.
Communicative UUD: participate in the dialogue; cooperate with classmates in the search and collection of information; make decisions and implement them; express your thoughts accurately;to allow the possibility of different points of view; to ask questions; use speech to regulate their actions; be able to work in groups.
Psychological goal : creating a comfortable microclimate for each student.
Teaching methods
By the nature of the educational cognitive activity: problematic - search engines.
According to the method of organization and implementation of cognitive activity : verbal, visual, practical.
According to the degree of pedagogical management by the teacher: methods of mediated management of educational and cognitive activity of students with the help of information sources.
Forms of organization of educational activities : frontal, group, individual.
Lesson type: lesson in discovering new knowledge
Applied technologies:
ICT
Elements of problem-based learning
Person-Centered: Collaborative Technology
Equipment: multimedia equipment, electronic supplement to the textbook, workbook, textbook “Biology. Person. Culture of Health" authors:L.N. Sukhorukova, V.S. Kuchmenko, T.A. Tsekhmistrenko - M., "Enlightenment", 2014, handout for group work.
During the classes
Organizational moment.
Invented by someone simply and wisely
When meeting, greet: - Good morning!
Good morning! Smiling faces.
Please sit down quietly to work.
Hello guys! Today I will teach you a biology lesson. My name is Antonina Mikhailovna. Let's smile and wish each other Have a good mood and success in discovering new mysteries.
II . Motivation.
What do you think the word "hello" means?
Do you want to be in good health?
At biology lessons, you not only reveal the secrets of the structure and functioning of your body, but also learn to take care of your health and preserve it. I think that today you will replenish your knowledge and will apply it in practice.
Updating of basic knowledge.
What system of the human body do you study over the course of several lessons?
What is the cardiovascular system formed by?
Does blood always move through the vessels at the same speed and with the same pressure?
Do you know what it depends on?
What do you understand by the term regulation?
What types of regulation of body functions do you know?
What do you think, and work circulatory system regulated?
IV . Definition of the topic and objectives of the lesson.
1) Statement of a problem question.
- Surely, each of you paid attention to how strongly the heart beats when you are worried, it is not for nothing that there are expressions - “the heart is ready to jump out of the chest”, “the heart ran away from fear”, “the heart flutters like a frightened bird”, etc.
Problematic question: What happens to the heart? Why does it behave differently?
2) Definition of the topic and objectives of the lesson.
What do you think the topic of our lesson is?
What should we do to find answers to these questions?
V. Discovery of new knowledge.
1) opening speech teachers:
The French physiologist, academician and professor at the University of Paris, Claude Bernard, conducting his numerous experiments, discovered that if the right cervical sympathetic nerve is cut, then the right side of the dog's muzzle becomes warmer than the left. Obviously, there is an expansion of blood vessels, increased blood flow.
But how to see these changes? Through the delicate skin of the rabbit ear, small blood vessels are clearly visible, and under a microscope you can see how they shrink or expand.
Experience Claude Bernard proves the vasomotor role of sympathetic nerves. irritation electric shock of the cervical sympathetic nerve causes constriction of the blood vessels in the rabbit's ear, and it turns visibly pale. Transection of the same nerve entails vasodilation, and the ear turns pink.
2) Independent work students in groups. (Appendix No. 1)
You have assignments and materials on your desks(Appendix No. 2) to work using them, you will have to talk about the results of your work on the task in 5-6 minutes.
Physical education minute
3) Speech by the speakers of the groups with the presentation of the results of the work.
VI . Consolidation of knowledge.
Fulfillment of tasks of the simulator test of the electronic application to the textbook. Joint verification of completed tasks.
Performance test tasks students independently with subsequent self-examination according to the standard.
VII . Summing up the lesson.
VIII . Reflection. Complete the sentences:
To have a healthy heart and blood vessels, it is necessary
Today I found out...
It was interesting to me …
I will need…
I would like to know more...
Homework: §25, work with EP, compose 10 questions on the topic “Circulation regulation” or a crossword puzzle on this topic.
APPS
Application No. 1
Tasks for work in groups
Group #1. "Nervous regulation of blood circulation"
a) Where are the centers that carry out the nervous regulation of blood circulation?
b) How does the nervous regulation of blood circulation occur?
c) What is local nervous regulation?
d) What are conditioned cardiovascular reflexes? Where are their centers?
