what are vessels?
tubes that transport fluid, such as blood or lymph
what is ischemia?
deficiency in the supply of oxygenated arterial blood to a tissue, caused by obstruction of a blood vessel
what is complete and partial blockage?
complete obstruction: leads to death of distal tissue
partial obstruction: causes supply to be insufficient and ischemia may only be apparent with exercise (when O2 needs to increase)
are veins or arteries a low pressure system and why?
veins are low-pressure unlike arteries because they don’t have a pump to generate blood flow. Veins need a mechanism to keep blood moving
what are the 3 mechanisms to keep blood moving?
- the contracting skeletal muscles that move blood proximally toward heart
- the pressure gradient caused by breathing in which inspiration makes the thoracic pressure decrease and abdominal pressure increase
- the intraluminal valves which ensure one direction of blood flow. Each valve is a paired semilunar pocket that opens toward the heart and closes tightly when filled to prevent backflow of blood
what is venous flow?
venous structures have a lower pressure and the diameter is larger and therefore can expand/hold more blood when volume increases. This is a compensatory mechanism to reduce stress on heart. Because of veins ability to stretch, they are called capacitance vessels.
what can cause venous disease internally? and how can this occur?
problems with contraction of skeletal muscles, incompetent valves in the veins, and a non patent lumen. This is causes by prolonged standing, sitting, or bed rest because of the absence of the milking action that walking accomplishes
what is the function of lymphatic vessels?
retrieves excess fluid from the tissues spaces and returns to blood stream
what are the two main trunks where lymphatic vessels drain?
- Right lymphatic duct empties into the right subclavian vein. It drains the right side of the head and neck, right arm, right side of thorax, right lung and pleura, right side of heart and right upper section of liver
- The thoracic duct drains rest of body and it empties into left subclavian vein
functions of the lymphatic system?
A) Conserve fluid and plasma proteins that leak out of the capillaries
B) To form a major part of the immune system that defends body against disease
C) Absorb lipids from intestinal tract
How does the immune system detect and eliminate foreign pathogens (from environment and those arising from inside (abnormal or mutant cells))?
It accomplishes this by phagocytosis (digestion) of the substances by neutrophils and by monocytes or macrophages. Also by production of specific antibodies or specific immune responses by the lymphocytes.
what are lymph nodes?
small oval clusters of lymphatic tissue located at intervals along vessels and they filter fluid before it is returned to the bloodstream and filter out microorganisms that could be harmful to the body
what are lymphocytes?
they are disease fighting cells that defend the body against infection
what are the four functions of the spleen?
Destroy old red blood cells, produce antibodies, store RBC’s, and to filter microorganisms from the blood.
why is the thymus gland important?
important in developing the T lymphocytes of the immune system in children (but serves no function in adults)
where do T and B lymphocytes originate and mature?
originate in bone marrow and mature in lymphoid tissue
what are the developmental considerations for infants and children?
- this system has same function in children as it does in adults.
- lymph nodes are large in children and superficial ones are often palpable even in healthy children
what are the developmental considerations for older adults?
-Peripheral blood vessels grow more rigid with age which results in arteriosclerosis
○ This condition produces the rise in systolic blood pressure
-Atherosclerosis= deposition of fatty plagues on the intima of the arteries
-As a result of the loss of lymphatic tissue, fewer numbers of lymph nodes present in older people and size of remaining nodes decrease
what is the subjective data for peripheral?
- Leg pain or cramps
- Skin changes on arms or legs
- Swelling in arms or legs
- Lymph node enlargement
when is a doppler stethoscope used?
this device is used to
- detect a weak peripheral pulse
- to monitor BP in infants/children
- measure a low BP
- BP in a lower extremity
how do you use a doppler?
first make sure patient is in supine position with legs externally rotated so medial ankles are accessible.
-place gel on transducer and place transducer on pulse site where you swivel it at 45 degrees
why is foot care important?
to check for sores and wounds
what can foot problems mean?
arthritis, diabetes, nerve/circulatory disorders
what does good foot care entail?
- checking feet everyday and asking for help if you cant on your own
- keep blood flowing to your feet by increasing activity (walking)
- wearing shoes that fit and are comfortable
- keep skin soft and smooth
what represents pitting edema and what is the scale?
if finger pressure leaves indent in skin
1+ mild pitting, slight indentation, remains for short time and leg looks swollen
2+ moderate pitting, indentation subsides rapidly
3+ deep pitting, indentation remains for a short time, leg looks swollen
4+ very deep pitting, indent lasts very long time, leg is very swollen (these are somewhat subjective ratings)
what is bilateral edema?
when edema is present in both legs or both sides of somewhere
what can localized swelling to calf mean?
deep vein thrombosis (clotting)
what are unexpected outcomes?
- pulsations, vibrations are palpable
- extra heart sounds are auscultated
- murmur is heard
- HR is irregular (less than 60 or greater than 100)
- pulse deficit is noticed
what is the function a a SCD sleeve?
it prevents DVT!
how often should an SCD sleeve or compression stocking be left on for?
should be changes atleast once per shift (every 12 hrs)
what occurs when skin is exposed to hot temperature?
vasodilation/perspiration occur to promote heat loss
what occurs when skin is exposed to cold temperature?
systemic response includes vasoconstriction and piloerection to preserve heat
how does vasoconstriction help with cold temperature?
it slows the bleeding into damaged tissues by reducing blood flow, reduces fluid accumulation and slows hematoma formation associated with trauma
what temperature reduces edema?
what are the advantages of moist application? and what are some examples?
reduces drying of skin, penetrates deep in tissue layers, lessens sweating and insensible fluid loss
examples: hot water packs and baths
what are the disadvantages of moist application?
cools rapidly b/c of moisture evaporation, greater risk for burns to skin b/c moisture conducts heat
what are the advantages of dry application and what are some examples?
less likely to burn skin, retains temperature longer b/c not influenced by evaporation
examples: electric heating pads
what are some disadvantages of dry application?
increases insensible fluid loss through sweating , doesn’t penetrate into tissue, causes increased drying of skin
what is the PRICE method?
its used for sprains and strains to limit amount of swelling at injury site and promote healing P-protect from further injury R-rest activity I-ice C-compression E-elevating
what does cold therapy do?
it reduces pain, spasm, metabolism, blood flow, inflammation, edema
what is a normal and abnormal artery like?
normal: elastic, easily palpable
abnormal: hard, inelastic, and calcified
what is strength of a pulse measure by?
measurement of the force at which blood is ejected against arterial wall
what is tissue perfusion?
condition of skin, mucosa, and nail beds offers data on staus of circulatory blood flow
-clubbing= insufficent oxygen
what occurs on skin if arterial OCCLUSION is present?
has signs resulting from an absence of blood flow
The P’s: pain, pallor, pulselessness, paresthesias, and paralysis
what is phlebitis? and when is it most common?
inflammation of a vein that occurs after trauma to vessel wall, infection, immobilization, and prolonged insertion of IV catheters. Common with unilateral edema
what are signs of venous insufficiency or right-sided heart failure?
edema is present around feet and ankles and brown pigmentation