Human Coordination System, Sense Organs, Endocrine System, Reproductive System, and Homeostasis

Comprehensive vocabulary flashcards covering nervous system anatomy, sense organs, endocrine glands, human reproductive biology, addictive substances, and homeostatic regulation based on 9th-grade science study notes.

Coordination System (Sistem Koordinasi)

A system that regulates and controls all body activities so that they work harmoniously and in balance, consisting of the nervous system, endocrine system, and sense organs.

Neuron (Sel Saraf)

The smallest structural and functional unit that makes up the nervous system, consisting of three main parts: cell body, dendrites, and axon.

Cell Body (Perikarion)

The part of a neuron containing the nucleus and cytoplasm, functioning as the metabolic control center of the nerve cell.

Dendrite

Short, branched fibers that receive and conduct impulses toward the cell body.

Axon (Neurit)

A long fiber that conducts nerve impulses away from the cell body toward other nerve cells, muscles, or glands.

Myelin Sheath (Selubung Mielin)

A fatty layer wrapping around the axon that protects it and accelerates impulse transmission.

Schwann Cell (Sel Schwann)

A cell that forms the myelin sheath and aids in the regeneration of damaged axons.

Node of Ranvier (Nodus Ranvier)

Unmyelinated sections of the axon that speed up impulse conduction through saltatory propagation.

Synapse Terminal (Terminal Akson)

The end of an axon where neurotransmitters are released to pass impulses to the next neuron or cell.

Sensory Neuron (Afferent)

A neuron that conducts impulses from receptors (sense organs) to the central nervous system.

Motor Neuron (Efferent)

A neuron that conducts impulses from the central nervous system to effectors (muscles or glands) to produce a response.

Interneuron (Neuron Konektor)

A neuron that connects sensory neurons with motor neurons, located primarily in the brain and spinal cord.

Polarization

The resting state of a nerve membrane where the outside is positively charged and the inside is negatively charged.

Depolarization

The state when a stimulus is received, causing $\text{Na}^+$ ions to enter the cell and turning the inside of the membrane positively charged.

Repolarization

The process after an impulse passes where $\text{K}^+$ ions exit the cell to restore the membrane to its resting potential.

Neurotransmitter

A chemical substance (such as acetylcholine) released into the synaptic cleft to transmit nerve impulses across neurons.

Voluntary Movement (Gerak Sadar)

Conscious movement processed in the cerebrum along the pathway: Receptor $\rightarrow$ Sensory Nerve $\rightarrow$ Brain $\rightarrow$ Motor Nerve $\rightarrow$ Effector.

Reflex Movement (Gerak Refleks)

Rapid, spontaneous, and unconscious movement processed in the spinal cord along a short pathway called the reflex arc.

Human Brain (Ensefalon)

The central control organ of the nervous system located inside the skull, protected by meninges and cerebrospinal fluid.

Cerebrum (Otak Besar)

The largest part of the brain consisting of two hemispheres connected by the corpus callosum; controls thinking, memory, intelligence, sensory perception, and conscious motor activity.

Thalamus

A structure in the diencephalon that functions as a relay station for sensory impulses traveling to the cerebrum.

Hypothalamus

A section of the diencephalon regulating body temperature, hunger, thirst, sleep cycles, and controlling the pituitary gland.

Mesencephalon (Otak Tengah)

The midbrain acting as the center for visual reflexes (pupil reflex to light), auditory reflexes, and muscle tone maintenance.

Cerebellum (Otak Kecil)

Located at the lower back of the cerebrum; regulates body balance and coordinates muscle movements for smooth motion.

Medulla Oblongata (Sumsum Lanjutan)

Connects the brain to the spinal cord and regulates involuntary vital functions such as heart rate, blood pressure, respiration, coughing, and sneezing.

Spinal Cord (Medula Spinalis)

Nerve structure extending through the vertebral column that conducts impulses to/from the brain and serves as the processing center for reflex actions.

Autonomic Nervous System

A division of the peripheral nervous system consisting of sympathetic and parasympathetic nerves that regulate involuntary internal organ activities.

Photoreceptor

Sensory receptors that detect light stimuli, located in the retina of the eye.

Phonoreceptor

Mechanoreceptors that detect sound waves and vibrations, located in the cochlea of the ear.

Chemoreceptor

Receptors that detect chemical stimuli (smell and taste), located in the nasal olfactory epithelium and tongue papillae.

Termoreceptor

Sensory receptors located in the skin that respond to temperature changes (heat and cold).

Nociceptor

Receptors located in the skin and almost all body tissues that detect pain stimuli.

Eye (Indra Penglihat)

The organ of vision responsible for focusing light and converting it into nerve impulses for visual perception.

Cornea

The transparent front section of the eye that transmits and refracts light into the eye.

Sclera

The white outer protective layer of the eye that maintains eyeball shape.

Choroid

The vascular, pigmented middle layer of the eye providing nutrients and preventing internal light reflection.

Iris

The colored muscular ring that regulates the size of the pupil.

Pupil

The central opening in the iris that allows light to enter the eye.

Retina

The innermost layer of the eye containing photoreceptor cells (rods and cones) that convert light into nerve impulses.

Fovea (Bintik Kuning)

The most light-sensitive area of the retina where visual images are formed most clearly.

Ear (Indra Pendengar)

The sensory organ responsible for hearing sound vibrations and maintaining body balance.

Eustachian Tube

A canal in the middle ear that equalizes air pressure between the middle ear cavity and the outside atmosphere.

