Nervous system Flashcards
. (35 cards)
Brain
Main control centre, it process information, controls thoughts, emotions, memory and body functions
Spinal Cord
Connects the brain to the rest of the body. It carries messages back and forth and controls reflexes
Nerves
Bundles of neurons fibers that spread out from the CNS to the entire body. Carries messages to and from the brain
Sensory Neurons
Carries signals from sensory organs (eyes & skin) to CNS. They help the brain detect things like heat, pain or light
Motor Neurons
Carry out VOLUNTARY and INVOLUNTARY functions. Allows the spinal cord and brain to COMMUNICATE THROUGH muscles, organs and glands
Relay Neurons (interneurons)
Found within CNS and connects sensory and motor neurons, processes information receives and decides how the body should respond.
Central Nervous System (CNS)
Made up of the brain and spinal cord.
which helps receive, process and responds to sensory information
Peripheral Nervous System (PNS)
Made up of nerves that branch off from the spinal cord.
Sends information from different area of your body back to your brain, as well as carrying out commands from your brain to various parts of the body
Definition of Homeostasis
The tendency of an ORGANISM to maintain a stable internal state
Positive Feedback
The effector PRODUCES a REPSONSE that enhances and reinforces that initial change
Ex. when giving birth the body releases hormones = more contractions and pressure, increases the release of hormones meaning more contractions which then helps push the baby out
Negative Feedback
The effecter responds in a way that reverses the direction of the initial change
Ex. Regulating blood pressure/ glucose
Synapse
The connection between the end of a nerve cell. Nerve impulses are often carried to the neighboring cells by chemicals called “neurotransmitters”
Endocrine Glands
Endocrine glands are organs that produce and release hormones DIRECTLY into the bloodstream to regulate various body functions like growth, metabolism, and mood.
Ex. IncludeS the pituitary, thyroid, adrenal, pancreas, and ovaries/testes.
What is the endocrine system?
Is a system in your body made up of glands that PRODUCES and RELEASES hormones. These hormones are CHEMICAL MESSENGERS that travel through your bloodstream to organs and tissues and helps with growth and developement
Exocrine Glands
Glands that release substance through DUCTS to the outside of the body or into the digestive system, not into the bloodstream like endocrine glands do
Ex. sweat glands, salivary glands, digestive glands in the stomach, pancreas and intestines
Types of Glands
Hypothalamus:
🧠Located in the brain, just above the pituitary gland.
Pituitary gland:
🧠Under the brain, behind the eyes.
Pineal gland:
🧠Deep in the center of the brain.
Thyroid gland:
🦋Front of the neck, below the Adam’s apple.
Parathyroid glands
🦋Four tiny glands on the back of the thyroid.
Thymus gland
❤️ Upper chest, behind the breastbone.
Adrenal glands
🔺 On top of each kidney, in the upper abdomen.
Pancreas
🍽️ Behind the stomach, in the middle abdomen.
Ovaries (female)
🍒 Lower abdomen/pelvis, one on each side of the uterus.
Testes (male)
⚽ In the scrotum, outside the body.
why must the body keep constant conditions around the cells, #Reason 1
The body must keep constant internal conditions called homeostasis so that cells can function properly and stay alive.
Cells rely on specific conditions like the right temperature, water balance, pH, and glucose levels.
Enzymes, which CONTROL ALL the CHEMICAL reactions in cells, only work well within a NARROW TEMPERATURE and pH range. If it’s too hot or too cold, enzymes can slow down or stop working altogether.
Why must the body keep constant conditions around the cells
#Reason 2
Water balance is also crucial, too much water can make cells swell and burst, while too little can make them shrink.
Why must the body keep constant conditions around the cells
#Reason 3
Glucose levels must stay steady because cells, especially brain cells, need it for energy. If glucose is too low, cells can’t function, if it’s too high, it can damage tissues
What is oxytocin
Oxytocin is a natural hormone made in the brain. It is stored and released into the blood stream by the pituitary gland.
How are messages transmitted as electrical impulses through
neurons
When a neuron is stimulated ( by touch, light, or a chemical signal), it creates an electrical signal called a NERVE IMPULSE or ACTION POTENTIAL This impulse travels quickly along the neuron’s axon.
Once the electrical impulse reaches the end of the neuron, it often needs to pass the message to another neuron or to a muscle or gland.
where the electrical signal triggers the release of chemicals called neurotransmitters. These chemicals cross the synapse and start a new electrical impulse in the next neuron.
Dendrites
Receive signals from other cells
Cell body
organizes and keep the cell functional
Cell membrane
Protects the cell
