Aphy102 - Marieb - Chapter 20 - Lymphatic System

Front 1

What's the main function of the lymphatic system?

Back 1

To collect and transport tissue fluids from the intercellular spaces in all the tissues of the body back to the veins in the blood system.

Front 2

The lymphatic system plays a vital role in returning what kind of proteins to the bloodstream?

Back 2

Plasma proteins

Front 3

What are the six main functions of the lymphatic system? Try this mnemonic device involving a british stripper -- For Five Pounds Lola Dances Twice

Back 3

1) Fluids -- transportation of tissue fluids from intercellular spaces to veins

2) Fats -- transportation of digested fats from villi in small intestine through lacteals and lymph vessels to blood strem

3) Plasma -- returning plasma proteins to the bloodstream

4) Lymphocytes -- creation of lymphocytes

4) Defense -- defending against invading microorganisms and disease by removing and destroying them

6) Transportation -- moving large molecular compounds from their manufactured sites to the bloodstream

Front 4

The name of the dilated sac at the base of the thoracic duct is the ____ ____.

Back 4

Cisterna chyli

Front 5

Define "lymphatic vessel."

Back 5

A one-way system in which lymph flows toward the heart

Front 6

What are four types of lymph vessels?

Back 6

1) Capillaries (microscopic, permeable, blind-ended)

2) Lymphatic collecting vessels

3) Ducts

4) Trunks

Front 7

What are three main characteristics that differentiate lymphatic capillaries from blood capillaries?

Back 7

1) They're remarkably permeable

2) They have loosely joined endothelial minivalves

3) They withstand interstitial pressure and remain open

Front 8

What do minivalves allow to enter lymph capillaries?

Back 8

Interstitial fluid

Front 9

What don't minivalves allow to escape from lymph capillaries?

Back 9

lymph

Front 10

What three things can lymph capillaries absorb during inflammation?

Back 10

1) Cell debris

2) Pathogens

3) Cancer cells

Front 11

What are lacteals?

Back 11

Specialized lymph capillaries found in intestinal mucosa that absorb digested fat and deliver chyle to the blood

Front 12

What are lymphatic trunks?

Back 12

Large lymphatic vessels formed by the union of the largest collecting ducts

Front 13

What are the major lymphatic trunks?

Back 13

Paired trunks:

1) Lumbar trunks
2) Bronchomediastinal trunks
3) Subclavian trunks
4) Jugular trunks

Single trunks:

1) Intestinal trunk

Front 14

What are the two large lymphatic ducts called?

Back 14

The right lymphatic duct and the thoracic duct

Front 15

What areas of the body does the right lymphatic duct serve?

Back 15

1) Right arm
2) Right side of head and neck
3) Right thoracic region

Front 16

To what vein does the right lymphatic duct deliver lymph?

Back 16

Right subclavian vein

Front 17

What areas of the body does the thoracic duct serve?

Back 17

1) Lower extremities
2) Abdomen
3) Left arm
4) Left side of head and neck
5) Left thoracic region

Front 18

To what vein does the thoracic duct deliver lymph?

Back 18

Left subclavian vein

Front 19

Does the lymphatic system have any sort of organ that serves as a pump?

Back 19

No

Front 20

What methods do lymph vessels use to propel lymph?

Back 20

The same as veins -- muscular pumping, respiratory pumping.

Also, pulsations of nearby arteries promote lymph flow.

Finally, contractions of smooth muscle in lymphatic trunks propel lymph.

Front 21

Lymph vessels are usually packaged with what?

Back 21

With blood vessels in connective tissue sheaths

Front 22

How much lymph enters the bloodstream each day?

Back 22

About 3L

Front 23

What are the main cells involved in the immune response?

Back 23

Lymphocytes

Front 24

What are the two main varieties of lymphocytes?

Back 24

T cells and B cells

Front 25

Against what do T and B cells protect us?

Back 25

Antigens -- these include bateria and their toxins, viruses, mismatched RBCs and cancer cells

Front 26

What do T cells do?

Back 26

Manage the immune response and attack and destroy foreign cells

Front 27

What do B cells do?

Back 27

Produce plasma cells which secrete antibodies

Front 28

What do antibodies do?

Back 28

Immobilize antigens

Front 29

Besides lymphocytes, what are the main lymphoid cells?

Back 29

1) Macrophages
2) Dendritic cells
3) Reticular cells

Front 30

What do macrophages do?

Back 30

Phagocytize foreign substances and help activate T cells

Front 31

What are dendritic cells?

Back 31

Spiny-looking cells that function similarly to macrophages

Front 32

What are reticular cells?

Back 32

Fibroblast-like cells that produce a stroma, which is a network that supports other lymphoid cells in lymphoid organs

Front 33

What are the two types of lymphoid tissue?

Back 33

Reticular connective tissue and diffuse lymphatic tissue

Front 34

What is reticular connective tissue?

Back 34

Solid, spherical bodies consisting of tightly packed reticular elements and cells

Front 35

Does a lymphatic follicle (nodule) consist of reticular connective tissue or diffuse lymphatic tissue?

Back 35

reticular connective tissue

Front 36

What's diffuse lymphatic tissue?

Back 36

Scattered reticular tissue elements in every body organ

Front 37

What are the principle lymph organs?

Back 37

Lymph nodes

Front 38

Where are aggregations of lymph nodes found?

Back 38

Along lymphatic vessels near the surface in the inguinal, axillary, and cervical regions of the body

Front 39

What are the two main functions of lymph nodes?

