Anatomy & Physiology Exam Study Guide: Chapters 13–15

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Q1. What are dermatome maps and why are they important?

Background

Topic: Dermatome Maps

This question tests your understanding of how specific areas of skin are innervated by spinal nerves and the clinical significance of these maps.

Key Terms:

Dermatome: An area of skin supplied by a single spinal nerve.
Spinal nerves: Nerves that emerge from the spinal cord and innervate various body regions.

Step-by-Step Guidance

Recall that each spinal nerve (except C1) innervates a specific region of skin called a dermatome.
Understand that dermatome maps are diagrams showing which spinal nerves supply which skin regions.
Consider why clinicians use dermatome maps to diagnose nerve injuries or diseases.
Think about how loss of sensation in a specific area can indicate damage to a particular spinal nerve.

Try solving on your own before revealing the answer!

Final Answer:

Dermatome maps are diagrams that show the areas of skin innervated by each spinal nerve. They are important because they help clinicians localize neurological damage or disease based on sensory loss patterns.

Q2. What are thermoreceptors and how do their pathways transmit temperature sensations?

Background

Topic: Sensory Receptors and Pathways

This question focuses on the function of thermoreceptors and the neural pathways involved in transmitting temperature information.

Key Terms:

Thermoreceptors: Sensory receptors that detect changes in temperature.
Spinothalamic pathway: The neural pathway that carries temperature and pain sensations to the brain.

Step-by-Step Guidance

Identify where thermoreceptors are located (skin, mucous membranes).
Recall that thermoreceptors respond to changes in temperature and generate action potentials.
Understand that these signals travel via afferent neurons to the spinal cord.
Consider the spinothalamic tract, which transmits these signals to the thalamus and then to the cerebral cortex.

Try solving on your own before revealing the answer!

Final Answer:

Thermoreceptors detect temperature changes and send signals through afferent neurons to the spinal cord. The spinothalamic pathway then transmits these signals to the thalamus and cerebral cortex, allowing us to perceive temperature.

Q3. What are the five elements of a reflex arc?

Background

Topic: Reflex Arcs

This question tests your knowledge of the basic components involved in a reflex action.

Key Terms:

Reflex arc: The neural pathway that mediates a reflex.

Step-by-Step Guidance

Recall that a reflex arc is a simple neural circuit.
List the five elements: receptor, sensory neuron, integration center, motor neuron, effector.
Think about the function of each element in the pathway.
Consider how these elements work together to produce a rapid, involuntary response.

Try solving on your own before revealing the answer!

Final Answer:

The five elements of a reflex arc are: (1) receptor, (2) sensory neuron, (3) integration center, (4) motor neuron, and (5) effector. Each plays a role in detecting a stimulus and producing a response.

Q4. What is a crossed extensor reflex and how does it differ from other reflex arcs?

Background

Topic: Reflex Arc Types

This question examines your understanding of complex reflexes, specifically the crossed extensor reflex.

Key Terms:

Crossed extensor reflex: A reflex that involves both sides of the body.
Withdrawal reflex: A reflex that removes a body part from a painful stimulus.

Step-by-Step Guidance

Recall that the crossed extensor reflex occurs in response to a painful stimulus.
Understand that it involves withdrawal of the affected limb and extension of the opposite limb.
Compare this to simple reflex arcs, which typically involve only one side of the body.
Think about the neural pathways that allow for coordination between both sides.

Try solving on your own before revealing the answer!

Final Answer:

The crossed extensor reflex is a complex reflex that causes withdrawal of one limb and extension of the opposite limb, allowing balance and protection. It differs from simple reflex arcs by involving both sides of the body.

Q5. What is the Golgi tendon reflex and what is its function?

Background

Topic: Reflexes

This question tests your understanding of the Golgi tendon reflex and its role in muscle function.

Key Terms:

Golgi tendon organ: A sensory receptor in tendons that monitors tension.
Golgi tendon reflex: A reflex that prevents excessive muscle tension.

Step-by-Step Guidance

Recall that the Golgi tendon organ senses tension in the tendon.
Understand that when tension is too high, the Golgi tendon reflex inhibits muscle contraction.
Think about how this reflex protects muscles and tendons from injury.
Consider the pathway: sensory neuron → spinal cord → inhibitory interneuron → motor neuron.

