blood and lymph

describe blood

specialized connective tissue, only fluid tissue in human body

3 layers of blood

erythrocytes (red blood cells), white blood cells and platelets (the buffy coat), plasma

describe the blood hematocrit

percentage of erythrocytes in blood, around 45%

describe color range of blood

oxygen rich is scarlet red, oxygen poor is dull red

pH of blood

slightly basic, 7.35-7.5

density and viscosity of blood

high density and 5 times thicker than water

temperature of blood

around 100.4 F or 38 C

volume of blood

8 percent of body weight, 5-6 liters in males, 4-5 liters in females

blood is the medium for

deliver of oxygen and nutrients, removal of metabolic wastes and transport to elimination sites, and distribution of hormones

blood aids in

regulating body temperature, body fluid pH, and fluid volume

blood protects the body against excessive

blood loss through clotting, and from infection through the immune system

describe blood plasma

straw colored liquid, 90% water, around 100 dissolved substances in it

substances in blood plasma

glucose, fat, amino acids, vitamins, oxygen, carbon dioxide, albumin, fibrinogen, globulins, metal ions, urea, uric acid, hormones

function of plasma proteins

mostly albumin, function as carriers

where are plasma proteins made

except for antibodies and protein-based hormones, plasma proteins are made by the liver

function of albumin

regulates osmotic pressure

function of clotting proteins

help to stop blood loss when a blood vessel is injured

function of antibodies

helps protect the body from antigens

function of erythrocytes

to carry oxygen

anatomy of circulating erythrocytes

biconcave disks, bags of hemoglobin, anucleate, few organelles

what do erythrocytes lack and how does this benefit them

lack mitochondria and use anaerobic mechanisms to make ATP, they do not use any of the oxygen, making them efficient oxygen transporters

ratio of white blood cells to red

1:1000

hemoglobin structure

made up of iron-bearing globin protein bound to red heme pigment

function of hemoglobin

oxygen-binding pigment that is responsible for transport of most of the oxygen in the blood

each hemoglobin has

4 oxygen binding sites

each erythrocyte has

250 million hemoglobins

normal blood hemoglobin levels

12-18 g/100 ml

hemoglobin content in men vs women

higher in men, 13-18 than women 12-16

anemia is

decrease in oxygen carrying ability of the blood

cause of anemia

lower number of RBCs, deficiency of hemoglobin

polycythemia

excess of RBCs

polycythemia that results from bone marrow cancer

polycythemia vera

polycythemia that results from living at high altitudes with low oxygen

secondary polycythemia

what is the problem with polycythemia

causes blood to flow sluggishly and impairs circulation

blood doping

artificially induced polycythemia, blood is drawn out to produce more RBCs, blood is then reinjected, causes polycythemia

movement of leukocytes

able to move in and out of blood vessels (diapedesis), move through tissue spaces by forming cytoplasmic extensions (ameboid motion)

why are WBCs important

crucial in defense against bacteria, viruses, parasites, and tumors, respond to chemicals released by damaged tissues (positive chemotaxis)

normal levels of WBC in blood

4,000-11,000 cells per ml of blood

leukocytosis

above 11,000 cells/ml, indicates an infection

leukopenia

low wbc count, caused by drugs (corticosteroids and anticancer agents)

2 major groups of WBCs

granulocytes and agranulocytes, depending of if they have visible granules in their cytoplasm

describe granulocytes

larger, short life span, phagocytes, lobed nuclei, stain specifically with wright’s stain, includes the neutrophils, eosinophils, and basophils

describe neutrophils

most numerous, multilobed, has 2 types of granules (basic and acidic), has some enzymes that act as lysosomes, and some antimicrobial proteins called defensins, act as phagocytes as infection, lyses bacteria through respiratory burst

describe eosinophils

bilobed nucleus, response to allergies and parasites, has unique digestive enzymes that release onto the surface of the parasitic worm digesting it outside the cell

describe basophils

least numerous, u or s shaped nucleus with histamine containing purple granules, causes vasodialation

describe agranulocytes

spherical/oval/or kidney shaped nuclei, include lymphocytes and monocytes

describe lymphocytes

dark purple nucleus, immune system, t lymphocytes attack viral infected and tumor cells, b lymphocytes produce plasma cells that produce antibodies

describe monocytes

large white blood cells, macrophages, activate t lymphocytes, fighting chronic infections

leukemias summery

clones of a single white blood cell that remains unspecialized and divides out of control, impairing normal bone marrow functions

myelocytic leukemia

involves myeloblast descendants, lymphocytic leukemia involves lymphoblast descendants

acute leukemia

quick advancing, involves blast cells

chronic leukemia

slow advancing, involves later cell stages

this disease is caused by the Epstein-Barr virus

infectious mononucleosis

diagnosis of infectious mononucleosis

fever, sore throat, swollen lymph glands, young adult, elevated WBC count, increased percentage of certain atypical WBCs, positive reaction to a “mono spot” test

