lecture 9 blood & circulatory system review

blood

• Fluid connective tissue (cells in ECM)

• Cells:

  • Erythrocytes

  • Leukocytes

  • Thrombocytes

• Extracellular matrix:

  • Plasma (watery substance)

  • Dissolved proteins (ex/ antibodies, hormones)

blood separation and composition

• Red blood cells ~44% of blood volume

• Buffy coat ~1%

  • Leukocytes and platelets

• Plasma ~54%

transportation

• Respiratory gases

• Nutrients and wastes

• Hormones

• function of blood

regulation

• Body fluid distribution (leak plasma)

• Body temperature

• function of blood

protection

• Immune cells

• Platelets

• Inflammatory response

• function of blood

plasma

• Composition

  • ~ 92% water

  • Ions (Na+ and Cl-) (Ca+)

  • Nutrients (Sugars, amino acids, etc.)

  • Proteins (ex/ antibodies)

• Plasma leaks out of capillaries to form interstitial fluid

  • Plasma proteins stay in blood vessels

erythrocytes (RBCs)

• No nuclei → biconcave disk

  • 30% more surface area (flat in middle)

• No organelles

  • No mitochondria – do not consume O2

  • Life span ~120 days

• 97% composed of hemoglobin

  • Transport O2 and CO2

• New cells made in the red marrow (spongy bone)

• Life span ~120 days

• Old cells removed in liver or spleen

hemoglobin

• 280 million molecules of hemoglobin per RBC

• 1 molecule holds up to 4 O2 molecules and 4 CO2 molecules

• O2 is bound by iron atoms in molecule

  • Oxygenated blood is bright red

  • Deoxygenated blood is dark/deep red

blood typing

• describes antigens on the surface of erythrocytes.

• Two factors determine blood type:

  • ABO blood group

  • Rh factor

• Blood type determines what antibodies the immune system will produce:

  • Anti-A, Anti-B, and Anti-Rh

• Important for blood transfusions, organ transplants, health risks, etc.

ABO blood group

presence or absence of A and B antigens

Rh factor

presence or absence of Rh surface antigen (aka: D antigen, have +)

A+ blood type

• antigens: A, D

• antibodies: anti-B

A- blood type

• antigens: A

• antibodies: anti-B, anti-D

B+ blood type

• antigens: B, D

• antibodies: anti-A

B- blood type

• antigens: B

• antibodies: anti-A, anti-D

AB+ blood type

• antigens: A, B, D

• antibodies: none

• universal acceptor

AB- blood type

• antigens: A, B

• antibodies: anti-D

O+ blood type

• antigens: D

• antibodies: anti-A, anti-B

O- blood type

• antigens: none

• antibodies: anti-A, anti-B, anti-D

• universal donor

anemia

• low erythrocyte level or hemoglobin concentration

• Erythrocyte Volume Disorders

sickle cell disease

• erythrocytes distort into a sickle shape

  • Hereditary – mutation in DNA results in defective hemoglobin molecule

  • Insufficient O2 and CO2 binding

• Erythrocyte Volume Disorders

polycythemia

• abnormal excess of erythrocytes

  • Thicker, more viscous blood

  • Tremendous strain on the heart

• Erythrocyte Volume Disorders

leukocytes

• Part of the immune system - defend against pathogens

• Originate in red bone marrow

• Mainly function outside the bloodstream in loose CT

  • Diapedesis: circulating leukocytes leave the capillaries

granulocytes

• have granules filled with chemicals

  • Neutrophils, Eosinophils, Basophils

• leukocytes

agranulocytes

• no granules

  • Lymphocytes, Monocytes

• leukocytes

leukocytes cells to most to least

• Neutrophils (60%)

• Lymphocytes (30%)

• Monocytes (6%)

• Eosinophils (3%)

• Basophils (1%)

Never Let Monkeys Eat Bananas

neutrophils

• Phagocytize and destroy pathogens (harmful cells)

• Granules of various digestive enzymes

• First responder to infection

• granulocytes

eosinophils

• Fights parasitic worm infections

• Granules of parasite-killing proteins

• Also involved in allergies

• granulocytes

basophils

• Granules of histamine and heparin

• Secrete during inflammatory response and allergic reactions

• granulocytes

lymphocytes

• Involved in adaptive immune response --> fight specific foreign molecules (antigens)

• T-Lymphocytes

• B-Lymphocyte

• Natural Killer Cells: Attack abnormal and infected cells

• agranulocytes

T-lymphocytes

• Attack intracellular pathogens (viruses and cancer cells)

• Attack cells directly

B-lymphocyte

• Attack extracellular pathogens (bacteria, fungi, etc.)

• Produce antibodies

monocytes

• Leave circulation to enter tissues and differentiate into macrophages (not in blood, in tissues)

• Macrophages perform phagocytosis of pathogens, cellular debris, etc.