Back 39

1) Filtration, in which macrophages destroy microorganisms and debris

2) Immune system activation, or monitoring for antigens and mounting attacks against them

Front 40

What are the two histologically distinct regions of a lymph node?

Back 40

Cortex and medulla

Front 41

What extends inward from a lymph node's capsule, dividing it into compartments?

Back 41

Trabeculae

Front 42

What's a brief physical description of lymph nodes?

Back 42

Bean shaped, surrounded by a fibrous capsule

Front 43

What does a lymph node cortex contain?

Back 43

Follicles with germinal centers, heavy with dividing B cells

Front 44

What type of cells practically encapsulate lymph node follicles?

Back 44

Dendritic cells

Front 45

What does the deep cortex of a lymph node contain?

Back 45

T cells in transit

Front 46

When are T cells present in blood, lymph nodes, and the lymphatic stream?

Back 46

Always

Front 47

____ ____ extend from the cortex and contain B cells, T cells, and Plasma cells.

Back 47

Medullary cords

Front 48

Throughout a lymph node you will find ____ _____ crisscrossed by reticular fibers.

Back 48

lymph sinuses

Front 49

Where do macrophages reside?

Back 49

On reticular fibers in lymph sinuses

Front 50

Besides lymph nodes, what lymphoid organs do we have?

Back 50

Spleen, thymus gland, tonsils

Front 51

Where else do we find lymphoid tissue?

Back 51

Scattered in connective tissue and in Peyer's patches in the intestines

Front 52

What organs filter lymph?

Back 52

Lymph nodes

Front 53

What's the largest lymphoid organ?

Back 53

The spleen

Front 54

Where is the spleen located?

Back 54

On the left side of the abdominal cavity beneath the diaphragm, extending to curl around the anterior aspect of the stomach.

Front 55

What blood vessels serve the spleen?

Back 55

Splenic artery and vein

Front 56

What are the spleen's three main functions?

Back 56

1) Proliferation of lymphocytes
2) Immune surveillance and response
3) Cleansing of blood

Front 57

What are the secondary functions of the spleen?

Back 57

Breakdown of RBC products for later use, salvaging and storing iron for later use in bone marrow, production of fetal erythrocytes, blood platelet storage

Front 58

Briefly describe the structure of the spleen

Back 58

Surrounded by a fibrous capsule, it has trabeculae that extend inward and it contains lymphocytes, macrophages, and huge numbers of erythrocytes

Front 59

What are the two distinct sections of the spleen?

Back 59

Red pulp and white pulp

Front 60

Describe white pulp of the spleen

Back 60

An area containing mostly lymphocytes suspended in reticular fibers and involved in immune functions

Front 61

Describe red pulp of the spleen

Back 61

Splenic tissue concerned with disposal of worn-out RBCs and bloodborne pathogens

Front 62

Where do you find most white pulp in the spleen?

Back 62

Clustered around arteries

Front 63

What's the thymus gland?

Back 63

A bilobed organ that secretes hormones (thymosin and thymopoietin) that cause T lymphocytes to become immunocompetent

Front 64

define "immunocompetent."

Back 64

Possessing the capacity for a normal immune response

Front 65

With what does the size of the thymus gland vary?

Back 65

age

Front 66

When is the thymus gland most active?

Back 66

Childhood

Front 67

Where is the thymus gland found in infants?

Back 67

In the inferior neck extending into the mediastinum where it partially overlies the heart

Front 68

What happens to the thymus gland during adolescence?

Back 68

It stops growing and begins to atrophy through adulthood

Front 69

What are the two portions of a thymic lobe?

Back 69

Outer cortex, inner medulla

Front 70

What does the outer cortex of a thymic lobe contain?

Back 70

Densely packed lymphocytes and scattered macrophages

Front 71

What does the inner medulla of a thymic lobe contain?

Back 71

A few lymphocytes and thymic (Hassal's) corpuscles

Front 72

What two characteristics make the thymus gland different from other lymphoid organs?

Back 72

1) It functions strictly in T cell maturation

2) it does not directly fight antigens

Front 73

Of what does the stroma of the thymus consist?

Back 73

Star-shaped epithelial cells (not reticular fibers)

Front 74

What do the star-shaped endothelial cells found in the stroma of the thymus gland do?

Back 74

Secrete hormones that stimulate lymphocytes to become immunocompetent

Front 75

What are the simplest lymphoid organs?

Back 75

Tonsils

Front 76

What are the four groups of tonsils called?

Back 76

1) Palatine tonsils
2) Pharyngeal tonsils
3) Lingual tonsils
4) Tubal tonsils

Front 77

Where are the palatine tonsils found?

Back 77

Either side of the posterior end of the oral cavity

Front 78

Where are lingual tonsils found?

Back 78

The base of the tongue

Front 79

Where is the pharyngeal tonsil found?

Back 79

Posterior wall of the nasopharynx

Front 80

Where are the tubal tonsils found?

Back 80

Surrounding the openings of the auditory tubes into the pharynx

Front 81

What do tonsils do?

Back 81

Tonsils trap and destroy bacteria and particulate matter in their crypts

Front 82

What do tonsils consist of?

Back 82

Follicles with germinal centers

Front 83

What are the functions of Peyer's patches and the appendix?

Back 83

1) Destroying bacteria and preventing them from breaching the intestinal wall

2) Generating memory lymphocytes for long-term immunity

Front 84

What is MALT?

Back 84

Mucosa-associated lymph tissue

Front 85

What does MALT consist of?

Back 85

Peyer's patches, tonsils, appendix, and the walls of bronchi in the respiratory tract