Lymphatics and lymph nodes



Download 29.3 Kb.
Date conversion08.02.2017
Size29.3 Kb.
Histology Block Review

LYMPHATICS AND LYMPH NODES


  • How many liters out of the 20 liters of blood that circulates in the body each day are filtered through the walls of capillaries in the form of an ultra filtrate of plasma?

    • 3 liters

  • When looking at a histological section, how can you tell the difference between an Arteriole and a Lymphatic Capillary?

    • Arterioles are more round, and they contain red blood cells.

    • Lymphatic Capillaries have an irregular outline, and have a thinner wall. They do NOT have red blood cells in them.

  • What do larger Lymph Vessels and Lymphatic Ducts have that Lymphatic Capillaries do not have? Can you see these?

    • They have VALVES

    • They also have an Intima, Media, and Adventita

    • You can see valves in the histological section

  • How can you tell that you are looking at Lymphoid Tissue (and not Lymph Nodules)?

    • Right under the Lamina Propria, you see a poorly outlined area of Lymphoid Tissue, but no obvious organization.

  • Dr. Devan showed a slide of Lymphoid Tissue. What organ was this taken from, and what do we call this type of Lymphoid Tissue based on the location?

  • Where would you find GALT?

    • In the GI Tract – Gut Associated Lymphoid Tissue

  • Where would you find BALT?

    • Bronchi of the lungs

    • Broncus Associated Lymphoid Tissue

  • A histological slide of Secondary Nodules in the Appendix was shown. What type of Lymphoid Tissue would this be characterized as?

    • GALT (appendix is in the gut)

  • What are the two parts of a Secondary Lymph Nodule? What types of cells are in each?

    • Outer Portion – T-Lymphocytes

    • Inner Portion (Germinal Center) – B-Lymphocytes

  • What is the difference between a Lymph Node and a Lymph Nodule?

  • Through what Lymphatic Vessel does Lymph flow into the Lymph Node? Where is this vessel located?

    • Afferent Lymphatic Vessel

    • Cortex

  • Though what Lymphatic Vessel does Lymph flow out of the Lymph Node? Where is this vessel located?

    • Efferent Lymphatic Vessel

    • The Hilum

  • What separates one Lymph Nodule from another in the Lymph Node (cortex specifically)

    • Trabeculae

  • Besides the actual Nodules, where are most T-Lymphocytes located and where are most B-Lymphocytes located?

    • T-Lymphocytes – Cortex

    • B-Lymphocytes – Medulla

  • What do B-Lymphocytes mature into?

    • Plasma Cells

  • Is there blood flowing through the Lymph Node?

    • NO!!!

    • Blood is supplying the cells with nutrients, but the only thing filtered through a Lymph Node is LYMPH.

  • Dr. Devon showed a slide of the Subcapsular Sinus of the Lymph Node to demonstrate the two types of cells found in this area. What are the two types of cells, and how do you tell them apart?

    • Reticular Cells – look empty

    • Macrophages – Round cells dispersed throughout

  • High Endothelial Venules are located in the Lymph Node. Why are they important functionally?

    • This is the site where the majority of T-Lymphocytes migrates out of the vascular system and makes their way into the lymph node (90%)

  • Does blood come through the HEVs?

    • NO!!

  • When the T-Lymphocytes migrate out of the HEVs, where do they go?

    • To the Paracortex

  • How can you tell a Lymph Node from the Spleen? How can you tell it from the Lymph Nodule?

    • A Lymph Node has a Subcapsular Sinus in pictures (Lymph Nodules do not)

    • A Lymph Node only filters Lymph, so it has no arteries running through it (the Spleen does have arteries)

  • What two structures are found in the medulla of the Lymph Node? What is in them?

    • Medullary Cords – Lymphocytes, Plasma Cells, Macrophages

    • Medullary Sinus – Channels where the lymph flows through

  • What type of simple epithelium do HEV’s have that sets it apart from other veins?

    • Cuboidal Epithelium (not squamous) – does NOT let blood out

_________________________________________________________________________________________________
SPLEEN


  • What is the main function of the Spleen?

  • How do you tell that a histological section of the Spleen is a Spleen and not a Lymph Node?

    • It has arterioles BETWEEN the GERMINAL CENTER and the T-LYMPHOCYTES of the White Pulp. They are very difficult to see. Pay attention. 

  • What is the White Pulp?

    • The Splenic Nodules (with the Lymphocytes)

  • What is the Red Pulp?

    • Where all of the blood drains around the White Pulp areas.

  • What is the path of blood into the Spleen?

    • Splenic Artery  Trabecular Artery  Central Artery (PALS)  Pennicilus Artery (Red Pulp)

  • What is a PALS?