Group #2. " Humoral regulation circulation"
Assign responsibilities to the group.
Using §25 and additional material, answer the following questions:
a) What biologically active substances enhance the work of the cardiovascular system?
b) What biologically active substances inhibit the work of the cardiovascular system?
c) What ions and how do they affect the functioning of the cardiovascular system?
3. Arrange the results of your work in the form of a diagram.
Group #3. "Influence of environmental factors on blood circulation"
Assign responsibilities to the group.
Using the materials of §25, give answers to the questions:
a) What is the impact physical activity on the cardiovascular system?
b) What factors external environment and lifestyles Negative influence on the cardiovascular system?
c) What environmental and lifestyle factors contribute to normal operation of cardio-vascular system?
3. Arrange the results of your work in the form of a diagram.
Application number 2.
Additional Information for group №2
Humoral regulation (lat. humor - liquid) is one of the mechanisms for coordinating vital processes in the body, carried out through the liquid media of the body (blood, lymph, tissue fluid) with the help of biologically active substances secreted by cells, tissues and organs during their functioning. Hormones play an important role in humoral regulation.
Humoral regulation of the lumen of blood vessels is carried out by vasoconstrictor (adrenaline, vasopressin, serotonin) and vasodilator (acetylcholine, histamine) hormones. A lack of oxygen and an excess of carbon dioxide also dilate blood vessels, and damage to the walls of blood vessels narrows.
Application No. 3.
Tasks for self-fulfillment
Set a match. To do this, for each element of the left column, select the elements of the right column.
A. Strengthens the work of the heartB. Slows down the work of the heart
B. Expands blood vessels, lowers blood pressure
G. Constricts blood vessels, increases blood pressure
1) Sympathetic nerves
2) Parasympathetic nerves
3) Elevated temperature environment
4) Low temperature environment
5) adrenaline
6) norepinephrine
7) potassium ions
8) calcium ions
9) vasopressin
10) acetylcholine
11) nicotine
12) high levels of carbon dioxide in the blood
Answers:
A - 1, 5, 6, 8,
B - 2, 7, 10
B - 3, 12
G - 4, 9, 11
Show the systemic circulation in the picture.
1. In what part of the heart does it begin?
2. Where does the blood come from the left ventricle?
3. What is the name of the widest blood vessel in the systemic circulation?
4. Through which vessels does blood enter the organs of the body?
5. In what vessels does gas exchange occur?
6. Through which vessels and into which part of the heart does blood flow?
1. Does arterial blood always flow through arteries, and venous blood through veins?
2. What kind of blood is called arterial, and what kind of venous?
3. What changes are taking place:
a) in the pulmonary circulation;
b) in the systemic circulation?
1. What vessels are shown in the picture?
2. What is the difference between their structures?
Choose one correct answer:
1. The highest blood pressure in:
2. Blood pressure on the walls of large arteries occurs as a result of contraction:
- aorta
- capillaries
- femoral artery
- inferior vena cava
- left ventricle
- atrial
- Butterfly valves
- semilunar valves
3. Speed of movement in capillaries:
4. Valves are available only for:
- 0.2 mm/s
- 0.5 mm/s
- 0.25-0.5 mm/s
- Arteries
- capillaries
Install Sequence: Arrange blood vessels in order of decreasing blood pressure
Establish a correspondence between the department of the heart
man and the kind of blood that fills him:
HEART DEPARTMENT TYPE OF BLOOD
A) left ventricle 1) arterial
B) right ventricle 2) venous
AT) right atrium
D) left atrium
Answer: 1 2 2 1
2. Through the veins of the systemic circulation in humans
blood flows
- From the heart
- To the heart
- Saturated with carbon dioxide
- Oxygenated
- Faster than in capillaries
- Slower than in capillaries
Establish the sequence of blood flow according to big circle circulation in humans, starting from the left ventricle.
A) left ventricle
B) capillaries
B) right atrium
D) arteries
D) veins
E) aorta
A) left ventricle
E) aorta
D) arteries
B) capillaries
D) veins
B) right atrium
Determine in what sequence the blood vessels should be arranged in order of decreasing speed of movement in them
A) inferior vena cava
B) aorta
B) brachial artery
D) capillaries
Answer: B C A D
Cardiac cycle
Reduction
atrial
General
relaxation
Contraction of the ventricles
Knowing the cardiac cycle and the time of heart contraction
in 1 min (70 strokes),
it is possible to determine which 80 years old life:
ventricular muscles rest
50 years.
atrial muscles rest
70 years old.