after one week of the onset of the kissing disease

many patients develop heterophile antibodies

how long can mono last

weeks to years

cytoplasmic fragments derive from

ruptured multinucleate cells (megakaryocytes)

describe megakaryocyte

bone marrow cell that is 10-15 times larger than a typical red blood cell, derived from hemocytpblast

formation of platelets

regulated by throbopoietin hormone, involves repeated mitosis of megakaryoblast without cytokinesis, megakaryoblast becomes a megakaryocyte that presses against the sinusoidal capillaries in the bone marrow, sending cytoplasmic extensions through the sinusoidal walls, extensions rupture and form dark, irregular shaped bodies around the other blood cells

function of platelets

needed for the clotting process forming the temporary seal when a blood vessel breaks

normal platelet count

300,000 /mm³

hematopoiesis

blood cell formation

where does hematopoiesis occur

red bone marrow or myeloid tissue

what is myeloid tissue made up of

reticular connective tissue and wide blood capillaries called blood sinusoids

where is myeloid tissue found

flat bones of the skull and pelvis, the ribs, sternum, and proximal epiphyses of the humerus and femur

how is each type of blood cell produced

in different numbers in response to changing body needs

all blood cells are derived from:

common hematopoietic stem cell (hemocytoblast) found in the red bon emarrow

hemocytoblast forms 2 types of cells (and what do these produce)

lymphoid stem cell produces lymphocytes, myeloid stem cell produces other formed elements

erythropoiesis

formation of erythrocytes

hemocytoblast transformation during rbc formation

myeloid stem cell, proerythroblast, early erythroblast (has many ribosomes, produces lots of hemoglobin), late erythroblast, normoblast (when enough hemoglobin has been accumulated, the nucleus and most organelles are ejected and the cell collapses inward), reticulocyte (still contains some rough ER)

fate of reticulocytes in the blood stream

transport oxygen, within 2 days of release, they have ejected the remaining ER and have become erythrocytes, takes 15 days

mature erythrocytes are unable to

divide, grow, or synthesize proteins

rate of erythrocyte production is controlled by

hormone erythropoietin

kidneys produce most erythropoietin as a response to

reduced oxygen levels in the blood

dietary requirements for erythrocyte formation

iron, vitamin b12, folic acid, proteins, lipids, carbs

red blood cells life span and why

short life span (100-120 days) due to lack of nuclei and organelles

how are blood cells destroyed

macrophages in the spleen or liver

the protein part of hemoglobin is broken down

to amino acids for reuse

the iron part of the heme group is

recycled and stored

the rest of the heme group is

degraed to bilirubin, a yellow pigment that is released into the blood

function of bilirubin

taken by the liver and released into the intestine where it is converted into urobilinogen, most of the degraded pigment leaves the feces a yellow/brown pigment called stercobilin

lost cells are replaced by

division of hemocytoblasts

leukopoiesis

formation of white blood cells

leukopoiesis is regulated by two types of:

glycoproteins called interluekins and colony stimulating factors

leukopoiesis involves differentiation of hemocytoblasts along 2 pathways

lymphoid stem cells: produce lyphocytes, myeloid stem cells: produce monocytes, neutrophils, basophils, eosinophils, red blood cells, and megakaryocytes

lymphoid stem cells fate

lymphoblasts, prolymphocytes, lymphocytes

myeloid stem cell fate to eosinophils, basophils, neutrophils

myeloblasts → promyelocytes → eosinophilic myelocytes, basophilic myelocytes, neutrophilic myelocytes → eosinophilic band cells, basophilic band cells, neutrophilic band cells → eosinophils, basophils, neutrophils

myeloid stem cells fate to monocytews

monoblasts, promonocytes, monocytes

myeloid stem cells fate to red blood cells and megakaryocytes

just go to red blood cells and megakaryocytes

hemostasis

fast, localized response to reduce blood loss through clotting, result of a break in a blood vessel

hemostasis involves three phases

platelet plug formation, vascular spasms, coagulation or blood clotting

normally platelets do what

do not stick to each other or to the walls of blood vessels

a break in a blood vessel exposes what

collagen fibers

what do platelets do when the blood vessel breaks

with the help of von Willebrand factor (large plasma protein formed by the endothelial cells) adhere to the colalgen fibers, swell and form spiked processes

granules within the anchored platelets

release chemicals such as serotonin that causes vascular spasms and adenosine diphosphate (ADP) to attract more platelets

platelets pile up to form

a platelet plug

a prostaglandin called prostacyclin is produced by____ and does:

intact endothelial cells, limits platelet plug to the needed area only

factors that trigger vascular spams

direct injury to vascular smooth muscle, reflexes by local pain receptors, chemicals released by endothelial cells and platelets

anchored platelets release:

serotonin, which causes blood vessel muscles to spasm

what do vascular spams do

vasoconstriction to decrease blood loss