    • Periarterial Lymphoid Sheath

    • A sheath of Lymphocytes surrounding the Central Artery

  • When the blood goes from the Penicillus Artery  Capillaries, it then goes through a Splenic Sinus before leaving via veins. What are the Splenic Sinuses called?

    • Cords of Biliroth

  • What cells are filtering the blood when the Penicillus Artery dumps it into the Red Pulp?

    • Macrophages

  • Do humans have a Opened or Closed system?

    • Open

  • What type of shape do Splenic Sinusoids have?

    • Barrel shaped with arterioles wrapping around it.

_________________________________________________________________________________________________


THYMUS


  • What is the main function of the Thymus?

  • What are the two general regions of the Thymus? (Microscopically)

    • Cortex

    • Medulla

  • What is the HUGE distinguishing feature to tell that you are looking at a Thymus?

    • In the Medulla, you see a bunch of Hassel’s Corpuscles. They look like empty holes in the medulla region.

  • Does the Thymus have Afferent and Efferent channels?

    • No – just Efferent

  • Which type of Endothelial Cell forms the Blood-Thymus Barrier?

    • Endothelial Type 1

  • Is the Blood-Thymus Barrier in the Cortex or the Medulla?

    • Cortex

  • How are cells “educated in the Thymus?”

    • CFUs leaving the capillary in the Medulla and migrate to the Cortex.

    • When they reach the Cortex, they display CD4 and CD8.

    • Double Positive Selection: If you have CF4 and CD8, you pass and go through the Blood-Thymus Barrier and into the Medulla

    • In the Medulla, the cells lose either the CD4 or CD8 (and become the cell that corresponds with the marker they kept)

    • They are then presented with Self Antigen

    • Negative Selection: If they still contain a Self Antigen on the surface, they are killed.

    • The rest are allowed into the blood.

_________________________________________________________________________________________________


PITUITARY GLAND


  • What type of tissue is the Anterior Lobe?

    • Endocrine

  • What type of tissue the Posterior Lobe?

    • Nervous

  • What is the Anterior Pituitary derived from?

    • Rathke’s Pouch

  • What is the Posterior Pituitary derived from?

    • Downgrowth of the Infundibulum (Diencephalon)

  • What are the three parts of the Anterior Pituitary?

    • Pars Distalis

    • Pars Intermedia

    • Pars Tuberalis

  • Which part of the Anterior Pituitary contains remnants of the Rathke’s Pouch?

    • Pars Intermedia

  • What is the tissue called in the Posterior Pituitary?

  • What is the Blood Supply to the Pars Distalis?

    • Internal Carotid  Two Superior Hypophyseal Arteries  Primary Capillary Beds  Hypophyseal Portal Veins  Secondary Capillary Bed

  • What is the Blood Supply to the Pars Nervosa?

    • Inferior Hypophyseal Artery  Hypopphyseal Veins

  • What two releasing factors does the hypothalamus release, causing release at the Pars Distalis?

    • TSH

    • RH

  • What two inhibitory factors does the hypothalamus release, causing inhabitation at the Pars Distalis?

    • Somatostatin

    • Dopamine

  • What are the three types of cells found in the Pars Distalis?

    • Acidophils

    • Basophils

    • Chromophobes

  • What do Acidophils produce?

    • Growth Hormone

    • Prolactin

  • What do Basophils produce?

    • ACTH

    • TSH

    • FSH

    • LH

  • What do Chromophobes produce?

    • Nothing

  • How do you tell the difference between Acidophils. Basophils, and Chromophobes in a Histological Section?

    • Acidophils – reddish colored, medium in stain

    • Basophils – blue colored, darkest in stain

    • Chromophobes – do no stain

  • What are the relative percentages of these three cells?

    • Acidophils – 40%

    • Basophils – 10%

    • Chromophobes – 50%

  • What two hormones are released by the Posterior Pituitary?

    • ADH

    • Oxytocin

  • Which hormone is produced by the Paraventricular Nuclei?

    • Oxytocin

  • Which hormone is produced by the Supraoptic Nuclei?

    • ADH

  • What lobe of the Pituitary do you find Herring Bodies?

  • What are Herring Bodies?

    • Collections of the ends of the axons that release neurotransmitters

  • What does the Pineal Gland produce?

    • Melatonin

  • What is the function of the Pineal Gland?

    • Circardian Rhythm

  • What are the two cell types and their functions?

    • Pinealocytes – produce melatonin

    • Glial Cells – support

  • What is the unique feature of the Pineal Gland that you use to identify it?

    • Brain Sand (Corpora Arencaea)

_________________________________________________________________________________________________


ADRENAL GLAND


  • Where are the Adrenal Glands located?

    • On top of the kidneys

  • What are the two areas of the Adrenal Gland?