Try solving on your own before revealing the answer!

Final Answer:

The Golgi tendon reflex is a protective reflex that inhibits muscle contraction when tension becomes too high, preventing damage to muscles and tendons.

Q6. What are the major nerve plexuses of the lower spine and brachial region?

Background

Topic: Peripheral Nervous System (PNS)

This question tests your knowledge of the organization of nerve plexuses in the body.

Key Terms:

Nerve plexus: A network of intersecting nerves.
Brachial plexus: Supplies the upper limb.
Lumbar and sacral plexuses: Supply the lower limb.

Step-by-Step Guidance

Recall the locations of the major nerve plexuses: cervical, brachial, lumbar, sacral.
Identify which plexuses supply the lower spine and limbs.
List the main nerves that arise from each plexus.
Consider the functions of these nerves in motor and sensory innervation.

Try solving on your own before revealing the answer!

Final Answer:

The major nerve plexuses are the brachial plexus (upper limb), lumbar plexus, and sacral plexus (lower limb). These plexuses provide motor and sensory innervation to their respective regions.

Q7. What are tactile sensation receptors and how do they function?

Background

Topic: Sensory Receptors

This question tests your understanding of the types and functions of tactile (touch) receptors.

Key Terms:

Tactile receptors: Sensory receptors that detect touch, pressure, and vibration.
Examples: Meissner's corpuscles, Merkel cells, Pacinian corpuscles.

Step-by-Step Guidance

Recall the main types of tactile receptors and their locations in the skin.
Understand how these receptors respond to mechanical stimuli.
Consider the neural pathways that transmit touch information to the brain.
Think about the differences in sensitivity and adaptation among receptor types.

Try solving on your own before revealing the answer!

Final Answer:

Tactile sensation receptors include Meissner's corpuscles, Merkel cells, and Pacinian corpuscles. They detect touch, pressure, and vibration by responding to mechanical stimuli and sending signals to the brain.

Q8. What are the classes and functions of PNS nerves, receptors, and neurotransmitters?

Background

Topic: Peripheral Nervous System

This question tests your knowledge of the classification and function of nerves, receptors, and neurotransmitters in the PNS.

Key Terms:

Sensory (afferent) nerves: Carry information to the CNS.
Motor (efferent) nerves: Carry information from the CNS to effectors.
Neurotransmitters: Chemicals that transmit signals across synapses.

Step-by-Step Guidance

Recall the two main classes of nerves: sensory and motor.
Identify the types of receptors (mechanoreceptors, thermoreceptors, nociceptors, etc.).
List common neurotransmitters in the PNS (acetylcholine, norepinephrine).
Consider the functions of each class and how they interact in the PNS.

Try solving on your own before revealing the answer!

Final Answer:

PNS nerves are classified as sensory (afferent) and motor (efferent). Receptors detect various stimuli, and neurotransmitters like acetylcholine and norepinephrine transmit signals between neurons and effectors.

Q9. What is receptor adaptation and why is it important?

Background

Topic: Sensory Physiology

This question tests your understanding of how sensory receptors adjust their response to constant stimuli.

Key Terms:

Receptor adaptation: The decrease in response of a receptor to a constant stimulus over time.
Phasic receptors: Rapidly adapting receptors.
Tonic receptors: Slowly adapting receptors.

Step-by-Step Guidance

Recall the difference between phasic and tonic receptors.
Understand how adaptation allows the nervous system to ignore unimportant stimuli.
Consider examples of adaptation (e.g., feeling clothes on skin).
Think about the importance of adaptation in sensory processing.

Try solving on your own before revealing the answer!

Final Answer:

Receptor adaptation is the process by which sensory receptors decrease their response to a constant stimulus. It is important because it prevents the nervous system from being overwhelmed by unchanging stimuli.

Q10. What is the anatomy of a spinal nerve?

Background

Topic: Spinal Nerves

This question tests your knowledge of the structure and components of a spinal nerve.

Key Terms:

Spinal nerve: A mixed nerve formed from dorsal and ventral roots.
Dorsal root: Contains sensory fibers.
Ventral root: Contains motor fibers.

Step-by-Step Guidance

Recall that spinal nerves are formed by the union of dorsal and ventral roots.
Identify the components: epineurium, perineurium, endoneurium.
Understand that spinal nerves are mixed, carrying both sensory and motor fibers.
Consider the branching of spinal nerves into rami.

