Book Notes Flashcards
Assessment of the hematologist system is based on:
Patients health history, physical examination, and results of diagnostic studies
Hematopoiesis
Blood cell production
Where does hematopoiesis occur?
Bone marrow
What is bone marrow?
Soft material that fills central core of bones
The two types of bone marrow
Yellow (adipose) and red (hematopoietic)
Which bone marrow actively produces blood cells?
Red marrow
Hematology
Study of blood and blood forming tissues; including bone marrow, bone, spleen and lymph system
Where is red marrow found?
in flat and irregular bones, like ends of long bones, pelvic bones, vertebrae, sacrum, sternum, ribs, flat cranium bones, and scapulae
What are the 3 types of blood cells?
RBC, WBC, platelets
Where do blood cells develop from?
from a common hematopoietic stem cell within the bone marrow
What is a stem cell?
immature blood cell that is able to self renew and to differentiate into hematopoietic progenitor cells
what is blood?
a type of connective tissue
3 major functions of blood
- transportation
- regulation
- protection
blood: transportation function defintion
- O2 from lungs to cell
- nutrients from GI tract to cells
- hormones from endocrine glands to tissues and cells
- waste products from cells to lungs, liver and kidneys
blood: regulation function definition
- fluid and electrolyte balance
- acid-base balance
- maintaining oncotic pressure (BP in wall vessels)
2 major components of blood
plasma 55%
blood 45%
what is plasma composed of?
mostly water, but contains proteins, electrolytes, gases, nutrients and waste
what is serum?
plasma minus clotting factors (fibrinogen)
what is plasma protein produced by?
liver
what are antibodies produced by?
plasma cells
what is albumin?
protein that helps maintain oncotic pressure in the blood
primary function of erythrocytes (rbc)
transportation of gases (O2 and Co2) and assisting w/ acid-base balance
primary function of leukocytes
protecting the body from infection
primary function of platelets
promote blood coagulation
shape of RBC
flexible cells with biconcave shape; flexibility enables the cell to alter shape so it can pass in small capillaries
what are erythrocytes primarily composed of?
hemoglobin
what is hemoglobin?
complex protein iron compound composed of heme (iron compound) and globin (simple protein) that binds with o2 and co2
what is oxyhemoglobin?
as RBCs circulate through capillaries, o2 attaches to the ironm and becomes oxyhemoglobinm and is what gives blood bright red color
how does oxyhemoglobin work?
as rbcs flow to body tissues, o2 detaches from hemoglobin and diffuses from the capillary into tissue cells. co2, diffuses from tissue cells into capillary and attaches to the globin of hemoglobin and transported to lungs for removal
what does hemoglobin act as?
a buffer and plays a role in maintaining acid base balance
what is erythropoiesis?
process of rbc production
what is erythropoiesis stimulated by?
hypoxia (low o2 level)
what is a pTTT for?
activated partial thromboplastin time- for continuous IV heparin ( lots of heparin)
what is a pTT for?
heparin
what is a pT w/ INR for?
coumadin
what is erythropoiesis controlled by?
erythropoietin- a glycoprotien made and released by the kidney. it stimulates the bone marrow to increase rbc production
lifespan of an erythrocyte
120 days
nutrients needed for erythropoiesis
protein, iron, folic acid, vitamin b12, b2, b6, vitamin e. hypothyroidism is often associated with anemia
what is a reticulocyte?
immature erythrocyte. this count measures the rate at which rbcs appear in circulation.
hemolysis definition
destruction of rbc. by monocytes and macrophages removing abnormal, defective, damaged, and old rbcs from circulation.
where does hemolysis occur?
bone marrow, liver and spleen
what are leukocytes?
wbcs. provide protection from infections; originates from stem cells within bone marrow
what are granulocytes?
leukocytes that contain granules within the cytoplasm
3 types of granulocytes
- neutrophils
- basophils
- eosinophils
what are agranulocytes?
leukocytes that don’t have granules withing the cytpolasm
2 types of agranulocytes
- lymphocytes
2. monocytes
how many nuclei do monocytes and lymphocytes have?
one discrete nucleus, referre to as mononuclear cells
function of granulocytes
phagocytosis, process by which wvcs ingest or engulf any unwanted organism and then digest and kill it
granulocyte: neutrophil
most common type of granulocyte; 50% to 70%; primary phagocytic cell. die in 1 to 2 days; first to arrive at infection;
granulocyte: eosinophil
2-4% of all WBCs. engulf antigen-antbody complexes formed during an allergic response. elevated levels is seen in neoplastic disorders like hodgkins lymphoma and other skin/connective tissue disorders. able to defend agains parasitic infections
granulocyte: basophils
make up less than 2% of all wbcs. allergic and inflammatory reactions
mature vs. immature neutrophils
segmented / bands; segmented neutrhils more effective at phagocytosis than bands
lymphocytes
20 to 40% of wbcs; form basis of cellular and humoral immune responses. B cells and T cells; originate in bone marrow and migrate to thymus to differentiate into T cells.
