Immune, Lymphatic and Endocrine System

Learning intentions •To secure knowledge by explaining the function of each system•To further develop knowledge by identifying organs within each system•To show excellence by explaining how systems interrelate

The Immune system

Immune system

Spleen

White blood cells•Lympocytes•Monocytes•monocytes

Adenoids Other Lymphoid tissue e.g in the intestine

Lymphatic vessels and lymph nodes Thymus gland

Tonsils

Natural Body Defences• Despite the fact

that our bodies are often exposed to harmful microbes, we rarely become ill.

• The body is good at keeping microbes out.

• The skin acts as a barrier to keep microbes out of our body.

• If our skin gets broken, first of all the blood forms a clot, Then a scab forms.

• This keeps most microbes out of the body.

• Microbes can get into the body in the air we breathe.

• The passages in the lungs are lined with sticky mucus. The microbes stick to this.

• They are then removed from the passages by the action of the cilia (tiny hairs that beat to remove the mucus).

• If microbes do get into your body, white blood cells help to protect us.

• They do this in three ways:

1.Surrounding and digesting microbes.

2.Producing antibodies, chemicals which destroy microbes.

3.Producing antitoxins, chemicals which prevent microbes poisoning your body.

Natural Body Defences• Despite the fact that our bodies are often exposed to harmful

microbes, we rarely become ill.• The ____ acts as a barrier to keep microbes out of our body.• If our skin gets broken, first of all the blood forms a clot, Then a

_____ forms.• The passages in the lungs are lined with sticky _______. The

microbes we breathe in stick to this.• They are then removed from the passages by the action of the

______ (tiny hairs that beat to remove the mucus).• If microbes do get into your body, ______ blood cells help to

protect us. They do this in three ways:1. Surrounding and digesting __________.2. Producing antibodies, chemicals which destroy microbes.3. Producing antitoxins, chemicals which prevent microbes

poisoning your ______.

scab microbes white body cilia mucus skin

Natural Body Defences• Despite the fact that our bodies are often exposed to harmful

microbes, we rarely become ill.• The skin acts as a barrier to keep microbes out of our body.• If our skin gets broken, first of all the blood forms a clot, Then a

scab forms.• The passages in the lungs are lined with sticky mucus. The

microbes we breathe in stick to this.• They are then removed from the passages by the action of the

cilia (tiny hairs that beat to remove the mucus).• If microbes do get into your body, white blood cells help to

protect us. They do this in three ways:1. Surrounding and digesting microbes.2. Producing antibodies, chemicals which destroy microbes.3. Producing antitoxins, chemicals which prevent microbes

poisoning your body.

The Immune System

Phagocytes– foot soldiersT-lymphocytes – search team

B-lymphocytes – elite attack squad

Phagocytes• Made in the bone

marrow

• 2 types: Neutrophils and macrophages

• Patrol the body, searching for invaders

• Engulf and digest pathogens (and dead human cells/debris)

PathogensWill form phagocytic vesicle

Lysosomes move in with enzymes to digest pathogens

How do phagocytes detect invaders?

Pathogen

Antigen Receptor

Phagocyte recognises a non-human cell and begins to

engulf it

Move towards pathogen chemicals /

toxins

Phagocyte

BUT – there are not enough phagocytes to cope with the onslaught

of the flu virus

Antigen presentationThousands of new viruses produced every second

Macrophage

T-lymphocyte

Phagocytes have a key role because they alert other white blood cells through antigen presentation.

TRUE OR FALSE?

Tissue fluid and lymph

This is another series of tubes (like the blood vessels) that transport fluid around your body.

• Tissue fluid is the liquid that surrounds the cells, allowing for transport between blood and cells (e.g. Respiratory gases) - DIFFUSION

• Capillary walls are partially permeable

• Tissue fluid is the result of an interplay of:

1. Hydrostatic pressure2. Osmosis

• Lymph passes through the lymphatic system and drains back into the circulatory system

• Lymph contains lymphocytes (type of white blood cell) which are made in lymph nodes.

• Lymphocytes are part of the immune system and help to filter out foreign material from the lymph

The fluid transported in the blood vesselsis called: blood.

The fluid in the lymphatic vessels is called: lymph.

The fluid in between these two types of vessels (so

In between the cells) is called tissue fluid.

What is the connection between these 3 fluids?

Blood flows from an artery into the capillaries.Imagine capillaries having small holes in them.The blood pressure (caused by the pumping of the heart muscle) pushes part of the blood from the capillaries into the tissue that surrounds the capillaries.

