Nervous System and Eye Quiz

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Questions and Answers

What is the primary function of neuroglia cells in the nervous system?

Facilitate muscle contractions

Insulate, support, and protect neurons (correct)

Carry sensory information to the brain

Transmit impulses between neurons

Which type of nerve carries impulses from the peripheral body to the CNS?

Motor neurons

Efferent neurons

Afferent neurons (correct)

Associative neurons

What function do Schwann cells serve in the peripheral nervous system?

Line the ventricles of the brain

Transport nutrients to neurons

Form the myelin sheath around neuronal axons (correct)

Remove cellular debris

Which system is responsible for the 'flight or fight' response?

Sympathetic nervous system Signup and view all the answers

What is the role of microglia in the nervous system?

Remove cellular debris and pathogens Signup and view all the answers

Dendrites are responsible for which of the following functions?

Receive information and transmit electrical stimulation to the soma Signup and view all the answers

What is presbycusis?

A type of sensorineural deafness potentially caused by aging Signup and view all the answers

The peripheral nervous system (PNS) is primarily composed of which of the following?

All nerves connecting to the brain and spinal cord Signup and view all the answers

What is the function of the lacrimal gland?

Lubricates the eye Signup and view all the answers

Which structure of the eye is responsible for transparent vision?

Cornea Signup and view all the answers

What is the primary role of the retina?

Contains photoreceptor cells Signup and view all the answers

What condition is characterized by distant objects appearing blurry?

Myopia Signup and view all the answers

What is the role of the optic disc in the eye?

Is where the optic nerve leaves the eyeball Signup and view all the answers

Which part of the inner ear is primarily responsible for equilibrium?

Vestibular apparatus Signup and view all the answers

What type of humor is found in the posterior segment of the eye?

Vitreous humor Signup and view all the answers

What describes an instance of the photopupillary reflex?

Pupils constricting in bright light Signup and view all the answers

Which part of the external ear is shaped to funnel sound waves into the auditory canal?

Pinna Signup and view all the answers

What is presbyopia?

Loss of near vision with age Signup and view all the answers

What is the primary function of the frontal lobe?

Voluntary motor activity Signup and view all the answers

Which structure is involved in both memory and learning?

Hippocampus Signup and view all the answers

What is the primary function of the myelin sheath?

To insulate the axon and speed up nerve impulse transmission Signup and view all the answers

Which fissure separates the cerebrum from the cerebellum?

Transverse fissure Signup and view all the answers

Which neurotransmitter is primarily associated with motivation and reward?

Dopamine Signup and view all the answers

What role do inhibitory neurotransmitters play in neuronal activation?

They prevent activation of neurons Signup and view all the answers

What function does the hypothalamus connect to the pituitary gland?

Endocrine regulation Signup and view all the answers

What is the main difference between the subdural space and the subarachnoid space?

The subdural space is located between the dura mater and arachnoid mater, while the subarachnoid space is between the arachnoid and pia mater Signup and view all the answers

Which part of the brainstem is responsible for regulating heart rate?

Medulla Oblongata Signup and view all the answers

Which structure within the limbic system is crucial for processing emotions like fear and pleasure?

Amygdala Signup and view all the answers

What is the role of serotonin in the nervous system?

Regulation of emotion and mood Signup and view all the answers

Which artery supplies the occipital lobes of the brain?

Posterior cerebral artery Signup and view all the answers

Which part of the brain is primarily responsible for higher cognitive functions like thinking and intelligence?

Cerebral cortex Signup and view all the answers

What is the purpose of the blood-brain barrier?

To protect the brain by preventing certain substances from entering Signup and view all the answers

What role does the reticular-activating system play in the brain?

Sleep-wake cycle regulation Signup and view all the answers

What is the primary function of the hippocampus within the limbic system?

Facilitate storage of new memories Signup and view all the answers

What is the primary function of the Radial nerve?

Stimulates wrist and hand Signup and view all the answers

Which of the following conditions is characterized by the hypersecretion of Growth Hormone after long bone growth has ended?

Acromegaly Signup and view all the answers

What is the primary role of the Pineal gland?

Regulates sleep-wake cycles Signup and view all the answers

Which plexus is responsible for supplying motor movement to the muscles of the neck and shoulders?

Cervical Plexus Signup and view all the answers

What condition involves a collection of blood below the dura?

