Homework

Due Tuesday 4/9/13

HW #2 - Blood Vessel Chart

Due in Lab 2

PreLab #2

HW #4 – Immunity Matching

“Homework Section” page 7

Hint for the matching section

• #1, 3, 4, 6, 7, 10, & 13 each have (2) correct answers

• #15 & 17 each have (3) correct answers

L Y M P H A N D L Y M P H A T I C V E S S E L S

Cardiovascular System

Copyright © 2010 Pearson Education, Inc. Figure 19.2

Large veins (capacitance vessels)

Large lymphatic vessels

Arteriovenous anastomosis

Lymphatic capillary

Postcapillary venule

Sinusoid

Metarteriole

Terminal arteriole

Arterioles (resistance vessels)

Muscular arteries (distributing vessels)

Elastic arteries (conducting vessels)

Small veins (capacitance vessels)

Lymph node

Capillaries (exchange vessels)

Precapillary sphincter Thoroughfare channel

Lymphatic system

Venous system Arterial system

Heart

Figure 20.2a

Cervical nodes Entrance of right

lymphatic duct into vein

Internal jugular vein

Entrance of thoracic

duct into vein

Thoracic duct

Cisterna chyli

Lymphatic

collecting vessels

Axillary nodes

Aorta

Inguinal nodes

Regional

lymph nodes:

(a) General distribution of lymphatic collecting vessels

and regional lymph nodes.

Drained by the right

lymphatic duct

Drained by the

thoracic duct

Lymphatic System

Outflow of fluid slightly exceeds return

Consists of three parts

1. A network of lymphatic vessels carrying lymph

1. Transports fluid back to CV system

2. Lymph nodes

1. Filter the fluid within the vessels

3. Lymphoid organs

1. Participate in disease prevention

Lymphatic System

Functions

1. Returns interstitial fluid and leaked plasma proteins back to the blood

2. Disease surveillance

3. Lipid transport from intestine via lacteals

Figure 20.1

Lymphatic

system:

Lymph duct

Lymph trunk Lymph node

Lymphatic capillary

Blood capillaries

Lymphatic collecting vessels, with valves

Heart Arterial system Venous system

Tissue

fluid

Tissue cell Blood capillaries

Lymphatic capillaries

(a) Structural relationship between a

capillary bed of the blood vascular

system and lymphatic capillaries.

Filaments anchored

to connective tissue

Fibroblast in loose

connective tissue

Endothelial cell

Flaplike minivalve

(b) Lymphatic capillaries are blind-ended tubes in which

adjacent endothelial cells overlap each other,

forming flaplike minivalves.

Lymph

Interstitial fluid which enters lymph capillaries

Lower concentration of proteins than blood

Electrolyte differences

Hydrostatic and colloid osmotic pressure regulate exchange

Figure 19.17

HP = hydrostatic pressure

• Due to fluid pressing against a wall

• “Pushes” • In capillary (HP

c)

• Pushes fluid out of capillary

• 35 mm Hg at arterial end and

17 mm Hg at venous end of

capillary in this example • In interstitial fluid (HP

if)

• Pushes fluid into capillary

• 0 mm Hg in this example

OP = osmotic pressure

• Due to presence of nondiffusible solutes (e.g., plasma proteins) • “Sucks” • In capillary (OP

c)

• Pulls fluid into capillary • 26 mm Hg in this example • In interstitial fluid (OP

if)

• Pulls fluid out of capillary • 1 mm Hg in this example

Arteriole

Capillary

Interstitial fluid

Net HP—Net OP

(35—0)—(26—1)

Net HP—Net OP

(17—0)—(26—1)

Venule

NFP (net filtration pressure)

is 10 mm Hg; fluid moves out NFP is ~8 mm Hg;

fluid moves in

Net

HP

35

mm

Net

OP

25

mm

Net

HP

17

mm

Net

OP

25

mm

Lymphatic Vessels

One-way system, lymph flows toward the heart

Lymph vessels (lymphatics) include

Lymphatic capillaries

Lymphatic collecting vessels

Lymphatic trunks and ducts

Lymphatic Capillaries

Similar to blood capillaries, except…

Dead end vessels

No basement membrane = very permeable

Take up cell debris, pathogens and cancer cells

Endothelial cells overlap to form one-way mini-valves

Figure 20.1b

Filaments anchored

to connective tissue

Fibroblast in loose

connective tissue

Endothelial cell

Flaplike minivalve

(b) Lymphatic capillaries are blind-ended tubes in which

adjacent endothelial cells overlap each other,

forming flaplike minivalves.

Lymphatics

Collecting vessels

Capillaries join to form larger vessels = lymphatics Empty into thoracic duct or right lymphatic duct

Similar to veins, except Have thinner walls

Anastomose more frequently

More valves

Occasionally modified to form nodes

Lymphatic Ducts

Lymph is delivered into one of two large ducts

Right lymphatic duct

Drains the right upper arm & the right side of the head & thorax

Thoracic duct

Arises from the cisterna chyli & drains the rest of the body

Connect with subclavian veins

Figure 20.2b

Left jugular trunk

Internal jugular veins

Left subclavian trunk

Left subclavian vein

Esophagus

Trachea

Left lumbar trunk

Left bronchomediastinal

trunk

Entrance of thoracic

duct into vein

Thoracic duct Hemiazygos vein

Intestinal trunk

Inferior vena cava

Right jugular trunk

Right lymphatic duct

Right subclavian trunk

Right subclavian vein

Right broncho-

mediastinal trunk

Brachiocephalic veins

Superior vena cava

Azygos vein

Cisterna chyli

Right lumbar trunk

(b) Major lymphatic trunks and ducts in relation to veins and

surrounding structures. Anterior view of thoracic and abdominal wall.

