LYMPHATIC SYSTEM Flashcards
originate as small, dead-end tubes
called lymphatic capillaries
Lymphatic vessels
The unidirectional valves divide lymphatic vessels
into a series of chambers, which function as “primitive
hearts.
” Lymph moves into a chamber, smooth muscle in
the chamber wall contracts, and lymph moves into the
next chambe
1.Contraction oflymphatic vessels
Form a one-way system
Lymphatic vessels
Excess fluid passes through the tissue spaces and
enters lymphatic capillaries to become lymph.
flows only toward the heart
Lymph
lymphatic vessels
are compressed, causing lymph to mov
2.Contraction of skeleta
During inspiration, pressure in the thoracic cavity decreases,
lymphatic vessels expand, and lymph flows into them. During
expiration, pressure in the thoracic cavity increases, and
lymphatic vessels are compressed, causing lymph to
Thoracic pressure changes
Are round, oval, or bean-shaped structures ranging from 1mm to 25mm long. It is distributed along the various lymphatic vessels.
Lymph nodes
After passing through the lymph nodes, the lymphatic vessels converge to form larger vessels called ___, each of which drains lymph from a major portion of the body
lymphatic trunks
filter lymph before it is returned to the blood
Lymph nodes
engulf and destroy bacteria, viruses, and
other foreign substances in lymph
- Macrophages -
respond to foreign substances
- Lymphocytes -
Contains phagocytic macrophages
Medulla inner part
Contains follicles- collections of
lymphocytes
Germinal centers enlarge when antibodies are released by plasma cells
- Cortex (outerpart)
Jugular trunks drain lymph from the head and neck
Subclavian trunks drain lymph from the upper limbs, superficial
thoracic wall, and mammary glands
Bronchomediastinal trunks drain lymph from the thoracic
organs and the deep thoracic wall
Intestinal trunks drain lymph from abdominal organs, such as the intestines, stomach, pancreas, spleen, and liver
Lymphatic ducts -large veins in the thorax or join to yet larger
vessels which then connect to the large veins
Right lymphatic duct -joins a right thoracic vein, it drain lymph from
the right side of the head, upper-right limb, and right thorax
Thoracic duct -drains lymph from the right side of the body inferior
to the thorax and the entire left side of the body
Cisterna chyli -is a dilated sac at the lower end of the thoracic duct
which lymph from the intestinal trunk and two lumbar lymphatic
trunks flow
When the body is exposed to microorganisms or other foreign substances, the lymphocytes _____ that destroys microorganisms and foreign
substances
divide, increase in number, and become
part of the immune response
Small masses of lymphoid tissue deep to the mucosa surrounding
the pharynx (throat)
Tonsils
Trap and remove bacteria and other foreign pathogens
Tonsils
Tonsillitis results when the tonsils become congested with bacteria
Three groups of tonsil:
1.Palatine tonsils
2.Pharyngeal tonsil
3.Lingual tonsi
Destroys worn-out blood cells
SPLEEN
Located on the left side of the abdomen
SPLEEN
Filters and cleans blood of bacteria, viruses, debris
SPLEEN
Provides a site for lymphocyte proliferation and immune
surveillance
SPLEEN
Forms blood cells in the fetus
Only lymphoid organ that primarily filters blood
SPLEEN
Found in the superior mediastinum, the partition dividing the thoracic cavity into the left and right parts.
THYMUS
Critically important to the immune system which serves as the body’s defense mechanism providing surveillance and protection
against diverse pathogens, tumors, antigens and mediators of tissue damage
THYMUS
Found in the wall of the small intestine
Peyer’s patches
a hormone secreted by the thymus, is important in the T-cell maturation process
Thymosin -
Protect the digestive system against harmful pathogens
Peyer’s patches
Macrophages capture and destroy bacteria in the intestine
Peyer’s patches
Act as immunosurveillance, which activates appropriate
immune response to protect the body.
Peyer’s patches
Specific defense is required for each type of invader
Adaptive (specific) defense system
The ability to resist damage from foreign
substances, such as microorganisms;
harmful chemicals, such as toxins released
by microorganisms; and internal threats,
such as cancer cells
IMMUNITY
Mechanisms protect against a variety of invaders
Innate (nonspecific) defense system
Fights invaders that get past the innate system
Adaptive (specific) defense system
Responds immediately to protect body from
foreign materials
Innate (nonspecific) defense system
The highly specific resistance to disease is immunity
Adaptive (specific) defense system
is a complex sequence of
events involving many of the chemical mediators and
cells of innate immunit
inflammatory response
Bacteria enter the tissue, causing damage
that stimulates the release or activation of
chemical mediators, such as histamine,
complement, kinins, and eicosanoids
(e.g., prostaglandins and leukotrien
inflammatory response
are large groups of lymphatic nodules and diffuse lymphatic tissue located deep to the mucous membranes within the
pharynx (throat; figure 22.5). The tonsils protect against bacteria
and other potentially harmful material entering the pharynx from
the nasal or oral cavity. In adults, the tonsils decrease in size and
eventually may disappear.
Tonsils
Rubor (Redness)
Tumor (Swelling)
Calor (Heat)
Dolor (Pain)
Functio laesa (Loss of function
They are relatively
large, oval, lymphatic masses on each side of the junction between
the oral cavity and the pharynx
palatine tonsils.
is a collection of somewhat closely aggregated lymphatic
nodules near the junction between the nasal cavity and the pharynx
pharyngeal tonsil
is a loosely associated collection of lymphatic nodules on the posterior surface of the tongue
lingual tonsil
A dense connective tissue capsule surrounds each lymph node
Extensions of the capsule, called _______ form a delicate internal skeleton in the lymph node.
trabeculae
In some areas of the
lymph node, lymphocytes and macrophages are packed around the
reticular fibers to form lymphatic tissue; in other areas, the reticular
fibers extend across open spaces to form
lymphatic sinuses.
The consists of a subcapsular sinus, beneath the
capsule, and cortical sinuses, which are separated by diffuse lymphatic tissue, trabeculae, and lymphatic nodules
outer cortex
The ____is organized into branching, irregular strands of diffuse lymphatic tissue, called the _____, separated by medullary sinuses.
inner medulla
medullary cords
is a soft organ located in the left side of the abdominal cavity, just beneath the diaphragm, that curls around the anterolateral aspect
of the stomach.
spleen
to destroy worn-out red blood
cells and return some of their breakdown products
to the liver
which functions at peak level
only during youth, is a lymphoid mass found in
the anterior mediastinum overlying the heart
thymus,
acts as a sentinel to protect the upper respiratory
and digestive tracts from the constant attacks of
foreign matter entering those cavities
MALT