Subdural hematoma Signup and view all the answers

Study Notes

Eye Anatomy

The eyelids meet at the medial and lateral commissure, also known as the canthus.
Eyelashes produce an oily secretion that lubricates the eye.
The conjunctiva is a membrane lining the eyelids and eyeball.
The lacrimal gland produces lacrimal fluid and is located on the lateral end of each eye.
Six extrinsic eye muscles attach to the outer surface of the eye.
The eye is filled with fluids called humors that are located in two chambers: the anterior and posterior segments.
The lens is a flexible, biconvex, crystal-like structure located between the two chambers. It changes shape to focus light.
The sclera is the white connective tissue layer of the eye.
The cornea is the transparent, central anterior portion of the eye.
The choroid is a blood-rich nutritive layer containing pigment. It modifies anteriorly into two smooth muscle structures: the iris and pupil.
The iris regulates the amount of light entering the eye.
The pupil is the rounded opening in the iris.
The retina is a layer of photoreceptor cells containing two layers:
- The outer pigmented layer absorbs light and prevents scattering.
- The inner neural layer contains receptor cells.
The optic disc, also known as the blind spot, is where the optic nerve leaves the eyeball.
Rods are predominantly found at the edges of the retina and are responsible for vision in low light conditions.
Cones are responsible for detailed color vision.
The anterior aqueous segment lies anterior to the lens and contains aqueous humor, a clear, watery fluid.
The posterior aqueous segment contains vitreous humor, a gel-like substance.
Aqueous humor is a watery fluid found between the lens and cornea.
Vitreous humor is a gel-like substance located posterior to the lens which prevents the eye from collapsing.
The ophthalmoscope is an instrument used to illuminate the interior of the eyeball and fundus.
There are four types of refractive errors in the eye:
- Emmetropia: the eye focuses images correctly on the retina.
- Myopia (nearsightedness): distant objects appear blurry.
- Hyperopia (farsightedness): near objects are blurry, while distant objects are clear.
- Astigmatism: images are blurry due to an irregularly shaped cornea.
Convergence is a reflexive movement of the eyes medially when focusing on a close object.
The photopupillary reflex causes the pupils to constrict in bright light.
The accommodation pupillary reflex causes the pupils to constrict when viewing close objects.

Ear Anatomy

The external acoustic meatus (auditory canal) is a narrow chamber in the temporal bone.
The middle ear cavity (tympanic cavity) is an air-filled, mucosa-lined cavity located within the temporal bone.
The pharyngotympanic tube (auditory tube) links the middle ear cavity with the throat.
The inner ear includes the sense organs for hearing and balance.
The membranous labyrinth is suspended in perilymph and contains endolymph.
The vestibular apparatus is the equilibrium receptors of the inner ear.

Static Equilibrium

The maculae are receptors located in the vestibule.
Hair cells within the maculae are embedded in the otolithic membrane.
Otoliths are tiny stones that float in a gel around hair cells.
The crista ampullaris responds to angular or rotational movements of the head.

Hearing

The spiral organ of Corti is located within the cochlear duct.
Receptor hair cells are located on the basilar membrane.
The cochlear nerve attached to hair cells transmits nerve impulses to the auditory cortex.

Chemical Senses: Smell and Taste

Chemoreceptors are stimulated by chemicals in solution.
Olfactory hairs with long cilia detect chemicals.
Olfactory receptors are dissolved in mucus for detection.
The tongue is covered with projections called papillae.

Developmental Aspects of Special Senses

Presbyopia, also known as old vision, is a condition that results from decreasing lens elasticity.
Presbycusis is a type of sensorineural deafness that may result from otosclerosis.

Nervous System

The nervous system is a complex network of nerves and cells that coordinates the body.
The nervous system has three main functions:
- Sensory input: gathering information.
- Integration: processing and interpreting sensory input.
- Motor output: a response to integrated stimuli.
The peripheral nervous system (PNS) consists of nerves connecting the brain and spinal cord to sensory receptors, muscles, and glands.
- Cranial nerves: originate from the brain.
- Spinal nerves: originate from the spinal cord.
- Ganglia are clusters of neuron cell bodies.
The central nervous system (CNS) is the communication and coordination system of the body.
The autonomic nervous system (ANS) consists of nerves and plexuses that carry impulses to smooth muscles, secretory glands, and heart muscles.
- Sympathetic nervous system (SNS): "fight or flight" response.
- Parasympathetic nervous system (PNS): "rest and digest" or "housekeeping" response.