• agranulocytes

leukemia

• cancer in leukocyte-forming cells

• Abnormal development and proliferation of leukocytes

• Poorly differentiated cells – don’t function properly

• Interfere with maturation of normal blood cells

• Poor resistance to infection

platelets

• Platelets are cell fragments that break off from megakaryocytes

• Function in blood clotting

hemopoiesis

• Occurs in the red marrow

• Red marrow transplant for certain blood disorders

lumen

Central blood-filled space of vessel

endothelium

• simple squamous ET

• Smooth surface to prevent RBC rupture

• tunica intima

subendothelium

• areolar CT

• Nourish endothelium

• tunica intima

tunica media

• Circular sheets of smooth muscle

• Vasoconstriction (contract)

• Vasodilation (relax)

  • Elastic fibers help with recoil

tunica adventitia/externa

• Dense irregular CT that loosens

• Anchor neighboring tissues

• Vaso vasorum in larger vessels to nourish tissue

arteries

• thicker walls

• higher blood pressure

• tunica media thickest layer

veins

• thinner walls

• lower blood pressure

• tunica adventitia thickest

• valves present

• skeletal muscle pumps propel blood towards heart

elastic arteries

• Largest arteries. Located closest to the heart.

  • Ex Aorta, pulmonary trunk, brachiocephalic trunk.

• Unique feature: Abundant elastin fibers throughout tunics (prevent stretch) for stretch and recoil to pump blood (systole)

muscular arteries

• Distal to elastic arteries (middle size)

• Regulate diameter to control blood supply to organs

• Unique feature: Internal and external elastic laminae separate tunics – provide stretch and recoil

arterioles

• Smallest arteries

• Can close off diameter completely to shunt blood away from capillary bed

• Metarterioles just upstream of capillary bed

• Thoroughfare channel in the center of capillary bed

capillaries

• Smallest blood vessels

• Lumen is ~ diameter of RBCs

• Endothelium (and small subendothelium) only

• Leak plasma to supply interstitial fluid

• Gas exchange (O2 and CO2)

• Nutrient/waste exchange

continuous capillaries

• Intercellular clefts for diapedesis and to leak plasma

• in most tissues

fenestrated capillaries

• Have small windows for extra plasma leakage

• in kidney

• in synovial membrane

sinusoid capillaries

• Have large holes where RBC’s can enter/exit

• red marrow (new RBC can enter)

• liver/spleen (old RBC can leave)

venules

• smallest veins (microscopic)

• Venules merge to form veins

valves

• prevent backflow of blood

• Cusps forms from tunica intima

• veins

varicose veins

• occurs when valves prolapse

• lots of standing

• old age (loss of elastic fibers)

deep vein thrombosis

• a blood clot forms in a deep vein, usually in the leg or pelvis.

• Clot can break loose, travel to the lungs and block blood flow (pulmonary embolism)

arteriosclerosis

hardening of arteries

atherosclerosis

• fatty deposits (plaques) build up in arterial walls.

• Narrows arteries over time

• Can damage lining of blood vessel (rupture RBC, blood clot from tear)

hypertensive arteriosclerosis

hardening and thickening of arteries and arterioles caused by chronic high blood pressure

aneurysm

• “bulge” or “ballooning” in the wall of an artery due to weak areas in the blood vessel wall

• Most commonly seen in the brain and aorta

• Ruptured aneurysm is a medical emergency

Arteriovenous Malformation

• abnormal, tangled network of blood vessels where arteries and veins connect without a bed of capillaries

• Can lead to tissue damage, hemorrhagic stroke, or rupture

aorta

brachiocephalic trunk (right side only)

• splits into Common carotid a. and Subclavian a

subclavian artery (to arm)

common carotid artery (brain & face)

external carotid artery (to face)

internal carotid artery (to brain)

subclavian artery (under clavian)

axillary artery (armpit)

brachial artery (arm)

ulnar artery (pinky)

radial artery (thumb)

thoracic aorta

abdominal aorta artery (at the diaphragm)

celiac trunk

• (splits into branches that go to the stomach, spleen, and liver)

superior mesenteric artery (to various intestines)

renal artery (2) (to kidneys)

gonadal artery (2) (to gonads)

inferior mesenteric artery (to intestines)

abdominal aorta artery (until pelvic area)

common iliac artery

external iliac artery (leg)

internal iliac artery (to pelvic organs)

femoral artery (to thigh)

anterior tibial artery

superior vena cava vein (brachiocephalic veins merge)

brachiocephalic veins (2)

• internal jugular vein and subclavian vein merge

internal jugular vein (from brain)

• drains into brachiocephalic vein

external jugular vein (from face)

• drains into subclavian vein

brachiocephalic vein

subclavian vein

axillary vein

brachial vein

ulnar vein

radial vein

renal vein

gonadal vein

inferior vena cava (common iliac veins merge)

common iliac vein

external iliac vein

internal iliac vein

femoral vein