1A - Nervous & Endocrine System

Question 1

What is homeostasis?

Answer 1

The tendency of the body to maintain a relatively constant internal environment.

Question 2

Congenital Analgesia

Answer 2

Born without the ability to feel pain.
-more prone to injury
-increased risk of infection
-more likely to have unnoticed disease
-self mutilation

Question 3

What is the central nervous system?

Answer 3

The central nervous system (CNS) is made up of the brain and spinal cord, and it controls the body’s activities by processing information and sending signals.

Question 4

What is the peripheral nervous system?

Answer 4

The peripheral nervous system (PNS) includes all the nerves outside the brain and spinal cord, connecting the CNS to the rest of the body to control movement and sensation

Question 5

What are the key differences between the central and peripheral nervous systems?

Answer 5

The CNS (brain and spinal cord) processes information and controls the body, while the PNS (nerves outside the CNS) connects it to the rest of the body for movement and sensation.

Question 6

Somatic nervous system/nerves

Answer 6

The somatic nervous system is part of the PNS and controls voluntary movements by sending signals between the brain, spinal cord, and skeletal muscles.

Question 7

Autonomic nervous system/nerves

Answer 7

The autonomic nervous system is part of the PNS and controls involuntary functions like heartbeat, breathing, and digestion without conscious effort.

Question 8

differences between autonomic and somatic nerves

Answer 8

The somatic nervous system controls voluntary movements of skeletal muscles, while the autonomic nervous system controls involuntary functions like heart rate and digestion

Question 9

neurons

Answer 9

Neurons are nerve cells that send and receive electrical and chemical signals in the nervous system, allowing the body to think, move, and respond to stimuli.

Question 10

nerves

Answer 10

Nerves are bundles of neurons (nerve fibers) that carry electrical signals between the brain, spinal cord, and other parts of the body to control movements and processes.

Question 11

Schwann or glial cells

Answer 11

-outnumber neurons 10-1

-support cells that nourish neurons and provide a structural framework (glial=glue)

-non-conducting cells (support neurons without transmitting impulses themselves)

Question 12

sympathetic

Answer 12

The sympathetic nervous system is part of the autonomic nervous system that prepares the body for “fight or flight” during stressful situations by increasing heart rate, dilating pupils, and redirecting blood to muscles.

Question 13

parasympathetic

Answer 13

The parasympathetic nervous system is part of the autonomic nervous system that helps the body return to a calm state after stress, slowing the heart rate, promoting digestion, and conserving energy

Question 14

key differences between sympathetic and parasympathetic

Answer 14

The sympathetic nervous system prepares the body for stress or danger (“fight or flight”), increasing heart rate and energy, while the parasympathetic nervous system calms the body down (“rest and digest”), slowing heart rate and promoting relaxation and digestion.

Question 15

motor

Answer 15

motor neurons transmit signals from the brain and spinal cord to muscles, enabling voluntary and involuntary movements

Question 16

sensor

Answer 16

refers to anything related to sensing or detecting stimuli; in the nervous system, sensory neurons carry information from sensory organs (like the skin, eyes, or ears) to the brain to process sights, sounds, touch, and other sensations.

Question 17

motor neuron

Answer 17

A motor neuron is a type of nerve cell that carries signals from the brain and spinal cord to muscles or glands, enabling movement or other responses

Question 18

inter neuron

Answer 18

An interneuron is a type of neuron that connects other neurons within the brain and spinal cord, processing and relaying signals between sensory and motor neurons.

Question 19

sensory neuron

Answer 19

A sensory neuron is a type of nerve cell that carries information from sensory receptors (like your skin, eyes, or ears) to the brain and spinal cord to be processed as sensations.

Question 20

sensory receptors

Answer 20

recieve stimuli from light, touch,sound,smell,and taste

Question 21

effectors

Answer 21

respond to signals from the nervous system. muscles and ducts.

Question 22

dendrites

Answer 22

Dendrites are branch-like extensions of a neuron that receive signals from other neurons and transmit them toward the cell body.

