Do Now Activity #5 List 3 anatomical parts of the male reproductive system. Describe their functions. List 3 anatomical parts of the female reproductive system. Describe their functions. Which cycle develops the female gamete? Which cycle develops the egg & uterus for fertilization?

chapter 20: The Lymphatic System Essential Question: Explain the importance of vessels in the Lymphatic System. chapter 20: The Lymphatic System Learning Targets Identify structure and function of 3 types of muscle tissue. Identify the functional characteristics of muscle tissue. List the functions of muscle Describe the anatomy of skeletal muscle

Don’t forget to chunk your notes Don’t forget to chunk your notes! You Do not have to write down the red text

Overview: The Lymphatic System The lymphatic system is a network of lymphatic vessels and lymphoid tissues and organs scattered throughout the body.

Overview: Physiology The Lymphatic System returns fluid and leaked plasma proteins back to the blood. Lymph: interstitial fluid/plasma once it has entered lymphatic vessels It houses white blood cells that defend the body.

Don’t forget to chunk your notes Don’t forget to chunk your notes! You Do not have to write down the red text

Lymphatic Vessels & Capillaries The vessels in the Lymphatic System are a one-way system in which lymph flows toward the heart. Lymphatic capillaries are remarkably permeable, and they have mini-valves that allow interstitial fluid to enter, but do not allow lymph to escape.

Don’t forget to chunk your notes Don’t forget to chunk your notes! You Do not have to write down the red text

Lymph Transport The lymphatic system lacks an organ that acts as a pump. Vessels are under low-pressure. In order to transport lymph, the Lymphatic System uses the pulsations of nearby arteries and the contractions of smooth muscle in the walls of the lymphatic structures. The presence of valves prevent back flow.

Don’t forget to chunk your notes Don’t forget to chunk your notes! You Do not have to write down the red text

Lymph Nodes Lymph nodes are the principal lymphoid organs of the body. These monitor cell debris in the lymph. Their two basic functions are: To filter out debris To monitor for antigens and mount an immune attack against them

Afferent lymphatic vessels Cortex: • Lymphoid follicle • Germinal center • Subcapsular sinus Efferent lymphatic vessels Follicles Trabecula Subcapsular sinus Hilum Medulla: Capsule • Medullary cord • Medullary sinus Medullary cords Medullary sinuses Trabeculae (a) Capsule (b)

Don’t forget to chunk your notes Don’t forget to chunk your notes! You Do not have to write down the red text

Spleen The spleen is the largest lymphoid organ. It stores blood platelets. The spleen functions: --at the site of lymphocyte rapid growth --as immune surveillance & response --to cleanse the blood The spleen stores breakdown products of red blood cells for later reuse. Spleen macrophages salvage and store iron for later use by bone marrow.

Structure of the Spleen Capsule Trabecula Splenic cords Venous sinuses Red pulp White pulp Hilum Splenic artery Central artery Splenic vein Arterioles and capillaries (a) (b) Splenic artery Splenic vein Diaphragm Capsule Spleen Adrenal gland Left kidney White pulp Splenic artery Red pulp Pancreas (c) (d)

Don’t forget to chunk your notes Don’t forget to chunk your notes! You Do not have to write down the red text

Thymus This is the organ that secretes hormones (thymosin) that cause T lymphocytes to mature. It functions strictly in the maturing of T lymphocytes. It does not directly fight antigens.

Thymic (Hassall’s) corpuscle Medulla Cortex

Don’t forget to chunk your notes Don’t forget to chunk your notes! You Do not have to write down the red text

Tonsils This is the simplest lymphoid organs; it forms a ring of lymphatic tissue around the pharynx. It traps and destroys bacteria and particulate matter.

Don’t forget to chunk your notes Don’t forget to chunk your notes! You Do not have to write down the red text

Aggregates of Lymphoid Follicles The appendix destroys bacteria, preventing them from breaching the intestinal wall. The appendix generates “memory” lymphocytes for long-term immunity.

Don’t forget to chunk your notes Don’t forget to chunk your notes! You Do not have to write down the red text