AUTOMATISM
The experience of reviving an isolated human heart for the first time in the world was successfully carried out by the Russian scientist A. A. Kulyabko in 1902 - he revived the heart of a child 20 hours after death from pneumonia.
Automatism of the heart - this is
the ability of the heart to contract rhythmically without external stimuli under the influence of impulses that arise in itself.
- nervous
- humoral
Nervous regulation (vegetative NS)
Sympathetic
Wandering
1) Strengthens the activity of the heart
2) Narrows arterial vessels
3) Pressure rises
- Weakens the activity of the heart
- Expands blood vessels
- The pressure is rising
Humoral regulation
Substances
Strengthen the heart
activity
Weaken the heart
activity
1) Adrenaline
2) Calcium salts
- Acetylcholine
- Potassium salts
- Practical work "Proving the harm of smoking"
2nd year students of the 1st and 2nd medical
faculty studying in the specialty
"Medicine"
2016
V.M.
circulatory system
Lecture #3
REGULATION OF CIRCULATION
State regulation mechanismsblood vessels
Mechanisms that provide regulation
cardiac activity
Conjugate regulation
functional state of the CCC
General principles of regulation of blood circulation
1. Volumetric blood flow in most organsdetermined by their metabolic activity on
microcirculatory level.
2. IOC is controlled by the sum of all local
blood flow.
3. Systemic blood pressure is controlled regardless of
local blood flow and cardiac output.
Compliance with these conditions in the body is provided
complex multi-level system of regulation,
including:
a) physiological properties of CCC elements,
b) neuro-reflex,
c) humoral mechanisms. The first level of regulation is myogenic, based
on the properties of both myocardium and smooth muscle
vascular wall cells.
The second is humoral, except for hormones, due to
also the effect on smooth muscle cells of various
vasoactive compounds produced in tissues or
directly in the vascular wall itself (in
muscle or endothelial cells). Especially
vasoactive metabolites are intensively formed in
conditions of inadequate blood supply to the organ.
The third is neuro-reflex.
In many organs there is another type of neurogenic regulation of the microvasculature,
carried out by local reflexes. The tasks of the mechanisms of regulation of the CCC,
are conjugated:
Blood volume
Works of the heart
tone
vessels
Properties
myocardium
Mechanical
incentives
blood ions
neuroreflex
Hormones
Tasks of regulation systems
In the body to fulfill alldiverse functions of the blood, there are
regulatory mechanisms that harmonize three
main components of circulation:
a) blood volume
b) the work of the heart,
c) vascular tone.
Regulation of the function of the heart is provided by:
Properties of the myocardiumInfluence of nerves
Influence of ions
The influence of hormones.
Effects on the heart of regulatory mechanisms
Chronotropic influence (frequency)Inotropic influence (strength)
Dromotropic influence (conductivity)
Batmotropic influence (excitability)
The influence can be "+" - reinforcing
or "-" - weakening.
Hemodynamic regulation
I. Heterometric - contraction forcedepends on the original length of the muscle fibers.
Example: Frank-Starling Law (Law of the Heart) −
the greater the length of the muscle fibers during
diastole, those stronger force cardiac
abbreviations.
II. Homeometric - the strength of heart contractions
does not depend on the initial length of the muscle
fibers.
Examples: Bowditch's "ladder" (strength of heart
contractions increases with increasing
heart rate);
Anrep phenomenon (the strength of heart contractions increases with increasing pressure in the aorta)
Frank-Starling mechanism
Strength of myocardial contraction in systoleproportional to the degree of stretch
myofibril in diastole is
heterometric mechanism of regulation.
(positive inotropic effect).
Dependence of IOC on increased venous return
Increase in cardiac output and (MOC) withincreased return of blood to the atria
due to:
1. Frank-Starling mechanism.
2. An increase in heart rate.
3. Bainbridge reflex.
Atrial baroreceptor reflex (Bainbridge)
Bainbridge reflex:excitation
baroreceptors
atrium - cardiovascular center
medulla oblongata.
.
Sympathetic
influence on the myocardium.
Anrep effect
The greater the resistance to heartejection (with stenosis of the semilunar valves)
the greater the force of myocardial contraction
ventricles.