Components of the blood that can leave the capillaries are: white blood cells and plasma. Remember that plasma was fluid with (small) nutrients, waste products and all other kinds of stuff in it.Components that cannot leave the capillaries are large nutrients, red blood cells and platelets.

The fluid that is pushed out is now present in the tissue between the cells. It is now called tissue fluid!

The cells take from the tissue fluid what they need and they give waste products back.

The tissue fluid can’t stay in between the cells. More and more fluid is pushed out of the capillaries by the blood pressure.

If all that fluid stays in between the cells, you would explode!

And, on top of that, the amount of bloodwithin your blood vessels would decreasedramatically.

Some of the tissue fluid will be pushed back into the capillaries. But because the pressure inside the capillaries is higher than the pressure inside the tissue, not all fluid will flow back.

To get rid of the remaining fluid would be a waste.

Luckily your body found a solution!

The tissue fluid that cannot flow back into the capillaries is collected in the lymphatic vessels. The fluid is now called lymph.

The lymph will flow through lymphatic vessels away from the organs. To keep the flow going in the right direction lymphatic ducts contain valves!

Some vessels will join up to form larger vessels. Eventually the vessels unite into two main ducts; the right lymphatic duct and the thoracic duct.

Both these ducts empty their contents into the subclavian veins (sleutelbeen aderen) and then into the superior vena cava.

Thus, the volume of fluid that couldn’t be brought back to the blood in the organ itself, is brought back to the blood in these specific places.

Let’s draw a comparison between the threetypes of fluid. 1) Copy the table. Add a + when a component is

present, add a – when it is not present.component blood tissue fluid lymph water proteins vitamins red blood cells white blood cells amino acids platelets oxygen carbondioxide antibodies

component blood tissue fluid lymph water + + + proteins + - - vitamins + + + red blood cells + - - white blood cells + + + amino acids + + + platelets + - - oxygen + + + carbondioxide + + + antibodies + + +

Answer

Blood is pumped from the left ventricle towards your organs. In your organs, part of the blood is removed from the blood vessels due to the blood pressure. Thus, the volume of blood decreases.

2) Does the right ventricle contain less, the same or more blood than your left ventricle? Explain your answer!

Answer

They contain the same volume of blood. Some blood volume is lost in the organs (forms tissue and lymph), but this volume is returned by the lymphatic vessels via the subclavian veins and vena cava (before it enters the heart!)

3) Does the pulmonary circulation produce more, less or the same amount of tissue fluid? Explain your answer!

AnswerThe pulmonary circulation produces less tissue fluid. This because there is a lower blood pressure in the pulmonary circulation compared to the systemic circulation. (less distance to cross).

If there would be lots of tissue fluid in your lungs, you would not be able to take up oxygen and will drown in your own fluids.

Lymphatic vessels may pass lymph nodes on their way to the superior vena cava. Theselymph nodes are important white blood cell factories. When you are infected with forinstance bacteria, white blood cells attack the invaders. Since the lymph nodes contain many white blood cells, an enormous war against the invaders will take place here.

This war can result in swollen lymph nodes. When you have a common cold, you can sometimes feel the swollen lymph nodes in your neck, just below your jaw. These are your tonsils.

The Endocrine System

• What Is the Endocrine System?• Although we rarely think about the

endocrine system, it influences almost every cell, organ, and function of our bodies. The endocrine system plays a role in regulating mood, growth and development, tissue function, metabolism, and sexual function and reproductive processes. • http://kidshealth.org/teen/your_

body/body_basics/endocrine.html

• the endocrine system is in charge of body processes that happen slowly, such as cell growth. Faster processes like breathing and body movement are controlled by the nervous system. But even though the nervous system and endocrine system are separate systems, they often work together to help the body function properly.

• The foundations of the endocrine system are the hormones and glands. As the body's chemical messengers, hormones transfer information and instructions from one set of cells to another. Many different hormones move through the bloodstream, but each type of hormone is designed to affect only certain cells.

• A gland is a group of cells that produces and secretes, or gives off, chemicals. A gland selects and removes materials from the blood, processes them, and secretes the finished chemical product for use somewhere in the body.

• Some types of glands release their secretions in specific areas. For instance, exocrine (pronounced: EK-suh-krin) glands, such as the sweat and salivary glands, release secretions in the skin or inside the mouth. Endocrine glands, on the other hand, release more than 20 major hormones directly into the bloodstream where they can be transported to cells in other parts of the body.

• The major glands that make up the human endocrine system include the:

• hypothalamus• pituitary gland• thyroid• parathyroids• adrenal glands• pineal body• reproductive glands (which include the ovaries and testes)• Pancreas explain the role of each of the above in your booklet