A/P II Lab Practical 1

What are the main components of a neuron?

• Cell Bodies/Soma

• Dendrites

• Axons

What is a Graded Potential? Which part of the Neuron detects it?

• Graded Potential: a change in a neuron’s membrane potential (carrying in magnitude based on the strength of the stimulus).

• Dendrites

What is an Action Potential? Which part of the Neuron detects it?

• Action Potential: a rapid, large, and all-or-nothing electrical signal that travels along the length of a neuron, allowing it to communicate with other neurons, muscles, or glands.

• Axon Hillock

What are the main structural classes of neurons?

• Multipolar

• Bipolar

• Unipolar

Where are multipolar neurons usually found (CNS/PNS)? Is this a structural or functional neural classification?

• CNS (Brain & Spinal Cord)

• Structural

Where are bipolar neurons usually found (CNS/PNS)? Is this a structural or functional neural classification?

• PNS: Retina, Olfactory Mucosa, & Cochlea

• Structural

Where are unipolar neurons usually found (CNS/PNS)? Is this a structural or functional neural classification?

• PNS: Dorsal Root Ganglia, Cranial Nerve Ganglia

• Structural

What are the main functional classes of neurons?

• Sensory

• Motor

• Interneurons

Where are sensory neurons usually found (CNS/PNS)? Are they afferent or efferent? Is this a structural or functional neural classification?

• PNS

  • Dorsal Root Ganglia, Cranial Merve Ganglia

• Afferent

• Almost all are unipolar.

• Functional

Where are motor neurons usually found (CNS/PNS)? Are they afferent or efferent? Is this a structural or functional neural classification?

• CNS

• Efferent

• Multipolar

• Functional

Where are interneurons neurons usually found (CNS/PNS)? Is this a structural or functional neural classification?

• Lie between sensory and motor neurons.

• Most are entirely within the CNS.

• Functional

List the different types of Glia? Which ones are in the CNS? PNS?

• Central Nervous System

  • Oligodendrocytes

  • Ependymal

  • Astrocytes

  • Microglia

• Peripheral Nervous System

  • Schwann Cells

  • Satelite Cells

List the role of the following cell and state whether it is found in the CNS or PNS: Oligodendrocytes.

• Produce Myelin Sheath

• CNS

List the role of the following cell and state whether it is found in the CNS or PNS: Ependymal.

• Line the central cavities of the brain and spinal cord; involved on the production and circulation of CSF.

• CNS

List the role of the following cell and state whether it is found in the CNS or PNS: Astrocytes.

• Most abundant, versatile, and highly branched of glial cells that cling to neurons, synaptic endings and capillaries.

• CNS

List the role of the following cell and state whether it is found in the CNS or PNS: Microglial Cells.

• Cells that touch and monitor neurons, migrate toward injured neurons and phagocytize microorganisms and neuronal debris.

• CNS

List the role of the following cell and state whether it is found in the CNS or PNS: Schwann Cells.

• Similar function to oligodendrocytes of CNS.

• Located in PNS

List the role of the following cell and state whether it is found in the CNS or PNS: Satellite Cells.

• Similar function to astrocytes of CNS.

• Located in PNS

Define: Synapse

The functional connection between a neuron and the cell it is signaling.

Can a pre-synaptic cell be a neuron, muscle, or gland cell? What about post-synaptic cells?

A pre-synaptic cell is typically a neuron, but it can sometimes be a muscle cell or gland cell.

A post-synaptic cell can be a neuron, muscle cell, or gland cell, depending on the synapse type.

State the function: Cell Body/Soma/Cyton

Synthesize proteins, membranes, and chemicals.

State the function: Dendrite

Conduct a graded impulse toward the cell body/soma when stimulated.

State the function: Nissl Body

What is it composed of?

• Composition: Rough ER

• Function: Protein Modification

State the function: Nucleus

Store Genetic Information

State the function: Axon Hillock

Triggers action potentials (APs).

State the function: Axon

Carry electricals from neurons to other cells.

