SISTEM KOORDINASI, REPRODUKSI, DAN HOMEOSTATIS PADA MANUSIA (PART 1) - IPA KELAS 9 SMP

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Hello, friends, still with Kak Febri on the Sigma Smart Study learning channel. In this video, we will discuss IPA materials for the 9th grade, human coordination, reproduction, and homeostasis systems. For those of you who haven't subscribed, don't forget to subscribe, then share the video with your friends as much as possible so that we can learn together on this channel. We will start discussing the coordination system. The coordination system in humans is organized on the nervous system, the nervous system, and the hormone system.

Well, we will start discussing starting from the human nervous system. The nervous system is responsible for controlling and coordinating all parts of our body. The nervous system is organized over millions of nervous cells or what we usually call neurons. Every nervous cell or neuron has parts that have their own functions. There is a dendrite, a short circuit that has the function of receiving impulses from the receptors or from the previous neurons.

The impulse will be continued by the dendrite towards the body of the cell. So the body of the cell receives the impulse from the dendrite and continues to the axon. Then the axon will receive the impulse from the body of the cell and continues to the next neuron. Well, along the axon there is a myelin wall that functions to protect and provide nutrition for the axon.

Then there is the SELS1 cell which functions to repair damaged axon cells. And there is the Ranvier nodus which functions to accelerate impulse transmission. Then at the end of the axon there is a terminal axon which is directly connected to the synapses. The synapses are the links between one neuron and another neuron.

Then, based on its function, neurons are divided into three, namely sensoric neurons, motoric neurons, and connector neurons. Sensoric neurons transmit impulses from the receptor or nervous system to the central nervous system. Motoric neurons transmit impulses from the central nervous system to the effector, usually a muscle or muscle effector. Neuron connectors function to connect sensoric neurons with motoric neurons.

Next we will discuss the central nervous system in humans. The central nervous system of humans consists of the brain and the spine. The brain regulates conscious movements while the spine regulates reflex movements. The brain in humans is protected by three layers of the brain cover, or what is commonly called the meninges. These three layers from the outside to the inside, the most outer, the dorameter, are attached to the spine, then there is the arachnoid, and the one inside is attached to the brain, the piameter.

The brain itself is divided into several parts, there is the large brain or what is commonly called the cerebrum, its function as the center of conscious movement and a place to process various impulses from various kinds of emotions. Then there is the small brain or cerebellum, its function as a balance of motion, there is the pituitary gland which functions as the hormone output gland and the pineal gland which plays a role in the biological clock, for example when you sleep and when you wake up.

Next, we will discuss the human nervous system. The nervous system is the receptor that receives radiation. Humans have five nerves. We will discuss one by one starting from the eyes. The eyes are the nervous system that receives light radiation. So the eyes can also be called photoreceptors.

Our eyes are protected by three layers of eye wraps, the outer layer is the sclera, which is the place of contact with the muscle outside the eyeball. Then the middle layer is the choroid,

namely layers that contain a lot of blood to provide nutrition to the eyeballs and the deepest layer is the retina layer, namely the place where the shadow falls or the place where the shadow is caught. In the retina there are stem cells that contain rhodopsin pigment that work when it is dark and there are also stem cells that contain iodopsin pigment that function to differentiate various colors and work actively when it is bright.

In addition to the three layers of eye wraps, there are other eye parts such as cornea, which is the eye protector in the front that is light-colored, then there is iris, which gives a special color to the eyes of each person, there is pupil, which together with iris, adjusts the number of light that enters the eye, then lens, its function is to focus the light so that the shadow falls exactly on the retina, then there is aqua sumor, which provides nutrition for the eyes, and vitro sumor, which maintains the shape of the eye.

We go to the next nervous system, namely the ear. The ear is the receptor that receives the vibration or sound resonance. Therefore, the ear is commonly called the phonoreceptor. The ear is divided into three parts, namely the outer, middle, and inner ear. The outer ear consists of the earlobe and the timpani membrane. The earlobe functions to capture the sound waves, while the timpani membrane functions to strengthen the sound waves.

In the middle ear, there are the hearing tubes that continue the sound waves from the tympanic membrane. There are three types of hearing tubes, namely the malleus or martil, the incus or the lumbar tube, and the steps or sangurdi tube. Meanwhile, the Eustachius channel balances the air pressure in the outer ear and the middle ear.

Next, in the inner ear there is the cochlea or the siphon house and three semicircular channels. The cochlea contains fluids that function to continue the sound vibration, so that it vibrates the hair on the hearing receptors in the cortical organ. Next, the receptor will continue the impulse to the central nervous system. Then, the three semicircular channels function to maintain body balance.

So the vibration moves from the ears to the tympanic membrane to the hearing and cochlear tubes. The third ender instrument is the nose. The nose receives a chemical particle as a substance, so it is commonly called a chemoreceptor. Small chemical particles that enter the nose will dissolve in the moisture layer in the nose, then detected as a smell by olfactory cells in the nose.

Olfactory cells then continue to the olfactory nerves until finally brought to the central nerves as an impulse. Do you know that our nose can detect 2000 to 10000 kinds of smells?

we continue to the fourth nervous system, namely the tongue, the tongue also receives a chemical particle form, so it is also called a chemoreceptor, our tongue can be infected because there are thousands of glands called papillaes, papillaes will detect the taste of food that is dissolved in water.

The tip of the tongue is most sensitive to sweet taste, the edge is most sensitive to acid and salt, while the tip of the tongue is most sensitive to bitter taste. Let's continue to the fifth instinct, which is skin. Skin contains millions of tip of the tongue that send information about touch, irritation, pressure, and temperature to the brain.

There are several types of end of the syrup on the skin, including Ruffini syrup that receives hot pressure, then non-slip syrup that receives a bitter pressure, Krauss syrup that receives a cold pressure, Meissner syrup that receives a touch or a rub and Pasini syrup that receives a pressure pressure. Well, those are the five Indra tools that we have discussed, we continue to the next coordination system, namely the hormone system in humans.

Hormones are produced by endocrine glands that are spread throughout the human body. Endocrine glands are glandules that do not have a channel so that hormones are carried by blood. Hormones have various functions such as growth and development, water balance, reproductive system, and chemical reaction rate in cells.

There are many endocrine strains, including pineal gland that produces melatonin hormones that function as biological drugs, then the hypophysis or pituitary gland that produces many hormones, including GH that stimulates growth, TSH that functions as a thyroid function,

ACTH hormone that stimulates adrenal work, FSH triggers ovulation, LH triggers ovulation, ADH triggers water absorption in the kidney, and oxytocin triggers muscle contraction when giving birth. Next, there is thyroid gland that produces tyroxine hormones that play an important role in body metabolism. Then the thyroid gland that produces hormone parathormones, its function is to change bone calcium into blood calcium.

Next, there is an adrenal gland that produces adrenaline hormones that are used to accelerate heart rate. The pancreas gland produces insulin hormones that are used to regulate blood sugar levels. And there is the gonad gland or the chlamydia gland, which is the testis on men and the ovarian on women.

Testis cheloners produce testosterone hormones that regulate sexual development in men, while ovarian cheloners produce estrogen hormones that stimulate the development of female sex secondary and progesterone hormones that maintain breast thickness.

Okay, that's it, the coordination system is finished, we discussed it. Next for the reproduction system, don't forget to watch the continuation video. Thank you for watching, keep the spirit of learning and keep learning with Sigma Smart Study. Because learning can be from anywhere.