Neuroscience Quiz on Myelin and Neurotransmitters

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Questions and Answers

What substance do Schwann cells contain that is crucial for their function?

Myelin (correct)

Cholesterol

Collagen

Keratin

What is formed when Schwann cells wrap around an axon?

Dendrite

Node of Ranvier

Axon terminal

Myelin sheath (correct)

Which type of axons typically possesses a myelin sheath?

Damaged axons

Unmyelinated axons

Short axons

Long axons (correct)

What are the gaps between myelin sheaths called?

Nodes of Ranvier Signup and view all the answers

What is the significance of the myelin sheath after an axon is severed?

It serves as a pathway for new fiber growth Signup and view all the answers

What is the term used for the process when the sending membrane reabsorbs the neurotransmitter?

Reuptake Signup and view all the answers

Which neurotransmitter is specifically mentioned as being associated with mood and wakefulness?

Norepinephrine Signup and view all the answers

What type of drugs block the reuptake of neurotransmitters?

Antidepressants Signup and view all the answers

Which neurotransmitter is involved in thermoregulation and perception?

Serotonin Signup and view all the answers

Among the following neurotransmitters, which one is linked to the regulation of complex movements?

Dopamine Signup and view all the answers

What is the primary function of arrector pili muscles?

They contract to create goosebumps. Signup and view all the answers

What is the primary role of the sodium-potassium pump in neuronal activity?

To establish and maintain the correct ion concentrations across the membrane Signup and view all the answers

Which type of gland is responsible for producing sebum?

Sebaceous glands Signup and view all the answers

What occurs during the repolarization phase of an action potential?

Potassium ions rush out of the cell Signup and view all the answers

What condition is characterized by inflammation of the sebaceous glands?

Acne Signup and view all the answers

In myelinated axons, where do action potentials primarily occur?

At the nodes of Ranvier Signup and view all the answers

How do sweat glands assist in homeostasis?

By regulating body temperature. Signup and view all the answers

What does the term homeostasis refer to?

A relatively constant internal environment. Signup and view all the answers

Which sequence correctly represents the order of ion movement when a neuron is stimulated?

Sodium gates open → Sodium enters → Potassium gates open → Potassium leaves Signup and view all the answers

What process allows for faster conduction of action potentials in myelinated fibers?

Saltatory conduction Signup and view all the answers

Which of the following substances is primarily transported by blood?

Oxygen Signup and view all the answers

Which statement best describes action potentials in terms of their propagation?

They are self-propagating along the axon Signup and view all the answers

What are the two main components of the internal environment?

Blood and interstitial fluid Signup and view all the answers

Which of the following conditions is NOT typically maintained within a narrow range to ensure homeostasis?

Fat distribution Signup and view all the answers

What is the primary consequence of having a greater sodium concentration inside the axon?

It disrupts the normal action potential process Signup and view all the answers

What type of conduction occurs in unmyelinated axons?

Continuous conduction Signup and view all the answers

What is the function of the nodes of Ranvier?

They allow faster transmission of nerve impulses. Signup and view all the answers

Which type of cell forms the myelin sheath in the central nervous system?

Oligodendrocytes Signup and view all the answers

Which term describes the conduction of nerve impulses as they jump from one node of Ranvier to the next?

Saltatory conduction Signup and view all the answers

Which part of the neuron is primarily responsible for receiving signals?

Dendrites Signup and view all the answers

What condition is characterized by the progressive destruction of myelin sheaths in the nervous system?

Multiple sclerosis Signup and view all the answers

Which type of nerves contain both sensory and motor neurons?

Mixed nerves Signup and view all the answers

What are the main components that make up a nerve?

Parallel axons and connective tissue Signup and view all the answers

What can be a potential result of multiple sclerosis?

Loss of sensation Signup and view all the answers

What type of impulse conveys information within the nervous system?

Electrochemical changes Signup and view all the answers

In terms of nerve categorization, what type of nerve is primarily involved in sending signals to muscles?

Efferent nerves Signup and view all the answers

What is the primary function of the sclera in the human eye?

To protect and give shape to the eye Signup and view all the answers

Which part of the eye contains photoreceptors that respond to light?

Retina Signup and view all the answers

What role does the ciliary body play in vision?

It holds the lens in place and changes its shape Signup and view all the answers

How does the iris contribute to vision?

It regulates the amount of light entering the pupil Signup and view all the answers

What is the function of the photoreceptors known as rods?

They operate in low light conditions for night vision Signup and view all the answers

Where is the fovea located and what is its significance?

In the retina; it has the greatest concentration of cones for sharp vision Signup and view all the answers

What happens at the blind spot of the retina?

Images cannot be seen due to lack of photoreceptors Signup and view all the answers

Which of the following accurately describes the cornea?

It is transparent and allows light to enter the eye Signup and view all the answers

What is the optic nerve responsible for?

Carrying visual information from the eye to the brain Signup and view all the answers

Which component of the eye is involved in the regulation of light intake?

Iris Signup and view all the answers

What happens to the pupil in bright light?

It constricts Signup and view all the answers

Which layer of the eye is primarily vascular and contains blood vessels?

Choroid Signup and view all the answers

What distinguishes cones from rods in the retina?

Cones are responsible for color vision, while rods are not Signup and view all the answers

What does the middle layer of the eyeball consist of?

Choroid, ciliary body, and iris Signup and view all the answers

Study Notes

Anatomical Terms

Standard terms are used when referring to human anatomy, always in the upright, standing position (anatomical position).
Body erect, feet slightly apart, palms facing forward, thumbs pointing away from the body.
Ventral/anterior refers to the front of the body, dorsal/posterior refers to the back.
Superior means toward the head, inferior means toward the feet.
Medial is closer to the midline of the body, lateral is farther away.
Proximal is closer to the trunk, distal is farther away from the trunk.