State the function: Myelin Sheath

Increase AP conduction speed.

State the function: Shwann cell

Produce Myelin Sheath (PNS)

State the location and function: Node of Ranvier

• Location: Small gaps between myelin sheath.

• Function: Speed up the transmission of impulses by allowing them to jump from one to the next.

State the location and function: Axolemma

• Location: The outer covering/cell membrane of an axon.

• Function: Helps send signals and maintain axon’s environment.

State the location and function: Axon Collateral

Extensions from the main axon.

State the function: Axon Terminal

Send information to next cell.

State the function: Vesicles

Transport Substances

What are the three general steps of neuronal processing?

• Sensory Input

• Integration

• Motor Response

What types of neurons are present in the following step of neural processing: Sensory Input? Is this step involved in the CNS or PNS?

• Sensory Neurons

• PNS

What types of neurons are present in the following step of neural processing: Integration? Is this step involved in the CNS or PNS?

• Interneurons

• CNS

What types of neurons are present in the following step of neural processing: Motor Output? Is this step involved in the CNS or PNS?

• Motor Neurons

• PNS

Define: White Matter

Is this located in the CNS or PNS?

• Regions of brain and spinal cord with dense collections of myelinated fibers.

• Location: CNS

Define: Gray Matter

Is this located in the CNS or PNS?

• Mostly neuron cell bodies and unmyelinated fibers.

• Location: CNS

Define: Fascicle

What connective tissue wraps around it? What is inside it?

A bundle of nerve fibers (axons) that are grouped together within a nerve.

It is wrapped by perineurium; the fascicle contains axons of sensory, motor, and autonomic neurons, which transmit signals to and from the CNS.

Are blood vessels inside or outside a fascicle?

Outside

What is the space that Spinal Nerves pass through in the Vertebral Column?

Intervertebral Foramen

Do spinal nerves have motor axons, sensory axons, or both?

Both

True/False - Parts from a single neuron can be present in BOTH the CNS and the PNS.

True

True/False - Interneurons are present in BOTH the CNS and the PNS.

False

Fill in the blank: Spinal nerves are formed by ___ and ___ roots.

• Dorsal

• Ventral

Select the best answer choice: In terms of function, spinal nerves are classified as ___?

A. Sensory

B. Motor

C. Both/Mixed

D. None of the above

C. Both/Mixed (Sensory & Motor)

List the cranial nerves in order.

• Olfactory Nerve

• Optic Nerve Nerve

• Oculomotor Nerve

• Trochlear Nerve

• Trigeminal Nerve

• Abducens Nerve

• Facial Nerve

• Vestibulocochlear Nerve

• Glossopharyngeal Nerve

• Vagus Nerve

• Accessory Nerve

• Hypoglossal Nerve

State the Cranial Nerve name nemonic

Oh Oh Oh To Touch And Feel Very Green Vegetables At Home

Olfactory Nerve

List:

• Roman Numeral/Number

• Functional Class (S, M, or B)

• Target (Supply) & Function

• Autonomic Function (Yes/No)

• I (1)

• Sensory (S)

• Inferior Temporal Lobe; Smell

• No

Optic Nerve

List:

• Roman Numeral/Number

• Functional Class (S, M, or B)

• Target (Supply) & Function

• Autonomic Function (Yes/No)

• II (2)

• Sensory (S)

• Occipital Lobe; Vision

• No

Oculomotor Nerve

List:

• Roman Numeral/Number

• Functional Class (S, M, or B)

• Target (Supply) & Function

• Autonomic Function (Yes/No)

• III (3)

• Motor

• Target:

  • Superior Rectus

  • Medical Rectus

  • Inferior Rectus

  • Inferior Oblique

• Function: Eyeball Movement

• Yes—-Parasympathetic: Pupil Dilation/Contractions

Trochlear Nerve

List:

• Roman Numeral/Number

• Functional Class (S, M, or B)

• Target (Supply) & Function

• Autonomic Function (Yes/No)

• IV (4)

