The Lymphatic SystemThe Lymphatic System

LymphLymph

Straw-colored fluid Straw-colored fluid (similar to plasma)(similar to plasma)

INTERSTITIAL FLUID INTERSTITIAL FLUID or tissue fluid because it or tissue fluid because it is in the spaces between is in the spaces between cellscells

Composed of H2O, Composed of H2O, lymphocytes, some lymphocytes, some granulocytes, O2, granulocytes, O2, digested nutrients, digested nutrients, hormones, salts, CO2 hormones, salts, CO2 and urea.and urea.

LymphLymph NO red blood cells or NO red blood cells or

protein molecules (too protein molecules (too large)large)

Carries digested food, O2 Carries digested food, O2 and hormones to cellsand hormones to cells

Carries wastes back to Carries wastes back to capillaries for excretioncapillaries for excretion

Since the lymphatic Since the lymphatic system has no pump, system has no pump, skeletal muscle action skeletal muscle action squeezes lymph alongsqueezes lymph along

Valves prevent backward Valves prevent backward flowflow

Function of LymphFunction of Lymph LYMPH –LYMPH – fluid fluid

that goes that goes between between capillary capillary blood and blood and tissuestissues

Lymph flows Lymph flows only in one only in one direction – direction – from body from body organs to the organs to the heart.heart.

Lymph Lymph VesselsVessels

Closely parallel veinsClosely parallel veins

Located in almost all tissues Located in almost all tissues and organs that have blood and organs that have blood vessels vessels

Tissue lymph enters small Tissue lymph enters small lymph vessels which drain into lymph vessels which drain into larger vessels called lymphatics larger vessels called lymphatics – they flow into one of two – they flow into one of two large, main lymphatics – the large, main lymphatics – the THORACIC DUCT and right THORACIC DUCT and right lymphatic duct.lymphatic duct.

FUNCTION OF LYMPH VESSELS FUNCTION OF LYMPH VESSELS – transport excess tissue fluid – transport excess tissue fluid back into circulatory system.back into circulatory system.

Lymph Lymph DrainageDrainage

THORACIC DUCT gets THORACIC DUCT gets lymph from left side of lymph from left side of chest, head and neck, chest, head and neck, abdominal area and abdominal area and lower limbs lower limbs left left subclavian vein subclavian vein superior vena cava superior vena cava heart.heart.

RIGHT LYPHATIC DUCT RIGHT LYPHATIC DUCT gets lymph from right gets lymph from right side of chest, head, neck, side of chest, head, neck, and right upper extremity and right upper extremity right subclavian vein right subclavian vein superior vena cava superior vena cava heart.heart.

Lymph Lymph NodesNodes

Tiny, oval shaped - size Tiny, oval shaped - size of pinhead to size of of pinhead to size of almondalmond

Some are located alone Some are located alone but most are grouped but most are grouped (submandibular, cervical,(submandibular, cervical,

axillary, inguinal, etc.)axillary, inguinal, etc.)

Site for white cell Site for white cell production and filter for production and filter for screening out harmful screening out harmful substancessubstances

If substance can’t be If substance can’t be destroyed, node destroyed, node becomes inflamedbecomes inflamed

Inflamed Lymph NodeInflamed Lymph Node

Function of Lymph Function of Lymph NodesNodes

LYMPH NODES LYMPH NODES – produce – produce lymphocytes, lymphocytes, filter out filter out harmful harmful bacteria.bacteria.

TonsilsTonsils Masses of lymphatic Masses of lymphatic

tissue that produce tissue that produce lymphocytes and filter lymphocytes and filter bacteria – they get bacteria – they get smaller in size as smaller in size as person gets olderperson gets older

PALATINE TONSILS – PALATINE TONSILS – sides of soft palatesides of soft palate

ADENOIDS – tonsils on ADENOIDS – tonsils on upper part of the throatupper part of the throat

LINGUAL TONSILS - LINGUAL TONSILS - back of the tongueback of the tongue

SpleenSpleen Sac-like mass of lymphatic Sac-like mass of lymphatic

tissue – largest lymphoid tissue – largest lymphoid organ in the bodyorgan in the body

Upper left abdominal cavity, Upper left abdominal cavity, lateral to the stomachlateral to the stomach

Forms lymphocytes and Forms lymphocytes and monocytesmonocytes

Filters bloodFilters blood Stores large amounts of RBCs Stores large amounts of RBCs

(over a pint) – contracts (over a pint) – contracts during vigorous exercise or during vigorous exercise or loss of blood, to release RBCsloss of blood, to release RBCs

Destroys or removes old or Destroys or removes old or fragile RBCsfragile RBCs

Thymus GlandThymus Gland Upper, anterior Upper, anterior thorax, above the thorax, above the heartheart

Thymus is also Thymus is also considered an considered an endocrine glandendocrine gland

Largest at pubertyLargest at puberty Forms lymphocytes Forms lymphocytes

before birth involved before birth involved in the development of in the development of “T-Lymphoctes or T-“T-Lymphoctes or T-Cells.”Cells.”

Completes is work by Completes is work by puberty and is puberty and is replaced by fat (this is replaced by fat (this is called called involutioninvolution))