Anatomy 2 Exam 1

blood tissue type

a specialized type of connective tissue

formed elements

Red Blood Cells, White Blood Cells, and Platelets

Blood functions

-delivering oxygen / nutrients to tissues and removing cellular waste

-Defense via WBC and Platelets

-Homeostasis for body temperature, pH, water, etc.

Hematocrit

Percentage of RBCs (heaviest elements)

What is plasma

-92% water

-7% proteins

-1% other solutes (electrolytes, dissolved gasses, lipids, glucose, Amino acids, waste, etc.)

Albumin protein

most abundant plasma protein (54% of plasma proteins)

-serves as binding protein for fatty acids and steroid hormones

-major contributor to osmotic pressure of blood

Globulin protein

helps fight infections, clot blood, and move nutrients

Fibrinogen protein

Produced by liver just like albumin and alpha + beta globulins

-Essential for clotting

RBC / Erythrocyte lifespan

average life span of 120 days

what is hematopoiesis

creation of all new blood cells and platelets from a single type of stem cell

Main site of hematopoiesis after birth

Within red bone marrow

Totipotent stem cell

zygote / fertilized egg; gives rise to all cells of human body

Pluripotent stem cell

gives rise to multiple cell types

Mesenchymal stem cell

only develops into different types of connective tissue

Hematopoietic stem cell

develops into all formed elements of the blood

Lymphoid stem cells

give rise to lymphocytes

-( T cells, B cells, NK cells )

Myeloid stem cell

give rise to all other formed elements

-RBC, megakaryocytes (platelets), monocytes, and leukocytes

Erythropoietin ( EPO )

glycoprotein secreted by interstitial fibroblasts of kidneys

-promotes production of RBCs to increase oxygen

Thrombopoietin

glycoprotein produced by liver + kidneys

-triggers megakaryocytes to turn into platelets

Cytokines

glycoproteins secreted by many cells ( red marrow, leukocytes, macrophages, etc. )

-2 main subtypes

Colony-stimulating factors (CSFs)

local autocrine or paracrine factors

-differentiation of myeloblasts into leukocytes, production of monocytes

Interleukins

produced by a variety of cells ( marrow, endothelium, etc. )

-a type of cytokines

-involved in hemopoiesis, immunity, and inflammation through cell to cell Communication

function of RBCs

transport inhaled oxygen from lungs to tissues + pick up some carbon dioxide from tissues and transport back to lungs for exhalation

RBC structure

biconcave disc for gas exchange surface area

-lack endoplasmic reticulum

Reticulocyte

An immature RBC ( 1-2% of total RBCs )

Hemoglobin structure

4 folded chains of globin

-Each chain bound to heme

-Each heme contains iron that can bind to 1 oxygen

Hemoglobin and CO2

Within capillaries, 76% of CO2 dissolves in plasma, some of which forms a bicarbonate ion

-Remaining CO2 binds to amino acids in hemoglobin → carbaminohemoglobin

Anemia

Decrease in # of RBCs

polycythemia

-less O2

Increase in # of RBCs

-thicker blood

hypoxemia

under normal levels of oxygen within blood

Hypoxia in kidneys

When low O2, Fibroblasts in kidney can secrete EPO which acts to increase RBCs

-negative feedback, so once O2 is stable, less EPO is produced

Elevation and hematocrit

Higher hematocrit for higher elevations due to lack of O2

RBC Iron trace mineral

-Heme iron from animal protein, Non-heme from plants

-stored as ferritin & hemosiderin in liver, bone marrow, and spleen

-Transported by ferroportin out of storage cells into blood stream

-Transferrin (blood plasma protein) carries iron throughout body

RBC copper trace mineral

Composed of 2 plasma proteins

-Hephaestin enables iron to be absorbed in gut

-Ceruloplasmin transports copper

• Both help oxidize iron so it can bind to transferrin,

• Copper deficiency → iron accumulation in tissues

RBC other required trace minerals

Zinc

-Co-enzyme that helps with synthesis of heme

B-Vitamins

-Specifically B12 and folate (B9), which help with DNA synthesis(more RBC)

