Anatomy and Physiology 1.1b Flashcards
Cardiovascular System?
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Passage of Blood Through Heart?
1) Superior Vena Cava
2) Right Atrium
3) Tricuspid Valve
4) Right Ventricle
5) Semi-lunar Valve
6) Pulmonary Artery
7) Lungs
8) Pulmonary Vein
9) Left Atrium
10) Bicuspid Valve
11) Left Ventricle
12) Semi-lunar Valve
13) Aorta
14) Body
SA Node?
Generates Electrical Impulses - atria walls contract
AV Node?
Collects impulse and delays by 0.1 seconds
Bundles of His?
Located in the Septum - splits impulse into two
Bundle Branches?
Carry impulse to base of ventricle
Purkinje Fibres?
Distribute the Impulse through Ventricles - Contract
Heart Rate (HR)?
Number of Times the Heart Beats Per Minute - 72bpm
Stroke Volume (SV)?
Amount of Blood ejected from left V per HB - 70ml
Cardiac Output (CO)?
Amount of Blood pumped out of LV per Min - 5L/min
Bradycardia?
A resting Heart rate below 60bpm
Maximum Heart Rate?
220 - Age = HRmax (bpm)
Stroke Volume Response to Exercise?
- Increases until Plateau - 40-60% working capacity
- Occurs during sub-maximal intensity
Why does SV plateau during Sub Maximal Exercise?
- Due to it allowing time for Ventricles to fill
- Maximal Energy does not allow this
Why is SV able to increase?
- Increased Venous Return
- Starling’s Law
What is Starling’s Law?
- Increased Venous Return leads to Increased SV
- Due to an increased Stretch in Ventricle Walls
What is Venous Return?
-The return of the blood to the right atria through the veins
What is the Cardiac Control Centre (CCC)?
- Responsible for regulating the heart beat
- Controlled by autonomic nervous system
- Located in Medulla Oblongata
Three types of factors which control CCC?
Neural, Intrinsic and Hormonal
Types of Neural Control?
Proprioceptors, Chemoreceptors and Baroreceptors
Function of Proprioceptors?
- Inform CCC that movement has increased
- Located in Muscles, tendons
Function of Chemoreceptors?
- Detect decrease in blood pH due to inc. in lact. + co2
- Located aorta and arteries
Function of Baroreceptors?
- Inform CCC of increased in Blood pressure
- Located in Blood Vessel Walls
2 Types of Intrinsic Control?
Temperature and Venous Return
How does temp effect Intrinsic control CCC?
The changes will effect blood viscosity and speed of nerve impulses
How does Venous Return effect Intrinsic control CCC?
Affect stretch of Ventricle Walls causing increase in SV
Type of Hormonal Control
Nor/Adrenaline
What is Nor/Adrenaline for CCC?
Released from Adrenal Glands and increase SV and HR
Parts of the Vascular System?
- Arteries and Arterioles
- Capillaries
- Veins and Venules
Function of Arteries?
- Carry Oxygenated Blood to muscles and organs
- Contain Blood under high pressure
- Large layer of smooth muscle and elastic tissue
Function of Arterioles?
- Distribute blood to capillaries
- Ring of Smooth Muscle
5 Venous Return Mechanisms?
- Pocket Valves
- Smooth Muscle
- Gravity
- Muscle Pump
- Respiratory pump
Function of Pocket Valves?
-Located within veins and prevent backflow of blood
Function of Smooth Muscle?
- Within wall of vein
- helps venoconstrict pushing blood back to heart
Function of Gravity?
-Blood from upper body aided by Gravity
Function of Muscle Pump?
-Muscle pumps squeeze on veins and help blood back towards heart
Function of Respiratory Pump?
- Helps return blood back to thoracic cavity and abdomen back to heart
- Helps change pressure in thorax when breathing
Function of Capillaries?
- One Cell thick
- Gas exchange takes place
- Oxygen into vessels > < Carbon Dioxide into Capillaries
Function of Veins?
- Carry Deoxygenated blood - have thin walls
- Smaller layer of smooth muscle allowing them to Venoconstrict
