Anat & Phys II - Test 2

Functions of blood

transportation, regulation, protection

Formed elements of blood

erythrocytes, leukocytes, platelets

Plasma

Liquid part of blood

Plasma includes

water, ions, proteins, nutrients, hormones, wastes. Albumin, urea, fibrogen, glucose

Hematopoiesis

Formation of blood cells (RBC WBC & Platelets) in red bone marrow.

Hematocrit

percentage of blood volume occupied by red blood cells

Hemoglobin

An iron-containing protein in red blood cells that reversibly binds oxygen.

Lifespan of RBC

120 days

Anemia

A condition in which the blood is deficient in red blood cells, in hemoglobin, or in total volume. O2 capacity is reduced. Not adequate oxygen delivery to tissues

3 types of anemia

iron deficiency, sickle cell, pernicious

iron deficiency anemia

anemia resulting when there is not enough IRON to build HEMOGLOBIN for red blood cells. The most common type.

pernicious anemia

Vitamin B12 deficiency. Interferes with DNA synthesis of rapidly dividing cells. Common cause includes blood loss.

abnormal hemoglobin

sickle cell anemia

Erythropoiesis

formation of red blood cells

Low Blood O2 causes kidneys and liver to release

Erythropoietin (EPO)

Erythropoietin (EPO)

hormone secreted by the kidneys; stimulates red blood cell formation

Hypoxia

Low oxygen saturation of the body, not enough oxygen in the blood

Hypoxemia causes

blood loss/low RBC count
high altitude
increased exercise
loss of lung tissue in emphysema

What do you expect from someone who lives in high altitude

High RBC count

how does oxygen get transported in blood

Oxygen attaches to hemoglobin in red blood cells.

Worned out and damaged RBC are removed by

Spleen and liver

Leukocytes

white blood cells

Granulocytes

neutrophils, eosinophils, basophils

Neutrophils

Most abundant white blood cell, first responders. ., The most abundant type of white blood cell. Phagocytic and tend to self-destruct as they destroy foreign invaders, limiting their life span to a few days.

Basophils

A circulating leukocyte that produces histamine. Releases heparin to stop clotting

Eosinophils

elevated levels in the blood during asthma and parasitic infections
increased numbers during an allergic reaction

Agranulocytes

lymphocytes and monocytes

Lymphocytes

Smallest WBC, T cells and B cells. Important got immunity. Long life span

Monocytes

Largest WBC. Leave bloodstream to become macrophages

Leukopoiesis

formation of white blood cells in the bone marrow

myeloid stem cells

give rise to red blood cells, monocytes, neutrophils, eosinophils, basophils, and platelets

lymphoid stem cells

give rise to lymphocytes

HIV/AIDS

Low in T Cells

Platelets

Also called thrombocytes

Platelet function

They play a key role in retention of blood loss by forming a * plug at the site of tears when connective tissue is exposed. Serotonin is released and smooth muscles contract in the in walls of broken blood vessels

formation of platelets

thrombopoiesis: hematocytoblast to megakaryocyte to platelet

Hemostasis

stoppage of bleeding

Hemostasis steps

1. vascular spasm-slows bleeding allowing for next steps. Trigger by simulation in blood vessels wall
2. platelet plug formation- Triggered by exposure of platelets to collagen and the release of von Willebrand. Platelets adhere to surface to form plug
3. coagulation-Fibrinogen is converted to fibrin by coagulation cascade

Coagulation Cascade Pathways

intrinsic and extrinsic

Vitamin K

Helps blood clot

Plasmin

an enzyme that dissolves the fibrin of blood clots

plasma function

transport of nutrients, blood gases, wastes, chemical messengers, blood cells and platelets

plasma proteins

albumin (60%, maintains fluid balance), globulins (38%, antibodies/transport), and fibrinogen (2%, clotting), regulatory proteins (<1% enzymes, proenzymes, and hormones)

Albumin

Produced in liver. Responsible for blood colloid osmotic pressure.

colloid osmotic pressure

Pressure that tends to keep fluid in the intravascular compartment.