RBC lifespan compared to most WBC

RBCs up to 120 days, WBCs up to 14 days

Degradation of hemoglobin

Once macrophages remove RBC

-Globin recycled into amino acids for more RBCs, stragglers are broken down into chains and cleared by kidneys

-Iron from heme is stored in liver / spleen

-Rest of heme degraded into biliverdin, moved to liver, made into bile, then removed via stool. Urine also removes bilirubin

Anemia main groups

-blood loss

-faulty or decreased RBC production

-destruction of RBCs

Leukocyte characteristics

-Smaller and less than RBC

-capable of mitosis

-can leave bloodstream to assist in immune response

emigration / diapedesis

white blood cells leaving blood vessels to enter surrounding tissues

• Either:

-Move to lymph, bone, spleen, thymus, etc.

-Wander freely

-Move towards direction of chemical signals

Granulocytes

abundant granules in cytoplasm, arise from bone marrow

Neutrophils

50-70% of total WBCs, lobular nucleus, lilac granules

-Rapidly respond to primarily bacterial infections

-Granules contain lysozymes, defensins, and oxidants like H2O2

Eosinophils

2-4% of total WBCs, 2-3 lobes in nucleus, red/orange granules

-Granules contain anti-histamine molecules + molecules toxic to parasites

Basophils

<1% of total WBCs, large granules that stain blue

-Intensify inflammatory responses

-Release histamines, heparin

-Associated with allergies, parasites, and hypothyroidism

Agranulocytes

smaller/less visible granules in cytoplasm, simple nucleus

Lymphocytes

20-30% of total WBCs, lobular nucleus, lilac granules

-Arise from lymphoid stem cells, development + production in lymphatic tissue

-Size varies

-3 types

Lymphocyte: Natural killer (NK) cells

recognize cells w/o “self” proteins or have abnormal/foreign markers

- cancer cells, viruses; non-specific immunity

B cells and T cells

Defend against pathogens involved in specific immunity using memory cells that live for years

Lymphocyte: B cells

humoral/fluid immunity, produce antibodies + immunoglobulins, mature in bone marrow

Lymphocyte: T cells

cellular level immunity, physically attack foreign + diseased cells, mature in thymus

Monocytes

2-8% of total WBCs, very large, horseshoe-shaped nuclei

-Originate from myeloid stem cells

-Macrophages = monocytes that left circulation to phagocytize debris, foreign pathogens, old RBCs + cells

-release antimicrobial defensins and chemotactic to lure WBCs to infxn site

Hemostasis

physiological process that stops bleeding after a blood vessel is injured

1st step of hemostasis

Vascular spasm (~30 minutes)

-Triggered by endothelins, blood vessel contracts, constricting blood flow

2nd step of hemostasis

Formation of platelet plug ( starts w/in 15-20 sec and finishes in about 1 min )

-Platelets clump together and bind to exposed collagen and endothelial lining

-Requires von Willebrand factor (vWF)- protein that acts like glue

3rd step of hemostasis

Coagulation = formation of a blood clot

Extrinsic pathway (trauma)

Quicker/more direct, takes seconds

Intrinsic pathway (internal damage)

Longer/more complex, takes minutes

Common Pathway

fibrin produced to seal vessel

End result of hemostasis

Fibrin formation

-Fibrin = protein mesh that traps platelets and blood, comes from fibrinogen

Fibrinolysis

breakdown of clots/fibrin mesh

• Plasminogen → plasmin → gradually breaks down clot

-Bradykinin also works to relax smooth muscle

Plasma Anticoagulants

Helps to restore normal/clot-free blood

-ex. protein C of intrinsic pathway, and Basophils secrete heparin, a short-acting anticoagulant

Thrombus vs Embolus

-thrombus is a blood clot that stays attached to the blood vessel wall

-embolus is a detached mass (like a piece of a clot, fat, or air) that travels through the bloodstream until stuck

