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100 Cards in this Set

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Name the specialized lymph vessel that transports chyle. _____________________________

lacteals

Name the primary type of white blood cell associated with the lymphatic system. ___________

Neutrophils

Describe one difference between a blood capillary and a lymph capillary. _________________

1) are blind-endtubes.


2) have larger diameters with lower resistance and pressure.


3) havethinner walls that are more permeable.


4) typically have a flattened orirregular shaped lumen.

Name the lymphatic duct that drains the right chest, right arm and right head. _____________

right lymphatic duct

Name the blood vessel that the previous duct empties into. ____________________________

The rightlymphatic duct empties into the right subclavian vein.

Name the lymphatic duct that drains the legs and trunk. _______________________________

thoracic duct

Name predominant tissue type of lymphatic tissue. __________________________________

connective tissue

Name three locations of lymph nodes. ____________________________________________-

cervicalregion, axillary region, and inguinal region

Name the vessel that brings in “unfiltered” lymph to the lymph node. _____________________

Afferent lymphatic vessels

Name the lymph organ associated with the storage site for old, dying or dead red blood cells. ___________________________________________________________________________

Spleen

Name the four types of tonsils. __________________________________________________

palatine tonsils


pharyngeal tonsil


lingual tonsils


tubal tonsils

Who would have the largest thymus (infant, pre-teen, adult, or elderly)? __________________

Infant

What type of cell matures in the thymus gland? _____________________________________

T-lymphocytes

Where are Peyer’s Patches commonly found? ______________________________________

deepin the epithelial linings of the distal small intestine

Name a lymph organ found in the junction between the small and large intestines. __________

appendix, atype of MALT

How fast is lymph flow compared to blood flow? _____________________________________

verylow

Name one physical barrier of yournon-specific defenses. _____________________________

immunological surveillance

Name the non-specific cell that punches holes inthe cell membrane of foreign cells using enzymes called perforins. ______________________________________________________

NK cells

Which type of interferon is produced by cells infected with a virus to enhance the resistance of other body cells to the infection? _________________________________________________

Alpha interferons

The process by which antibodies and complement “coat” a microorganism to make it more susceptible to phagocytosis is called ______________________________________________

Opsonization

The four cardinal signs of inflammation are: ________________________________________

redness


heat


swelling


pain

Fever inducing chemicals are called ______________________________________________

Pyrogens

Name the clone that forms from the stimulation of a B lymphocyte by antigen and is responsible for secreting antibodies. ______________________________________________

Plasma

Name the term that refers to “programmed celldeath”. _______________________________

apoptosis

APCs with an MCH Class I protein stimulate which type of T lymphocytes to kill the infected cell? ______________________________________________________________________

cytotoxic

The variable region in the structure of an antibody is known as the ______________________.

immunoglobulins

The antibody function best seen in the “clumping” of RBC during blood typing tests is called __________________________________________________________________________.

agglutination

The type of T-cell that does not attack infected cells directly but instead activate other immune system cells by the secretion of cytokines and interleukin 2 is called ____________________.

Helper T cells

The immunoglobulin (antibody) class associated with breast milk is _____________________.

IGA immunoglobulin A

The immunoglobulin class associated with crossing the placenta is _____________________.

IgG immunoglobulin G

The enzyme used by natural killer cells and Tc Cells to kill infection is called ______________.

Cytotoxic

Name the cell that hangs around after the infection has been defeated in case you encounter the infection again. ___________________________________________________________

Plasma B-cells

A vaccine is best described as _____________ ____________ ____________ humoral immunity.

antibody-mediated immunity

Contact dermatitis is an example of which type of hypersensitivity? ______________________

Delayed hypersensitivity (Type IV)

Name one example of an autoimmune disease. _____________________________________

Multiplesclerosis

Oxygen combines with hemoglobin to form ________________________________________.

oxyhemoglobin (HbO2).

The greatest percentage of carbon dioxide is transported in plasma as _________________.

PCO2

Exchange of gases between the blood and the tissue cells is known as __________________.

Internal respiration

The lymphatic system has three important functions:

drains excess interstitialfluid from the interstitial space and transports it to the bloodstream. Once this tissue fluid enters into thelymphatic vessels, it is no longer called interstitial fluid; it is nowreferred to as lymph. Any blockage in the normal drainage of lymphproduces lymphedema.


houses thephagocytic cells and lymphocytes that clean the tissue fluid before it isdumped into circulation.


absorbsdigested fats from the intestine by specialized lymph vessels called lacteals. The fatty lymph is known as chyle.



