Pembahasan SiSTEM Koordinasi Dan ALAT Indra

The correct answer is A because it accurately describes the pathway of an impulse in a reflex action. The impulse starts at the receptor, which detects a stimulus, then travels through the sensory nerve to the spinal cord, where it is processed by interneurons. From there, the impulse is relayed through the motor nerve to the effector, which carries out the response to the stimulus. This sequence of events represents the reflex arc, which is responsible for quick, involuntary responses to stimuli.

Dendrit adalah bagian sel saraf yang berfungsi menghantarkan impuls ke badan sel. Dendrit merupakan serabut pendek dan bercabang yang menerima sinyal atau impuls dari neuron lain melalui sinapsis. Dendrit mengumpulkan dan mentransmisikan impuls listrik ke badan sel neuron untuk diproses lebih lanjut.

The correct answer is A. Selaput mielin. The myelin sheath is a protective covering that surrounds the axon of a neuron, acting as an insulator. It helps to increase the speed of nerve impulses by preventing the loss of electrical signals. The Schwann cells, option B, are responsible for producing the myelin sheath in the peripheral nervous system. The nodes of Ranvier, option C, are gaps in the myelin sheath where the axon is exposed. The nucleus of the Schwann cell, option D, is located within the cell and is not directly involved in insulation.

The central nervous system consists of two main components: the brain and the spinal cord. These two structures work together to process and transmit information throughout the body. The brain is responsible for higher cognitive functions, such as thinking, memory, and emotions, while the spinal cord serves as a pathway for communication between the brain and the rest of the body. Therefore, option B, which includes both the brain and the spinal cord, is the correct answer.

Rodopsin adalah protein yang ditemukan dalam sel batang di retina mata. Protein ini berperan penting dalam penglihatan dalam kondisi cahaya redup atau gelap. Ketika cahaya masuk ke mata, rodopsin akan berinteraksi dengan pigmen visual dan mengubah sinyal cahaya menjadi sinyal listrik yang kemudian dikirim ke otak untuk diinterpretasikan sebagai gambar. Oleh karena itu, sel batang membutuhkan rodopsin agar dapat berfungsi dengan baik dalam proses penglihatan.

Sistem saraf simpatik bertanggung jawab untuk merangsang respons "fight or flight" dalam tubuh. Hal ini melibatkan peningkatan denyut jantung (B), memperbesar pupil (C), dan meningkatkan sekresi empedu (D). Namun, sistem saraf simpatik tidak berperan dalam menurunkan sekresi ludah (A).

Hipermetropi adalah gangguan mata di mana seseorang memiliki kesulitan melihat benda dekat dengan jelas. Penderita hipermetropi biasanya memiliki fokus yang lebih jauh dari retina, sehingga benda dekat menjadi kabur. Ini berbeda dengan miopi, di mana penderita memiliki fokus yang terlalu dekat dengan retina dan mengalami kesulitan melihat benda jauh dengan jelas. Hipermiopi juga berbeda dengan presbiopi, yang merupakan gangguan penglihatan terkait usia di mana kemampuan mata untuk melihat objek dekat menurun seiring bertambahnya usia.

The correct answer is C. telinga. The ear serves as a balance tool because it contains the vestibular system, which is responsible for maintaining balance and spatial orientation. It detects changes in head position and movement, allowing us to stay upright and steady. The inner ear also plays a crucial role in detecting sound waves and transmitting them to the brain for interpretation. Therefore, the ear serves a dual function of both hearing and maintaining balance.

The correct answer is A. langit-langit rongga hidung. The sensory organ for smell, or the olfactory organ, is located in the upper part of the nasal cavity, specifically on the roof or ceiling of the nasal cavity, which is known as the langit-langit rongga hidung in Indonesian. This is where the olfactory receptors are located, which are responsible for detecting and transmitting smell signals to the brain.

The correct answer is A. alat indra, otak, dan autonom. This answer is correct because the components mentioned are all related to the nervous system. The alat indra, or sensory organs, receive stimuli from the environment and transmit this information to the brain. The brain processes this information and sends signals to the rest of the body through the autonomous nervous system, which controls involuntary functions such as heart rate and digestion. Therefore, these components play a crucial role in influencing the reactions of the nervous system.