• Motor

• Superior Oblique; Eyeball Movement

• No

Trigeminal Nerve

List:

• Roman Numeral/Number

• Functional Class (S, M, or B)

• Target (Supply) & Function

• Auntonomic Function (Yes/No)

• V (5)

• Subdivisions:

  • Ophthalmic

    • Sensory: Face

    • Motor: Mastication

    • Muscles Innervated: Masseter

  • Maxillary

    • Sensory

  • Mandibular

    • Both

• No

Abducens Nerve

List:

• Roman Numeral/Number

• Functional Class (S, M, or B)

• Target (Supply) & Function

• Autonomic Function (Yes/No)

• VI (6)

• Motor

• Lateral Rectus; Lateral Eye Movement

• No

Facial Nerve

List:

• Roman Numeral/Number

• Functional Class (S, M, or B)

• Target (Supply) & Function

• Autonomic Function (Yes/No)

• VII (7)

• Both

  • Sensory: Taste Buds

  • Motor: Facial Muscles

• Yes—-Parasympathetic: Lacrimal & Savillary Glands (Submandibular & Sublingual Salivary Glands)

Vestibulocochlear Nerve

List:

• Roman Numeral/Number

• Functional Class (S, M, or B)

• Target (Supply) & Function

• Auntonomic Function (Yes/No)

• VIII (8)

• Sensory

• Cochlea; Balance & Hearing

• No

Glossopharyngeal Nerve

List:

• Roman Numeral/Number

• Functional Class (S, M, or B)

• Target (Supply) & Function

• Autonomic Function (Yes/No)

• IX (9)

• Both

  • Sensory: Taste

  • Motor: Swallowing

• Yes—-Parasympathetic: Savillary Glands

Vagus Nerve

List:

• Roman Numeral/Number

• Functional Class (S, M, or B)

• Target (Supply) & Function

• Autonomic Function (Yes/No)

• X (10)

• Both

  • Sensory:

    • Thoracic & Abdominal Viscera

    • Aortic Arch (Blood Pressure)

    • Breathing

  • Motor: Pharynx

• Yes—-Parasympathetic: Gag Reflex

Accessory Nerve

List:

• Roman Numeral/Number

• Functional Class (S, M, or B)

• Target (Supply) & Function

• Autonomic Function (Yes/No)

• XI (11)

• Both

  • Sensory: Proprioception of Muscles

  • Motor: Contractions

*Innervates TRAPEZIUS & STERNOCLEIDOMASTOID

• No

*Both ( S & M), but mainly MOTOR.

Hypoglossal Nerve

List:

• Roman Numeral/Number

• Functional Class (S, N, or B)

• Target (Supply) & Function

• Auntonomic Function (Yes/No)

• XII (12)

• Both

  • Sensory: Proprioception of Tongue

  • Motor: Tongue

• No

List the CN that have autonomic (i.e Parasympathetic) functions.

• CN 3: Oculomoter - Pupil Dilation

• CN 7: Facial - Lacrimal Glands, Submandibulary & Sublingual Salivary Glands

• CN 9: Glossopharyngeal - Salivary Glands

• CN 10: Vagus - Gag Reflex

How many cranial nerves are involved in the movement of eyeballs? Which specific muscles are innervated by these nerves?

• CN 3 - Oculomoter

  • Superior Rectus

  • Medical Rectus

  • Inferior Rectus

  • Inferior Oblique

• CN 4 - Trochlear

  • Superior Oblique

• CN 6 - Abducens

  • Lateral Rectus

Which cranial nerves that serve the eye are motor? Which are sensory?

• CN 3 - Oculomoter: Motor

• CN 4 - Trochlear: Motor

• CN 6: Abducens: Motor

What are accessory structures to the eye?

• Eyebrows

• Eyelids

• Conjunctiva

• Lacrimal Apparatus

• Extrinstic Eye Muscles

List the function of the eye accessory structure: Eyebrows

• Shade Eye From Sunlight

• Prevent Perspiration From Reaching Eye

List the function of the eye accessory structure: Eyelids

• Lubrication (Oil Secretions)

What is the conjunctiva?