Try solving on your own before revealing the answer!

Final Answer:

A spinal nerve is formed from the dorsal (sensory) and ventral (motor) roots, and contains both types of fibers. It is surrounded by connective tissue layers and branches into rami.

Q11. What are the effects of the sympathetic nervous system (fight or flight)?

Background

Topic: Autonomic Nervous System (ANS)

This question tests your understanding of the physiological effects of sympathetic activation.

Key Terms:

Sympathetic nervous system: Part of the ANS responsible for fight or flight responses.
Effects: Increased heart rate, dilated pupils, etc.

Step-by-Step Guidance

Recall the main functions of the sympathetic nervous system.
List the physiological changes during fight or flight (heart rate, blood pressure, etc.).
Consider the role of neurotransmitters (norepinephrine, epinephrine).
Think about how these changes prepare the body for action.

Try solving on your own before revealing the answer!

Final Answer:

The sympathetic nervous system increases heart rate, dilates pupils, raises blood pressure, and redirects blood flow to muscles, preparing the body for fight or flight.

Q12. What are the effects of the parasympathetic nervous system (rest and digest), and which nerves are involved?

Background

Topic: Autonomic Nervous System

This question tests your understanding of the parasympathetic system's effects and the nerves involved.

Key Terms:

Parasympathetic nervous system: Part of the ANS responsible for rest and digest functions.
Vagus nerve: Major parasympathetic nerve.

Step-by-Step Guidance

Recall the main functions of the parasympathetic nervous system.
List the physiological changes during rest and digest (decreased heart rate, increased digestion).
Identify the nerves involved, especially the vagus nerve.
Consider the neurotransmitters used (acetylcholine).

Try solving on your own before revealing the answer!

Final Answer:

The parasympathetic nervous system decreases heart rate, increases digestion, and promotes relaxation. The vagus nerve is the primary nerve involved, using acetylcholine as its neurotransmitter.

Q13. What are the main neurotransmitters of the autonomic nervous system (ANS)?

Background

Topic: Neurotransmitters

This question tests your knowledge of the chemicals used for communication in the ANS.

Key Terms:

Acetylcholine: Used by parasympathetic neurons.
Norepinephrine: Used by sympathetic neurons.

Step-by-Step Guidance

Recall the two main divisions of the ANS: sympathetic and parasympathetic.
Identify which neurotransmitter is used by each division.
Consider the effects of each neurotransmitter on target organs.
Think about the receptors that respond to these neurotransmitters.

Try solving on your own before revealing the answer!

Final Answer:

The main neurotransmitters of the ANS are acetylcholine (parasympathetic) and norepinephrine (sympathetic). They act on muscarinic and adrenergic receptors, respectively.

Q14. What are adrenergic and muscarinic receptors, and how do they differ?

Background

Topic: ANS Receptors

This question tests your understanding of the types of receptors in the ANS and their functions.

Key Terms:

Adrenergic receptors: Respond to norepinephrine and epinephrine.
Muscarinic receptors: Respond to acetylcholine.

Step-by-Step Guidance

Recall which neurotransmitter each receptor responds to.
Identify the locations of adrenergic and muscarinic receptors in the body.
Consider the effects of activating each receptor type.
Think about the physiological responses mediated by each receptor.

Try solving on your own before revealing the answer!

Final Answer:

Adrenergic receptors respond to norepinephrine and epinephrine (sympathetic), while muscarinic receptors respond to acetylcholine (parasympathetic). They mediate different physiological effects in target organs.

Q15. Where do ANS neurons originate, and what are their synapses, receptors, and ganglia?

Background

Topic: ANS Anatomy

This question tests your knowledge of the origin, synapses, and structure of ANS neurons.

Key Terms:

Preganglionic neuron: Originates in CNS.
Postganglionic neuron: Synapses in ganglia.
Ganglia: Clusters of neuron cell bodies.

Step-by-Step Guidance

Recall the origin of preganglionic neurons (brainstem or spinal cord).
Understand that preganglionic neurons synapse in autonomic ganglia.
Identify the receptors involved at each synapse (nicotinic, muscarinic, adrenergic).
Consider the role of collateral ganglia in the sympathetic division.

Try solving on your own before revealing the answer!

