Biological Sciences: Nervous System

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Questions and Answers

What is released by motor nerve endings onto muscle?

Serotonin

Acetylcholine (correct)

Dopamine

Norepinephrine

Which term refers to a group of cell bodies outside the central nervous system (CNS)?

Ganglion (correct)

Nerve

Nucleus

Tract

How does the concentration of potassium and sodium ions relate to the negative charge inside a nerve cell membrane?

Sodium ions are more permeable than potassium ions.

Lower sodium concentration inside allows for a negative charge.

Potassium ions cannot easily leave the cell, maintaining a negative charge. (correct)

Higher potassium concentration leads to a positive charge inside.

What distinguishes a bipolar neuron from other types?

It has one axon and one dendrite. Signup and view all the answers

Which statement about tracts and nerves is correct?

Tracts are groups of nerve fibers within the CNS. Signup and view all the answers

Which ionic change occurs during the passage of an action potential along a nerve fiber?

Sodium ions enter the cell, causing depolarization. Signup and view all the answers

What is the primary function of myelination in neurons?

To reduce resistance and increase impulse speed. Signup and view all the answers

Which type of neuronal structure includes multiple dendrites and a single axon?

Multipolar neuron Signup and view all the answers

What is the primary function of oligodendrocytes?

To wrap around nerve fibers in the central nervous system Signup and view all the answers

How do Schwann cells differ from oligodendrocytes?

They surround nerve fibers in the peripheral nervous system Signup and view all the answers

What role do ependymal cells play in the central nervous system?

They line the ventricles and move cerebrospinal fluid Signup and view all the answers

What is the function of satellite cells?

To surround and support neuron cell bodies in the PNS Signup and view all the answers

Which cells are responsible for myelination in the central nervous system?

Oligodendrocytes Signup and view all the answers

What type of shape do ependymal cells exhibit?

Ciliated squamous to columnar Signup and view all the answers

What distinguishes the types of glial cells in the CNS from those in the PNS?

The types and functions of glial cells differ between these systems Signup and view all the answers

Which cellular function is shared by both oligodendrocytes and Schwann cells?

They are involved in the production of myelin sheath Signup and view all the answers

What role do rods play in vision?

They are sensitive to dim light. Signup and view all the answers

What type of cones are responsible for detecting red light?

L cones Signup and view all the answers

Which area of the retina contains the highest concentration of cones?

Fovea centralis Signup and view all the answers

What is the blind spot in the context of vision?

The optical nerve entry point devoid of receptors. Signup and view all the answers

How does a concave lens correct myopia?

By diverging light rays. Signup and view all the answers

What condition results from the inability to focus light correctly on the retina?

Myopia or hyperopia Signup and view all the answers

What type of lens is used to correct hyperopia?

Convex lens Signup and view all the answers

In which part of the retina do you find no rods or cones?

Blind spot Signup and view all the answers

Which structure is part of the limbic system?

Hippocampus Signup and view all the answers

What is the main function of the superior colliculi?

Vision Signup and view all the answers

Which part of the hindbrain is involved in controlling balance?

Cerebellum Signup and view all the answers

Which region of the brain connects the forebrain and hindbrain?

Midbrain Signup and view all the answers

What function does the substantia nigra primarily serve?

Motor function Signup and view all the answers

What is the role of the reticular formation?

Regulating sleep and alertness Signup and view all the answers

Which part of the brainstem is responsible for breathing and heart rate control?

Medulla oblongata Signup and view all the answers

Which function is associated with the pons?

Chemical production for sleep Signup and view all the answers

What is the diameter of the human ear drum?

0.7 inches Signup and view all the answers

What is the main function of the STAPEDIUS muscle?

To control the STAPES bone Signup and view all the answers

Why do children have more sensitive ears than adults?

Their brains process sound differently Signup and view all the answers

What is indicated by the 'watch-tick test'?

The dominant ear's sensitivity Signup and view all the answers

How does the brain respond to the sounds children hear?

It ignores most of them Signup and view all the answers

What is the size comparison of the area of the middle ear?

No bigger than an M&M Signup and view all the answers

What occurs to the ear drum when hearing sound?

It moves less than a billionth of an inch Signup and view all the answers

What is the approximate length of the STAPEDIUS muscle?

1/20th of an inch Signup and view all the answers

Study Notes

Types of Neuroglia

Oligodendrocytes: Glial cells in the central nervous system that wrap around nerve fibers to form myelin sheath.
Schwann cells: Glial cells in the peripheral nervous system that also wrap around nerve fibers to produce myelin sheath.
Ependymal cells: Ciliated glial cells lining cerebrospinal fluid (CSF) cavities in the brain and spinal cord; involved in CSF movement.
Satellite cells: Glial cells that surround and support neuron cell bodies in peripheral nervous system ganglia.

Nerves and Nervous Tissue

Nerve: A group of nerve fibers located outside the central nervous system (CNS).
Ganglion: A collection of neuron cell bodies found outside the CNS.
Tract: A bundle of nerve fibers within the CNS.
Nucleus: A group of neuron cell bodies located within the CNS.

Action Potential and Nerve Impulses

Concentration of potassium is higher inside the nerve cell membrane than sodium outside, resulting in a negative internal charge due to selective permeability.
Ionic and electrical changes occur during action potential propagation along a nerve fiber.

Neuron Classification

Unipolar neurons: One axon and one dendrite extend directly from the cell body.
Bipolar neurons: Have one axon and one dendrite.
Multipolar neurons: Feature multiple dendrites and one axon.
Pseudounipolar: Single process that divides into two branches.

The Limbic System

Composed of hypothalamus, amygdala, and hippocampus; plays roles in emotion, memory, and navigation.

Midbrain Functions

Connects forebrain and hindbrain.
Contains superior colliculi (vision), inferior colliculi (hearing), and tegmentum (consciousness).
Also includes motor function areas like the cerebral peduncle, red nucleus, and substantia nigra.

Hindbrain Functions

Comprised of cerebellum, pons, and medulla oblongata.
Cerebellum: Controls posture, balance, and coordination of voluntary movements.
Pons: Acts as a bridge between cerebellar hemispheres and aids in producing sleep-related chemicals.
Medulla oblongata: Regulates breathing, heart rate, and reflexes; relays signals between brain and spinal cord.

Visual System

Blind spot: Area on the retina where optic nerve exits; lacks photoreceptors, resulting in no image formation.
Fovea centralis: Contains the highest concentration of cones, providing sharp central vision necessary for detailed tasks.

Common Vision Problems

Myopia (nearsightedness) and hyperopia (farsightedness) require concave and convex lenses, respectively, for correction.

Ear Anatomy and Function

Middle ear equivalent in size to an M&M; contains the smallest bones in the body.
Stapedius: The smallest muscle, controlling the stapes bone.
Ear drum: Moves less than one billionth of an inch in response to sound; continues to work while asleep.

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Description

Explore the fascinating world of neuroglia with this quiz on the nervous system. Learn about the types of glial cells, such as oligodendrocytes, and their functions. Test your knowledge and deepen your understanding of coordination and control in biological systems.