Blood Vessels P 2 and Hemodynamics

Question 1

What are 3 Factors that affect resistance (peripheral resistance- outer area!

Answer 1

Blood viscosity- Viscosity is directly proportional to resistance.
Total blood vessel length- Size of a person is directly proportional.
Average blood vessel radius- changes due to vasoconstriction and vasodialation radius is inversely proportional.

Question 2

How do Arterioles play a big role in resistance?

Answer 2

They play a big role in resistance by vasoconstriction and vasodialation as needed to supply blood to specific tissue.

Question 3

What is Venous return?

Answer 3

This is blood returning to the heart via 2 main mechanisms:
Skeletal muscle pump and Respiratory pump.
Sympathetic venoconstriction also helps by reducing the volume of blood in veins.

Question 4

How does Blood Pressure Naturally decrease?

Answer 4

Since pressure decreases as we move away from the heart and its lowest in the vena cava, the pressure difference helps bring blood back to the heart.

Question 5

How does a Skeletal muscle pump work? aka (muscular pump)

Answer 5

Skeletal muscle contraction closes the distal(lower) valve, then blood flows up through a proxinal valve. When valves open blood flows towards the heart. The distal valve opens when skeletal muscle relaxes. Milking action moves blood up against gravity.

Question 6

Howe does a Respiratory pump work?

Answer 6

inhalation and exhalation sets up a pressure differential between the veins of the thoracic cavity, when compared the veins in the abdominal cavity the pressure difference contributes to the movement of blood.
With inhalation: the diaphragm moves down and increases the pressure in the veins of the abdominal cavity. Tpressure in the thoracic cavity decreases. Blood will flow from the abdominal cavity to the thoraci cavity. (High pressure to low pressure)
With exhalation: the opposite is true but the valves prevent backflow of blood.

Question 7

What are the 3 factors to maintaining blood pressure?

Answer 7

Cardiac output (CO), peripheral resistance and blood volume (BV) Blood pressure id directly proportional to blood volume.

Question 8

What is Pulse?

Answer 8

by the contraction of the heart, arteries naturally expand and retract. The recoil can be felt as the pulse if your artery is close to the skins surface.

Question 9

What is Pulse Pressure?

Answer 9

heart rate, apical pulse is the true pulse.

Question 10

What is a sphygmomanometer and what does it read?

Answer 10

its an instrument used to measure blood pressure.
Systolic blood pressure: is the pressure when the first sound is heard, corresponds to ventricular diastole.
Diastolic blood pressure: the pressure when the sound disappear or becomes faint, corresponds to ventricular diastole.

Question 11

Korotkoff sounds

Answer 11

Sounds due to the turbulence of the blood from the partially occluded blood vessel.

Question 12

Hypertension

Answer 12

high blood pressure; either systolic is grater than 130mmHg or diastolic is greater than 90mmHg

Question 13

Pulse Pressure Formula:

Answer 13

pulse pressure = systolic BP - diastolic BP and

MAP = diastolic + 1/3 (pulse pressure)

Question 14

The medulla oblongata is the cardiovascular center f the brain, what receptors is it in charge of? (neural controls)

Answer 14

Baroceptor, chemoreceptors, proprioceptors (monitor movement and body position).

Question 15

Cardiovascular center outputs

Answer 15

sympathetic impulse travel to heart via the cardiac accelerator nerves. parasympathetic impulses travel to the heart via vagus nerves. vasomotor nerves innervate smooth muscle in blood vessels, mostly arterioles. vasomotor tone-regulated by a center in the medulla. it is the state of moderate contraction of blood vessels. Blood vessels that supply the skin and abdominal organs are altered more frequently.

Question 16

Short-term Mechanisms: Neural controls

Answer 16

Neural regulation can also work as a negative feedback loop reflex stimulated by either baroreceptors or chemoreceptors.

Question 17

Baroreceptor reflexes and Chemoreceptor reflexes

Answer 17

Baroreceptor: Carotid sinus reflex- this intrinsic regulatory mechanism regulates blood to the brain. Aortic reflex- this reflex regulates the blood pressure of systemic circuit. The aortic reflexes are especially important in changes of body position.
Chemoreceptor refleses: Hypoxia, acidosis and hypercapina ( high carbon dioxide) Medullary effects: White coat hypertension. Conscious affect of BP.

Question 18

Short term chemical controls

Answer 18

Epinephrine and norepinephrine (adrenal) - both cause vasoconstriction of vessels in the skin and abdominal organs,epinephrine causes vasodialation of the vessels in cardiac and skeletal muscle.
ADH-(antidiuretic hormone), vasoconstiction
ANP- ( atrial natriuretic peptide ) vasodialation
Nitric oxide-vasodialtion
Vasoactive factors- relaesed by blood cells to alter the diameter of vessel.
Vasodilators: potassium, hydrogen ion, lactic acid,adenosine and histamine.
Vasoconstrictors: thromboxane A2, serotonin, superoxide radicals.
Alcohol- initially decreases BP by effectin the vasomotor center, inhibition of ADH, vasodialation itself.

Question 19

Where are veins draining?

Answer 19

Drin into heart by the superior vena cava, inferior vena cava or coronary sinus. The superior vena cava is formed by the brachiocephalic veins.

Question 20

Description of the Brachiochephalic veins (left and Right)

Answer 20

it is formed by the internal jugular and subclavian veins( drains left and right limbs as well as the head and neck. the external jugular veins feed into the subclavian vein. The vertebral vein feeds into the brachiocephalic vein.

Question 21

where does the vertebral vein drain?

Answer 21

it drains the cervical vertebrae, the spinal cord and neck muscles. the external jugular passes over the sternocleidotoid muscle.
The internal jugular runs along side the internal carotid and drains blood from the brain and face. the transverse sinus drains blood from the brain to internal jugular.

Question 22

More about Veins drains

Answer 22

drainage from the upper limb show a pattern similar to arteries with radial, ulnar, and brachial veins.
Aditional vessels: Chephalic vein, basilic vein and median cubital vein. The median cubital vein is a coomon site for the removal of blood. The median cubital vein branches from the cephalic vein and merges with the basilic vein. Brachial and basilic veins merge to form axillary vein and the axillary and chephalic veins merge to form the subclavian vein.

Question 23

Inferior vena cava drainage: leg and thoraci regions.

Answer 23

Hepatic, renal, gonadal and lumbar veins all feed into the inferior vena cava. The inferior vena cava is formed by the merging of the right and left common iliac veins. The lateral vein of the leg, the fibular vein which feeds off of the posterior tibial vein. Tow additions are the great saphenous (medial) and small saphenous (lateal).