So there are 11 organ systems in the body. Can you name them?
Here's a good way to remember the 11 different organ systems.
They include Mrs. Includer. 'Mrs. Includer' stands for muscular system, respiratory system,
skeletal system, integumentary system, nervous system, cardiovascular system,
lymphatic system, urinary system, digestive system, endocrine system,
and finally the reproductive system.
So now let's talk about each of these systems individually.
So we'll first start with the integumentary system which is actually the largest organ system of the body.
It includes the skin and all the associated structures of the skin
such as your hair, fingernails, toe nails, sweat glands, and oil glands.
Now while we probably don't normally think of the integument as having a lot of functions,
it actually is a very important organ system of the body.
It helps to protect our body, it separates the external environment
from the internal environment of the body, and it helps us to regulate body temperature.
It also plays a role in things such as elimination of certain waste
and one really important role that the skin has is in helping us to make vitamin D.
This is the reason why it's important for us to get out and into the sunlight so that we can make vitamin D
which is very important for other processes to occur in the body.
This organ system is also responsible for detection of sensation such as touch, pain, warmth, and cold.
And finally, it helps us to store fat and provides us insulation so all fat is actually not bad
and we actually need it, and it is a part of the integumentary system.
So the second organ system that we'll discuss is the skeletal system.
The skeletal system is going to be made up of your bones
and the joints of the body, and also the associated cartilages.
The skeletal system has multiple functions including supporting and protecting our body.
It also provides a surface area for muscle attachment so without the bones,
your muscles do not work or your skeletal muscles do not work.
The bones are also important in helping with body movements again, together with the muscular system.
And finally, in your bones, we actually have the cells that producing
such as our red blood cells and also store things such as certain minerals and lipids
that our body needs in order to perform other functions.
Then we get to our muscular system.
The muscular system is actually specifically the skeletal muscles.
We'll learn later that there are actually other types of muscle tissue
as well including the smooth muscles and the cardiac muscles
but your skeletal muscles which are attached to the bones are important because they allow us to move.
We would not be able to walk, we would not even be able to talk or do any of the things
that we do that require movement without the presence of our muscular system.
Along with our skeletal muscles allowing us to move, they also allow us to stand still.
They help us to maintain our posture so that we are able to stand upright
or as you're sitting here, sit upright, and listen to this lecture.
The muscles are also important in producing heat.
It is actually the contraction of the muscles that allow us to produce or to increase our body temperature.
So for example, when you get really cold, sometimes you might shiver.
This is actually a way for your body to increase the body temperature through muscular contractions.
The next organ system that we'll discuss is the nervous system.
The nervous system is going to include your brain, your spinal cord, all of the nerves of your body,
and also some of your special sense organs including your eyes and your ears.
The nervous system specifically functions by way of action potentials
which is another fancy way of saying sending electrical impulses.
And so it sends these impulses throughout the body in order to regulate body activities.
The main function of your nervous system
is going to be to detect changes in the body's internal and external environments,
interpret those changes, and then respond.
So pretty much, the nervous system is a major player in maintenance of homeostasis.
The endocrine system is also another very important system when it comes to maintenance of homeostasis.
This includes all of your hormone-producing glands such as your pineal gland,
the pituitary gland, the hypothalamus, the thymus, the thyroid gland, parathyroid gland,
adrenal glands, the pancreas, ovaries, and testes.
It also includes hormone-producing cells and other organs of the body as well.
The endocrine system is responsible for regulating the body's activities
by releasing hormones and is specific for hormones.
So in a way, the nervous system and the endocrine system have a very similar function.
It's just the way they perform that function is different.
With the nervous system, using electrical impulses and the endocrine system
using chemicals or hormones in order to perform its function.
The next organ system that we have is the cardiovascular system.
The cardiovascular system is going to include the blood, the heart, and all of your blood vessels in the body.
It functions by pumping blood through the vessels and also while you're pumping this blood,
it is actually carrying oxygen and nutrients to the cells of the body.
It also, at the same time as it brings that oxygen and those nutrients to the cells,
it removes the carbon dioxide and other waste products from the cells
so that they can be removed from the body eventually.
And it also contains the components that help us fight against disease.
So a lot of the cardiovascular system includes cells, are called white blood cells
that help us to fight off bacteria and virus, and other invaders that we don't want in our bodies.
So then we have the lymphatic system and the lymphatic system
works very intimately with the cardiovascular system.
It's going to include your lymphatic fluid as well as the lymphatic vessels, organs
such as the spleen, the thymus, the lymph nodes and the tonsils,
and also the cells that carry out their immune responses.
Those white blood cells such as B cells and T cells, and other types of immune cells.
So the functions of the lymphatic system are going to return proteins and fluid to the blood
while also carrying lipids from our gastrointestinal tract to the blood
and also containing those B cells and T cells that help us fight against disease-causing microbes.
The next organ system is going to be our respiratory system.
In the respiratory system, we have our lungs and our air passages and they function
by transferring oxygen that we bring in from our external environment through inhalation
and taking that oxygen and bringing it to the cells.
It also helps us regulate our acid-base balance and basically maintain a very strict pH in the body.
And also, we are able to make sounds because of our respiratory system.
Without the respiratory system, I would not be able to deliver this lecture to you right now.
The next organ system is the digestive system.
This one is probably my favorite because I love to eat.
The organs in this system include the GI tract which starts at the esophagus, goes down to the stomach,
and then includes your small intestines and large intestines, and finally ends at the anus.
The interesting thing about the digestive tract is because it is open at both ends of the tract,
it is technically external to the body and that is kind of like a straw.
Other organs in the digestive system also include things such as the liver, the gallbladder, and the pancreas.
These are actually very important organs that allow digestion to occur
and the digestive process to occur even though they are not a part of that straw.
The digestive system is going to function by helping us to break down the nutrients
that we bring in through our food and then absorb those nutrients
so that we can use them in order for our body to perform other functions,
and also to get rid of the stuff that we don't need.
The next organ system is our urinary system.
The organs in our urinary system are gonna include our kidneys,
the ureters, the urinary bladder, and the urethra.
The urinary system is going to function by producing, storing, and eliminating urine from the body.
This allows us to eliminate waste and also regulate the volume and composition of the blood.
Because of this regulation, we are able to maintain our body's pH
or our acid-base balance using the urinary system as well.
And finally, it also helps regulate the production of red blood cells
so that we have enough in order to perform the functions we need to.
The next organ system is the reproductive system.
The reproductive system for females and males is different
so we will actually start with the female reproductive system and then move to the male.
In the female reproductive system, we have the ovaries and the other associated organs
such as the uterine tubes, the uterus, the vagina, and also the mammary glands.
The functions of each of these organs is involved in basically the continuation of life.
Without the reproductive system, we will cease to exist.
So this is actually a very important organ system.
The ovaries are going to produce the oocytes and they also release certain hormones
that help us to regulate certain body processes that we need to occur in the body.
And also, the other organs associated with the ovaries are going to transport and store oocytes,
and also store the fetus and allow for a fetus to grow so that, again, we can continue the species.
And then finally, the mammary glands in the reproductive system
are there to produce milk or nourishment once the baby is born.
The male reproductive system has the testis and other associated organs
such as the epididymis, the vas deferens, the seminal vesicles, the prostate, and the penis.
The function of each of these organs is again, to allow for reproduction to occur.
The testis is going to produce the sperm that is going to unite with the oocytes
in order to form a new organism.
And the testis, like the ovaries, is also going to release hormones
that regulate reproduction as well as other body processes.
The other associated organs are there to help transport and store the sperm
so that reproduction can occur.