Cochlea (Rumah Siput)

A snail-shell-shaped organ in the inner ear that transforms mechanical sound vibrations into electrical nerve signals.

Infrasonic

Sound waves with frequencies lower than $20\,\text{Hz}$, inaudible to humans but audible to animals such as elephants and crickets.

Audiosonic

Sound waves within the frequency range of $20\,\text{Hz}$ to $20{,}000\,\text{Hz}$, which human ears can perceive.

Ultrasonic

Sound waves with frequencies exceeding $20{,}000\,\text{Hz}$, inaudible to humans but audible to animals like bats and dolphins.

Nose (Indra Pembau)

The olfactory organ responsible for capturing dissolved airborne chemical molecules and sending odor signals to the brain.

Olfactory Bulb (Bulbus Olfaktorius)

A neural structure in the nasal pathway that gathers nerve impulses from olfactory receptors and sends them toward the brain via cranial nerve I.

Tongue Taste Zones

Specific regions on the tongue sensitive to fundamental taste categories: sweet (tip), salty (front sides), sour (lateral sides), bitter (back), and umami (entire surface).

Skin (Indra Peraba)

The outermost body organ containing various tactile receptors that detect touch, pressure, temperature, and pain.

Epidermis

The outermost layer of the skin that protects underlying structures and undergoes continuous regeneration.

Dermis

The middle skin layer containing blood vessels, hair follicles, sweat glands, sebaceous glands, and sensory nerve receptors.

Endocrine Gland

Ductless glands that secrete chemical messengers (hormones) directly into the blood to act on target organs.

Endocrine Glands Locations

Anatomical distribution of ductless glands including pituitary, thyroid, parathyroid, adrenal, pancreas, pineal, and gonads.

Pituitary Gland (Hipofisis)

The 'master gland' attached beneath the hypothalamus that secretes hormones (e.g., GH, TSH, ACTH, FSH, LH, prolactin, oxytocin, ADH) regulating other endocrine glands.

Thyroxine

A thyroid hormone that regulates the rate of cellular metabolism and growth throughout the body.

Parathormone

A hormone produced by the parathyroid glands that regulates calcium and phosphate levels in the blood.

Adrenaline (Epinephrine)

An adrenal hormone that triggers the 'fight or flight' response under stress, increasing heart rate and blood glucose levels.

Insulin

A hormone produced by the pancreatic Islets of Langerhans that lowers blood glucose by promoting glucose storage as glycogen.

Glucagon

A pancreatic hormone that elevates blood glucose levels by triggering the breakdown of glycogen into glucose.

Melatonin

A pineal gland hormone that regulates circadian rhythms and sleep-wake cycles.

Narcotics

Substances derived from natural or synthetic sources that lower consciousness, eliminate pain, and induce physical dependence (e.g., opium, morphine, heroin, cocaine, marijuana).

Psychotropics

Non-narcotic psychoactive substances affecting the central nervous system to alter mental state and behavior (e.g., methamphetamine, ecstasy, sedatives).

Depressant

A category of psychoactive drugs that slows down central nervous system activity and lowers alertness.

Stimulant

A category of drugs that accelerates central nervous system activity, increasing heart rate, energy, and alertness.

Male Internal Reproductive Organs

Internal male reproductive structures comprising testes, epididymis, vas deferens, seminal vesicles, prostate gland, and Cowper's gland.

Testis

Male gonad responsible for producing sperm cells and testosterone.

Epididymis

A coiled tubular structure attached to the testis where sperm cells are stored and matured.

Vas Deferens

The sperm canal that transports mature sperm from the epididymis toward the urethra.

Seminal Vesicle (Vesikula Seminalis)

A gland producing fructose-rich seminal fluid to supply energy for sperm motility.

Prostate Gland

A male gland that secretes an alkaline fluid to protect sperm against acidic conditions in the reproductive tract.

Cowper's Gland (Bulbourethral Gland)

A gland that secretes a lubricating fluid into the urethra prior to ejaculation.

Male External Reproductive Organs

External organs of the male reproductive system consisting of the penis and scrotum.

Scrotum

An external skin pouch protecting the testes while regulating temperature for optimal sperm production.

Female Reproductive System

Anatomical structures involved in producing ova, facilitating fertilization, and supporting fetal development, including ovaries, fallopian tubes, uterus, cervix, and vagina.

Ovary (Ovarium)

Female gonads that produce egg cells (ova) and secrete estrogen and progesterone.

Fallopian Tube (Tuba Falopi)

Ducts conveying ova from the ovaries to the uterus, serving as the site of fertilization.

Uterus (Rahim)

A hollow muscular organ where a fertilized egg implants and develops into a fetus during gestation.

Estrogen

A female sex hormone produced by ovarian follicles that stimulates secondary sex traits and endometrial proliferation.

Progesterone

A hormone produced by the corpus luteum that maintains endometrial thickness during pregnancy.

Ovulation Phase

The phase around day 14 of the menstrual cycle when a mature egg is released from the ovary triggered by an LH surge.

Homeostasis

The body's mechanism to maintain a stable internal environment despite variable external conditions via nervous and hormonal regulation.

Vasodilation

The widening of cutaneous blood vessels in warm environments combined with sweating to promote body heat loss.

Vasoconstriction

The narrowing of cutaneous blood vessels in cold environments, accompanied by shivering and piloerection to conserve heat.

Antidiuretic Hormone (ADH)

A hormone released by the pituitary gland that promotes water reabsorption in the kidneys to maintain fluid balance.