Antigens

-Body has self-antigens that are recognized by your immune system

-When foreign or non-self antigens are introduced it can trigger an immune response

Antibodies

Immunoglobulins produced by plasma cells (type of B cell)

-Attach to antigens on plasma membrane of infused erythrocytes during blood transfusion if wrong blood type is used, causing them to stick together

• can block vessel and deprive O2 and nutrients

secondary erythrocyte antigen

Rh D, determines +/- blood typing

Blood serum clumping meaning

If the serum and blood cause coagulation, the blood as X antigen

Ways blood enter the Right Atrium

superior vena cava, inferior vena cava, and coronary sinus

foramen ovale / Fossa ovalis

opening between the atria in a fetal heart

-closes and turns to “fossa ovalis” after

Interatrial septum

muscle wall between atria

Interventricular septum

muscle wall between ventricles, thicker because they generate more pressure during contraction

pericardial sac

Membrane surrounding heart + roots of major vessels

Outer fibrous layer of pericardial sac

fibrous pericardium

Inner serous layer of pericardial sac

• Parietal pericardium ( fused to pericardium )

• Epicardium ( fused to heart, reinforced with areolar CT )

Pericardial cavity

between epicardium and pericardium

-filled with serous fluid that acts as a lubricant

Deep coronary sulcus

area on surface of heart between atria and ventricles

Anterior interventricular sulcus

anterior surface of heart between left and right ventricle

Posterior interventricular sulcus

area on posterior surface of heart

Myocardium

mostly cardiac muscle cells w/accompanying nerves + collagen fibers

-Left ventricle thicker for pumping strength

Endocardium

Connected to myocardium with thin layer of connective tissue

-Lines chambers

Endothelins

proteins that lines vessels, act to regulate ionic concentrations and contractility via vasoconstriction

Atrioventricular septum

muscle wall between atria and ventricles

-cardiac skeleton ( dense CT ) helps reinforce

Coronary sinus

feeds blood coronary veins into posterior atrium just superior and medial to opening of inferior vena cava

pectinate muscles

Internal anterior surface of right atrium has ridges that help to increase contractile force

chordae tendinae

super strong strands of CT in heart

trabeculae carnage

ridges that line right ventricle

moderator band

band of cardiac muscle that connects lower part of IV septum to base of anterior papillary muscle

-Within Right ventricle ( NOT Left Ventricle )

cardiomyocytes

Cardiac cells

Left coronary artery

supplies blood to left atrium, left ventricle, and IV septum

Circumflex artery

arises from left coronary and later fuses with right coronary artery

Anterior interventricular artery ( aka LAD )

2nd major branch off left coronary artery

-”widowmaker”

Right coronary artery

Distributes blood to right atrium, right and left ventricles, and heart conduction system

Marginal arteries

arise from right coronary artery

- supply blood to superficial portions or right ventricle

posterior interventricular artery ( aka posterior descending artery )

runs along the bottom surface of the heart

-supply blood to the lower and back walls of the heart

Coronary Veins

Drain heart and parallel arteries

Great cardiac vein

starts on surface of heart and then dives into the coronary sinus

-Receives:

-Posterior cardiac vein

-Middle cardiac vein

-Small cardiac vein

autorhythmicity

can initiate electrical impulses that spread from cell to cell to stimulate contraction

How heart rate is controlled

Via endocrine & nervous systems

Myocardial contractile cells

99% of cells in atria and ventricles

-conduct impulses → heart contractions + pumping

Myocardial conducting cells

1% of cells

- form conduction system of heart (spark electrical rhythm + coordinate heartbeat)

Cardiac muscle differences from skeletal

• 1/2 as many T-tubules compared to skeletal muscle

• Cardiac mm has less Ca2+ ions as well, resulting in slower contraction

• Cardiac has 1 nucleus, skeletal is multinucleated

• Cardiac is branched via intercalated discs