Ribs

Figure 20.2a

Cervical nodes Entrance of right

lymphatic duct into vein

Internal jugular vein

Entrance of thoracic

duct into vein

Thoracic duct

Cisterna chyli

Lymphatic

collecting vessels

Axillary nodes

Aorta

Inguinal nodes

Regional

lymph nodes:

(a) General distribution of lymphatic collecting vessels

and regional lymph nodes.

Drained by the right

lymphatic duct

Drained by the

thoracic duct

Lymphatics

Lymph Transport

No pump

Lymph movement similar to venous return

Valves

Skeletal muscle contraction

Thoracic pump

Pressure gradients

Contraction of nearby arteries & smooth muscle within vessels

Movement is slow and sporadic

Edema

Lymphedema

Prevention of return of lymph to blood

May be due to:

Osmotic changes

Blockage of lymph vessels

Parasites

Inflammation

Surgery

Elephantiasis

Lymphatic Tissues

Tissues house and provide a proliferation site for lymphocytes

Furnish a surveillance vantage point

Mucosa-associated lymphatic (MALT)

Respiratory, digestive, urinary, reproductive systems

Peyer’s patches

Junction of large and small intestine

Figure 20.9

Smooth muscle in

the intestinal wall

Lymphoid nodules

(follicles) of

Peyer’s patch

Lymph Nodes

Solid, spherical, well-defined organs

Distributed along course of lymphatic vessels

Concentrated

Cervical region

Behind the ear, inferior mandible and lateral neck

Axillary region

Abdomen

Along abdominal aorta and mesenteric arteries

Inguinal region

Lymph Nodes

Functions

1. Filter lymph

Macrophages destroy microorganisms and debris

2. Immune system

Lymphocytes are activated and mount an attack against antigens

Lymph Nodes

Structure

Outer parenchyma

Inner medulla

Medullary sinuses

Macrophages

Cortex contains follicles with germinal centers, heavy with dividing B cells

Copyright © 2010 Pearson Education, Inc. Figure 20.3

Macrophage

Medullary sinus

Reticular fiber

Lymphocytes

Reticular cells on

reticular fibers

Figure 20.2a

Cervical nodes Entrance of right

lymphatic duct into vein

Internal jugular vein

Entrance of thoracic

duct into vein

Thoracic duct

Cisterna chyli

Lymphatic

collecting vessels

Axillary nodes

Aorta

Inguinal nodes

Regional

lymph nodes:

(a) General distribution of lymphatic collecting vessels

and regional lymph nodes.

Drained by the right

lymphatic duct

Drained by the

thoracic duct

Abdominal

Figure 20.4

Afferent

lymphatic

vessels

Efferent

lymphatic

vessels

Capsule

Trabeculae

Hilum

Cortex

• Lymphoid follicle

• Germinal center

• Subcapsular sinus

Medulla:

• Medullary

cord • Medullary

sinus

Follicles

Trabecula

Subcapsular

sinus

Capsule

Medullary

cords

Medullary

sinuses

(b) Photomicrograph of part of a

lymph node (72x) (a) Longitudinal view of the internal structure

of a lymph node and associated lymphatics

Spleen

Largest lymphoid organ

Macrophages remove old RBC’s, platelets and bacteria

Production of RBC’s

In fetus and severely anemic patients

Splenic contraction

May return 200-300 mls of blood to circulation from sinuses

Figure 20.2a

Cervical nodes Entrance of right

lymphatic duct into vein

Internal jugular vein

Entrance of thoracic

duct into vein

Thoracic duct

Cisterna chyli

Lymphatic

collecting vessels

Axillary nodes

Aorta

Inguinal nodes

Regional

lymph nodes:

(a) General distribution of lymphatic collecting vessels

and regional lymph nodes.

Drained by the right

lymphatic duct

Drained by the

thoracic duct

Spleen

Figure 20.6a,b

Arterioles and

capillaries

Capsule

Trabecula

Venous sinuses

Red pulp

Splenic cords

White pulp

Central artery

Splenic artery

Splenic vein

(b) Diagram of spleen histology

Splenic

artery

Splenic

vein Hilum

(a) Diagram of the

spleen, anterior view

Big spleen!

Thymus

Involution

Stops growing during adolescence and then gradually atrophies

Replaced by adipose and connective tissue

Figure 20.7

Cortex

Medulla

Thymic (Hassall’s)

corpuscle

Thymus

Thymus

Hormones

Thymopoetin and thymosin

Assist in lymphocyte differentiation

Tonsils

Simplest lymphoid organs 3 pairs

Palatine tonsils

Posterior end oral cavity

“Sore throat”

Lingual tonsils

Grouped at the base of the tongue

Pharyngeal tonsils

Adenoids

Posterior wall of the nasopharynx

Figure 20.8

Tonsil

Tonsillar crypt

Germinal centers

in lymphoid follicles

Pharyngeal tonsil

Palatine tonsil

Lingual tonsil

Tonsillitis