: With an increase in blood pressure in the aorta, proportionally
the force of contraction of the ventricles increases, which
increases stroke volume and IOC.
This is a homeometric mechanism of regulation.
Bowditch stairs:
With an increase in heart rate, the force of contraction increasesmyocardium.
This is due to the fact that when shortening
cardiac cycle time during diastole
the concentration of Ca ++ in the sarcoplasm increases
for the development of the next PD.
This mechanism works when
physical activity, when due to heart rate and
contraction force is growing UO and IOC.
This is the (+) chronotropic effect
Influence of ions
Decreased concentration of ions in the bloodleads:
Na - bradycardia.
K - tachycardia,
Ca - bradycardia
Increase in ions in the blood:
Na - bradycardia.
K - bradycardia, and with a double
increase - even cardiac arrest,
Sa - tachycardia
Influence of nerves
Sympathetic nerves - exert on the heart(positive effects)
Parasympathetic nerves [negative
effects]
Chronotropic effect (frequency of contractions)
Inotropic effect (strength of contractions)
Dromotropic effect (conductivity)
Bathmotropic effect (excitability) Sympathetic and parasympathetic innervation of the heart
Mechanisms of influence of mediators
ACh interacting with M-receptorsa) - inactivates Ca ++ channels,
b) - activates K + channels.
NA interacting with -receptors -
activates Ca++ channels and
enhances myocardial contractions.
effects
Norepinephrinepositive
dromotropic,
2. bathmotropic,
3. chronotropic
4. inotropic
1.
acetylcholine:
negative
1. dromotropic,
2. bathmotropic,
3. chronotropic
4. inotropic
Reflex regulation
ALLOCATE:intracardiac reflexes,
Extracardiac reflexes.
Intracardiac reflexes are carried out:
Through intracellularmechanisms.
Through intercellular
interactions.
through cardiac reflexes.
Innervation of the heart
The centers of reflex regulation of blood circulation belong to the ANS
The main centers are inmedulla oblongata.
a) sensory center (impulses arrive here
from receptors)
b) depressor center
(parasympathetic nerve - vagus),
c) pressor center - (sympathetic
fibers).
The relationship between the pressor and depressor centers.
Reciprocal interaction of centersthing is:
excitation of the pressor department inhibits
depressive and vice versa.
As a result: depressor department through n.
vagus weakens the work of the heart, and through
inhibition of the sympathetic centers of the spinal
brain - dilates blood vessels.
Pressor department through sympathetic centers
stimulates the heart and constricts
vessels.
Reflexes from receptors
Baroreceptors:Perceive
pressure,
vasodilatation
and blood volume)
Chemoreceptors:
blood pH,
CO-2 content and
O-2 in the blood.
Major reflexogenic zones and afferent nerves
1. Aortic arch -n.depressor
in
composition
wandering
nerve
2. Carotid
sinus sinus
nerve in
glossopharyngeal
nerve
The value of reflexes on the heart
Irritation of baroreceptors with an increaseBP through n. vagus reduces heart rate and cardiac output (BP
decreases).
Decreased pressure in the aortic arch leads to
an increase in heart rate and an increase in blood pressure.
Irritation of chemoreceptors during hypoxia (pH
blood) through the sympathetic nerve stimulates
work of the heart - IOC increases, blood flow
is improving.
Neurogenic regulation of CVS
Together withheart always
conjugate
turns on and
vascular
system.
Mechanisms of regulation of vascular blood flow
Object of influence -SMOOTH MUSCLES
(phasic and tonic)
Mechanical
incentives
Humoral
incentives
Neural Influences
Mechanical stimuli
The effect of changing the internal volumeblood to the smooth muscle of the vessel wall
With a rapid increase in volume
With a slow increase
reduction
relaxation
Normal state of blood vessels - vascular tone
Vascular tone -degree of active
vascular tension
walls
Vascular or basal tone
Basal tone is created:the response of smooth muscle cells to
blood pressure,
- the presence of vasoactive substances in the blood
compounds,
- tonic impulses of sympathetic
nerves
(1-3 imp./s).
Basal tone
Made up of myogenictone and stiffness
vascular wall,
properties
collagen fibers.
Myogenic tone
Smooth muscles of blood vessels1. Have automatism
2. Capable of long lasting
tonic contractions
3. Momentum excitation easily
is spreading through
nexuses
Humoral regulation of the heart
Acetylcholine has a negative inotropic,chronotropic, bathmotropic, dromotropic and
actions.
