Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Neuroscience > Exam 2 - Clinical Scenarios and Other Notes > Flashcards

Exam 2 - Clinical Scenarios and Other Notes Flashcards

1
Q

Neurocranium vs Viscerocranium

A

Neuro: cartilaginous neurocranium cradles skull in the first 10 weeks, then forms the membranous neurocranium

Viscerocranium: cartilaginous (first branchial arch cartilage - Meckels, second arch - Reicherts, third, fourth, and sixth) and membranous components too (maxillary and mandibular prominence of first branchial arch)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Cranioschisis (acrania)

A

Failure of the occipital and parietal bones to completely form or close

Associated with arrested brain development and rudimentary forebrain (anencephaly)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Microcephaly vs Macrocephaly

A

Micro: small cranium due to fusion of cranial structures

Macro: enlarged secondary to hydrocephalus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Craniosynostosis

A

One or more of the fibrous sutures in an infant skull prematurely fuses by turning into bone, thereby changing growth pattern

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Development from Morula to Embryo

A

Morula: dense ball of cells
Blastocyst: divided into inner cell mass and hypoblasts
Bilaminar embryo: epiblasts and hypoblasts
Gastrulation occurs at this level to form the embryo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Places where mesenchymal cells will not invade:

A

Prochordal plate (mouth) and cloacal membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

At four weeks, the embryo will have:

A

Stomodeum (mouth) surrounded by five facial swellings of the first branchial arch
- includes the frontal, maxillary, and mandibular prominences

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Buccopharyngeal Membrane

A

Divides the anterior 2/3 and posterior 1/3 of the tongue (supplied by GVE)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Development of the face occurs during:

A

Weeks 5-10

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Maxillary Prominence forms:

A

Lateral parts of the upper lip, jaw, and secondary palate or palatine shelves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Mandibular Prominence forms:

A

Lower jaw and lips

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

If the mandibular prominence fails to fuse:

A

Cleft chin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Development of the Nasal Cavity

A
  1. Nasal pits deepen to form primitive nasal cavity
  2. Medial nasal prominences Duse as intermaxillary process
  3. Intermaxillary process forms nasal septum and primary palate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Formation of the Palate occurs:

A

Weeks 5-12

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Mid-posterior landmark between the palates:

A

Incisive Foramen (Foramen of Cecum)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Formation of the Secondary Palate

A

Formed by shelf-like projections, lateral palatine processes or palatine shelves

appears at week 6

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Anterior Cleft Deformity

A

Caused by a failure of medial nasal and maxillary swellings to fuse

Can be unilateral or bilateral - if bilateral, will see the intermaxillary prominence in between the two clefts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Posterior Cleft Deformity

A

Caused by the palatine shelves not fusing during development

Usually unilateral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Cleft Lip vs Cleft Palate

A

Cleft lip is more prominent and occurs more frequently in males
- maternal age may play a role in occurrence

Cleft palate is more frequent in females

no genetic relationship between cleft lip and isolated cleft palate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Oblique Facial Cleft

A

Caused by failure of maxillary swelling to merge with its corresponding lateral nasal swelling

Nasolacrimal duct is exposed - may have phonation issues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Median Cleft Lip and Bifid Nose

A

Caused by failure of medial nasal prominences to fuse

very rare, may be autosomal recessive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Macrostomia vs Microstomia

A

Dysfusion of the maxillary and mandibular swellings

Macro: will have a very wide mouth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Agathnia

A

Dysgenesis of the mandibular swelling

  • first branchial arch
  • position of the auricle
  • congenitally deaf
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Holoprosencephalic

A

Includes cyclopia, cebocephaly, defect of the midface

Weeks 5, 6, 7, and 10

may be associated with fetal alcohol syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Formation of the Branchial Arches

A

Induction of migratory neural crest cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Branchial Arch Nerves

A

1: CN 5
2: CN 7
3: CN 9
4: CN 10
6: CN 10

direct relationship between arches and cranial nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Blood Supply to the Branchial Arches

A

An aortic arch artery develops with each arch

Most will atrophy but some will incorporate into adult arterial system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

First Branchial Arch Fate

A

Muscles: mastication
Nerve: CN 5
Artery: degenerates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Second Branchial Arch Fate

A

Muscles: mimetic muscles
Nerve: CN 7
Artery: degenerates
Bony structures: stapes, hyoid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Third Branchial Arch Fate

A

Muscles: stylopharyngeus
Nerve: CN 9
Artery: stem of internal carotids
Bony structures: hyoid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Fourth Branchial Arch Fate

