Lymphatic System

Question 1

• Consists of lymphatic tissues and vessels

Answer 1

Lymphatic System

Question 2

• This system returns protein-rich fluid to the blood circulation that escapes from the blood capillaries into tissue spaces

Answer 2

Lymphatic System

Question 3

not present in the brain, spinal cord or bone marrow

Answer 3

Lymph Vessels

Question 4

blind-ended tubes located throughout the body

Answer 4

Lymph Capillaries

Question 5

More permeable than blood capillaries, they “pick up” the excess interstitial fluid,

Answer 5

lymph

Question 6

the larger vessels formed by the convergence of lymph capillaries

Answer 6

• Lymphatic vessels

Question 7

the ovoid or bean-shaped, encapsulated structures located along the course of the medium-sized lymphatic vessels

Answer 7

• Lymph nodes

Question 8

o function as filters and germinal centers for lymphocytes
o picks up lymphocytes and is subjected to macrophages as it passes through the node
o Each node has a capsule of fibrous connective tissue
o Trabeculae extend from the capsule into the lymph node
o The outer cortex and inner medulla make up the parenchyma of the node

Answer 8

• Lymph nodes

Question 9

• located in the lymph nodes, they differentiate into lymphocytes and/or plasma cells

Answer 9

• Primitive cells

Question 10

• the phagocytic cells lining the walls of the sinuses

Answer 10

Macrophages

Question 11

• Group of lymph nodes draining the same region of the body in all species

Answer 11

Lymphocenters

Question 12

is where the ducts or trunks empty into the large veins in the thoracic inlet

Answer 12

venous angle

Question 13

• represents the parotid lymphocenter

Answer 13

Parotid Lymph Node

Question 14

o located under the cranial edge of the parotid gland
o It drains the dorsal part of the head, including the orbit and parotid gland, then the lymph continues to the retropharyngeal nodes
o It is palpable in the dog and ox

Answer 14

Parotid Lymph Node

Question 15

represents the mandibular lymphocenter and consists of nodes located ventral to the angle of the jaw

Answer 15

• Mandibular lymph node

Question 16

drain that part of the head not drained by the parotid gland to the medial retropharyngeal node
o Present in all species, they are palpable in the dog, ox and horse

Answer 16

• Mandibular lymph node

Question 17

drains the deeper structures of the head and neck, including the pharynx and larynx

Answer 17

• Retropharyngeal lymphocenter

Question 18

o Also receive lymph coming from the parotid and mandibular lymph nodes

Answer 18

Retropharyngeal lymphocenter

Question 19

-the largest lymph node of the head and neck, present in all species
- Lies between the larynx and the wing of the atlas and is not normally palpable

Answer 19

o Medial retropharyngeal lymph node

Question 20

Lymph node usually absent in dog and palpable in the ox

Answer 20

o Lateral retropharyngeal lymph node

Question 21

represent the superficial cervical lymphocenter

Answer 21

• Superficial cervical lymph nodes

Question 22

o Drain the superficial neck and dorsal thorax along with the proximal part of the forelimb
o Located in front of the shoulder joint under the superficial neck muscles
o Present in all species and palpable in dog, ox and horse

Answer 22

• Superficial cervical lymph nodes

Question 23

the chain of deep lymph nodes (cranial, middle and caudal) along the length of the trachea

Answer 23

• Deep cervical lymph nodes

Question 24

o Drains the deep and ventral structures of the neck into the thoracic duct on the leftside or into the lymphatic duct on the right

Answer 24

Deep cervical lymph nodes

Question 25

o Traveling along the trachea, draining the lymph nodes of the head and neck o Empty into the thoracic duct on the left side, the right lymphatic duct, or the vessels of the thoracic duct

Answer 25

* Right and Left Tracheal (Jugular) Trunks

Question 26

the thoracic lymphocenters can be divided into

Answer 26

Parietal and Visceral

Question 27

dorsal and ventral thoracic lymphocenters represented by the intercostal and sternal lymph nodes

Answer 27

Parietal

Question 28

mediastinal and bronchial lymphocenters

Answer 28

Visceral

Question 29

consist of the cranial mediastinal lymph nodes in all species o Carnivores lack the caudal mediastinal lymph nodes that are huge in ruminants

Answer 29

* Mediastinal lymphocenters

Question 30

consists of nodes located around the tracheal bifurcation

Answer 30

* Bronchial lymphocenters

Question 31

o Located in the axilla, it drains the forelimb and the thoracic wall, including the first three pairs of mammary glands in the dog o constantly present in all species and palpable in dog

Answer 31

* Axillary lymph node

Question 32

lymph node that is present in the cat and inconstant in the dog and ox

Answer 32

accessory axillary lymph node

Question 33

consist of lumbar lymph nodes located along the abdominal aorta

Answer 33

* Lumbar lymphocenters -

Question 34

o Drains the kidney, loins, adrenal glands, and abdominal portion of the urogenital system, including testes, into the lumbar trunks or cisterna chyli

Answer 34

* Lumbar lymphocenters

Question 35

o Carnivores lack renal lymph nodes

Answer 35

Yes

Question 36

a lymphatic structure found at the caudal end of the thoracic duct that receives lymph draining from the abdominal and pelvic viscera and lower limbs

Answer 36

Cisterna chyli

Question 37

* The major lymphatic vessel drawing the entire body, except the right thoracic limb, right cranial thorax, and the right side of the neck

Answer 37

Thoracic duct

Question 38

o Begins at the cisterna chyli, passes through the aortic hiatus cranially on the right side between the azygous vein and the aorta o Passing to the left side of the thorax in the cranial mediastinum o Empties near the thoracic inlet (venous angle) into the jugular vein or the caudal vena cava

Answer 38

Thoracic duct

Question 39

masses of unencapsulated lymphoid tissue below mucous membranes (pharyngeal, palatine, and lingual)

Answer 39

Tonsils

Question 40

- diffuse accumulation of lymphatic tissue in the wall of the ileum

Answer 40

Peyer’s patches

Question 41

* The largest lymphoid organ in the body * Flat, elongated structure interposed in the blood stream located next to the left abdominal wall * In the fetus, it produces red blood cells * In the adult, it stores red blood cells that can be squeezed back into circulation when needed * Produces lymphocytes, stores iron, and destroys worn out red blood cells

Answer 41

Spleen

Question 42

- the area where vessels and nerves enter the spleen - A long groove in the carnivores, horse and pig and a small indentation in ruminants

Answer 42

Hilus

Question 43

consist of splenic, gastric, hepatic and pancreaticoduodenal lymph nodes that drain associated structures to the cisterna chyli

Answer 43

Celiac lymphocenters

Question 44

consist of jejunal, cecal, and colic lymph nodes o Located near these organs and drain into the cisterna chyli

Answer 44

* Cranial mesenteric lymphocenters

Question 45

large node located in the root of the mesentery of the dog

Answer 45

Cranial mesenteric lymph nodes