Question 23

axon

Answer 23

An axon is the long, tube-like part of a neuron that carries electrical signals away from the cell body to other neurons, muscles, or glands.

Question 24

cell body

Answer 24

The cell body (also called the soma) is the part of a neuron that contains the nucleus and organelles, processes incoming signals, and sends them down the axon

Question 25

terminus

Answer 25

The terminus (also called the axon terminal or synaptic knob) is the end of an axon, where it sends signals to other neurons, muscles, or glands by releasing neurotransmitters.

Question 26

myelin sheath

Answer 26

The myelin sheath is a fatty layer that wraps around the axon, insulating it and speeding up electrical signal transmission.

Question 27

node of ravier

Answer 27

The nodes of Ranvier are small gaps in the myelin sheath along the axon where the nerve signal is boosted, allowing for faster transmission of electrical impulses through a process called saltatory conduction.

Question 28

neurolemma

Answer 28

The neurolemma (also called the sheath of Schwann) is the outermost layer of a Schwann cell that helps repair damaged nerve fibers in the peripheral nervous system. on the PNS neurons.

Question 29

soma

Answer 29

meaning body

Question 30

resiting potential

Answer 30

📌 What happens? The neuron is at rest, not firing. 🔋 Charge inside: -70mV (negative) ⚡ Ions moving: None actively moving (Na⁺ is outside, K⁺ is inside) 🔄 Maintained by: Sodium-Potassium Pump (Na⁺ out, K⁺ in)

Question 31

stimulus and threshold

Answer 31

📌 What happens? A small signal makes some Na⁺ channels open. If strong enough, it reaches -55mV (threshold), triggering an action potential. 🔋 Charge inside: Becoming less negative ⚡ Ions moving: A little Na⁺ rushes in

Question 32

depolarization

Answer 32

📌 What happens? Voltage-gated Na⁺ channels fully open, causing a flood of Na⁺ inside. 🔋 Charge inside: +30mV (positive) ⚡ Ions moving: Na⁺ rushes in

Question 33

repolarization

Answer 33

📌 What happens? Na⁺ channels close, and K⁺ channels open to restore negativity. 🔋 Charge inside: Becoming negative again ⚡ Ions moving: K⁺ rushes out

Question 34

hyperpolarization

Answer 34

📌 What happens? The neuron overshoots and becomes too negative. 🔋 Charge inside: Below -70mV (extra negative) ⚡ Ions moving: K⁺ still leaving

Question 35

Return to Resting Potential

Answer 35

📌 What happens? The sodium-potassium pump restores the original balance (Na⁺ out, K⁺ in), preparing for the next signal. 🔋 Charge inside: Back to -70mV ⚡ Ions moving: Na⁺ pumped out, K⁺ pumped in

Question 36

Are there pain receptors in the brain

Answer 36

No

Question 37

White matter

Answer 37

Fat. Myelinated neurons. Motor and sensory

Question 38

Grey matter

Answer 38

Unmyelinated interneurons

Question 39

Cerebrospinal fluid

Answer 39

Cerebrospinal Fluid (CSF) Brain’s cushion & cleaner Protects brain/spinal cord from shocks Delivers nutrients Removes waste Made in choroid plexus, flows & recycles constantly

Question 40

Meninges

Answer 40

Meninges = Brain & spinal cord’s protective layers 🧠 3 Layers (Out to In): Dura mater – Tough outer layer (like a helmet) Arachnoid mater – Web-like middle layer (shock absorber) Pia mater – Thin inner layer (hugs the brain) ✨ Job: Protect, cushion, and hold cerebrospinal fluid (CSF)

Question 41

three regions of the brain

Answer 41

3 Main Regions of the Brain Forebrain 🧠 – Thinking, emotions, senses (cerebrum, thalamus, hypothalamus). Midbrain 🔄 – Relay station (passes messages between brain areas). Hindbrain ❤️💨 – Basic survival (cerebellum, pons, medulla; controls breathing, balance, heart rate).