A

Muscles: pharyngeal muscles
Nerve: CN 10
Artery: LEFT = aortic arch
RIGHT = subclavian

Bony structures: laryngeal cartilages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Sixth Branchial Arch

A

Muscles: internal larynx
Nerve: CN 10 - RLN

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Treacher Collins Syndrome

A

Impaired growth of the midface

Deformities include: small chin, enlarged nose, cleft palate, and possible cleft lip

May have some conductive hearing loss

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Formation of the Pharyngeal Arches and Pouches occur during:

A

Early 5th week - Day 31 to be exact…

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

First Branchial Pouch Derivatives

A

Eustachian tubes, tympanic cavity (tubotympanic recess), mastoid air cells, and body of the tongue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Second Branchial Pouch Derivatives

A

Pharyngeal tonsil, palatine tonsil, lingual tonsil, and the root of the tongue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Third Branchial Pouch Derivatives

A

Inferior parathyroid gland, ventral portion of the thymus, tongue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Fourth Branchial Pouch Derivatives

A

Superior parathyroid gland, ultimobranchial body (C cells of the thyroid), and parafollicular cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Pharyngeal Cleft (lateral to the first branchial pouch)

A

Forms the external auditory meatus (middle ear bones form)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Lateral Cervical Sinus or First Pharyngeal Cleft Cysts

A

Can either be isolated, or seen with external/internal fistulas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Aural and Cervical Cysts

A

Aural: form anterior to the ear (derivative of the first pharyngeal cleft)

Lateral cervical: located anterior to the SCM*

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

First gland to appear in development at 24 days post-fertilization:

A

Thyroid - forms in the floor of primitive pharynx just caudal to the median tongue bed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Pyramidal Lobes

A

Ductal remnants may persist extending from the isthmus of the thyroid through the hyoid

Along the midline, this is called a pyramidal lobe and occurs in 50% of people

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Thyroglossal Duct Cysts and Sinuses

A

May develop from remnants of the early migration of the thyroglossal duct and may include ectopic thyroid tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Formation of the Anterior 2/3 of Tongue

A

Lateral lingual swellings (from arch 1) overgrown the tuberculum impar and fuse in the midline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Formation of the Posterior 1/3 of Tongue

A

Develops from overgrowth of the copula (arch 2) by the hypobranchial eminence (arch 3)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Line demarcating the anterior and posterior portions of the tongue:

A

Sulcus Terminalis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

Innervation of the Tongue

A

Anterior 2/3: sensory from CN 5, taste fibers from CN 7

Posterior: sensory from CN 9

Motor of the tongue: CN 12

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Congenital Malformations of the Tongue

A

Ankyloglossia (tongue tied)
Macroglossia/Microglossia
Cleft tongue/Bifid tongue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Early fusion of branchial arches causes deformities in which ages?

A

First three years of life

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Landmarks of the Lips

A

Nasolabial sulcus: lateral corner of nose to angle of the mouth
Philtrum: shallow, midline sulcus between nose and upper lip
Red Margin: red portion of the lips
Labial frenulae: inside of lips to gingivae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Lymphatic Drainage of the Lips

A

Drains directly into the submental and submandibular lymph nodes –> deep cervical nodes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Unilateral Diminution of Nasolabial Sulcus

A

May be indicative of a neurological disorder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Skin Cells of the Cheek

A

Keratinized stratified squamous epithelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Buccal Fat Pad

A

In infants, provide leverage for sucking

Immediately deep to this is the buccinator muscle (innervated by CN 7)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Cells of the Mucosa of the Cheek

A

Non-keratinized stratified squamous epithelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

Relationships in Sublingual Region

A

In dissection, the submandibular duct will be ABOVE the lingual nerve and the sublingual gland will be lateral

Also pay attention to hypoglossal nerve in this area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

Innervation to the Sublingual Gland

A

very similar to the submandibular gland

Parasympathetic: superior salivatory nucleus –> CN 7 –> Chorda tympani joins with lingual –> submandibular ganglion –> gland

Sympathetic: superior cervical ganglion –> perivascular plexus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Mylohyoid Muscle Problems

A

Food can get stuck if the muscle is paralyzed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

Blood Supply and Innervation to Sublingual Gland

A

Sublingual branch of the lingual artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

Palatoglossus Muscle

A

Muscle of the tongue - arises from posterolateral hard palate
Overlies the palatoglossal fold and elevates the tongue/closes faucial isthmus during swallowing