Thelymphatic system includes:

the vessels, cells,tissues, and organs responsible for defending the body against bothenvironmental hazards (such as various pathogens) and internal threats (such ascancer cells).

LYMPH VESSELS

carry lymph fromthe peripheral tissues to the venous system. The lymphatic network begins with lymphatic capillaries, which merge toform progressively larger vessels as they make their way towards circulation.

Lymph capillaries

presentin almost every tissue and organ in the body; are believed to be as abundant asblood capillaries.


in areas of thebody that lack a blood supply, such as the cornea of the eye, and are alsoabsent from the central nervous system and bone marrow.

Lymphaticcapillaries differ from blood capillaries in that they:

1) are blind-endtubes,


2) have larger diameters with lower resistance and pressure,


3) havethinner walls that are more permeable, and


4) typically have a flattened orirregular shaped lumen.

lymphatic capillaries are lined by

simple squamous epithelium, the basal lamina is incomplete or absent. Furthermore, the endothelial cells overlapforming a type of one-way valve called a mini-valve. The mini-valves permit the entry of fluidsand solutes (such as proteins) as well as viruses, bacteria, and cell debris,but prevent their return to the intercellular spaces.

Lymph collecting vessels

from the lymphcapillaries, lymph flows into larger lymph collecting vessels that lead towardthe body’s trunk. Like veins, thelymph collecting vessels possess valveswhich are located very close together and bulge noticeably. As a result, large lymph collecting vesselsresemble a string of beads. Pressureswithin the lymph collecting vessels are very low, and the valves are requiredto prevent the backflow of lymph and to maintain normal lymph flow toward thethoracic cavity.

Superficial lymph collecting vessels

are located inthe subcutaneous layer deep to the skin; in the areolar tissues of the mucousmembranes lining the digestive, respiratory, urinary, and reproductive tracts;and in the areolar tissues of the serous membranes lining the pleural,pericardial, and peritoneal membranes.

Deep lymph collecting vessels

accompany thedeep arteries and veins supplying skeletal muscles and other organs of theneck, limbs, trunk and the walls of visceral organs.

Lymph trunks:

the superficial and deep lymph collecting vessels converge to form larger vessels known as lymphatic trunks and are named by the areas of body they drain

Thejugular trunks and are

located inthe neck and drain the head.

Thesubclavian trunks are

locatedin the shoulders and drain the arms.

The bronchomediastinal trunks are

located in thechest and drain the thoracic cavity and lungs.

Thelumbar trunks are

located in thelower back and drain the pelvis and lower limbs.

Theintestinal trunk is

located in theabdomen and drains the walls of the digestive organs.

Blockageof the lumbar trunks or subclavian trunks by a filarial worm

Wuchereria bancrofti, causes severe lymphedema known as Elephantiasis.

Lymph ducts

the lymph trunks merge to form the twolargest lymphatic vessels called the right lymphatic duct and thoracic duct.

right lymphatic duct

forms from the merger of the right jugular trunk, the right subclavian trunk and the right bronchomediastinal trunk. The right lymphatic duct drains the right side of the head, right arm, right shoulder, and right side of the thoracic cavity. The right lymphatic duct empties into the right subclavian vein.

Thethoracic duct

ascends along the left side of the vertebral column, collecting lymph from the left bronchomediastinal trunk, the left subclavian trunk, the left jugular trunk. At the base of the thoracic duct is an enlarged sac-like chamber called the cisterna chyli which receives lymph from the lumbar trunk and intestinal trunk. The thoracic duct drains the left side of the head, the left arm, the left shoulder, and the left side of the thoracic cavity, all of the abdomen, pelvic region and both legs. It empties into the left subclavian vein.

LYMPH CELLS

areresponsible for the immune functions of the lymphatic system.

lymphocytes/span>

account for 20-30percent of the circulating leukocyte populations, circulating lymphocytes areonly a small fraction of the total lymphocyte population. The body contains some 1012lymphocytes with a combined weight of more than a kilogram (2.2 lbs). The majority of these reside within the lymphorgans of the body such as the lymph nodes, spleen, tonsils, thymus, etc.

Three classes of lymphocytes circulate in blood and are sensitive to specific antigens:

T cells


B cells


NK cells

T cells

approximately 80percent of the circulating lymphocytes are classified as T cells. T cells are diverse and provide cell-mediated immunity (discussedlater).

