Anatomy Lecture: Components of the blood, immune, and lymph

What are the 4 components of the blood?

RBCs, WBCs, plasma, platelets

Hematocrit:

A test that determines the % of RBCs in a patients blood

steps of a hematocrit:

1. blood is drawn

2. blood is centrifuged

What is the average percent of plasma in the blood?

55%

What is the average percent of white blood cells and platelets in the blood?

4%

What is the average percent of RBCs in the blood?

41%

What is the layers in a hematocrit from bottom to top? (most to least dense)

RBCs, WBCs/platelets, RBCs

What are RBCs AKA?

Erythrocytes

Role of RBCs:

Carry oxygen from the lungs to cells and contain hemoglobin to bind to and carry oxygen

What do RBCs not contain?

Nucleus and mitochondria

Shape of RBCs:

Biconcave disc

Erythropoiesis:

Production of RBCs in the bone marrow

What are some things that signal erythropoesis?

Low O2 levels in blood, vitamin B12 levels, iron levels, growth factors, erythropoietin

Lifespan of RBCs:

4 months

What happens as an RBC ages?

Loses effeciency and flexability.

What can hasten the damage of RBCs?

Free radicals

What can create free radicals in the enviorment?

UV, pollution, cigarette smoke, chemicals

What organs remove old RBCs?

Spleen and liver

What is heme used for in recycled RBCs?

To make new RBCs

What are proteins broken down to in recycled RBCs?

Amino acids

What is excreted in the urine and feces from old RBCs?

Bilirubin

Anemia:

Condition where body does not produce enough healthy RBCs to deliver adiquate oxygen to the tissues.

Sickle cell anemia:

Mutation in DNA makes abnormal shaped hemoglobin that makes RBC not fit through capilaries

What kind of inheritance is sicle cell anemia?

Recessive inheritance

What is sickle cell anemia an adaptation of?

Those with one allele of the gene get bit less by mosquitos as a way to combat malaria

Polycythemia:

Increased number of RBCs caused by genetic mutations

What are the effects of polycythemia on the blood other than an increased number of cells?

Thicker blood and an increased chance of blood clots

What is the percent RBCs in a hematocrit to be polycythemic for women?

Greater than 48%

What is the percent RBCs in a hematocrit to be polycythemic for men?

52%

What is the hemoglobin levels in a hematocrit to be polycythemic for women?

greater than 16.5 g/dL

What is the hemoglobin levels in a hematocrit to be polycythemic for men?

18.5g/dL

What is the percent occurance of polycythemia in newborns?

1-5%

Causes of newborn polycythemia:

Blood transfusions, transfers of placental blood after delivery, interuterine hypoxia due to placental deffeciency

Blood doping:

Process where athlete removes their blood before an event and reinjects in up to a week ahead of time to increase number of RBCs in blood

What does an increased number of RBCs allow for in blood doping?

Muscles that work longer and harder without cramping by carrying more oxygen

Shape of WBCs:

No fixed shape, can chage form

What percent of the blood is made up of WBCs?

Less than 1%

Function of WBCs:

Fight pathogens, destroy cancerous cells, neutralize toxins

What is the layer in a hematocrit with WBCs/platelets AKA?

The buffy coat

WBCs listed in order of high to low % in blood:

Neutrophils, Lymphocytes, Monocytes, Eosinophils, Basophils (never let monkeys eat bananas!)

What do agranulocytes have?

Specific/adaptive immunity

What WBCs are agranulocytes?

Monocytes and lymphocytes

What do granulocytes have?

Innate immunity

What WBCs are granulocytes?

Neutrophyls, basophyls, and eosinophyls

Neutrophyls:

First responders involved in phagocytosis

Eosinophyls:

Defend against parasites and are involved in allergic reactions

Basophyls:

Release histamine and heparin during allergic and inflamatory responses

Lyphocytes:

Produce B cells, T cells, and NK cells

B cells:

Recognize pathogens and produce antibodies in response

T cells:

Help destory cancer cells and prevent auto immune reactions

NK cells:

Destroy virus infected and cancerous cells

Monocytes:

Differentiate into macrophages which do phagocytosis

What STEM cell are RBCs formed from?

Myeloid proginator cells

What are platelets formed from?

Broken off pieces of megakaryocytes

What are plasma cells formed from?

B cells

What WBC arrives first during inflamation and why?

Neutrophils which release enzymes to kill bacteria and other pathogens

Extravasation:

Process where WBCs migrate from the bloodstream to infected tissue

Diapedesis:

Final phase of extravasion when WBCs squeeze out of capilaries

Platelets role:

Form scabs to stop bleeding

Description of platelets:

Small colorless fragments of cells

What percent of the blood is made up of platelets?

Less than 1%

Where are platelets made?

In the bone marrow

What are platelets AKA?

Thrombocytes

What activates platelets?

Mechanical changes in body tissues and chemicals released at the injury site

Plasma function:

Carries other components of blood around body

What percent of the plasma is made up of water?

90-92%

Examples of molecules found in plasma:

Proteins, electrolytes, nutrients, hormones, anibodies

Lymph:

Clear, colorless fluid that collects waste, extra protein and fluid, and fats

Examples of waste that lymph carries:

Damaged cells and bacteria

Lymph contains…:

Lympocytes, water, protein, electrolytes, and fats

Where do t cells mature?

In the thymus

What does the lymph system work together with the circulatory system to acheive?

Maintain the immune system, maintain blood pressure and fluid balance, transport hormones

Which side of a blood vessel has more fluid exit: The arteriole or venous side?

Arteriole

Why does less fluid flow through the venous side?

Because proteins leak out of the capilary beds to be reabsorbed by the lymphatic vessels

How does lymph flow?

Only towards the heart

What causes lymphedema?

Blockage or removal of lymphatic vessels/nodes

Primary lymphedema:

Caused by hyper/hypoplasia or aplasia of the vessels

Secondary lymphedema:

Caused by injury of vessels from surgery, injury, diesease

Primary lympoid organs:

Responsible for producing lymphocytes

What are the primary lymphoid organs?

Thymus and bone marrow

Secondary lympoid organs:

Hold mature lympocytes and initiate the immune response with antigens

What are the secondary lymph organs:

Spleen, lymph nodes, tonsils, appendix, mucosal associated lympoid tissues (MALT)

What happens to the thimus as a person ages?

It is replaced by fat

What hormones does the thymus release?

Thymosin and thymulin

Spleen:

Stores WBC, RBC, and platelets and removes old/damaged blood cells

Lymph nodes:

Filters cancer cells and stores T and B cells

What are the inner folds of lymph nodes called?

The trabeculae

Tonsils:

Encapuslayed lymph tissue made of epithelium with crypts that are the first line of defense against pathogens

How can tonsils contribute to illnesses?

Crypts can trap bacteria with some tonsils needed to be removed

Where is MALT found?

Deep to the mucous membranes open to the outside enviorment

Cysterna chyli:

Lymph sac in abdominal cavity that drains lymph and absorbs fat from the intestines. Origin of the thoracic duct

Lyphatic duct:

Drainage resivor for lymph coming from the right side of the head, neck, and upper body

Thoracic duct:

Drainage resevior for the left side of the head, neck, body, legs

Mononucleosis:

Infection caused by Epstein-barr virus that affects b lymphocytes

Symptoms of mononucleosis:

Swollen lymph nodes