Innervation: vagus via the pharyngeal plexus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

Innervation of the Muscles of the Tongue

A

all muscles of the tongue EXCEPT the palatoglossus are innervated by the hypoglossal nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Paralysis of the Tongue

A

Unilateral paralysis: atrophy (looks like large bumps on the tongue) and fasciculations of the intrinsic muscles
- tongue will protrude towards the affected side

Bilateral paralysis: airway obstruction, dysarthria, and dysphagia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Lymphatic Drainage of the Tongue

A

Drains primarily into the deep cervical lymph nodes (including the jugulodigastric and juguloomohyoid)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

Divisions of the Palate

A

Anterior 2/3: hard, bony part

Posterior 1/3: soft palate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

Action of the Soft Palate

A

Closes the pharyngeal isthmus during deglutition and prevents reflux of material into the nasopharynx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

Tensor Veli Palatini Muscle

A

Muscle of the palate:

  • located anterolateral to the levator palati muscle and auditory tube
  • characteristic white, convergent tendon
  • Innervation: small branch of mandibular nerve from CN 5
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

Levator Veli Palati Muscle

A

Muscle of the palate:

  • located inferior to the auditory tube
  • innervation: vagus nerve via the pharyngeal plexus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

Paralysis of the Tensor or Levator Palate

A

Allows the muscles on the non-paralyzed side to pull or deviate the uvula towards the normal (unaffected) side

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

Vessels and Nerves of the Palate

A

Includes the nasopalatine, greater and lesser palatine vessels and nerves supply the post-incisive hard and soft palate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

Adenoids

A

Swelling of the nasopharyngeal tonsils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

Tonsillectomy

A

Have to be care not to cut the tonsillar vein - frequently the source of bleeding

Also need to watch out for the glossopharyngeal nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

Lymphatic Drainage from Palatine Tonsil

A

Directly into the jugulodigastric (tonsillar) nodes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

Functions of the Nose

A

Warms and moistens inspired air in addition to acting as an airway

Part of the mucosa contains receptors for olfaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

Portions of the Nose

A

Upper portion: frontal, maxillae, and nasal bones

Lower portion: septal (midline cartilage) and alar cartilages (supports nostrils)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

Fractures of the Nose

A

Frequently occur at the junction between the septal cartilage and the ethmoid/vomer bones

Viewed by anterior rhinoscopy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

Deep Nose Bleeds

A

Caused by the sphenopalatine portion of the maxillary artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

Divisions of the Nasal Cavity

A

Vestibule: anterior portion, lined with hair
Olfactory region: located in the roof, contains olfactory receptors
Piriform apertures and choanae: anterior and posterior nasal apertures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

Nasal Congestion

A

Venous sinuses (swell bodies) in the vestibular region become dilated and engorged with blood during a cold

This will swell the conchae and obliterate air flow through the meatuses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

Bones of Lateral Nasal Wall

A

Most important: maxilla, inferior concha, and sphenoid

But also: nasal, lacrimal, ethmoid, and palatine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

Ethmoidal Bulla

A

Forms a bony eminence overlying the middle ethmoidal air cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

Hiatus Semilunaris

A

Crescent-shaped trough anterior/inferior to ethmoidal bulla

Opening for the maxillary sinus located in the posterior 1/3 of the hiatus semilunaris

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

Nasolacrimal Duct

A

Located in the inferior meatus

When crying, tears will enter the nasal cavity - this is what makes you sniff

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

Nasal Hemorrhage (epitaxis)

A

Typically occur at the junction of the septal branches of the superior labial and sphenopalatine arteries

This region = Kiesselbach’s Area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

Olfactory neurons are what type of neuron?

A

Bipolar and located in the olfactory epithelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

Innervation of the Nasal Cavity Mucosa

A

Anterior 2/3: anterior ethmoidal nerve (branch of the nasociliary nerve, V1)

Posterior 1/3: branches of the pterygopalatine ganglion

these are GVA and autonomic fibers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

Nasopalatine Nerve

A

Innervates mucosa of the gingiva and hard palate near the upper incisors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

Auditory (pharyngotympanic) Tube

A

Has both an osseous and cartilaginous region

3-4cm long and usually closed, except during swallowing or yawning

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

Salpingopalatine Fold vs. Salpingopharyngeal Fold

A

Salpingopalatine = NO underlying muscle

Salpingopharyngeal = formed by the salpingopharyngeus muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

Two most important facial developments:

A

Paranasal sinuses and dentition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q

Four Paranasal Sinuses

A

Maxillary, Ethmoidal, Frontal, Sphenoidal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q

