Nervous System- Class 1

What are the two main parts of the Nervous System?

Central Nervous System (CNS) and Peripheral Nervous System (PNS).

What is the role of the Central Nervous System?

It acts as the control center for the body.

What are the main organs of the Central Nervous System?

The brain and spinal cord.

What is the role of the Peripheral Nervous System?

It connects the body to the brain.

What is the function of the brain in the Nervous System?

It controls everything including thinking, breathing, moving, and feeling.

How many neurons does the human brain have?

Approximately 86 billion neurons.

What are the three main parts of the brain?

Cerebrum, Cerebellum, and Brainstem.

What is the function of the Cerebrum?

It is responsible for thinking, memory, and voluntary movement.

What are gyri and sulci in the brain?

Gyri are ridges/bumps on the brain's surface, while sulci are shallow grooves between the gyri.

What is the longitudinal fissure?

A deep groove that divides the left and right hemispheres of the brain.

What is an action potential?

It is the process of generating and propagating electrical signals in neurons.

What are neurotransmitters?

Chemicals that transmit signals across a synapse from one neuron to another.

What is the purpose of sleep according to the Nervous System overview?

To perform essential functions for the body and brain.

What types of neurons are part of the Peripheral Nervous System?

Sensory and motor neurons, as well as sympathetic and parasympathetic neurons.

What is a reflex arc?

A neural pathway that controls a reflex action.

Name a disorder associated with the Nervous System.

Epilepsy, Alzheimer's Disease, Multiple Sclerosis, Parkinson's Disease, Cerebral Palsy, Shingles, Stroke, or Amyotrophic Lateral Sclerosis (ALS).

What are the effects of alcohol on the nervous system?

Alcohol can impair brain function and affect neurotransmission.

What is proprioception?

The sense of the relative position of one's own parts of the body and strength of effort being employed in movement.

What is the ionic basis of the cellular membrane potential?

It is determined by the distribution of ions across the neuronal membrane.

What is the significance of understanding the anatomy of the brain?

It helps in recognizing important structures and functions that frequently appear on tests.

What is the purpose of studying the nervous system?

To understand how the body thinks, moves, and feels, and to treat diseases and boost brain health.

What is the largest part of the brain?

The cerebrum.

How is the cerebrum divided?

Into left and right hemispheres, each split into four lobes.

What are the four lobes of the brain?

Frontal lobe, parietal lobe, temporal lobe, and occipital lobe.

What is the primary role of the frontal lobe?

It controls thinking, emotions, personality, judgment, self-control, muscle control, movements, and memory storage.

Where is the parietal lobe located?

Behind the frontal lobe and at the top of the brain.

What does the parietal lobe help with?

It helps in understanding the world through touch and integrating input from other senses.

What is the location and role of the temporal lobe?

Located near the temples and ears, it manages emotions, processes sensory information, stores and retrieves memories, and understands language.

What is the primary function of the occipital lobe?

It processes vision and is involved in language, reading, memory storage, and recognizing places and faces.

Where is the insular lobe located and what is its role?

It is a hidden structure deep in the brain that plays a part in taste processing, sensorimotor functions, risk-reward behaviors, autonomics, pain pathways, and auditory/vestibular functioning.

What is the cerebral cortex?

The outermost layer of the cerebrum, known as the neocortex, responsible for memory, thinking, learning, reasoning, problem-solving, emotions, consciousness, and sensory processing.

What is the role of the cerebellum?

It is responsible for balance and coordination.

What does the brain stem connect and control?

It connects the brain to the spinal cord and controls automatic body functions like breathing, heartbeat, and digestion.

What are the three parts of the brain stem?

Midbrain, pons, and medulla oblongata.

What is the limbic system responsible for?

Emotions and memory.

What are the key components of the limbic system?

Hippocampus (memory) and amygdala (fear and emotions).

What is an EEG?

An electroencephalogram, a machine that records electrical activity in the brain using sensors placed on the scalp.

What can EEGs help doctors study?

They can check for seizures, study sleep disorders, and understand attention and focus levels.

What are the four types of brain waves?

Alpha, beta, delta, and theta.

What does the alpha wave indicate?

A calm, relaxing state, often during meditation.

What does the beta wave indicate?

A fast frequency associated with thinking, focus, and problem-solving.

What does the delta wave indicate?

A slow frequency that occurs during deep sleep.

What does the theta wave indicate?

A very slow frequency associated with drowsiness and light sleep.

What is a neural impulse?

A signal that travels along neurons to communicate information.

What is the pathway of a neural impulse through a neuron?

It travels from dendrites → cell body → axon → axon terminal → synapse.

How fast can a neural impulse travel?

Over 250 mph.

What are dendrites responsible for?

Receiving signals from other neurons.

What is the function of the cell body (soma) in a neuron?

It contains the nucleus and organelles.

What does the axon do?

Carries the impulse away from the cell body.