Low albumin levels cause

edema and drop in blood pressure

Globulins- plasma protein

antibodies

osmolarity of blood

the total molarity of those dissolved particles that cannot pass through the blood vessel wall

if osmolarity is too high

blood absorbs too much water, increasing the blood pressure

Is osmolarity is too low

too much water stays in tissue, blood pressure drops, and edema occurs

Viscosity of blood

how thick blood is which is dependent on size, weight and gender. whole blood: 4.5-5.5; plasma: 2.0

thrombus

stationary blood clot

embolus

A clot that breaks lose and travels through the bloodstream.

pulmonary pump

right side of the heart. Blood is pumped from right ventricle to lungs via pulmonary arteries

systemic pump

left side of the heart. Blood leaves ventricle through aorta to the body. Returning at the vena cavas then right atrium

blood flow of the heart order

-vena cava
-right atrium
-tricuspid
-right ventricle
-pulmonary arteries
-lungs (*oxygenated from here down!)
-pulmonary veins
-left atrium
-mitral / bicuspid
-left ventricle
-aorta

cardiac cycle

A complete heartbeat consisting of contraction and relaxation of both atria and both ventricles

1. Atrial systole

contraction of the atria initiated by the SA node, causing the ventricles to fill. P wave. AV valves are open. SEMILUNAR valves are closed.

3. Ventricular ejection (systole)

Contraction of ventricles. AV valves are closed. Semilunar valves are OPEN

2. Isovolumetric ventricular contraction

-start of systole
-ventricle contracts (increases pressure)
-AV and semilunar valves both closed
-no blood entering or exiting ventricle
AV VALVES create 'Lubb' S1

4. Isovolumetric relaxation

Diastole- heart relaxes but volume remains unchanged. AV valves closed. Semilunar valves closed. Semilunar cause 'dub' T Wave

5. ventricular filling (diastole)

AV valves open. Semilunar valves closed.

cardiac conduction system

a system of specialized muscle tissues that conducts electrical impulses that stimulate the heart to beat

cardiac conduction system pathway

1. SA node - "pacemaker", generates impulses
2. AV Node - "catches the signal", holds briefly
3. AV Bundle or bundle of his- connects atria to ventricles
4. Bundle Branches(right & left) - conduct impulses through system
5. Purkinje Fibers

EKG

(electrocardiogram) instrument used in measuring the electrical potential during a heartbeat. Records changes in heart that occurs in myocardium during cardiac cycle

during ventricle systole

atria are relaxed. Av valves are closed. Semilunar valves are open

The heart receives blood from the systemic circuit via

Superior and inferior vena cava

Factors that affect blood pressure

cardiac output, blood volume, viscosity, resistance, and elasticity of arteries

Anemia effect on blood pressure

Less hemoglobin leads to vasodilation which lowers BP. Heart compensates & heart rate and cardiac output increase

In tissues exchange in the capillaries by

Osmotic pressure, hydrostatic pressure and diffusion

Role of exercise in heart

Strengthens heart muscle. Improves blood circulation.

Why are pregnant Rh- women given an injection of Rh immune globulin?

Antibodies in the injection bind fetal RBC antigens so they cannot stimulate her immune system to produce anti-D antibodies.

What is NOT true of a patient with anemia

Blood viscosity is increased

A deficiency of ___ can cause pernicious anemia

Vitamin B12

The viscosity of blood is due more to the presence of ___ to any other factor

Erythrocytes

What is not normally found in plasma

glycogen

What would happen if all the hemoglobin contained within the RBC became free in plasma

It would significantly increase blood colloid osmotic pressure

Correction of hypoxemia is regulated by __________.

negative feedback loop

Some lymphocytes can survive as long as __________.

decades

Erythrocytes transport oxygen and __________.

carbon dioxide

What is not a function of blood

production of plasma hormones

Most strokes and heart attacks are caused by the abnormal clotting of blood in an unbroken vessel. Moreover, a piece of the __________ (clot) may break loose and begin to travel in the bloodstream as a(n) __________.

thrombus; embolus

The structural framework of a blood clot is formed by

a fibrin polymer

The cessation of bleeding is specifically called

hemostasis

The largest of the leukocytes, are the ________

monocytes

Most abundant granulocyte

neutrophils

Most abundant agranulocyte

lymphocyte

What is the final product of the breakdown of the organic nonprotein moiety of hemoglobin

bilirubin

Arteries

Blood vessels that carry blood away from the heart

Arterioles

small vessels that receive blood from the arteries-carry blood to capillaries

Capillaries

Microscopic vessel through which exchanges take place between the blood and cells of the body

Venules

small vessels that gather blood from the capillaries into the veins

Veins

Blood vessels that carry blood back to the heart

Tunics of blood vessels

tunica interna, tunica media, tunica externa

Capillaries are composed of

endothelium (simple squamous) and basal lamina

Tunica media is larger in

Arteries

sympathetic vasomotor nerves

regulate blood flow and renal resistance by altering arterioles. Constrict blood vessels and raise BP

cardiac sympathetic nerves

Nerves that increase heart rate and contractility and cardiac output

Baroreceptors

detect changes in blood pressure, sensors in aortic arch and carotid sinus

Cardiovascular center

composed of clusters of sympathetic neurons in medulla oblongata