Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
25 Cards in this Set
- Front
- Back
|
Baroreceptors (define) |
Pressure receptors stimulated by high/low pressure |
|
|
Where is the brain stem |
Back (Definition) |
|
|
Where is the medulla oblongata found |
In the brain stem |
|
|
Where is the brain stem |
Back (Definition) |
|
|
Function of medulla oblongata |
Controls breathing rate & heart rate |
|
|
Why does heart rate increase during exercise? |
To deliver oxygen & glucose to the muscles faster > movement & remove carbon dioxide by breathing out quicker |
|
|
Chemoreceptors |
Monitor the oxygen level in the blood & also the carbon dioxide and pH level (which are indicators of the o2 lvl) |
|
|
Aortic bodies |
Clusters of cells in the aorta |
|
|
Carotid bodies |
Clusters of cells in the carotid arteries |
|
|
Where is the carotid artery |
On either side of the neck |
|
|
How is breathing rate controlled? (Process) GENERAL |
1. Inspiratory centre sends nerve impulse to intercostal & diaphragm muscles > causes them to contract 2. Air enters lungs due to pressure difference between lungs & air outside 3. As lungs inflate, stretch receptors stimulated > nerve impulse sent to medulla oblongata > inhibit action of inspiratory centre 4. Expiratory centre sends nerve impulses to diaphragm & intercostal muscles to relax > lungs deflate > stretch receptors become inactive |
|
|
Define ventilation rate |
volume of air breathed in/ out during a period of time (ventilation rate = tidal volume x breathing rate) |
|
|
Cardiac output (equation to calculate) |
Cardiac output = heart rate x stroke volume |
|
|
Why does aerobic respiration increase during exercise? |
Muscles contract ^ frequently > use more energy > energy gained through respiration |
|
|
Baroreceptors (define) |
Pressure receptors stimulated by high/low pressure |
|
|
Where are baroreceptors found |
In the aortic and carotid bodies |
|
|
Why does ventilation rate increase with exercise ? |
^ during exercise as breathing rate and depth increase |
|
|
Where are chemoreceptors found |
In the aortic and carotid bodies & the medulla oblongata |
|
|
Role of sensory neurons |
Send electrical impulses from receptors to the medulla oblongata |
|
|
Role of cardiovascular control centre |
processes the info > controls rate at which SAN fires controls heart rate and stroke volume (& so cardiac output) |
|
|
Role of nervous system |
• 2 main elements: sympathetic & parasympathetic nervous system • SNS - prepares body for action > ^ HR during exercise > prepares body for ‘flight/fight’ • pSNS - calms body > decreases HR after exercise > ‘rest & digest’ system |
|
|
General response to environmental change (/stimulus) |
1. Receptor detects change • baroreceptor - BP • chemoreceptor - o2 lvl 2. Sensory neurone sends electrical impulse to medulla oblongata 3. Cardiovascular control centre sends impulse to sympathetic/parasympathetic (vagus nerve) neurones 4. pSNS/SNS neurones secrete neurotransmitter • acetylcholine = HIGH • noradrenaline = LOW 4. Neurotransmitter binds to receptors on SAN > SAN fires less/more 5. Increase/decrease = back to normal |
|
|
Response to low blood pressure |
1. Baroreceptors detect low Bp 2. Impulse sent to cardiovascular control centre (in medulla oblongata) > sympathetic neurones 3. Neurones secrete noradrenaline > binds to receptors on SAN 4. SAN fires impulses ^ frequently to ^ HR & BP (back to normal) |
|
|
Response to high o2/ low co2/ high pH |
1. Chemoreceptors detect chemical change in blood 2. Impulse sent to cardiovascular control centre > impulse to parasympathetic neurones 3. Neurones secrete acetylcholine which binds the receptors on the SAN 4. SAN fires impulses less frequently > HR & BP decreases (Return back to normal) |
|
|
Where is the cardiovascular control centre? |
In the medulla oblongata |