Monocytes
4 to 8% of total wbcs; ingest small or large masses or matter, like bacteria, dead cells. only present in blood for short time before they migrate to tissues and become macrophages.
main function of thrombocytes
(platelets) promote blood coagulation in response to injury or disease; initiate clotting process; produces a plug at site of injury; 1/3 of platelets reside in spleen; maintain capillary integrity; life span of 8-11 days; pt with history of splenectomy may have difficulty with blood clotting
what is platelet production regulated by?
thrombopoietin- a growth factor that acts on bone marrow to stimulate platelet production
what is platelet count?
number of platelets per microliter of blood.
normal platelet count?
150,000 and 400,000; 250,000 is good number
thrombocytopenia
platelet count have fallen below 100,000u/L; bleeding precautions; spontaneous hemorrhage with numbers 10,000 to 20,000
thrombocytosis
excessive platelets, disorder that occurs with inflammation and some malignant disorders, complications = excessive clotting
Spleen location
upper left quadrant next to kidney; highly vascular organ (storage of blood); bleeds easily with traumatic event
4 functions of spleen
- hematopoietic
- filtration
- immunologic
- storage
spleen: hematopoietic function
spleens ability to produce rbcs during fetal development
spleen: filtration function
spleens ability to remove old and defective rbcs from circulation; removes hemoglobin from rbcs and returns iron component to bone marrow for reuse; filters out bacteria, esp gram positive cocci
spleen: immunologic function
contains rich supply of lumpocytes anf stored immunoglobulins (antibodies)
spleen: storage function
storage site for RBCs and platelets; 1/3 of platelets are stored here; patients who have had splenectomy are at higher risk for infection, encourage to keep up with immunizations
Liver
- acts as filter
- produces clotting factors
- produces all initial coagulants for hemostasis and blood coagulation
- produces bile from rbc breakdown
- detoxifies substances in blood
- healthy functioning essential for hemostasis and metabolism
- stores excess iron
- hepcidin-produced by liver key regulator of iron balance (reduces the release of stored iron from enterocytes)
what does the lymph system consist of?
- lymph fluid
- lymphatic capillaries
- lymphatic ducts
- lymph nodes
- it carries fluid from the interstitial spaces to the blood (how proteins and fat from GI tract, and hormones are able to return to circulatory system
how to lymph nodes?
-found throughout body
-deep ones not palpable
-assess symmetrically from top of head/neck to bottom (note size in cm should be 0.5 to 1cm, mobile and nontender)
-
lymph nodes
- small clumps of lymphatic tissue found in groups along lymph vessels
- storage sites for lymphocytes
- more than 200 lymph nodes
- filter pathogens and foreign particles (carried out of body by lymph fluid)
lymph nodes assessment
a tender, hard, fixed, or enlarged (whether tender or not) node is considered abnormal; warrants further evaluation
- tender nodes are usually result of inflammation
- hard fixed nodes may suggest malignancy
hemoglobin normal count
- female: 11.7 to 16
- male: 13.2 to 17.3
hematocrit normal count
- female 35% to 47% (0.35- 0.47)
- male 39% to 50% (0.39-0.50)
Bone Marrow examination
preferred site for bone marroy aspiration and biopsy is the posterior iliac crest
- anterior iliac crest and sternum are alternatives
- sternum is only for aspiration
- must be performed by physician or credentialed nurse
end of bone marrow examination
monitor VS till stable, and assess site for excess drainage or bleeding.
-if bleeding is present advise pt to lie on side for 30 to 60min to maintain pressure
elder consideration
- decrease in bone marrow reserve
- limited reserve capacity of blood cell levels leaving elder more vulnerable to issues with clotting, transporting oxyen, and fighting infections.
- decrease t-cell function and number
- thymus organ atrophy
elderly considerations cont
- changes in vascular integrity with age leads to > bruising
- ineffective erythropoiesis, esp after blood loss
- increased prevalence and incidence of infection with age
- lower hemoglobin levels present
- total iron, iron binding capacity and intestinal iron absorption decrease (iron loss may be cause for low hemoglobin levels)
physical assessment
- elimination pattern: ask of patient has blood in urine or stool, ask about recent colonoscopy
- sleep/rest pattern: question if patient fells rested after nights sleep/fatigue with hematologic disorder does not resolve after sleep
nutritional pattern questions
- dietary review gives info about causes of anemia
- obtain patients current weight
- ask if pt has experienced any anorexia, nausea, emesis, oral discomfort
foods to help develop rbcs
iron, cobalamin, folic acid; liver, meat, eggs, whole-grain, enriched breads, cereals, potatoes, leafy green veggies