Maxillary Sinus Relationships

A

Superior: orbit
Inferior: molar teeth of maxilla
Posterior: pterygopalatine fossa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
93
Q

Maxillary Sinusitis

A

May originally present as a toothache of the molars

Infections can spread among the frontal, anterior ethmoidal cells, nasal cavity, teeth, and maxillary sinus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
94
Q

Transmaxillary Surgery

A

Maxillary sinus used as a surgical approach to its surrounding structures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
95
Q

Cells of the Ethmoidal Sinus

A

Anterior ethmoidal cells: open into the anterior part of the hiatus semilunaris
Middle ethmoidal cells: open onto the surface of the ethmoidal bulla
Posterior ethmoidal cells: open onto the superior meatus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
96
Q

Frontal Sinus

A

Regarded as displaced anterior ethmoidal cells that invaded the frontal bone

Frontonasal duct drains into either the ethmoidal infundibulum or the frontal recesses of the middle meatus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
97
Q

Sphenoidal Sinus Relationships

A 
Posterior: pons, basilar artery
Superior: pituitary
Anterior: nasal cavity
Inferior: nasopharynx
Lateral: internal carotid, V1, *cavernous sinus*
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
98
Q

Sphenoidal Sinusitis

A

Can also get infections in this area that will spread

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
99
Q

Transphenoidal Surgery

A

Approaching the area through the sphenoidal sinus versus the maxillary sinus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
100
Q

Pterygopalatine Ganglion

A

Attached to the maxillary nerve (V2) in the fossa and branches into:

  1. Vidian nerve (or nerve to pterygoid canal): formed by the merging of deep petrosal and great petrosal nerves
  2. Lesser and Greater Palatine nerves: largest branches, conveys GSA, GVA, and GVE fibers to mucosa of the inferior surface of the hard and soft palate
  3. Nasopalatine nerve: follows the palatine nerves
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
101
Q

Parts of the External Ear

A

Auricle (pinna) and external auditory meatus

Innervation: GSA sensory from auriculotemporal (V3), lesser occipital, great auricular

Blood supply: superficial temporal and posterior auricular artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
102
Q

Parts of the Middle Ear

A

(also called the tympanic cavity)

Roof of this cavity is formed by the tegmen tympani and includes the three ossicles for sound transmission (this is in the epitympanic space)

Innervation: GVA sensory of CN 9 via tympanic plexus

Blood supply: stylomastoid branch of the posterior auricular artery and the anterior tympanic artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
103
Q

Parts of the Inner Ear

A

Series of interconnected fluid-filled membranous ducts and sacs - suspended by bony canals and petrous temporal bone

Innervation: two divisions of CN 8 (cochlear and vestibular)

Blood supply: labyrinthine artery off of AICA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
104
Q

Sound Conduction

A

Sound vibrations are conveyed to the inner ear via vibrations of the ossicles and the fenestra vestibuli

Air transmission = external auditory meatus
Bone conduction = bones of middle ear
Fluid conduction = inner ear

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
105
Q

Auricular Hematoma

A

Trauma to the pinna may cause hemorrhaging in the subcutaneous tissue

If this isn’t evacuated and bandaged, may deform the auricle –> cauliflower ear

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
106
Q

Furuncle

A

When cerumen (wax) gets infect, it is very painful due to the close adherence of the skin to the underlying periosteum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
107
Q

Layers of the Tympanic Membrane

A

Outer layer: skin, innervated by GSA fibers for CN 5 and 10
Middle layer: fibrous, pars tensa
- if this layer is absent, pars flaccida
Inner layer: mucous membrane innervated by GVA fibers from CN 9

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
108
Q

Central concavity of the tympanic membrane is called the ____

A

Umbo (apex of concavity)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
109
Q

Tympanic Membrane Relationships

A

Supero-posterior: incus, stapes, fenestra vectibuli
Supero-anterior: auditory tube
Infero-anterior: carotid canal
Infero-posterior: fenestra cochleae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
110
Q

Otitis Media

A

Inflammation of the middle ear cavity relatively common in infants and children due to their auditory tubes being more horizontal and impeding drainage from the tympanic cavity

(the tubes move downward in an adult)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
111
Q

Fractures of the Petrous Temporal Bone

A

Severe head trauma may cause a basilar skull fracture such as transverse or longitudinal fractures of the temporal bone

Symptoms: otorrhea, otorrhagia, vestibular disturbances, deafness, or Bell’s palsy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
112
Q

