Mastering Cardiovascular and Respiratory Regulation

• Human Regulation and Reproduction
• Further Education (Key Stage 5)

Mastering Cardiovascular and Respiratory Regulation

Learning Objective

Understand the intricate mechanisms of cardiovascular and respiratory system regulation.

00:00

What is an action potential?

00:33

Depolarization in an action potential refers to the change in membrane potential towards a more positive value.

1. Correct
2. Depolarisation is unrelated to membrane potential
3. Depolarisation is a change toward a more negative value
4. Incorrect

01:20

What type of channel allows the depolarisation of an action potential?

00:40

what types of synaptic neurons are at each side of the synaptic cleft?

01:00

What causes the vesicles to release the neurotransmitters?

What do you already know about the regulation of the cardiovascular and respiratory systems?

Changes in Oxygen and Carbon Dioxide Concentrations

Tightly regulated to ensure the proper functioning of the various physiological processes. 

Changes in Oxygen and Carbon Dioxide Concentrations

Oxygen concentrations

Breathing Process:

Inhalation: Air with oxygen is drawn into the lungs.

Exchange in the Lungs: Oxygen diffuses into the bloodstream in the alveoli.

Transport in Blood:

Binding to Haemoglobin: Oxygen binds to haemoglobin in red blood cells.

Systemic Circulation: Oxyhaemoglobin is transported to tissues and organs.

Cellular Respiration: 

Oxygen utilisation: Cells use oxygen in cellular respiration to produce energy (ATP).

Carbon Dioxide (CO2) Production: 

Metabolism: Carbon dioxide is produced during cellular metabolism.

Changes in Oxygen and Carbon Dioxide Concentrations

Carbon Dioxide concentrations

Cellular Respiration:

Metabolic Processes: Carbon dioxide is produced as a byproduct.

Transport in Blood:

Dissolution and Binding: Carbon dioxide is transported in various forms in the blood.

Bicarbonate Formation: Majority converted to bicarbonate ions in red blood cells.

Return to the Lungs:

Circulation: Bicarbonate ions transported back to the lungs.

Exhalation:

Exchange in the Lungs: Carbon dioxide is exchanged for oxygen.

Exhalation: Carbon dioxide is expelled from the body.

What is a chemoreceptor?

1. Detects changes in pressure
2. Detects changes in chips
3. Detects changes in potatoes
4. Detects changes in chemical composition

Role of Chemoreceptors and Baroreceptors

Role of Chemoreceptors and Baroreceptors

Chemoreceptors

Two types: Peripheral and Central 

Functions: Oxygen sensing and Carbon Dioxide sensing

How does this tie in with the respiratory system? 

- Chemoreceptors send signals to the respiratory centres in the medulla, influencing the rate and depth of breathing. 

Role of Chemoreceptors and Baroreceptors

Baroreceptors: 

Location: Carotid sinus and aorta

Functions: Blood pressure regulation and vasoconstriction (low pressure)/dilation (high pressure)

Baroreceptor signals are sent to the cardiovascular centre in the medulla, influencing heart rate, stroke volume and vascular resistance. 

Role of Chemoreceptors and Baroreceptors

Baroreceptors: 

Baroreflex mechanism 

Heart rate and vessel 

dilation

Gaseous Exchange at Tissues and Alveoli

Draw a picture of the process of gaseous exchange at the tissue and alveoli level.

You have 10 minutes. 

Add a photo of the picture on the next slide.  

Upload your gas exchange image here.

Autonomic Nervous System

Sympathetic Nervous System (SNS): Flight or fight

Parasympathetic Nervous System (PNS): Rest and digest

Activation

Stressful situation: SNS activated in response to stress, danger or emergencies

Fight or flight: Prepared the body for action

Cardiovascular Effects

Increased heart rate (Tachycardia): Improves blood flow to vital organs

Vasoconstriction: Redirects blood to essential areas

Hormonal Influence

Release of Epinephrine and Norepinephrine. Enhances the SNS response.

Impact on Respratory system

Bronchodilation: Increases oxygen intake for heightened alertness

Activation

Relaxation and recovery: PNS dominated during restful periods

Post-stress adaptation: Returns the body to a state of balance

Cardiovascular Effects

Decreased heart rate (Bradycardia): Conserves energy during periods of calm.

Vasodilation: Promotes relaxation and optimal blood flow

Neurotransmitter

Acetylcholine: Key neurotransmitter for PNS activities

Impact on Respiratory System

Normalises respiratory rate: Supports a calm and controlled breathing pattern

Achieving Homeostasis

Dynamic Interaction:

Constant Adjustment: The ANS maintains cardiovascular and respiratory balance through the dynamic interaction of SNS and PNS.