B cells

account for 10-15 of circulating lymphocytes. When stimulated by antigen, B cells differentiate into plasma cells, which produce and secrete antibodies. B cells are said to be responsible for antibody-mediated immunity (also called humoral immunity) because antibodies circulate widely within body fluids and attack targets with foreign antigens.

NK cells

only about 5-10 percent of circulating lymphocytes are Natural Killer cells. This particular group of lymphocytes is part of the body’s non-specific defenses and they attack foreign cells, body cells infected with viruses, and cancer cells that appear in normal tissues. Their continuous monitoring of peripheral tissues has been called immunological surveillance.

lymphocyteproduction

calledlymphopoiesis, involves the red bonemarrow, thymus, and peripheral lymphoid tissues.

PRIMARY LYMPHATIC ORGANS

in contrast to lymph nodules, are separated from the surrounding tissues by a fibrous connective tissue called the capsule. Include the lymph nodes, thymus, and spleen.

Bone Marrow

is a loosecollection of cells where hematopoiesis occurs, and the yellow bone marrow is asite of energy storage, which consists largely of fat cells. The B cellundergoes nearly all of its development in the red bone marrow, whereas theimmature T cell, called a thymocyte, leaves the bone marrow and matures largelyin the thymus gland.

Thymus

producesseveral hormones, collectively called the thymosins,that are important to the development of functional T cells, and thus to the maintenanceof normal body defenses.

Thymus Facts

is large when aperson is born and continues to grow through childhood as the individual isexposed to infection. By puberty, thethymus weighs 40 g. However, afterpuberty, it gradually diminishes in size and becomes increasingly fibrous in aprocess known as involution. By the time an individual reaches age 50, thethymus may weigh less than 12 g and is correlated with an increase insusceptibility to infection and disease.


The thymus issurrounded by a capsule that dividesit into left and right lobes. Fibrous partitions called septa originate at the capsule anddivide the lobes into lobulesaveraging 2 mm in diameter.


Each lobuleconsists of a dark outer cortex anda lighter central medulla. The medulla is dominated by thymic corpuscles not present in thecortex.

SECONDARY LYMPHATIC ORGANS

is a specializedform of connective tissue called reticularconnective tissue which resembles areolar tissue but contains largernumbers of collagen, elastin, and reticular fibers.

Lymph nodes

aresmall lymphoid organs ranging in diameter from 1 mm to 25 mm. The shape of a typical lymph node resemblesthat of a kidney bean. The largestcollections of lymph nodes are located in the cervical region, axillary region,and inguinal region. As lymph flows througha lymph node, at least 99% of the antigens in the lymph are removed and theimmune response is stimulated as needed. Chey3W7VCsB3t

Swollenlymph nodes

arecalled buboes

Afferent lymphatic vessels

transport “dirty”lymph into the lymph node from the peripheral tissues. The afferent lymphatic vessels penetrate the capsule of the lymph node on the sideopposite the hilum (a shallowdepression where the blood vessels and nerves enter and leave the organ).

The path of lymphflow through a lymph node is as follows:

The afferentvessels deliver the lymph to the subcapsularspace, a meshwork of reticular fibers, macrophages, and dendritic cells. Dendriticcells are involved in the initiation of the immune response.


Lymph next flowsin the outer cortex which contains B cells within germinal centers thatresemble those of lymphoid nodules.


Lymph then flowsthrough the lymph sinuses to the deepcortex which is dominated by T cells.


Lymph continuesinto the medullary sinuses at thecore of the lymph node. This regioncontains B cells and plasma cells.


Efferent lymphatic vessels "Clean"

Efferent lymphatic vessels

drain the “cleaned” lymph out of the lymph node and exit at the hilum.

Spleen

is the largest lymphoid organ and performs the same functions for blood that the lymph nodes perform for lymph. The spleen removes abnormal red blood cells, stores iron from recycled RBCs, and initiates immune response by B cells and T cells to antigens in the bloodstream.

Thespleen is surrounded

by a capsule containing collagen and elastinfibers. The spleen tears so easily thata seemingly minor impact to the left side of the abdomen can rupture thecapsule. Because it is so fragile, it isdifficult to repair and is instead typically removed in a process called a splenectomy.