Nervous Tissue

Nervous tissue consists of two principal cell types: neurons and neuroglia.
Neuroglia (glial cells) insulate, support, and protect neurons.
- Astrocytes transport nutrients to neurons and restrict substances entering the brain.
- Microglia remove cellular debris, wastes, and pathogens from the nerve tissues by phagocytosis.
- Oligodendrocytes form the myelin sheath in the CNS.
- Ependymal cells line the ventricles of the brain and the central canal of the spinal cord.
- Schwann cells form the myelin sheath around neuronal axons in the PNS and are also called neurilemmal cells.
- Satellite cells surround neuron cell bodies in ganglia.

Neurons

Neurons are cells within the nervous system that transmit information.
Neurons have two key properties:
- Irritability: the ability to react to a certain stimuli.
- Conductivity: the ability to transmit impulses.
There are three types of neurons:
- Efferent (motor) neurons: convey information from the CNS to muscles and glands.
- Associative (interneurons) neurons: carry impulses from sensory neurons to motor neurons.
- Afferent (sensory) neurons: convey information from the periphery of the body to the brain and spinal cord.

Parts of a Neuron

The dendrite is a tree-like extension at the beginning of a neuron that receives information and transmits electrical stimulation to the soma.
The nucleus is the archivist and architect of the cell.
The cell body (soma) is the spherical part of the neuron.
The axon is the main conducting unit of the neuron, a long thread-like part of the nerve cell.
The nodes of Ranvier are gaps in the myelin sheath, allowing for rapid conduction.
The myelin sheath is a fatty substance that surrounds the axon.
The synaptic cleft is the gap between adjacent neurons.
The synapse is the junction between nerves.

Neurotransmitters

Neurotransmitters are chemical substances that facilitate the transmission of messages across the synapse.
Neurotransmitters can be either inhibitory or excitatory.
- Inhibitory: prevents activation of a neuron.
- Excitatory: leads to the activation of a neuron.
Examples of neurotransmitters include:
- Adrenaline (epinephrine): associated with stress, restlessness, and irritability.
- Noradrenaline (norepinephrine): associated with alertness, heightened nervous system activity, wakefulness, and memory formation.
- Dopamine: an inhibitory neurotransmitter involved in motivation, decision-making, movement, and reward.
- Endorphins: short for "morphine," they are involved in pain reduction and pleasure. They are opioids.
- Gamma-amino-butyric-acid (GABA): a major inhibitory neurotransmitter in the brain.
- Acetylcholine: linked to Alzheimer's disease.
- Glutamate: an excitatory neurotransmitter implicated in learning and memory (long-term potentiation).
- Serotonin: intimately involved in emotion and mood.

Nerve Impulse Transmission

Nerve impulse transmission occurs in a chain reaction that can be thought of as a domino effect.
Depolarization occurs when a stimulus depolarizes the neuron's membrane, causing a chain reaction that leads to the transmission of a nerve impulse.

The Brain

The brain is an intricate mass of soft nervous tissue.
The cerebral cortex is the outer layer of the brain, also known as the gray matter.
Memory is the process of storing "old" information. The hippocampus plays a key role in memory formation and storage.
The meninges are three layers of protective membranes that surround the brain:
- Dura mater: lines the inside of the skull.
- Arachnoid mater: resembles a fine cobweb with fluid-filled spaces.
- Pia mater: covers the brain surface itself and consists of blood vessels.
The subdural space is located between the dura mater and arachnoid mater.
The subarachnoid space is located between the arachnoid and pia mater and is filled with cerebrospinal fluid.
Cerebrospinal fluid (CSF) acts as a liquid shock absorber and provides nutrients to the brain.
A lumbar puncture (spinal tap) is the removal of cerebrospinal fluid.
The blood-brain barrier protects the brain by restricting the passage of certain substances.