Cardiovascular Homeostasis:

Blood Pressure Regulation: SNS and PNS work in tandem to adjust blood pressure as needed.

Respiratory Homeostasis:

Respiratory Rate Control: The ANS ensures appropriate breathing rates for different situations.

Impact on Overall Health:

Adaptive Responses: ANS adaptations support overall health and physiological well-being.

Role of Medulla Oblongata

Explain the coordination role of the medulla oblongata in regulating the cardiovascular and respiratory systems.

Create a spider diagram, covering cardiovascular and respiratory regulation, as well as the overall integration

The medulla oblongata is a crucial part of the brainstem, and it plays a central role in regulating essential autonomic functions, including those related to the cardiovascular and respiratory systems. The medulla oblongata contains nuclei that serve as vital control centers, influencing various physiological processes to maintain homeostasis. Here's a breakdown of its functions in regulating the cardiovascular and respiratory systems:

Cardiovascular Regulation:

Heart Rate (Chronotropic Control):

The medulla oblongata contains the cardiac center, which consists of the cardioaccelerator and cardioinhibitory centers.

Cardioaccelerator Center: Activates sympathetic neurons to increase heart rate (positive chronotropic effect).

Cardioinhibitory Center: Activates parasympathetic neurons to decrease heart rate (negative chronotropic effect).

Stroke Volume (Inotropic Control):

The medulla oblongata influences stroke volume (the amount of blood pumped by the heart in one contraction).

Sympathetic stimulation enhances contractility, leading to an increased stroke volume.

Blood Vessel Diameter (Vasomotor Control):

The vasomotor center in the medulla regulates the diameter of blood vessels (vasoconstriction or vasodilation).

Sympathetic activation causes vasoconstriction, increasing blood pressure.

Parasympathetic influence on blood vessels is limited compared to the sympathetic influence.

Respiratory Regulation:

Breathing Rate (Respiratory Rhythm):

The medulla oblongata contains the respiratory center, which includes the dorsal respiratory group (DRG) and the ventral respiratory group (VRG).

Dorsal Respiratory Group (DRG): Initiates inspiration (inhalation).

Ventral Respiratory Group (VRG): Involved in both inspiration and expiration.

Chemoreceptor Response:

The medulla senses changes in blood pH, carbon dioxide (CO2), and oxygen (O2) levels through chemoreceptors.

Elevated CO2 levels stimulate increased ventilation (via increased respiratory rate and depth) to remove excess CO2 and restore pH balance.

Integration with Autonomic Nervous System:

The medulla oblongata integrates signals from both the sympathetic and parasympathetic divisions of the autonomic nervous system to coordinate respiratory and cardiovascular responses.

Overall Integration:

Baroreceptor Reflex:

The medulla oblongata integrates signals from baroreceptors (pressure-sensitive receptors) to regulate blood pressure.

Baroreceptor reflexes involve changes in heart rate, stroke volume, and blood vessel diameter to maintain blood pressure within a normal range.

Integration of Reflexes:

The medulla integrates various reflexes, including the baroreceptor reflex and chemoreceptor reflex, to coordinate responses that maintain overall cardiovascular and respiratory homeostasis.

In summary, the medulla oblongata is a vital control center in the brainstem that regulates heart rate, stroke volume, blood vessel diameter, breathing rate, and responses to changes in blood chemistry. It integrates signals from various receptors and plays a key role in maintaining the balance of the cardiovascular and respiratory systems to support overall physiological stability.

Spider Diagram Images

Elasticity of Blood Vessels

Examine how the elasticity of blood vessels relates to their function in cardiovascular regulation - Practical - To be carried out next week. 

Control of Heart Rate

Analyze the role and action of the sinoatrial and atrioventricular nodes, Bundle of His, and Purkinje fibres in controlling heart rate.

Control of Inspiration, Expiration, and Ventilation Rate

Investigate the changes in contraction and relaxation of diaphragm and intercostal muscles, and the relative air pressure changes during breathing.

Balloons!

Write down 3 things you learned in this lesson.

Have students enter three things they learned in this lesson. With this they can indicate their own learning efficiency of this lesson.

Write down 2 things you want to know more about.

Here, students enter two things they would like to know more about. This not only increases involvement, but also gives them more ownership.

Ask 1 question about something you haven't quite understood yet.

The students indicate here (in question form) with which part of the material they still have difficulty. For the teacher, this not only provides insight into the extent to which the students understand/master the material, but also a good starting point for the next lesson.