Important Point about CN 7

A

IT’S NOT IN THE MIDDLE EAR CAVITY

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
113
Q

Path of the Facial Nerve

A

Leaves the brainstem –> nerve travels laterally in the internal auditory meatus –> enters the facial canal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
114
Q

Relationships to the Facial Nerve

A

Cochlea is anterior

Geniculate ganglion located just above and medial to the promontory of the middle ear cavity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
115
Q

Lesions of the Facial Nerve (5)

A
  1. Facial nerve = Bell’s Palsy
  2. Greater Petrosal = decreased lacrimation
  3. Nerve to Stapedius = hyperacusis
  4. Chorda tympani = loss of taste and salivation
  5. Posterior digastric
116
Q

Three Ossicles

A
  1. Malleus - chorda tympani nerve crosses over the neck of the malleus
  2. Incus - middle bone, part of the incudo-mallear joint
  3. Stapes - stirrup-shaped, articulates with the fenestra vestibuli
117
Q

Otosclerosis

A

Ossification or scarring of the small ossicular joints that prevents the transmission of sound from the tympanic membrane tot he fenestra vestibuli

Tests for bone conduction are normal, but nerve conduction is reduced - hearing is impaired

118
Q

Two Muscles of the Middle Ear Cavity

A

Tensor tympani and stapedius muscle

119
Q

Tensor Tympani Muscle

A

Location: in the semicanal of the auditory tube

Innervation: branch of mandibular nerve of CN 5

Action: tightens the tympanic membrane and attenuates its vibrations

120
Q

Stapedius Muscle

A

Location: in the pyramid on the posterior wall of the middle ear cavity

Innervation: facial nerve

Action: pulls the stapes out of the fenestra vestibuli (protective mechanism for loud sound)

121
Q

Arteriosclerosis of the Labyrinthine Artery

A

Symptoms: vertigo, nausea, inner ear abnormalities

122
Q

Functions of the Inner Ear

A
  1. Cochlear receptors hearing
  2. Receptors in semicircular ducts - detect angular acceleration
  3. Receptors in sacculus and utricle - detect linear acceleration
123
Q

Two Labyrinth Layers

A

Osseous Labyrinth: dense, hard bone called the otic capsule, surrounds membranous layer and encloses the perilymphatic space filled with perilymph

Membranous Labyrinth: consists of membranous ducts, tubes, and sacs which are filled with endolymph and suspended within the osseous labyrinth

124
Q

Semicircular Canals

A

Three pairs of semicircular canals (3 on each side)

125
Q

Vestibule of the Ear

A

Houses the utricle in the elliptical cavity and saccule in the spherical cavity

126
Q

Utricle

A

Communicates with all five semicircular ducts and contains a receptor organ, called the macula utricle which detects linear acceleration

127
Q

Saccule

A

Connected directly to the cochlear duct by the ductus reuniens

Receptor organ is called the macula saccule which detects low frequency vibrations

128
Q

Cochlea

A

Helical-shaped bony tube containing:

  • promontory: basal turn forms this eminence in the middle ear cavity
  • modiolus: bony core of the cochlea where the cochlear nerve passes through
  • spiral lamina: projects from modiolus like threads of a screw attached at the cochlear duct
129
Q

Cochlear Duct

A

Blind-ending, wedge-shaped membranous tube which is continuous with the saccule

The duct is coiled and turns into the apex of the cochlea

130
Q

Organ of Corti (spiral organ)

A

The cochlear duct contains this organ located along the entire length of the basilar membranes

Contains hearing receptors and tiny blood vessels called stria vascularis

131
Q

Prolonged Exposure to Sound

A

Excessive amounts of noise may lead to partial destruction of the organ of Corti

Ischemic necrosis might be one of the mechanisms

132
Q

Contents of the Anterior/Posterior Tongue

A

Anterior 2/3: intrinsic muscles innervated by CN9

Posterior 1/3: lymphatic tissue + lingual tonsils

133
Q

Types of Lingual Papillae

A
  1. Filiform papillae - most abundant, grabs food
  2. Fungiform papillae - registers taste
  3. Circumvallate papillae - has surrounding trench, found on sulcus terminalis
  4. Foliate papillae - tastebuds on lateral walls, serous glands
134
Q

Geographic Tongue

A

Oral manifestation of psoriasis - see areas of erythema/atrophy in between areas of white/hyperkeratotic regions

135
Q

Vitamin B12 Deficiency

A

B12 needs intrinsic factor - lacking after a gastric bypass

Can see this deficiency on the tongue = yellow streaks

136
Q

Taste Receptor Cells

A

Found in papillae (fungiform, circumvallate, foliate)

Also in the soft palate, posterior pharynx, and epiglottis (innervated by the vagus nerve)

137
Q

Where are taste buds NOT found?