Final Answer:

ANS neurons originate in the CNS (preganglionic), synapse in autonomic ganglia, and use nicotinic, muscarinic, or adrenergic receptors. Collateral ganglia are specific to the sympathetic division.

Q16. What are rami communicantes and their function?

Background

Topic: ANS Anatomy

This question tests your understanding of the structure and function of rami communicantes.

Key Terms:

Rami communicantes: Branches connecting spinal nerves to sympathetic trunk.
White ramus: Carries preganglionic fibers.
Gray ramus: Carries postganglionic fibers.

Step-by-Step Guidance

Recall the difference between white and gray rami communicantes.
Understand their role in connecting spinal nerves to the sympathetic trunk.
Consider the direction of nerve fibers in each ramus.
Think about their function in the sympathetic nervous system.

Try solving on your own before revealing the answer!

Final Answer:

Rami communicantes are branches that connect spinal nerves to the sympathetic trunk. White rami carry preganglionic fibers, while gray rami carry postganglionic fibers.

Q17. What are splanchnic fibers and their role in the ANS?

Background

Topic: ANS Anatomy

This question tests your understanding of splanchnic fibers and their function.

Key Terms:

Splanchnic nerves: Nerves that innervate abdominal organs.
Preganglionic fibers: Fibers that pass through sympathetic trunk to collateral ganglia.

Step-by-Step Guidance

Recall that splanchnic fibers are preganglionic sympathetic fibers.
Understand that they pass through the sympathetic trunk without synapsing.
Identify their target: collateral ganglia in the abdomen.
Consider their role in innervating abdominal organs.

Try solving on your own before revealing the answer!

Final Answer:

Splanchnic fibers are preganglionic sympathetic fibers that pass through the sympathetic trunk and synapse in collateral ganglia, innervating abdominal organs.

Q18. What is the anatomy of the spinal cord?

Background

Topic: Spinal Cord Anatomy

This question tests your knowledge of the structure and organization of the spinal cord.

Key Terms:

Gray matter: Contains neuron cell bodies.
White matter: Contains myelinated axons.
Central canal: Contains cerebrospinal fluid.

Step-by-Step Guidance

Recall the main regions: cervical, thoracic, lumbar, sacral.
Identify the arrangement of gray and white matter.
Understand the function of the central canal.
Consider the role of spinal cord in transmitting signals between brain and body.

Try solving on your own before revealing the answer!

Final Answer:

The spinal cord consists of gray matter (cell bodies) centrally, white matter (axons) peripherally, and a central canal with cerebrospinal fluid. It transmits signals between the brain and body.

Q19. What are the main structures of the eye, and what are the neurons of the retina?

Background

Topic: Eye Anatomy

This question tests your knowledge of the anatomy of the eye and the cellular organization of the retina.

Key Terms:

Outer structures: Cornea, sclera.
Inner structures: Retina, lens.
Retinal neurons: Photoreceptors, bipolar cells, ganglion cells.

Step-by-Step Guidance

Recall the three main layers of the eye: fibrous, vascular, and neural.
Identify the main structures in each layer.
List the types of neurons in the retina and their functions.
Consider how these neurons transmit visual information to the brain.

Try solving on your own before revealing the answer!

Final Answer:

The eye's main structures include the cornea, sclera, lens, and retina. The retina contains photoreceptors (rods and cones), bipolar cells, and ganglion cells, which transmit visual information to the brain.

Q20. What are the vision pathways from the eye to the brain?

Background

Topic: Visual Pathways

This question tests your understanding of how visual information travels from the eye to the brain.

Key Terms:

Optic nerve: Carries signals from retina.
Optic chiasm: Where fibers cross.
Optic tract: Carries signals to thalamus.
Visual cortex: Processes visual information.

Step-by-Step Guidance

Recall the sequence: retina → optic nerve → optic chiasm → optic tract → thalamus → visual cortex.
Understand the crossing of fibers at the optic chiasm.
Identify the role of the thalamus in relaying signals.
Consider how the visual cortex processes the information.

Try solving on your own before revealing the answer!

Final Answer:

Visual information travels from the retina through the optic nerve, crosses at the optic chiasm, continues via the optic tract to the thalamus, and is processed in the visual cortex.

Q21. What are photoreceptors and their function in vision?

Background

Topic: Photoreceptors

This question tests your understanding of the types and functions of photoreceptors in the retina.