Question 42

Thalamus

Answer 42

Thalamus 📬 – Brain’s mailroom 📩 Job: Sends sensory info (touch, sight, sound, taste) to the right brain areas. 🚦 Traffic control: Helps with alertness, focus, and movement. ❌ Exception: Doesn’t process smell! (That goes straight to the olfactory bulb.)

Question 43

Hypothalamus

Answer 43

Hypothalamus 🔥🍔😴 – Body’s control center 🧠 Job: Keeps your body balanced (homeostasis). 🌡️ Controls temperature – Keeps you from overheating/freezing. 🍔 Regulates hunger & thirst – Tells you when to eat/drink. 😴 Manages sleep – Helps control your sleep cycle. 💖 Controls hormones – Talks to the pituitary gland to regulate stress, growth, and more.

Question 44

corpus callosum

Answer 44

Corpus Callosum 🌉 – The bridge between the brain’s two halves 🌐 Job: Connects the left and right hemispheres of your brain, allowing them to communicate. 🔗 Function: Helps coordinate actions and share information between both sides (like connecting a team).

Question 45

cerebral cortex/cerebrum

Answer 45

Cerebral Cortex 🧠 – The outer layer of the cerebrum, like the brain’s "thinking cap" 🧠 Job: Controls higher functions – thinking, perception, reasoning, and memory. 🧑‍🏫 Divided into 4 lobes: Frontal lobe – Decision-making, problem-solving, motor control. Parietal lobe – Sensory info (touch, pain, temperature). Temporal lobe – Hearing, memory, speech. Occipital lobe – Vision. 👆 It's all about the thinking and processing!

Question 46

Frontal lobe

Answer 46

Frontal Lobe 🧠💡 – The CEO of the brain 🧑‍🏫 Job: Handles decision-making, planning, problem-solving, and reasoning. 💪 Movement: Controls voluntary muscles (like moving your arm). 🧠 Personality & Emotions: Affects how you act, think, and feel. 🧩 Critical Thinking: Helps you focus, solve problems, and make choices.

Question 47

Parietal lobe

Answer 47

Parietal Lobe 🧠🤲 – The sensory hub of the brain 👀 Job: Processes sensory info (touch, pain, temperature). 🖐️ Body awareness: Helps you understand where your body parts are in space. 📍 Spatial awareness: Helps you navigate your environment (like knowing how far away something is). It’s like your personal sensory control center!

Question 48

occipital lobe

Answer 48

Occipital Lobe 🧠👀 – The vision center of your brain 👁️ Job: Processes visual information from your eyes. 🔍 Function: Helps you interpret shapes, colors, and movement. 💡 Spatial awareness: Helps you recognize and understand what you see. It’s all about seeing and understanding the world around you!

Question 49

temporal lobe

Answer 49

Temporal Lobe 🧠🎶 – The sound and memory brain region 👂 Job: Processes hearing (sound) and speech. 💭 Memory: Helps you form and recall memories. 😌 Emotions: Plays a role in emotions and emotional responses. It's like your audio and memory manager!

Question 50

Cerebellum

Answer 50

Cerebellum 🧠🎯 – The balance and coordination center 🚶 Job: Controls movement, balance, and posture. 🤹 Coordination: Helps with smooth, precise movements (like catching a ball). ⚡ Muscle memory: Learns repeated actions (like riding a bike). It’s your brain’s autopilot for movement!

Question 51

spinal cord

Answer 51

Spinal Cord 🧠🔌 – The body’s information highway ⚡ Job: Sends messages between the brain and the body. 💪 Controls reflexes: Fast, automatic reactions (like pulling your hand from a hot stove). 🛤️ Pathway for movement & sensation: Carries signals for touch, pain, and muscle control. It’s like your brain’s Wi-Fi router, connecting everything!