A

In the filiform papillae!

138
Q

Serous Glands (Von Ebner Glands)

A

Found on the foliate, fungiform, and circumvallate papillae (anywhere there are tastebuds)

Secretes lingual lipase and Von Ebner’s gland protein (VEGP) to bind to chemicals in food

139
Q

Pathway of Tastants

A

Diffuse through the pore and activate GPCRs on taste receptor cells –> leads to an increase in calcium for release of the neurotransmitter

140
Q

Types of Tasters

A

Nontaster (few fungiform)
Normal taster
Supertaster (high density of fungiform)

141
Q

Locations of Taste Perception

A 
Sweet: tip of the tongue
Salty: posterior/lateral
Sweet: anterior 2/3 of dorsum, lateral margins
Bitter: on the back of the tongue
Umami: no specific location
142
Q

Salty stimuli utilize this type of channel:

A

Sodium channel

143
Q

Sour stimuli utilize this type of channel:

A

Hydrogen ion channel

144
Q

Genetic Control of Bitter Taste

A

Some people really can’t stand bitter tastes (caffeine, morphine, and nicotine)

Defect in hTAS2R38 taste receptor gene

145
Q

This additive in foods for enhacement:

A

monosodium glutamate (umami taste)

146
Q

Receptor for the flavor of fat:

A

Protein (CD36) Receptor

147
Q

Most sensory information of taste is actually this type of sensation:

A

Olfactory, by olfactory mucosa

148
Q

Functions of the Nasal Mucosa

A

Air hydration, air filtration, and temperature regulation

149
Q

Components of Nasal Cavity

A

Pseudostratified columnar epithelium with goblet cells

Serous/mucous glands to trap contaminants, extensive vascular plexus = lamina propia

Mast and plasma cells (IgA, IgE, IgG)

150
Q

Olfactory Epithelium Components

A

only found in the roof of the nasal cavity

Olfactory cells, supporting cells, and basal cells

151
Q

Olfactory Cells

A

Bipolar sensory neurons with a proximal process that extends basally to form a bundle of nerves (fila olfactoria)

These can be regenerated!

152
Q

Odorant Receptor

A

Each receptor expresses one OR gene

153
Q

Glands of Bowman

A

Secretes fluid that contains odorant-binding protein (OBP) to dissolve odoriferous substances and carries them to receptors

Contains lysozyme and IgA for protection

154
Q

Temporary or permanent damage to any part of the olfactory system can lead to:

A

Anosmia

155
Q

Kallman Syndrome

A

Characterized by anosmia (lack of neurons in the brain), small genitalia, and sterility (due to lack of GnRH)

May be due to a defective gene, KAL-1

156
Q

There are NO lymphatics in this part of the head:

A

Orbit or eyeball!

157
Q

Medial and Lateral Canthi

A

Corners of the eye

158
Q

Sty

A

Caused by ciliary glands becoming infected

159
Q

Levator Palpebrae Superiorus Muscle (LPS)

A

Responsible for lifting the eyelid, innervated by oculomotor

if oculomotor is cut, there will be COMPLETE PTOSIS

160
Q

Paralysis of Tarsal Muscle (of Muller)

A

Characteristic feature of Horner’s Syndrome providing partial ptosis and miosis

161
Q

Lacrimal Gland

A

Mostly rests on top of the lateral rectus muscle, oval-shaped, and secretes tears to keep the eyes moist

Innervation: (parasympathetic) superior salivatory nucleus –> CN7 –> greater superficial petrosal nerve –> vidian nerve –> sphenopalatine ganglion –> zygomatic –> lacrimal

(sympathetic) internal carotid plexus –> deep petrosal –> vidian nerve

162
Q

Bony Orbit Margins

A

Supraorbital margin: frontal bone
Medial margin: maxilla, lacrimal, and frontal bones
Lateral margin: zygomatic bone
Infraorbital margin: zygomatic and maxilla bones

163
Q

Hematoma or Edema in the Orbit

A

Usually appear in the medial margin in a characteristic sickle shape

164
Q

What goes through the optic canal?

A

Optic nerve and ophthalmic artery

165
Q

Traumatic Optic Neuropathy

A

The intracanalicular portion of the optic nerve is the most frequent site due to its vulnerable blood supply (ophthalmic artery)

Results in immediate or slow progressive loss of vision in the affected eye

166
Q

What goes through the superior orbital fissure?

