Exam 5 Flashcards
what does blood transport
nutrients
wastes
hormones
body heat
the only fluid tissue in the human body
blood
components of blood
formed elements (living cells)
plasma (nonliving fluid matrix)
separated blood layers
erythrocytes (bottom)
buffy coat (leukocytes and plateletes)
plasma (top)
blood volume in body
5 to 6 liters or 6 quarts
8% of body weight
Plasma makeup
90% water
includes dissolved substances (nutrients, salts, respiratory gasses, hormones, plasma proteins, waste products)
Plasma Proteins
made in the liver
includes albumin, clotting proteins, and antibodies
erthrocytes (RBCs)
red blood cells
main function is to carry oxygen
Anemia
decrease in the oxygen carrying ability of blood
Sickle Cell Anemia
abnormally shaped hemoglobin
Polcythemia
disorder resulting from excessive or abnormal increase of RBCs
Leukocytes (WBCs)
white blood cells
crucial in body’s defense against disease
Leokocytosis
generally indicates an infection
Leukopenia
abnormally low WBC count
Leukemia
cancerous bone marrow
List the WBCs from most to least abundant
Neutrophils
Lymphocytes
Monocytes
Eosinophils
Basophils
Neutrophils
function as phagocytes at active sites of infection
numbers increase during infection
Eosinophils
function is to kill parasitic worms and play a role in allergy attacks
Basophils
contain heparin (anticoagulant)
Lymphocytes
play a role in immune response
Hematopoiesis
blood cell formation
occurs in red bone marrow
forms 2 types of descendants (lymphoid and myeloid stem cells)
Thrombopoietin
stimulates production of platelets from megakaryocytes
Hemostasis phases
- Vascular spasms
- Platelet plug formation
- Coagulation (blood clotting)
Vascular spasms
immediate response to blood vessel injury
spasms narrow the blood vessel
Platelet plug formation
platelets become “sticky” and cling to fibers
pile up to form a platelet plug
Coagulation
injured tissues release tissue factor
fibrin forms a meshwork
Thrombus
a clot in an unbroken blood vessel
can be deadly in areas like lungs
Embolus
a thrombus that breaks away and flows freely in bloodstream
can clog vessels in critical areas like the brain
Thrombocytopenia
insufficient number of circulating platelets
small purplish blotches on the skin
even normal movements can cause bleeding
Hemophilia
hereditary bleeding disorder
normal clotting factors are missing
Sites of blood cell formation
the fetal liver and spleen are early sites of BCF
bone marrow takes over hematopoiesis by the 7th month
The lymphatic system consists of 2 semi-independent parts
lymphatic vessels
lymphoid tissues and organs
Lymphatic system functions
transports escaped fluids from the cardiovascular system back to the blood
plays essential roles in body defense and resistance to disease
Lymphatics
form a one way system
lymph flows only toward the heart
Lymph capillaries
weave between tissue cells and blood capillaries
walls overlap to form flaplike minivalves
fluid leaks into lymph capillaries
capillaries are anchored to connective tissue by filaments
higher pressure on the inside closes minivalves
fluid is forced along the vessel
Lymphatic collective vessels
collect lymph from lymph capillaries
carry lymph to and away from lymph nodes
return fluid to circulatory veins near the heart
Lymph transport is aided by
milking action of skeletal muscles
pressure changes in thorax during breathing
smooth muscle in walls of lymphatics
Lymph nodes
filter lymph before it is returned to the blood
harmful bacteria are filtered
defense cells within lymph nodes
Macrophages
engulf and destroy bacteria, viruses, and other foreign substance in lymph
Lymphocytes
respond to foreign substances in lymph
Cortex (outer part)
contains follicles-collections of lymphocytes
Medulla (inner part)
contains phagocytic macrophages
Flow of lymph through nodes
lymph enters the convex slide through afferent lymphatic vessels
lymph flows through a number of sinuses inside the node
lymph exits through efferent lymphatic vessels
because there are fewer efferent than afferent vessels, flow is slowed