Epithelial covering that lines the eyelids and anterior surface of the eye.

List the function of the eye accessory structure: Conjunctiva

• Lubrication (Mucus Secretion)

List the function of the conjunctival sac.

Serves as a tear reservoir—-where tears collect and are drained, helping maintain moisture and cleaning the eye.

What are tears? Why are they important?

Lacrimal secretions that contain mucus, dilute salt solution, antibodies, and lysosomes; important because they reduce friction, remove debris, and prevent bacterial infections.

What is the path tears take as the move from the lacrimal gland to the nasal cavity?

Tears are produced by the lacrimal gland, spread over the eye, drain into the puncta, travel through the canaliculi, collect in the lacrimal sac, move through the nasolacrimal duct, and finally enter the nasal cavity.

Extrinsic Muscles - Superior Oblique

List:

• Muscle Function/Action

• Innervation

• Depresses Eye; Turns It Laterally

• CN 4: Trochlear

Extrinsic Muscles - Superior Rectus

List:

• Muscle Function/Action

• Innervation

• Elevates Eye; Turns It Medially

• CN 3: Oculomoter

Extrinsic Muscles - Medial Rectus

List:

• Muscle Function/Action

• Innervation

• Moves Eye Medially

• CN 3: Oculomoter

Extrinsic Muscles - Lateral Rectus

List:

• Muscle Function/Action

• Innervation

• Moves Eye Laterally

• CN 6: Abducens

Extrinsic Muscles - Inferior Rectus

List:

• Muscle Function/Action

• Innervation

• Depresses Eye; Turns It Medially

• CN 3: Oculomoter

Extrinsic Muscles - Inferior Oblique

List:

• Muscle Function/Action

• Innervation

• Elevates Eye; Turns It Laterally

• CN 3: Oculomoter

Which layer of the eye do the extrinsic muscles attach to?

Sclera

What special “loop” does the superior oblique muscle pass through?

Trochlea

What do ciliary processes secrete? Where do the secretions go?

Aqueous humor, which goes first into the posterior compartment then through the iris into the anterior compartment of the (anterior segment).

What is the purpose of the brown pigment of the choroid?

Primarily composed of melanin, the brown pigment of the choroid aids in: light absorption, photoreceptors protection, and glare reduction.

What muscles contract to shape the lens?

Ciliary Muscles

Which side of the lens contains aqueous humor?

Anterior Segment

Which side of the eye contains vitreous humour?

Posterior Segment

Why is it important for the humours to be under pressure?

• Eye Shape

• Lens Protection

What bone directly connects to the tympanic membrane?

Malleus Bone

Know the order of the auditory ossicles.

Malleus Bone, Incus Bone, Stapes Bone

Name the muscles that connect to the malleus bone and stapes bone.

• Tensor Tympani Muscle

• Stapedius Muscle

Why is it important that the auditory tube equalize pressure?

This is important because for the eardrum (tympanic membrane) to vibrate properly in response to sound waves, the pressure on both sides of the eardrum must be equal. If there is a pressure imbalance, the eardrum can become stretched or distorted, leading to hearing difficulties or discomfort.

What is Otis Media? List some s/s.

Is an infection/inflammation of the middle ear. Signs/symptoms include: ear pain, hearing loss, fever, irritability, fluid drainage, etc.

Do structures in the vestibule detect equilibrium or sound?

Equillibrium

What are the maculae? What do they detect?

The maculae are specialized sensory regions found within the utricle and saccule, which are part of the vestibule of the inner ear. The maculae play a critical role in detecting changes in head position and motion (gravity).

Do the semicircular ducts detect equilibrium or sound?

Equillibrium

What region of the semicircular ducts have sensory cells?

Ampulla

What are is cristae ampullares? What do they detect?

The crista ampullaris consists of hair cells (sensory cells) embedded in a gel-like substance called the cupula; detect angular movement and rotation movement.