Brain Regions

The cerebrum is the largest part of the brain and controls thought, intelligence, consciousness, and memory.
The cerebral cortex is the outermost layer of the cerebrum. It controls conscious thought, judgment, memory, reasoning, and will power.
Fissures are deep grooves that divide the cerebrum.
- The longitudinal fissure divides the two cerebral hemispheres (left and right).
- The transverse fissure separates the cerebrum from the cerebellum.
- The Sylvian (lateral) fissure divides the temporal lobe from the frontal and parietal lobes.
The frontal lobe controls voluntary motor activity and includes Broca's area, which is responsible for expressive (motor) speech.
The parietal lobe is involved in concept formation, abstraction, and sensory perception.
The temporal lobe is responsible for hearing, processing auditory information, and encoding memory.
The occipital lobe processes visual information and stores visual memories.
The limbic system is located at the center of the brain and mediates emotions like fear, anger, pleasure, and sorrow.
- Olfactory bulb: associated with the sense of smell and emotions.
- Amygdala: influences behavior to meet the body's needs.
- Hippocampus: involved in memory and learning, particularly the recognition of new information and recall.
- Parahippocampus: monitors strong emotions.
- Fornix: pathway of nerve fibers from the hippocampus.
- Mamillary body: nucleus that transmits messages between the fornix and thalamus.
- Cingulated gyrus: comprises the limbic cortex.
- Septum pellucidum: connects the fornix to the corpus callosum.

Diencephalon

The diencephalon is located between the cerebrum and the midbrain.
The thalamus acts as a relay station for incoming and outgoing nerve impulses.
The hypothalamus controls body temperature, hunger, thirst, and emotions.

Cerebellum

The cerebellum controls voluntary motor activities, muscle movements, and position body parts. It is the second largest part of the brain.

Brain Stem

The brain stem is attached to the spinal cord.
The medulla oblongata is bulb-shaped and is found between the pons and the spinal cord.
- Cardiac centers: regulate heart rate.
- Vasomotor centers: regulate blood pressure (BP).
- Respiratory centers: regulate breathing.
- Reflex centers: control coughing, sneezing, swallowing, and vomiting.
The midbrain integrates visual and auditory reflexes.
The reticular formation controls skeletal motor movement and spinal reflexes.
The reticular-activating system controls the sleep-wake cycle.

Arterial Supply to the Brain

The carotid arteries supply blood to the brain via the internal carotid artery, which flows into the circle of Willis.
The subclavian artery supplies blood to the brain via the vertebral arteries, which flow into the circle of Willis.
The circle of Willis is a vascular structure located at the base of the brain.
The anterior cerebral artery supplies the frontal lobes.
The middle cerebral artery supplies the temporal and parietal lobes.
The basilar artery supplies the brainstem and cerebellum. It branches off from the vertebral arteries to the cerebellum.
The posterior cerebral artery supplies the occipital lobes.

Nerves

A nerve is a bundle of nerve fibers enclosed by connective tissue.
Cranial nerves originate from the brain and brain stem.
Spinal nerves connect to the spinal cord and a specific segment of the spinal cord.

Peripheral Nervous System

The cervical plexus supplies motor movement to the muscles of the neck and shoulders.
The brachial plexus supplies motor movement to the shoulder, wrist, and hand.
The radial nerve stimulates the wrist and the hand.
The lumbar plexus supplies motor movement to the buttocks, anterior leg, and thighs.
The sacral plexus supplies motor movement to the posterior leg and thighs.
The sciatic nerve passes through the gluteus maximus and down the back of the thigh and leg.

Nervous System Disorders

Cerebral edema is swelling resulting from an inflammatory response.
A subdural hematoma is a collection of blood below the dura mater.
A cerebrovascular accident (CVA) is a ruptured blood vessel supplying a region of the brain.
Alzheimer's disease is a progressive degenerative brain disease.

Endocrine System

The endocrine system is the second controlling system of the body. The nervous system is the fast-control system.
Endocrinology is the scientific study of hormones and endocrine organs.

Hormones

Growth hormone: plays a crucial role in determining final body size.
- Dwarfism: Body proportions are relatively normal, but individuals are short in stature.
- Gigantism: Individuals become extremely tall due to excessive growth hormone production.
- Acromegaly: hypersecretion of growth hormone after long bone growth has ended.
Prolactin: the only known target of prolactin in humans is the breast.
Oxytocin triggers strong contractions of the uterine muscle during labor.
Antidiuretic hormone (ADH): inhibits or prevents urine production.

Other

The pineal gland produces melatonin. Peak melatonin levels occur at night, and levels are lowest during daylight hours.

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Description

Test your knowledge on key concepts related to the nervous system and the anatomy of the eye. This quiz covers neuroglia, peripheral nervous system functions, and visual mechanisms. Ideal for students studying biology and human anatomy.