Norepinephrine, epinephrine, dopamine - positive
ino-, chrono-, batmo, dromotropic action.
thyroxine and triiodothyronine - positive
chronotropic effect.
Calcium ions are positive inotropic, chronotropic and bathmotropic effects; overdose
causes cardiac arrest in systole.
Potassium ions - high concentrations cause
negative bathmotropic and dromotropic
actions; overdose causes stop
Influence of factors formed locally (modulators of influences)
Currently great attention givenlocal mediators of vascular regulators
tone: factors that are formed in the endothelium
vessels.
EGF - endothelial relaxation factor,
EPS - (endothelin) - vascular contraction factor,
Prostaglandins - increase permeability
membranes for K +, which leads to expansion
vessels.
Reflex regulation
nerve center of the medulla oblongatasympathetic nerves regulate:
Influencing arterioles - the level of blood pressure,
Affecting the veins - the return of blood to the heart.
NA interacts with -, -adrenergic receptors.
C - narrowing of the vessel,
C is an extension.
In various vessels, the ratio of these
receptors are different! Means different
Effect!
Nerve centers for regulation of vascular tone
Spinal level - centers located inlateral horns C8 - L2 of the spinal cord
(sympathetic neurons)
Bulbar level - main vasomotor center(pressor department and depressor
Department)
Hypothalamic level - regulation of blood pressure during
emotions and various behavioral responses
Cortical level - regulation of vascular
responses to external stimuli
Humoral regulation
Vasoconstrictor substances:norepinephrine, epinephrine, vasopressin,
serotonin, angiotensin II, thromboxane
Vasodilators:
acetylcholine, histamine, bradykinin,
prostaglandins A, E, products
metabolism: CO2, lactic acid,
pyruvic acid
Peripheral receptors
Blood vessel receptors:Baroreceptors - register pressure
(ratio of vascular tone and volume
blood).
Chemoreceptors - pH (tissue trophism).
The atria and vena cava have
stretch receptors (provided
venous return response)
Vascular receptors
Mainbaroreceptors
located in the aortic arch
and in the carotid sinus.
in the carotid sinus
located and
chemoreceptors,
who control
PO2 blood,
entering the brain.
In addition, receptors
are available in many
other departments
vascular system. Normal frequency
impulses in
baroreceptors
increases
proportionately
BP starting from 80
up to 160 mm. rt. Art.
When overcoming
this level
addiction
disappears.
Conjugated regulation of CCC
The most importantregulated
parameter of the whole
CCC is
blood pressure level in
major
vascular areas.
For this
leading
receptors
are
baroreceptors.
Chemoreceptors are excited
with a decrease in the level of PO2 in
arterial blood and
an increase in pH (H+), which
depends on blood levels
underoxidized metabolites.
Reflexes with them, through
sympathetic influence
nerves, increase UV.
Simultaneously locally
blood vessels dilate
improves blood supply
tissues (HA+ receptors).
Intracardiac reflexes
Regulation through intramuralganglia of the heart.
In the very heart there are all structures
for reflex: receptors,
afferents, ganglia
and efferents.
Examples of intracardiac reflexes:
A - increased blood flow to
right atrium - enhances
contraction of the left ventricle
small filling it).
B - with a large filling of it
increased blood flow to the right
atrium - reduces contraction
left ventricle.
Changes in cardiac filling and output when various regulatory mechanisms are turned on
Capacity andstomach volumes.
The increase in heart rate occurs
due to a decrease in total diastole.
Therefore, with a significant
increase in heart rate to the ventricle
less blood flow
SV decreases (see figure on the left)
But with a significant increase
The heart rate drops slightly
systole duration.
An example of coupled regulation of the heart and blood vessels to compensate for the increase in blood pressure
When changing the position of the body, it is necessary to compensate for the effect of hydrostatic pressure in the veins:
Orthostatic reflex: transition fromhorizontal state to vertical.
Normally, there is an increase in heart rate by 624/min. This is due to the fact that under
influence of hydrodynamic pressure
Initially, there is a decrease in blood return to the heart.
therefore, the SV decreases. Reaction
baroreceptors of the aortic arch through
sympathetic influence leads to growth
heart rate.
Clinostatic reflex: (reverse
effect) - decrease in heart rate by 4-6 / min