A&P Exam 2

Cranial nerve I

Cranial nerve I

Olfactory nerve

Cranial nerve II

Optic nerve

Cranial nerve III

Oculomotor nerve

Cranial nerve IIII

Trochlear nerve

Cranial nerve V

Trigeminal nerve

Cranial nerve VI

Abducens nerve

Cranial nerve VII

Facial nerve

Cranial nerve VIII

Vestibulocochlear nerve

Cranial nerve VX

Glossopharyngeal nerve

Cranial nerve X

Vagus nerve

Cranial nerve XI

Accessory nerve

Cranial nerve XII

Hypoglosseal nerve

How many pairs of cranial nerves do we have?

12

How many pairs of spinal nerves do we have?

31

How many pairs of cervical nerves do we have?

8

How many pairs of thoracic nerves do we have?

12

How many pairs of lumbar nerves do we have?

5

How many pairs of sacral nerves do we have?

5

How many pairs of coccygeal nerves do we have?

1

Rest and digest

Parasympathetic nervous system

Fight or flight

Sympathetic nervous system

The area of skin innervated by the cutaneous branches of a single spinal nerve

Dermtome

Formed by C1-C4

Cervical plexus

Formed by ventral rami of C5-C8 and T1

Brachial plexus

Nerves of the brachial plexus

Axillary, musculocutaneous, median, ulnar, radial

Formed by L1-L4

Lumbar plexus

Which plexus innervates the thigh, abdominal wall, and psoas muscle?

Lumbar plexus

Formed by L4-S4

Sacral plexus

Which plexus is the sciatic nerve found?

Sacral plexus

How many cervical nerves are there?

8

How many thoracic nerves are there?

12

How many lumbar nerves are there?

5

How many sacral nerves are there?

5

How many coccygeal nerves are there?

1

How many pairs of cranial nerves are there?

12

How many pairs of spinal nerves are there?

31

Outermost layer of nerves

Epineurium

Middle layer of nerves- bundles fibers into fascicles

Perineurium

Innermost layer of nerves- surrounds individual axons

Endoneurium

Purely sensory nerve for smell

Olfactory nerve (CN I)

Purely sensory nerve for visual function

Optic nerve (CN II)

Mixed nerve responsible for raising the eyelid

Oculomotor nerve (CN III)

Motor nerve that directs eyeball and is associated with the superior oblique muscle

Trochlear nerve (CN IV)

Largest cranial nerve responsible for sensation of the face

Trigeminal nerve (CN V)

Motor nerve that innervates the lateral rectus muscle

Abducens nerve (CN VI)

Chief motor nerve of the face responsible for facial expression, parasympathetic impulses to lacrimal, salivary glands, and glands of the nose and palate

Facial nerve (CN VII)

Sensory nerve responsible for hearing and maintaining equilibrium

Vestibulocochlear nerve (CN VIII)

Mixed nerve responsible for taste and swallowing

Glossopharyngeal nerve (CN IX)

The only cranial nerve that extends beyond the face and neck- regulates the activities of the heart, lungs, and abdominal viscera

Vagus nerve (CN X)

Formed by the ventral rootlets from the C1-C5 region of the spinal cord- innervates the trapezius and sternocleidomastoid muscles

Accessory (Spinal Accessory) nerve (CN XI)

Somatic motor nerve that assists with muscles of the tongue associated with swallowing and speech

Hypoglossal nerve (CN XII)

Afferent

Towards CNS from rest of body

Efferent

Away from CNS towards muscles

Sensation

The awareness of changes in the internal and external environment

Perception

The conscious interpretation of those stimuli

Adaptation

A decrease in the strength of a sensation during a prolonged stimulus

Gustation

The sense of taste

Perceptual detection

Ability to detect a stimulus (requires summation of impulses)

Magnitude estimation

Intensity is coded in the frequency of impulses

Spatial discrimination

Identifying the site or pattern of the stimulus

Feature abstraction

Identification of more complex aspects and several stimulus properties

Quality discrimination

The ability to identify submodalities of a sensation (Ex. sweet or sour tastes)

Pattern discrimination

Recognition of familiar or significant patterns in stimuli (Ex. the melody in a piece of music)

Classification of sensory receptors is based on

-Stimulus type

-Location

-Structural complexity

Phasic receptors

Adapts rapidly to a stimulus

Tonic receptors

Adapts slowly or not at all to a stimulus

Levels of sensory integration

-Receptor level

-Circuit level

-Perceptual level

Classification by stimulus type

-Mechanoreceptors

-Thermoreceptors

-Photoreceptors

-Chemoreceptors

-Nociceptors

Mechanoreceptors

Responds to touch, pressure, vibration, stretch, and itch

Thermoreceptors

Responds to changes in temperature

Photoreceptors

Responds to light energy (Ex. retina)

Chemoreceptors

Responds to chemicals (Ex. smell, taste, changes in blood chemistry)

Nociceptors

Responds to pain-causing stimuli (Ex. extreme heat or cold, excessive pressure, inflammatory chemicals)

Olfactory receptors are examples of what stimulus receptor?

Chemoreceptors

Photoreceptors are to light as _ are to pain

Nociceptors

Classification by location

-Exteroceptors

-Interoceptors

-Proprioceptors

Extreroceptors

Respond to stimuli arising outside the body

Most special sense organs are

Exteroceptors

Interoceptors (visceroceptors)

Respond to stimuli arising in internal viscera and blood vessels

Proprioceptors

Respond to stretch in skeletal muscles, tendons, ligaments, joints, and connective tissue coverings of bone and muscle

Classification by structural complexity

-Complex receptors

-Simple receptors

Complex receptors

In special sense organs (Vision, hearing, equilibrium, smell, taste)

Simple receptors

For general senses (touch, pressure, stretch, vibration, temperature, pain, and muscle sense)

Conjunctiva

Lines the eyelids, covers the white of the eyes

Lacrimal apparatus

Secretes tears, connects to nasal cavity

Which cranial nerve controls the lateral rectus muscle?

VI (abducens)

Which cranial nerve controls the medial rectus muscle?

III (oculomotor)

Which cranial nerve controls the superior rectus muscle?

III (oculomotor)

Which cranial nerve controls the inferior rectus muscle?

III (oculomotor)

Which cranial nerve controls the inferior oblique muscle?

III (oculomotor)

Which cranial nerve controls the superior oblique muscle?

IV (trochlear)

Which muscle moves the eye laterally and what nerve controls it?

Lateral rectus, VI (abducens)

Which muscle moves the eye medically and what nerve controls it?

Medical rectus, III (oculomotor)

Which muscle elevates the eye and what nerve controls it?

Superior rectus, III (oculomotor)

Which muscle depresses the eye and what nerve controls it?

Inferior rectus, III (oculomotor)

Which muscle elevates the eye + rotates it laterally and what nerve controls it?

Inferior oblique, III (oculomotor)

Which muscle depresses the eye + rotates it medially and what nerve controls it?

Superior oblique, IV (trochlear)

3 layers of the wall of the eye

-Fibrous

-Vascular

-Sensory

_ separates the internal cavity into anterior and posterior segments (cavities)

The lens

The “white” of the eye, which gives shape to the eyeball, makes it more rigid, and protects its inner parts is the _

Sclera