Other lymphoid organs that contribute to lymphatic function
spleen, thymus, tonsils, Peyer’s patches, appendix
Spleen
filters and cleans blood of bacteria, viruses, and debris
provides a site for lymphocyte proliferation and immune surveillance
destroys worn out blood cells
acts as a blood reservoir
Thymus
functions at peak levels only during youth
Tonsils
trap and remove bacteria and other foreign pathogens
Peyer’s patches
macrophages capture and destroy bacteria in the intestine
Mucosa-associated lymphoid tissue (MALT)
Peyer’s patches, tonsils, appendix
acts as a sentinel to protect respiratory and digestive tracts
Innate (nonspecific) defense system
responds immediately to protect body from foreign materials
Adaptive (specific) defense system
fights invaders that get past the innate system
Body surface coverings
intact skin, mucous membranes
Natural Killer (NK) cells
burst and kill cancer cells
release chemicals called “perforin” and “granzymes” to degrade target cell contents
Inflammatory response
triggered when body tissues are injured
damaged cells release histamine and kinin
Life span of a RBC
around 120 days
Diapedesis
Neutrophils squeeze through the capillary walls to sites of infection
Phagocytes
cells such as neutrophils and macrophages engulf foreign material by phagocytosis
the phagocytic vesicle is fused with a lysosome and enzymes digest the cell’s contents
Antimicrobial proteins
enhance innate defenses by attacking microorganisms directly, hindering reproduction of microorganisms
most important types: complement proteins and interferon
Complement proteins
refers to a group of at least 20 plasma proteins that circulate in the plasm
complement is activated when these plasma proteins encounter and attach to cells
Interferons
small proteins secreted by virus-infected cells
bind to membrane receptors on healthy cell surfaces to interfere with the ability of viruses to multiply
Fever
inhibits the release of iron and zinc needed by bacteria from the liver and spleen
increases the speed of repair processes
Adaptive body defenses
3rd line of defense, antigens are targeted and destroyed by antibodies
3 aspects of adaptive defense
antigen specific
systemic
memory
2 arms of the adaptive defense system
humoral immunity
cellular immunity
Humoral immunity
antibody-mediated immunity
provided by antibodies present in body fluids
Cellular immunity
cell-mediated immunity
targets virus-infected cells, cancer cells, and cells of foreign grafts
Haptens
incomplete antigens that are not antigenic themselves
poison ivy, pet dander, detergents, hair dyes, and cosmetics
Lymphocytes
B cells and T cells
arise from hemocytoblasts of bone marrow
Immunocompetence
the capability to respond to a specific antigen by binding to it with antigen specific receptors that appear on the lymphocyte’s surface
T cells
develop in the thymus and oversee cell mediated immunity
B cells
develop in the bone marrow and provide humoral immunity
Active immunity
naturally acquired during bacterial and viral infections
artificially acquired from vaccines
Passive immunity
naturally acquired from breast milk
artificially acquired from immune serum
immunologically memory does not occur
protection is short-lived (2-3 weeks)
Autografts
tissue transplanted from 1 site to another on the same person
Isografts
tissue grafts from a genetically identical person
Allografts
tissue taken from a person other than an identical twin
Xenografts
tissue taken from a different animal species
Disorders of Immunity
allergies, autoimmune diseases, immunodefiencies
Myasthenia gravis
impairs communication between nerves and skeletal muscle
Graves disease
thyroid gland produces excess thyroxine
Multiple sclerosis
white matter of brain and spinal cord is destroyed
Type 1 diabetes mellituse
destroys pancreatic beta cells
Systemic lupus erythematosis
affects kidney, heart, lungs, and skin
Glomerulonephritis
severe impairment of kidney function due to acute inflammation
SCID
congenital immunodeficiency
HIV and AIDS
acquired immunodeficiency
