Section: Unit 4
Lab Report: Exercise 6: The Lymphatic System
Purpose: What was the purpose of doing this exercise?
The purpose of this exercise is to learn about the lymphatic system and how it works and helps the human body. Why we need it and the components associated with the lymphatic system.
Activity 1: Microscopic Anatomy of Lymphatic Structures
Sketch of Reticular Connective Tissue Slide (Lymph Node). Describe the structures you observed on the slide
I can see white blood cells, reticular fibers which are very dark.
Sketch of Spleen Slide: Describe the structures you observed on the slide
I can see a capsule covered by a mesothelium ,collagen, elastic and a few reticular fibers and trabeculae
Sketch of Tonsil Slide: Describe the structures you observed on the slide
I can see lymphocytes, macrophages, stratified squamous epithelium and reticular fibers
Sketch of Thymus Slide: Describe the structures you observed on the slide
I can see lymphocytes, large macrophages, fat cells, medulla and a capsule.
A. How are lymph, lymphatic vessels and lymph nodes related?
They are related because; the lymphatic system is a network of tissues and organs. It is made up mainly of lymph vessels, lymph nodes and lymph. Lymph vessels, which are different from blood vessels, carry fluid called lymph throughout your body. Lymph contains white blood cells that defend you against germs.
B. What are the two major functions of the lymph nodes?
The main function of lymph nodes is to act as a drainage system by absorbing and expelling proteins, dead cells, bacteria and other waste products from the body. Basically they clean and filter the lymph before it is returned to the blood. They are also a major part of the immune system, as they produce antibodies and lymphocytes. For example, if there is an infection present in the body, the lymph nodes produce more lymphocytes to combat the infection. As they are very active at this stage, they may swell and become painful.
C. What are the two functions of the spleen?
The spleen functions to fight infection, it acts as a giant lymph node scanning erythrocytes, platelets and antigens. Lymphocytes produced in the spleen fight disease causing pathogens. The spleen also filters aged erythrocytes, platelets and blood-borne antigens.
D. What is the function of the tonsils?
The tonsils function to guard against inhaled and ingested pathogens. They have deep pits that catch bacteria and food debris; then it is then circulated by the circulatory system and eaten by macrophages.
E. What are the structural similarities found in lymph nodes, spleen and tonsils?
They are all lymphatic organs and they all have a capsule and are rounded organs with an internal parenchyma of lymphoid cells. They are all placed strategically in the body in order to maximally filter air/blood/lymph.
Activity 2: Immunity and the Immune Response
Describe what happened to the red and green food coloring after 45 minutes: It was absorbed into the agar
Which sera was an antigen in section 2 of the dish? Describe what you observed in section 2 of the dish. Color change, white lines visible-reaction has occurred
Which sera was the antigen in the “unknown” sample used in section 3 of the dish? Describe what you observed in section 3 of the dish. Color change to white, slight lines seen, reaction occurred
A. Explain what is meant by “memory” as a characteristic of the immune response.
After an antigen is cleared from the body, immunological memory allows an antigen to be recognized and removed more quickly if encountered again.
B. How does our immune response distinguish between our own cells and foreign invaders?
This function is mediated by T cells and B cells (memory cells) in our body via adaptive immunity. The adaptive immune...