What is the role of axon terminals?

They send signals to the next neuron.

What is the myelin sheath and its function?

A fatty coating that speeds up impulses, made up of lipids.

What are the Nodes of Ranvier?

Gaps in myelin that help the signal jump.

What types of cells produce myelin in the CNS and PNS?

Oligodendrocytes in the CNS and Schwann cells in the PNS.

What are the three types of neurons?

Sensory neurons, motor neurons, and interneurons.

What is the role of sensory neurons?

They carry signals from the body to the brain/spinal cord.

What do motor neurons do?

They carry instructions from the brain to muscles.

What is the function of interneurons?

They connect neurons in the brain and spinal cord.

What is the resting membrane potential of a neuron?

About -70 mV, with the inside being negative and the outside positive.

What causes the resting membrane potential?

The sodium-potassium pump, selective ion channels, and negative proteins inside the cell.

What is action potential?

The signal that begins when the threshold is reached (usually -55 mV).

What happens during depolarization in action potential?

Voltage-gated Na⁺ channels open, Na⁺ rushes in, making the inside more positive.

What occurs during repolarization?

K⁺ channels open, K⁺ flows out, returning the charge to negative.

What is hyperpolarization?

A brief dip below resting potential after repolarization.

What is saltatory conduction?

The process where action potential jumps between nodes of Ranvier in myelinated neurons.

What is the absolute refractory period?

A period after firing when no new signal is possible.

What is the role of neurotransmitters?

They transmit signals across the synapse from the presynaptic neuron to the postsynaptic neuron.

What is the role of Acetylcholine (ACh)?

It is important for muscle movement.

What effect do agonists and antagonists have on neurotransmitters?

Agonists increase the effect of neurotransmitters, while antagonists decrease it.

What are the two types of neural synapses?

Chemical and Electrical.

How do electrical synapses transmit signals?

Ions pass directly through gap junctions, allowing for very fast communication.

What is the primary mechanism of communication in chemical synapses?

They use neurotransmitters, which results in slower signal transmission.

What drives all neural activity?

The ionic charge difference across the neuron's membrane.

What happens to nerve impulses in Multiple Sclerosis (MS)?

The immune system attacks myelin, slowing or blocking nerve impulses.

What can neurotoxins do to nerve function?

They can block ion channels or neurotransmitters, leading to paralysis, seizures, or death.

What ion enters the neuron during depolarization?

Sodium (Na⁺).

Which part of the neuron is responsible for sending impulses?

The axon.

What is the function of the myelin sheath?

It speeds up impulse transmission by insulating the axon for saltatory conduction.

What is the difference between chemical and electrical synapses?

Chemical synapses use neurotransmitters and are slower; electrical synapses pass ions directly and are faster.

What does the Central Nervous System (CNS) consist of?

The brain and spinal cord.

How does the CNS connect to the rest of the body?

It processes information and sends instructions throughout the body.

What protects the CNS?

The skull, vertebrae, meninges (three layers of tissue), and cerebrospinal fluid (CSF).

What are the two types of matter in the CNS?

Gray matter (inside) and white matter (outside).

What are the components of a reflex arc?

1. Sensory receptor 2. Sensory neuron 3. Interneuron (in spinal cord) 4. Motor neuron 5. Effector (muscle or gland).

What are the main functions of the brainstem?

It controls vital functions such as heartbeat, breathing, and digestion.

What is the function of the Midbrain?

It is responsible for visual and auditory reflexes.

What is the role of the Pons?

It connects the cerebrum to the cerebellum and regulates breathing.

What does the Medulla Oblongata control?

It controls heartbeat, breathing, and digestion.

How many pairs of cranial nerves are there?

There are 12 pairs of cranial nerves.

What are the three protective layers of the brain?

Dura Mater (outer), Arachnoid Mater (middle), and Pia Mater (inner).

What is the function of cerebrospinal fluid (CSF)?

It cushions the brain and spinal cord, circulates nutrients, and removes waste.

What is hydrocephalus commonly referred to as?

Water on the brain.

What are the essential functions of sleep?

Sleep is essential for brain activity, waste clearance, memory processing and storage, and body repair.

Which parts of the brain control sleep?

The brainstem, hypothalamus, and pineal gland.

What is the difference between NREM and REM sleep?

NREM sleep involves body rest and slow brain waves, while REM sleep is characterized by dreaming and active brain activity.

How long does one full sleep cycle last?

90 minutes.

What is REM rebound?

A natural response where the body tries to catch up on REM sleep when deprived.

What are some effects of CNS damage?

Concussions can cause confusion and memory loss; paralysis results from spinal cord damage; sleep disorders affect memory, focus, and mood; strokes lead to neuron death.

What connects the brain to the body?

The spinal cord.

What controls heartbeat and breathing?

The brainstem.

What is the role of cranial nerve I?

It controls the sense of smell.