Splenic blood vessels and lymphatic vessels communicate

withthe spleen on the medial surface (also called visceral surface) at the hilum. The medial surface also has two shallowdepressions that conform to the shape of the stomach (gastric area) and that of the kidney (renal area).r

Fibrous partitions

called trabeculae, radiate outward toward the capsule through the interior from the hilum. Blood vessels travel within the trabeculae.

Thecellular components

withinthe spleen constitute the pulp. The redpulp contains large quantities of red blood cells, whereas the white pulp resembles lymphoid nodulesand contains lymphocytes.

Theunusual circulatory arrangement

within the spleengives the phagocytes of the spleen an opportunity to identify and engulf anydamaged or infected cells in circulating blood.

LYMPH NODULES

areas of denselypacked lymph tissue or lymphocytes are called lymph nodules. Their boundaries are not distinct becausealthough they may cluster together and form large masses, there is no fibrous capsule surrounding them.

Tonsils

are large lymphoid nodules in the walls of the pharynx.


Left and right palatine tonsils


A single pharyngeal tonsil


pair of lingual tonsils


tubal tonsils

Left and right palatine tonsils

are located at the posterior, inferior margin of the oral cavity.

A single pharyngeal tonsil

(often called the adenoid) lies in the posterior superior wall of the nasopharynx,

pair of lingual tonsils

lies deep to the mucous epithelium covering the base of the tongue.

tubal tonsils

isfound in the base of each of the pharyngotympanic tubes.

tonsillitis

Mostof the time, our tonsils go unnoticed unless they are infected and swollen

Mucosa-associated lymphoid tissue (MALT)

protects the rest of the epithelia of the digestive, urinary, and reproductive tracts from pathogens and toxins. The appendix, a type of MALT found at the junction of the large and small intestine, contains rapidly-dividing lymphocytes. The peyer’s patches, a type of MALT found clustered deep in the epithelial linings of the distal small intestine, are especially important for immune responses against ingested substances.

Bronchus-associated lymphoid tissue (BALT)

protects theepithelia of the respiratory tract. These are effective against many inhaled pathogens.

Canceroriginating in any lymphoid cells or tissues is called

lymphoma. Hodgkin’s lymphoma is characterized by thepresence of Reed-Sternberg cells and has been associated with the Epstein-Barrvirus in 70% of cases. All other types oflymphoma are called Non-Hodgkin’s lymphoma of which there are at least 61types.

Characteristicsof the innate body defenses:

1. present and functioning at birth.


2. are non-specific, that is, they donot distinguish one threat from another and respond the same way regardless ofthe invading agent.


3. tend to be more localized andgenerally attack the infection where the invading agent is attempting to gainentry into the body.


4. no memory. Regardless of thenumber of times the body encounters the invading agent, innate defenses do notimprove their response to the infection.

Innate immunity includes physical barriers

cellular defensesvia phagocytes and NK cells, and chemical defenses via complement, inflammatorychemicals, interferon, and pyrogens.

PHYSICAL BARRIERS

keephazardous organisms and materials outside the body.


Skin


Mucous membranes


Skin

the integumentarysystem provides the major physical barrier to the external environment.

The epidermis of the skin is composed of

stratified squamous epithelium with keratinizedcells and a network of desmosomes that lock adjacent cells together.

Hairs

found on most areas of the body’s surface provide some protection against mechanical abrasion (especially on the scalp), and they often prevent hazardous materials or insects from contacting the skin.

epidermal surfaces

receive thesecretions of sweat glands. Thesesecretions, which flush the surfaces to wash away microorganisms and chemicalagents, may also contain bactericidal chemicals called defensins, destructive enzymes called lysozymes, and antibodies. receivesecretions from sebaceous glands. Sebum not only lubricates the skin butalso reduces the amount of free water on the surface of the skin, therebycreating an arid environment that most microorganisms find inhospitable.

Lymphatic system Three Functions

1) Drains excess interstitial fluid space and transports it to the bloodstream.


2) Houses the phagocytic cells and lymphocytes that clean the tissue fluid before it is dumped into circulation.


3) Absorbs digested fats from intestine by specialized lymph vessels called Lacteals. The fatty lymph is as Chyle.

Lymph Ducts

Right Lymphatic Duct


Thoracic Duct

Right Lymphatic Duct

forms from the merger of the right jugular trunk the right subclavian trunk and the right brochomediastinal trunk. The right lymphatic duct drains the right side of the head, right arm, right shoulder, and the right thoracic cavity. The right lymphatic duct empties into the right subclavian vein.