Key Terms:

Rods: Detect dim light.
Cones: Detect color and detail.

Step-by-Step Guidance

Recall the two main types of photoreceptors: rods and cones.
Understand the function of rods in low-light vision.
Consider the function of cones in color and high-acuity vision.
Think about how photoreceptors convert light into electrical signals.

Try solving on your own before revealing the answer!

Final Answer:

Photoreceptors are specialized cells in the retina (rods and cones) that detect light and convert it into electrical signals for vision.

Q22. What is accommodation in the eye?

Background

Topic: Eye Physiology

This question tests your understanding of how the eye adjusts focus for near and far objects.

Key Terms:

Accommodation: The process of changing lens shape to focus.
Ciliary muscle: Controls lens shape.

Step-by-Step Guidance

Recall that accommodation involves the ciliary muscle and lens.
Understand how the lens changes shape for near and far vision.
Consider the role of the parasympathetic nervous system in accommodation.
Think about the importance of accommodation for clear vision.

Try solving on your own before revealing the answer!

Final Answer:

Accommodation is the process by which the eye changes the shape of the lens, controlled by the ciliary muscle, to focus on near or distant objects.

Q23. What is the crista ampullaris and its function?

Background

Topic: Ear Anatomy

This question tests your understanding of the crista ampullaris and its role in equilibrium.

Key Terms:

Crista ampullaris: Sensory organ in the semicircular canals.
Equilibrium: Balance and spatial orientation.

Step-by-Step Guidance

Recall the location of the crista ampullaris in the semicircular canals.
Understand its role in detecting rotational movements.
Consider how hair cells in the crista ampullaris respond to movement of endolymph.
Think about its importance in maintaining balance.

Try solving on your own before revealing the answer!

Final Answer:

The crista ampullaris is a sensory organ in the semicircular canals that detects rotational movements of the head, helping maintain equilibrium.

Q24. What are the muscles of the eye and their functions?

Background

Topic: Eye Muscles

This question tests your knowledge of the extraocular muscles and their roles in eye movement.

Key Terms:

Extraocular muscles: Six muscles that move the eye.
Functions: Control direction and movement of the eyeball.

Step-by-Step Guidance

Recall the names of the six extraocular muscles.
Identify the actions of each muscle (e.g., superior rectus elevates the eye).
Consider how these muscles work together for coordinated movement.
Think about the cranial nerves that innervate these muscles.

Try solving on your own before revealing the answer!

Final Answer:

The six extraocular muscles (superior, inferior, lateral, and medial rectus; superior and inferior oblique) control eye movement. They are innervated by cranial nerves III, IV, and VI.

Q25. What are the main structures of the ear (outer and inner)?

Background

Topic: Ear Anatomy

This question tests your knowledge of the anatomy of the ear.

Key Terms:

Outer ear: Auricle, external auditory canal.
Middle ear: Tympanic membrane, ossicles.
Inner ear: Cochlea, vestibule, semicircular canals.

Step-by-Step Guidance

Recall the main structures of the outer, middle, and inner ear.
Identify the function of each structure.
Consider how sound is transmitted through these structures.
Think about the role of the inner ear in hearing and balance.

Try solving on your own before revealing the answer!

Final Answer:

The ear consists of the outer ear (auricle, external canal), middle ear (tympanic membrane, ossicles), and inner ear (cochlea, vestibule, semicircular canals), each with specific roles in hearing and balance.

Q26. What is the basilar membrane and its role in hearing?

Background

Topic: Hearing Physiology

This question tests your understanding of the basilar membrane's function in the cochlea.

Key Terms:

Basilar membrane: Structure in the cochlea.
Hair cells: Sensory cells for hearing.

Step-by-Step Guidance

Recall the location of the basilar membrane in the cochlea.
Understand how sound waves cause the basilar membrane to vibrate.
Consider how different frequencies affect different parts of the membrane.
Think about how hair cells on the membrane convert vibrations into electrical signals.

Try solving on your own before revealing the answer!

Final Answer:

The basilar membrane in the cochlea vibrates in response to sound, allowing hair cells to convert these vibrations into electrical signals for hearing.

Q27. What are maculae and their function in equilibrium?

Background

Topic: Equilibrium

This question tests your understanding of the maculae in the vestibular system.

