Cardiovascular and respiratory systems Flashcards
Cardiac output = ? x ?
Heart rate x stroke volume
What is the average resting value for heart rate?
72 bpm
What is the resting value for stroke volume?
70 ml
What is the resting value for caridac output?
5 l/min
A resting heart rate belown 60 bpm is known as?
Bradycardia
Name the 3 stages of the cardiac cycle?
- Atrial systole
- Ventricular systole
- Diastole
Which part of the conduction system generates the electrical impulse?
SA node
The AV node d_____ the electrical impulse by 0.1 seconds
delays
What is the role of the Bundle of His?
Splits electrical impulse into 2
Where do the Bundle Branches carry the electrical impulse to?
base of ventricles
The p________ f______ distribute the electrical impulse through the ventricles causing ventricular systole.
purkinje fibres
Name the 5 venuous return mechanisms?
- Pocket valves
- Smooth muscle
- Muscle pump
- Respiratory pump
- Gravity
Define vascular shunt
The redistribution of blood around the body
The _________ and ___ ________ __________ vasodilate and vasoconstrict at working muscles or non essential organs
arterioles and pre capillary sphincters
What regulates (controls) the vascular shunt mechanism?
VCC (Vasomotor Control Centre)
Where receptors does the VCC receive information from?
Chemoreceptors and baroreceptors
During exercise ?% blood flow goes to the working muscles and ?% blood flow goes to the non essential organs
80, 20
What controls heart rate regulation?
CCC (Cardiac Control Centre)
Name the three neural receptors that give information to the CCC?
Chemoreceptors, proprioceptors, baroreceptors
Increased body temperature and increased venous return are two in_________ receptors
intrinsic
What is the one hormonal receptor?
adrenaline
What are the four receptors that give information to the RCC (Respiratory Control Centre)?
- Proprioceptor
- Baroreceptor
- Chemoreceptor
- Thermoreceptor
Which muscle does the phrenic nerve cause to contract?
Diaphragm
The intercostal nerve causes the ? to contract
External intercostal muscles
Define breathing rate?
Number of inspirations/expirations per minute
_____ _______is the volume of air inspired/expired per breath
Tidal volume
Define minute ventilation?
volume of air inspired/expired per minute
What are the resting values and maximal values for breathing rate (breaths/min)
12-15, 50-60
? ml is the resting value for tidal volume and ? litres is the maximal value
500, 3-3.5
6-7.5 l/min is the resting value for what?
Minute ventilation
Which muscles contract during inspiration at rest?
Diaphragm and external intercostals
The ribs move ? and ? during inspiration at rest
up and out
What happens to the volume of the chest cavity during inspiration, during exercise
Increase more than at rest
What happens to the pressure in the lungs during inspiration, during exercise?
Decreases more than at rest
What extra muscles are used for inspiration during exercise?
Sternocleidomastoid, pectoralis minor
Expiration at rest is a ? process
Passive
Which muscles are involved in expiration during exercise?
- Diaphragm & EICs relax more than at rest
- Internal intercostals contract
- Rectus abdominus contract
What happens to the movement of the rib cage during expiration at rest?
down and in
What happens to the volume of the chest cavity and pressure in the lungs during expiration at rest.
decreases, increases
What is the memory hook for mechanics of breathing?
MMVP
Muscles
Movement
Volume
Pressure
External respiration is at what site in the body?
lungs
Internal respiration is at what site in the body?
muscles
All gases move from an area of ____ partial pressure to an area of ___ partial pressure
High, low
What is the memory hook for gaseous exchange?
Gas
Area
Special rule
Partial pressure
Diffusion
Diffusion gradient
The bohr shift is a shift to the ? on the oxyhaemoglobin dissociation curve.
right
An increase in ?, ?, ?, and a decrease in ? Causes more CO2 to be released (dissociated) from haemoglobin causing a steeper diffusion gradient
CO2, blood and muscle temperature, lactic acid, pH