  • What does the Cortex secrete?

    • Steroids

  • What does the Medulla secrete?

    • Cathecolamines

  • What are the three layers in the Cortex?

    • Zona Glomerulosa

    • Zona Fasciculata

    • Zona Reticularis

  • What is the main factor  hormone secreted in the Zona Glomerulosa?

    • Angiotensin II  Aldosterone

  • What is the main factor  hormone secreted in the Zona Fasciculata?

    • ACTH  Cortisol

  • What is the main factor  hormone secreted in the Zona Reticularis?

  • What cell type is unique in the Medulla of the Andrenal Gland?

    • Chromaffin Cells

  • What are the two blood supplies of the Adrenal Gland?

    • Medullary Arteriole  straight to the medulla

    • Adrenocortical/Adrenomedullary  Capillaries  Sinusoids

  • What does the Adrenal Gland secrete?

    • Epinephrine

    • Norepinephrine

  • DUAL INFLUENCE ON ADRENAL FROM NERVOUS SYSTEM AND HORMONES

  • What is one way to distinguish Adrenal Gland on a histological slide that is at a high power?

    • A bunch of fat droplets are in it.

  • What are Chromaffin cells?

    • Neuroendocrine cells (modified neurons)

_________________________________________________________________________________________________


THYROID/PARATHYROID GLAND


  • What is the function of the Thyroid Gland?

    • To control the metabolism of cells

  • What is unique about the Thyroid Gland?

    • It is the only one that stores its product

  • How do you recognize it in a histological section?

  • What does the Thyroid produce?

    • Calcitonin

  • In the large storage areas, there are empty white spots. What is this?

    • Where the product stored inside has been taken up by the cells

  • What do Parafollicular Cells produce?

    • Calcitonin

  • What is Calcitonin antagonistic to?

    • Parathyroid Hormone (PTH)

  • What two molecules need to come into the cell so that it can begin to form T3 and T4?

    • Iodide

    • Thyroglobulin

  • T3 and T4 are stored by being combined with what?

    • Iodine

  • What is the function of the Parathyroid Gland?

    • Regulate Calcium and Phosphate levels

  • What are the two cell types in the Parathyroid Gland?

    • Chief Cells

    • Oxyphil Cells

  • What is the function of these cells?

    • BOTH produce Parathyroid Hormones

  • How do you tell the difference between Chief Cells and Oxyphil Cells?

    • Oxyphil cells stain darker and look like fried eggs

_________________________________________________________________________________________________


PANCREAS


  • What are the cell islands in the Pancreas called? Where are they mainly located?

  • What two cells are located in the pancreas? What do they produce?

    • Alpha Cells – Glucagon

    • Beta Cells – Insulin

  • What do D-Cells produce?

    • Somatostatin to inhibit Alpha and Beta Cells

  • What do F cells produce?

    • Pancreatic Polypeptide

_________________________________________________________________________________________________


LIVER


  • What are some functions of the liver?

    • Detoxify the blood

    • Produce bile

    • Synthesize lipids

  • What do you look for when identifying the liver?

  • There are 3 concepts of Hepatic Organization. Given each one, describe what it means:

    • Classic Lobule

      • Blood Organ – making hormones and putting them into the Central Vein

    • Portal Lobule

      • From the Central Vein towards the Bile Duct

    • Liver Acinus

      • Cells that are furthest from oxygen are at risk

  • What is unique about the cells around the bile duct?

    • They are more cuboidal and usually darker than arterioles

  • What is an Ito cell?

  • What are Kupffer Cells?

    • Macrophages

  • What is the Canal of Herring?

    • Important because it has stem cells in it.

  • What is the Space of Disse?

    • The space that is lined with endothelial cells containing microvilli for absorption

_________________________________________________________________________________________________


GALL BLADDER


  • What is the function?

    • To store bile

_________________________________________________________________________________________________

SALIVARY GLANDS




  • What type of secretion does the Partoid Gland secrete?

    • Serous

  • What type of secretion does the Lingual Gland secrete?

    • Mucus

  • What type of secretion does the Submandibular Gland secrete?

    • Mixed

  • How can you tell the difference between a Intercalated and a Striated Duct?

    • The striated one has lines on it

  • How do you know when you are looking at the exocrine part of the Pancreas?

    • Acinar glands are present but you see NO striated ducts

_________________________________________________________________________________________________


THE TONGUE


  • What are the four types of Papillae?

    • Circumvallate

    • Foliate

    • Fungiform

    • Filiform

  • Which Papillae has Ebner’s Glands?

  • Which Papillae lack taste buds?

    • Filiform Papillae


The database is protected by copyright ©dentisty.org 2016
send message

    Main page