Key Terms:

Maculae: Sensory regions in the utricle and saccule.
Static equilibrium: Maintenance of position relative to gravity.

Step-by-Step Guidance

Recall the location of maculae in the utricle and saccule.
Understand their role in detecting head position and linear acceleration.
Consider how hair cells in the maculae respond to movement of otoliths.
Think about their importance in maintaining balance.

Try solving on your own before revealing the answer!

Final Answer:

Maculae are sensory regions in the utricle and saccule that detect head position and linear acceleration, helping maintain static equilibrium.

Q28. What is the sense of equilibrium and how is it maintained?

Background

Topic: Equilibrium

This question tests your understanding of the mechanisms involved in balance.

Key Terms:

Static equilibrium: Maintained by maculae.
Dynamic equilibrium: Maintained by crista ampullaris.

Step-by-Step Guidance

Recall the difference between static and dynamic equilibrium.
Identify the structures involved (maculae, crista ampullaris).
Understand how sensory input from these structures is integrated in the brain.
Consider the role of vision and proprioception in balance.

Try solving on your own before revealing the answer!

Final Answer:

The sense of equilibrium is maintained by the maculae (static) and crista ampullaris (dynamic), with input integrated by the brain along with vision and proprioception.

Q29. What are the structures and receptors involved in hearing and equilibrium?

Background

Topic: Hearing and Equilibrium

This question tests your knowledge of the anatomical structures and receptors for hearing and balance.

Key Terms:

Cochlea: Hearing.
Vestibule and semicircular canals: Equilibrium.
Hair cells: Sensory receptors.

Step-by-Step Guidance

Recall the main structures for hearing (cochlea) and equilibrium (vestibule, semicircular canals).
Identify the types of receptors (hair cells) in each structure.
Understand how these receptors convert mechanical stimuli into electrical signals.
Consider the pathways these signals take to the brain.

Try solving on your own before revealing the answer!

Final Answer:

Hearing involves the cochlea and hair cells, while equilibrium involves the vestibule, semicircular canals, and their hair cells. These structures convert mechanical stimuli into electrical signals for the brain.

Q30. What are olfactory receptors and how do they function in smell?

Background

Topic: Olfaction

This question tests your understanding of the structure and function of olfactory receptors.

Key Terms:

Olfactory receptors: Sensory cells in the nasal cavity.
Olfactory bulb: Processes smell signals.

Step-by-Step Guidance

Recall the location of olfactory receptors in the nasal epithelium.
Understand how odor molecules bind to receptors.
Consider how signals are transmitted to the olfactory bulb.
Think about the pathway to the brain for perception of smell.

Try solving on your own before revealing the answer!

Final Answer:

Olfactory receptors in the nasal cavity detect odor molecules and send signals to the olfactory bulb, which processes and relays them to the brain for perception of smell.

Q31. What are gustatory receptors and how do they detect flavors?

Background

Topic: Gustation

This question tests your understanding of taste receptors and flavor detection.

Key Terms:

Gustatory receptors: Taste cells in taste buds.
Flavors: Sweet, salty, sour, bitter, umami.

Step-by-Step Guidance

Recall the location of gustatory receptors in taste buds.
Understand how different chemicals stimulate different receptors.
Consider the neural pathways for taste.
Think about the five basic flavors detected by these receptors.

Try solving on your own before revealing the answer!

Final Answer:

Gustatory receptors in taste buds detect chemicals corresponding to five basic flavors (sweet, salty, sour, bitter, umami) and send signals to the brain for taste perception.

Q32. What are the cranial nerves and their functions?

Background

Topic: Cranial Nerves

This question tests your knowledge of the names and functions of the cranial nerves.

Key Terms:

Cranial nerves: Twelve pairs of nerves emerging from the brain.
Functions: Sensory, motor, or both.

Step-by-Step Guidance

Recall the names and numbers of the twelve cranial nerves.
Identify the main function of each nerve (sensory, motor, or both).
Consider examples of functions (e.g., optic nerve for vision).
Think about how these nerves contribute to sensory and motor functions in the head and neck.

Try solving on your own before revealing the answer!

Final Answer:

The twelve cranial nerves have various functions, including sensory (e.g., olfactory, optic), motor (e.g., oculomotor), and mixed (e.g., facial, vagus), controlling sensory and motor functions in the head and neck.