Circulatory Systems: Cardiovascular Lymphatic
Circulatory Systems: Cardiovascular Lymphatic
Circulatory Systems: Cardiovascular Lymphatic
Cardiovascular
Derived from mesoderm Transport System Has a pump (heart) Arteries Veins for return Veins have valves Carries RC, WBC, plasma
Lymphatic
Derived from mesoderm Transport System No pump No equivalent Lymph vessels for return Lymph vessels have valves Carries WBC, plasma
MAJOR FUNCTIONS OF LYMPHATIC SYSTEM 1. Collection of excess water and proteins from interstitial fluid. 2. Fat transport (tissue near small intestine into bloodstream). 3. Short term immune responses (microorganisms and other substances). 4. Development of long term immunity.
LYMPH ITSELF
Contains no red blood cells, fluid looks clear. Lymph is Latin for "clear water. In some ways similar to blood, but not identical. No red blood cells, and some proteins are too large to escape the cardiovascular system. Contains millions of white blood cells, particularly common are lymphocytes and monocytes.
MONOCYTES (Review): Capable of attacking foreign microorganisms or tissues. They are highly mobile. When they attack microorganisms individually = "macrophages." When they attack tissues in a coordinated fashion = "tissue macrophages" or "histocytes."
LYMPH VESSELS
Smallest are similar to capillaries in construction. Do not form a circuit like cardiovascular structures. Lymph capillaries have a "terminal end. Densely concentrated near surface of body and other places where body interfaces with external environment.
Smallest are similar to capillaries in construction. Do not form a circuit like cardiovascular structures. Lymph capillaries have a "terminal end. Densely concentrated near surface of body and other places where body interfaces with external environment.
LACTEALS
Specialized lymph capillaries associated with absorptive surfaces of small intestine. One of the ways fat is incorporated in body fluids. Absorb fat from small intestine for distribution throughout the body. (All the fat droplets make the lymph appear "milky," thus the name lacteal.)
THORACIC DUCT
Begins as a loosely dilated sac and connections in the abdomen called the CYSTERNA CHYLI. Drains both legs, and left side of body. Goes through thorax, receives tributaries from: LEFT SUBCLAVIAN TRUNK (from left arm) and LEFT JUGULAR TRUNK (left side of head and neck). Dumps into venous circulation at junction between left subclavian vein and left jugular vein. (Technically into left brachiocephalic vein.)
THORACIC DUCT Begins as a loosely dialated sac and connections in the abdomen called the CYSTERNA CHYLI. Drains both legs, and left side of body. Goes through thorax, receives tributaries from: LEFT SUBCLAVIAN TRUNK (from left arm) and LEFT JUGULAR TRUNK (left side of head and neck). Dumps into venous circulation at junction between left subclavian vein and left jugular vein. (Technically into left brachiocephalic vein.)
LYMPH NODES
Scattered along lymph vessels are concentrated masses of lymph tissue called "lymph nodes." Usually 1-25 mm in length, but they can be larger. Greatest concentration near groin, axilla, neck, thorax, and along gut tube in abdomen. In women, near mammary glands. Macrophages and lymphocytes resident in the outer ("cortex") region of a lymph node. Thus, the nodes can act as filters. Afferent (entering) vessels bring lymph in; lymph is filtered through cortex. "Medulla" is the inner collecting area. Efferent (exiting) vessel leaves at the "hilus."
Usually 1-25 mm in length, but they can be larger. Greatest concentration near groin, axilla, neck, thorax, and along gut tube in abdomen. Macrophages and lymphocytes resident in the outer ("cortex") region of a node.
Afferent (entering) vessels bring lymph in; lymph is filtered through cortex. "Medulla" is the inner collecting area. Efferent (exiting) vessel leaves at the "hilus."
TONSILS
(Sort of like large, glorified lymph nodes, but) They dont act as filters. Only produce lymphocytes for export. Phayrngeal tonsils, palatine tonsils, and lingual tonsils are defensive structures at the mouth, entrance to digestive and respiratory systems.
TONSILS They dont act as filters. Only produce lymphocytes for export. Pharyngeal tonsils, palatine tonsils, and lingual tonsils are defensive structures at the mouth, entrance to digestive and respiratory systems.
TONSILS They dont act as filters. Only produce lymphocytes for export. Pharyngeal tonsils, palatine tonsils, and lingual tonsils are defensive structures at the mouth, entrance to digestive and respiratory systems.
TONSILS They dont act as filters. Only produce lymphocytes for export. Pharyngeal tonsils, palatine tonsils, and lingual tonsils are defensive structures at the mouth, entrance to digestive and respiratory systems.