Organ Systems

Multiple organ systems work together in the body.
Some organs are part of more than one system (e.g., the pancreas aids the endocrine and digestive systems).

Body Cavities

Thoracic cavity: contains the esophagus, heart, and lungs.
Abdominal cavity: contains digestive organs.
Pelvic cavity: contains reproductive organs.

Body Membranes

Line body cavities and tubes that open to the exterior.
Four types: mucous (lines tubes of various systems, containing goblet cells that secrete mucus), serous (lines closed cavities, e.g., pleurae, pericardium, peritoneum), synovial (lines freely moving joints, secretes synovial fluid), and cutaneous (covers the body's outer surface).

Integumentary System

Protects underlying tissues from trauma, pathogen invasion, and water loss.
Regulates body temperature.
Receives sensory input (e.g., touch).
Synthesizes vitamin D.
Organs include skin, along with hair, nails, and glands (sweat and oil).
Skin has two main regions: epidermis (outer layer of dead cells), and dermis (inner layer of connective tissue with blood vessels, nerve endings and glands).
Hypodermis is below the dermis (not part of skin).

Cells of the Epidermis

Melanocytes produce melanin, a pigment that gives skin its color and protects from UV light.
Two primary forms of melanin: pheomelanin (yellow-red) and eumelanin (black-brown)
Other factors that contribute to skin color are carotene and hemoglobin.
Epidermal cells produce vitamin D when exposed to UV rays.

The Dermis

Contains dense irregular connective tissue, collagen, and elastic fibers for strength and flexibility.
Contains sensory receptors, blood vessels, and glands.

The Subcutaneous Layer

Composed of areolar and adipose tissue.
Functions include: protection, temperature regulation, fat storage.
The accessory structures of the skin are: nails, hair, and glands.

Glands

Oil glands (sebaceous) produce sebum which softens hair and skin, retards bacterial growth.
Sweat glands (sudoriferous) help to regulate body temperature.
Acne is an inflammation of the sebaceous glands.

Homeostasis

A relatively constant internal environment maintained by body systems.
Blood and interstitial fluid are the two parts of the internal environment, containing nutrients, oxygen, waste etc. that are exchanged through interstitial fluid.
The nervous and endocrine systems work together with other systems to maintain homeostasis. Chemical messengers (hormones) travel in the blood, affecting organs and systems over a longer time frame, whereas the nervous system effects are faster.

Feedback Mechanisms

Negative feedback: the primary method.
Three components: receptor (detects change), control center (integrates information & selects response), effector (carries out response).
Positive feedback: rare, moves in same direction as initial stimulus increasing intensity (e.g., childbirth, fever.)

The Nervous System

Overall function: receives, processes sensory information from internal and external environment to coordinate body functions.
Two major divisions: central nervous system - brain and spinal cord, peripheral nervous system - nerves.
Three functions: sensory (generating nerve signals to CNS), integration (summing up input, creating memory, etc.), motor (generate output to muscles, glands, organs).
Two major cell types: neurons, neuroglia.
Types of neurons: sensory (afferent), motor (efferent), interneurons (association).
Neuroglia (glial cells) outnumber neurons.

The Synapse

A specialized junction where neurons communicate.
Transmission of action potentials, neurotransmitters involved.

Neurotransmitters

More than 100 types.
Examples include acetylcholine, norepinephrine, serotonin, dopamine, GABA, glutamate.

Removal of neurotransmitters

Synaptic cleft; neurotransmitter removal prevents continuous stimulation of receiving membranes.
Enzymes, reuptake mechanisms eliminate neurotransmitters.

Sensory Receptors and General Senses

Receptors detect sensations in the body. Adaptations; receptor types, and location.
Mechanoreceptors: detect mechanical forces (touch, pressure, vibration, body position, hearing).
Thermoreceptors: detect temperature changes.
Photoreceptors: detect light (vision).
Chemoreceptors: detect chemical stimuli (taste, smell, blood chemicals).
Pain receptors: detect stimuli that damage or threaten to damage tissue

The Special Senses

Vision, hearing, equilibrium, smell and taste.
Vision has specialized photoreceptors, hearing has stereocilia on hair cells, equilibrium involves semicirular canals and otoliths, smell uses olfactory receptors and taste uses taste buds.

The Brain

Parts of the brain: cerebrum, thalamus, hypothalamus, cerebellum, brainstem.
Cerebellum functions: coordinates voluntary movements, balance and posture.
Brainstem functions: regulates breathing, heart rate, sleep-wake cycle, consciousness.
Thalamus: relay station, sensory input.
Hypothalamus: controls homeostasis, regulates emotions

Spinal Cord

Structure: tube of neural tissue protected by vertebral column.
Gray matter in the center, white matter surrounds it.
Functions: conducts messages between brain and body, serves as a reflex center.

Peripheral Nervous System

Includes spinal nerves that originate from the spinal cord; Cranial nerves (12 pairs) that originate from the brain.
Divisions: somatic nervous system (voluntary movement), autonomic nervous system (involuntary activities like heart rate and digestion; further divided into sympathetic and parasympathetic), functions, subdivisions, and nervous pathways.

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Description

Test your knowledge on the functions of Schwann cells, the myelin sheath, and neurotransmitter activity. This quiz covers essential topics in neuroscience, including the roles of various neurotransmitters and the mechanisms underlying neuronal activity. Perfect for students in neuroscience courses or anyone interested in understanding the nervous system.