A

CN 3, 4, 5 (V1), and 6 and the ophthalmic vein

167
Q

Blow Out Fractures

A

Happen on the floor of the orbit, typically due to a trauma to the front of the eyeball or a depressed fracture of the zygomatic bone

Can cause herniation into the maxillary sinus

168
Q

Le Forte Type 1

A

Transverse fracture of the maxilla just above the teeth (unilateral)

169
Q

Le Forte Type 2

A

Pyramid-shaped fracture of the maxilla usually involving part of the medial margin of one of the orbits (unilateral)

170
Q

Le Forte Type 3

A

Extensive fracture involving many facial bones and both orbits (panda bear appearance) - bilateral

171
Q

Lesion of Superior Division of Oculomotor Nerve

A

Paralysis of LPS and Superior Rectus = complete ptosis, inability to abduct and elevate the affected eye

172
Q

Lesion of Inferior Division of Oculomotor Nerve

A

Paralysis of medial rectus, inferior rectus, and inferior oblique = inability to adduct, abduct/depress, and adduct/elevate the eye

173
Q

Overall Oculomotor Lesion

A

Complete ptosis and eye down and out (external strabismus)

174
Q

Lesion of Trochlear Nerve

A

Paralysis of superior oblique = inability to adduct and depress the eye

Patient will tilt head away from the affected eye

175
Q

Lesion of Abducens Nerve

A

Paralysis of lateral rectus = inability to abduct

Causes diplopia (double vision)

Increased intracranial pressure may compress abducens

176
Q

Ophthalmic Division (V1) of CN 5

A

Remember this by N F L
N: nasociliary nerve = main sensory to the eyeball (GSA) and gives off five branches
- need to know: long ciliary, posterior ethmoidal (supplies the sinuses), and infratrochlear (supplies medial canthus)

F: frontal nerve = passes through the superior orbital fissure to branch as supraorbital and supratrochlear nerves

L: lacrimal nerve = entirely GSA and courses just above the lateral rectus, terminates in the lacrimal gland

177
Q

Stimulus Pathway of Direct and Consensual Corneal Reflex

A

Stimulus: lightly touching cornea with cotton swab
Afferent: nasociliary, esp long ciliary nerves
Efferent: facial nerve
Response: blinking (both eyes)

  • *in by 5, out by 7**
  • *this can be lost after endoscopic forehead lift**
178
Q

Innervation to the Eye

A

Parasympathetic: Edinger-Westphal nucleus –> CN 3 –> ciliary ganglion –> sphincter pupillae and ciliary muscle

response causes constriction of pupil and thickening of lens = accomodation

179
Q

Ophthalmic Artery

A

Chief artery of the orbit and the first branch of ICA

Has 12 branches; most important are the central retinal artery and posterior ciliary artery

Also includes: lacrimal (to the gland), supraorbital (upper eyelid and scalp), anterior and posterior ethmoidal (nasal cavity and sinuses), and short ciliary arteries

180
Q

Terminal Branches of Ophthalmic Artery

A

Supratrochlear and Dorsal Nasal Arteries

181
Q

Central Retinal Artery

A

Contributes the main blood supply to the retina - supplies the four quadrants of the retina through the upper and lower temporal branches, and upper and lower nasal branches = end arteries

182
Q

The central retinal artery and posterior ciliary artery form:

A

An incomplete circle of Zinn-Haller around the iris and deep pericorneal plexus

183
Q

Ophthalmic Veins

A

Superior ophthalmic vein and the central vein of the retina drain into the cavernous sinus

184
Q

Action of Ciliary Muscles

A

When stimulated, they decrease the tension on the ciliary fibers and thicken the lens

185
Q

Site of production of aqueous humor:

A

Ciliary Processes

186
Q

The pupil divides the space between the lens and cornea into:

A

Anterior and posterior chambers with the iris in the middle of the two

187
Q

Sphincter Pupillae Muscle

A

When contracted, they decrease the diameter of the pupil (postganglionic parasympathetic fibers from ciliary ganglion)

This is paralyzed by atropine to dilate pupil

188
Q

Dilator Pupillae Muscle

A

When contracted, increase the diameter of the pupil (postganglionic sympathetic fibers by the SNS branch to the ciliary ganglion)

Horner’s Syndrome characterized by paralysis of this muscle with the tarsal muscle