Question 52

medulla oblangata

Answer 52

Medulla Oblongata 🧠❤️💨 – The life support system of your brain 💖 Controls heart rate – Keeps your heart beating. 💨 Regulates breathing – Makes sure you breathe automatically. 🤮 Handles reflexes – Controls coughing, sneezing, swallowing, and vomiting. It’s your brainstem’s autopilot, keeping you alive without you thinking about it!

Question 53

pons

Answer 53

Pons 🧠🔄 – The brain’s messenger & relaxation center 📨 Job: Sends signals between the brain and spinal cord. 😴 Sleep & dreams: Helps regulate sleep cycles. 👀 Facial movements: Controls blinking, chewing, and facial expressions. 🏃 Coordination: Works with the cerebellum for smooth movements. It’s like your brain’s relay station and chill manager

Question 54

broca's area

Answer 54

Broca’s Area 🗣️🧠 – The speech control center 🗣️ Job: Helps you form words and speak clearly. 📝 Controls speech muscles: Moves your lips, tongue, and vocal cords. 💡 Located in the frontal lobe (left side) – Damage can make speech slow or difficult (Broca’s aphasia). It’s like your brain’s speech coach!

Question 55

Wernickes area

Answer 55

Wernicke’s Area 🧠🗯️ – The language comprehension center 👂 Job: Helps you understand spoken and written language. 💬 Meaning of words: Allows you to make sense of what you hear/read. 📍 Located in the temporal lobe (left side) – Damage can cause Wernicke’s aphasia (words sound fluent but don’t make sense).

Question 56

pituitary gland

Answer 56

Pituitary Gland 🧠🔧 – The “master gland” that controls hormones for growth, metabolism, stress, and reproduction by sending signals to other glands in the body

Question 57

acetylcholine

Answer 57

neurotransmitter that excites muscle cell membrane, causing depolarization and contraction of muscle fibre. in the parasympathetic ns, it works to rest and digest

Question 58

norepinephrine (also called noradrenaline)

Answer 58

neurotransmitter AND hormone. important for fight or flight sympathetic. pupil dilation, release of glucose from the liver to get ready to run. increase BP AND HR

Question 58

cholinesterase

Answer 58

Cholinesterase ⚡🧠 – An enzyme that breaks down acetylcholine, a neurotransmitter that helps with muscle movement and nerve signals, preventing overstimulation. LETS MUSCLE RELAX.

Question 59

epinephrine (also called adrenaline after the gland that secretes it)

Answer 59

neurotransmitter AND hormone. fight or flight. secreted by adrenal medulla and is a treatment for anaphlaxys (epi men!) open airwats, increasing blood flow

Question 60

dopamine

Answer 60

Dopamine 🧠🎉 – Controls motivation, pleasure, movement, and learning by sending reward signals; it makes you feel good when you achieve something and helps with focus and coordination.

Question 61

seratonin

Answer 61

Serotonin 🧠🙂 – The "mood stabilizer" neurotransmitter that helps regulate happiness, sleep, appetite, and emotions. It’s like your brain’s chill pill, keeping your mood and body in balance

Question 62

spatial summation

Answer 62

Spatial Summation 🧠🔀 – When multiple neurons fire at the same time, adding up their signals at different locations on a neuron, making it more likely to reach the threshold and trigger an action potential (a nerve signal). It's like getting several small pushes from different places to finally get something to move!

Question 63

temporal summation

Answer 63

Temporal Summation 🧠⏳ – When a single neuron fires multiple times in quick succession, adding up its signals over time to make the neuron reach the threshold and trigger an action potential. It’s like a fast series of pushes from one place, building up to get something to move!

Question 64

can a neurone fire at varying intensity

Answer 64

no, impossible, only at same intensity but varying frequencys

Question 65

all or nothing

Answer 65

when a neuron fires and it is sub-threshold, it does nothing. and no matter how strong the impulse is, as soon as it goes above threshold, it shoots at same frequencies It’s like flipping a light switch: either it’s on (full fire) or off (no fire)—there's no in-between!