lecture 2 ch 19 Flashcards
Describe the three layers of a vessel: tunica intima/interna, tunica media, and tunica externa/adventitia.
Tunica Interna on a vein is smaller than on an artery, tunica media on an artery is bigger than on a vein, and tunica externa is bigger on a vein than on an artery
What primary tissue is each layer made of?
Tunica externa-smooth muscle, Tunica Media- elastic fiber, Tunica Interna- simple squamous Endothelium
Which layer requires vaso vasorum and why?
Tunica Externa because it needs protection from rupturing due to external forces.
Direction of blood flow
Arteries carry blood away from the heart veins carry blood to the heart
Tissue layers present and relative thicknesses for each vessel types How is this related to function of vessel?
Tunica media is thicker on veins and veins are also smooth while Arteries are rough
Special features such as valves, single layer of cells, which layers are present, etc.
How is this related to function of vessel?
Arteries do not have valves while veins do because veins bring blood back to the heart.
Describe the three types of arteries
distributing: Brain, Head, Face, Neck Resistance: Heart alters resistance small narrow arteries Elastic: Throughout body maintains pressure
Describe the three types of capillaries.
Continuous- Not gap(valves) bodily tissues fenestrated-(valves) kidneys, endocrine glands, pancreas sinusoidal-proteins, blood flow is large liver, spleen, lymph nodes
How do systemic veins function as a blood reservoir/capacitance vessels?
Because of their ability to expand and store a high volume of blood
Why do veins have valves – where are those veins found in the body?
veins carry blood back to the heart so to prevent back flow they have valves. These valves are found on the limbs or the farthest parts away from the heart
What is a venous sinus and where are they found?
the venous sinus is the collection of veins in the cranial cavity between the dura mater
Explain the relationship between blood vessels and lymphatic vessels
Blood vessels circulate oxygen throughout the body while the lymphatic system drains waste form tissues it also moves WBCs
Lymph vessels resemble veins – how are they alike?
Lymph vessels have valves and they are low pressure
How and why does blood pressure change with vessel size and distance from the heart?
The longer the vessel the thinner it gets as It goes away from the heart as the vessel gets thinner resistance increases and blood flow decreases
Be able to explain why pressure decreases from elastic arteries to capillaries to large veins at heart
The pumping of the ventricles (Ventricular Contraction) causes blood to flow from areas of high pressure to areas of low pressure
Identify/describe the two factors that determine arterial blood pressure
Arterial pressure is determined by the kidney Excess fluid causes the pressure to rise low fluid causes the pressure to drop the what determines it is the volume of renal output and the amount of salt and water in
the system
Define systolic and diastolic blood pressure
systolic is going back to the heart =contraction diastolic=relaxation
What are Korotkoff sounds, and what are normal levels for systolic and diastolic blood pressures?
What are the dangers of high BP and low BP -Korotkoff Sounds are the sounds you listen for when taking blood pressure. Normal pressures are- Systolic: 120 mm Hg, Diastolic: 80 mm Hg. Dangers of High and low BP: High BP can cause heart disease strokes and fatal consequences Low BP can cut off blood supply to organs leading to shock this can be caused by blood loss.
What factors (5) contribute to venous return?
inspiration, increased total blood volume, increased venomotor tone, the cardiac suction effect, the presence of venous valves and the skeletal muscle pump
Hydrostatic pressures
Capillary hydrostatic pressure (HPc) – 35 mmHg (arteriole) or 17 mmHg (venule)
Interstitial fluid hydrostatic pressure (Hpif) – 0 mmHg
Colloid osmotic pressures
Capillary colloid osmotic pressure (OPc) – 26 mmHg
Interstitial fluid colloid osmotic pressure (OPif) – 1 mmHg
identify which pressures “push” fluid and which pressures “pull” fluids during capillary exchange
Hydrostatic: Push Osmotic:Pull
Identify where filtration and reabsorption occur in a capillary
Near the arterial end of the capillary
Calculate Net Filtration Pressure (NFP)
NFP = (HPc + OPif) – (HPif + OPc)
