Lecture 10 - Controlling Heart And Blood Pressure Flashcards
Which is higher pulmonary or systemic
Systemic
The left ventricles generates pressure for…
… the systemic circulation
What is the high blood pressure on the large systemic arteries linked to?
Ventricular contraction and ejection of blood
Describe the high blood pressure in the large systemic arteries
- pulsatile in major arteries (systolic/ diastolic)
What is the main critically important factor to determine of blood flow?
Mean arterial blood pressure (MAP)
Your blood fluctuates between a maximum _____ pressure and a minimal ______
Systolic
Diastolic
What determines blood flow
Mean arterial blood pressure
Amount of filling in pipes in our pipes is related to…
Election of blood
Blood pressure is ____ in major arteries
High (and oscillatory)
Blood pressure ______ steeply across the arterioles, capillaries and venules. ______ is also reduced
- falls
- oscillatory nature is also reduced
Most of your blood at any one time is in your _____ system
Venous
Blood pressure is very _____ in veins
Veins
What greates a driving force for blood flow?
- the large !!!difference!!!! in pressure between the arterial and venous sides
Pressure graph
What is haemodynamics?
- how blood flows in a single vessel
Equation for flow
Flow = pressure difference / resistance
Q= ^P/R
Flow is directly dependent on____ but inversely dependent on _____
Difference in pressure NOT ABSOLUTE
Resistance
Equation for mean arterial pressure
MAP = Q X R
(Assumed the difference between arterial pressure and vascular pressure is just mean arterial pressure - assume no pressure by the time of vena cava - so its arterial pressure minus zero which equals MAP)
Ejection of blood into the arterial system maintains _________ and ___________
- arterial blood volume
- arterial blood pressure
When blood flows in:
- fills arteries
- increases arterial blood volume
- raises arterial pressure
When blood flows out:
- drains arteries
- decreases arterial blood volume
- lowers arterial pressure
Pressure in arteries depends on
How much we put in and how much we put out ??
Veins / arteries hold more volume
Veins
Arterial blood volume and pressure are determined by:
- a balance between ‘blood flow in’ and ‘blood flow out’
(Blood flow is determined by resistance?)
Cardiac output and arterial resistance affect _______
Blood pressure
What is ‘blood flow in’ determined by?
- ventricular contraction
- ejection of blood
- CARDIAC OUTPUT (how much is put in (L/time))
(FLOW)
What is ‘blood flow out’ determined by?
- capillary flow
- controlled by resistance of the arteries
(RESISTANCE)
Can control pressure by putting more in or letting less out
True and real
- either of these things will increase volume and increase pressure
What is the goal?
- mean arterial pressure
Arterial pressure equation
Arterial pressure = cardiac output X total peripheral resistance
MAP = CO X TRP
Arterial
Cardiac output is determined by
- stoke volume
- heart rate
Equation for cardiac output
Cardiac output = strove volume (amount pumped out) (contraction strength) X heart rate (contraction speed/rate)
CO = SV X HR
Cardiac output: (L/min)
Stroke volume (L/beat)
Heart rate (beats/min)
Diagram of stroke volume
Two approaches for meeting the stroke volume vs heart rate in ANIMALS
Mouse: small stoke volume but high heart rate
Whale: big stoke volume but low heart rate
Stroke volume vs Heart rate: healthy heart v Failing heart
For homeostasis of arterial blood pressure, what is tightly regulated
Mean arterial pressure - within a narrow range
Can maintain arterial blood pressure homeostasis by maintaining :
- heart (cardiac output)
- blood vessels (vascular resistance)
How homeostasis is coordinated with the brain stem
- afferent input from both the CNS and ‘periphery’
- efferent output to heart and vessels (controls heart rate, stoke volume, TPR)
Harvesting information about physiological state and blood pressure and have afferent outputs to maintain homeostasis
Brain shit
What are baroreceptors ?
Blood pressure sensors
Where are baroreceptors found
Arch of aorta (checks pressure for rest of body)
Carotid arteries (checks pressure on way to brain)
Baroreceptors are
Tonically active
Neural control of cardiac output VERY IMPORTANT CARD
- harvesting information about mean arterial pressure from baroreceptors
- feeding it into the brain stem (afferent)
- two different outputs: depending on if BP is too high or low
- break output - reducing BP by reducing CO (by slowing heart rate) (parasympathetic)
VAGUS nerve feeds into Heart at SA node and AV node - accelerator output - increasing BP by increase stroke volume and heart rate (CO) (sympathetic)
SYMPTATHETIC CARDIAC nerve feeds into SA node and ventricular muscle to make it pump harder - increasing stroke volume and heart rate
- break output - reducing BP by reducing CO (by slowing heart rate) (parasympathetic)
- these nerves don’t tell it to beat - SA node is spontaneous - only to increase or decrease activity
BAROREFLEX
Difference between sympathetic and parasympathetic
Sympathetic speed things up
- sympathetic nerve speeds up both rate and ventricular contraction
Parasympathetic slow things down
- VAGUS nerve - just goes to the nodes influencing rate
Beroflelex in a whole body tilt
- reduced blood coming back to heart
- lower stroke volume
- drops cardiac output but not as much as expected because the heart rate goes up
- heart rate goes up to compensate due to equation - sympathetic
- therefore mean arterial blood pressure hardly changes as CO has dropped a little bit, but TPR increases (squeezed vessels) to compensate
Cardiac output is
Blood leaving the heart ( L/min)
Cardiac output is determined by
Stroke volume and heart rate (CO = SV x HR)
When is cardiac output increased
During exercise
Blood pressure is sensed by_____ and controlled by ______ via ________
Blood pressure is sensed by baroreceptors and controlled by changes to cardiac output via efferent signalling from the brain
- parasympathetic signalling through the vagus nerve slows heart rate
- sympathetic signalling through the sympathetic trunk ganglion speeds heart rate and increases stroke volume
Definintioin of lymphatic
The smallest vessels of the lymphatic system commence as large, blind ending capillaries that are thin walled, contain no RBC’s, and have valves.
Definition of cisterns Chyri
E N L A R G E D T E R M I N U S O F T H E T H O R A C I C D U C T T H A T R E C E I V E S L Y M P H F R O M T H E D I G E S T I V E VISCERA
Left and right side drainage
ALL of the LEFT side (+
Cervical nodes (neck)
EVERYTHING below the belly
button)
- Drains into the cisterna chyli Axillary nodes (underarms)
- Then into the left thoracic duct - Then into the left subclavian
vein
Some of the RIGHT side (hip + above)
- Drains into the right lymphatic
Inguinal nodes (groin)
duct
- Then into the right subclavian
vein
Lymphatic drainage of the breast explanation
• Lymphatic vessels of the
breast collect lymph, this
travels to the Axillary Nodes
and then the right lymphatic
duct to the right subclavian
vein into the blood vascular
space • Breast tissue lymphatic
drainage can carry cancer cells
into the blood vascular system
causing Metastatic cance
Sentinel node is most likely to be effected by cancer is breast
Idk bro