SPLEEN
Not part of the gut (just near it). Largest lymphoid organ of body. Highly vascularized (perfect for a filter). In spleen, BLOOD passes resident macrophages and lymphocytes. Not strictly a lymph filter, but its interaction with blood can stimulate production and action of materials normally found in lymph. Macrophages abundant: help to scavenge spent red blood cells and recycle hemoglobin. Antigens (nasty stuff) in blood active lymphocytes in spleen for antibody production. Produces red blood cells in fetus, can be called back into action in adults under stressful conditions.
Highly vascularized. In spleen, BLOOD passes resident macrophages and lymphocytes. Not strictly a lymph filter, but its interaction with blood can stimulate production and action of materials normally found in lymph. Macrophages abundant: help to scavenge spent red blood cells and recycle hemoglobin. Antigens (nasty stuff) in blood active lymphocytes in spleen for antibody production.
SPLEEN
SPLEEN
THYMUS GLAND
Ventral to heart and laryngeal structures. Has outer cortex (containing many lymphocytes) and inner medulla. Fetal thymus: transforms undifferentiated lymphocytes from bone marrow into Tlymphocytes. (More later)
Adult THYMUS
Adult THYMUS
PYERS PATCHES
(Also known as aggregated lymph nodes.)
Clusters of lymphoid tissue without a fibrous capsule. Common in tonsils, small intestine, and appendix. Secrete antibodies in response to antigens in gut tube, particularly ingested viruses and bacteria.
DEFENSIVE SYSTEMS
B-LYMPHOCYTES
Mature in bone marrow, then carried to lymphoid tissue via blood stream and lymphatic circulation. This process of maturation and migration takes place throughout life. Other lymphocytes can be generated via mitosis of B lymphocytes resident in lymphoid tissues.
T-LYMPHOCYTES
Immature lymphocytes leave bone marrow during fetal and early neonatal life. Go to thymus gland. Mature there before they go on to other lymphoid tissues. These are T-lymphocytes. Also, and lymphocyte that is derived from one of these original T-lymphocytes via mitosis is also a Tlymphocyte.
SPECIFIC IMMUNITY
The body must be able to recognize the difference between self and nonself. (Any lymphocytes with antibodies that recognize ones own body tissue as an antigen ar ekilled during fetal life.)
ANTIGENS
A foreign substance or organism. Any substance against which an antibody is produced. More specifically, antigens are proteins or polysaccarides on the cell surface of an invading organism.
ANTIBODIES
Proteins produced by lymphocytes in response to an antigen. They bind to specific sites on antigen surfaces. Antibodies dont kill organisms. However, they: can inactivate an invader, and initiate the process of activating phagocytic cells and other natural killers. Can combine with bacterial toxins or viruses to prevent attachment to target cells (inactivation). There is a SPECIFIC antibody for any one given type of individual invader.
(3) ATTACK B-lymphocytes have specific receptors on their cell membrane ANTIBODIES that bind with invading materials/organisms.
ANTIBODY STRUCTURE
(Remember, they belong to group of plasma proteins called globulins.)
Made up of four polypeptides (amino acid chains). Two longer and larger, two shorter and smaller. Have the shape of a letter Y. Intersection of arms and base of Y shape is flexible, allowing deformation of antibody when it attaches to an antigen.
TYPES OF ANTIBODIES
Because they are involved in immune response, they are called immunoglobulins, abbreviated Ig
SUMMARY OF IMMUNOGLOBULINS
T-LYMPHOCYTES
Do not produce antibodies. Function in cell-mediated immunity. NATURAL KILLER cells destroy viruses. Secrete lymphokines which attract phagocytic cells. Secrete perforin which eats holes in the cells membrane or viral coat of invaders. Helper T cells: Induce macrophages to destroy other antigens STIMULATE B-LYMPHOCYTES TO PRODUCE ANTIBODIES. (Can help hundreds of B-lymphocytes mature by releasing B-cell growth factor.) Suppressor T Cells prevent overreaction of the system. (Inhibit Blymphocye production.)
EARLY DEVELOPMENT
Trachea is a tubular outgrowth of the embryonic gut. Begins as a bud in pharynx floor. Each fork is called a primary bronchus.
Trachea is a tubular outgrowth of the embryonic gut. Begins as a bud in pharynx floor. Each fork is called a primary bronchus.
During Development Coelom wraps around lungs (as if the lungs were pushing into a mesodermally constructed balloon).
Nose
Nares
Nose
Frontal Nasal Vomer Ethmoid Maxilla
Nose
Nasal Cavity
Pharynx
Nasopharynx Oropharynx Laryngopharynx
Larynx
Larynx
Trachea
Smooth muscle Trachealrings Cilia
Bronchi
Leftandright primary bronchi
Bronchi
Leftandright primary bronchi
Bronchi
Bronchi
Further subdivided intotertiary bronchi
Bronchi
Further subdivisions resultinthe bronchialtree