189
Q

Causes of Horner’s Syndrome

A

Mass effect: pancoast tumor
Aortic aneurysm, carotid artery aneurysm
Idiopathic/congential

will see anhidrosis - patient’s face half flushed

190
Q

Lens of the Eye

A

Suspended by ciliary zonule fibers and focuses images onto the fovea of retina

Opacities that form = cataracts
Surgical procedure to place artificial lens

191
Q

Direct vs Consensual Light Reflex

A

Direct: in by 2, out by 3, ipsilateral pupil constriction
Consensual: contralateral pupil constriction

Direct reflexes will travel from the ipsilateral retina –> pretectum and then enters the POSTERIOR COMMISSURE where it will cross over to EWN and provide consensual reflexes in contralateral eye

192
Q

Lesion to the Posterior Commissure

A

Will still have direct reflexes, but NO consensual reflexes

193
Q

Other causes of pupillary constriction:

A

Parasympathetic response, opioids

194
Q

Pupillary Dilation Response

A

Stimulus: decreased light
Signal travels from retina –> pretectum –> reticular formation –> preganglionic sympathetics (ILCC at T1) –> SCG –> pupillary dilator muscle
Response: pupillary dilation

can also be a sympathetic response

195
Q

Triad of Accommodation

A

Convergence of gaze due to bilateral contraction of medial recti muscles

Pupillary constriction from sphincter pupillae muscles

Thickening of lens due to relaxation of ciliary fibers

helps view objects coming towards you, cortically-mediated

196
Q

Argyll-Robertson Pupil

A

Result of syphilis infection = pupils are unreactive to light but have accommodation

prostitute’s pupil

197
Q

Holmes-Adie Pupil

A

Tonic pupil, benign condition due to lesion of ciliary ganglion; more common in young females

Pupil is unreactive to light and very slowly reacts to convergence (slow accommodation)

198
Q

Hyphema

A

Vessel: Arterial circle of iris

Presence of blood in the anterior chamber of the eyeball due to trauma = serious medical emergency

199
Q

Subconjunctival Hemorrhage

A

Vessel: deep pericorneal plexus

Bleeding is restricted to the subconjunctival tissue or bulbar fascia (see blood in the white of the eye)

200
Q

Conjunctivitis

A

Vessel: superficial pericorneal plexus

Brick-red inflammation of conjunctiva; more noticeable at the fornices

When touched, the redness does not fade and vessels are moveable

201
Q

Photoreceptors in the DARK

A

Sodium channels are OPEN and the cell is DEPOLARIZED

202
Q

Photoreceptors in the LIGHT

A

Sodium channels are CLOSED and the cell is HYPERPOLARIZED

203
Q

Respiratory Quotient

A

Cells in the outer segment require a lot of oxygen and have the highest respiratory quotient in the body

204
Q

Retinoid Cycle

A
  1. Starts in the rod cell: converts 11-cis to 11-trans, exports all-trans-retinol with iBRP
  2. Moves to the retinal pigmented epithelium: esterification by LRAT, conversion to 11-cis by RPE65
  3. Back to the rod cell: uptake of 11-cis, covalent attachment to Schiff base to form Rhodopsin
205
Q

Process of Action and Recovery of Photoreceptors

A
  1. Dissociation of signal molecule from receptor
  2. Phosphorylation of the C-terminus
  3. Arrested by b-arrestin
206
Q

Activation and Recovery (chemical)

A

Activation: decrease in cGMP
Recovery: increase in cGMP

207
Q

Vitamin A Deficiency

A

Causes night blindness and xerophthalmia (dryness of the cornea, inflamed conjunctiva, ridge formation)

208
Q

Macular Degeneration

A

Macula: yellow area of the retina that contains the fovea (most cones) and responsible for high visual acuity

Perfect storm for MD: high respiratory quotient, high lipid content, and UV rays

Macular carotenoids (xanthophylls): found in green, leafy vegetables that can prevent MD; cigarettes/nicotine thought to be the top cause of MD

209
Q

Retinitis Pigmentosa

A

Damage to the back of the eye - degenerative, inherited disease that slowly kills off rod photoreceptors

210
Q

Defect in Rhodopsin

A

Inability for rhodopsin to be the correct shape - causes a degeneration of LRAT and RPE65

211
Q

Opsin Proteins and Genes

A

Rod opsin: chromosome 3
Blue opsin: chromosome 7
Red opsin: chromosome X
Green opsin: chromosome X

212
Q

Recombination Between Genes

A

Leaves one set without a color gene and another with multiple

213
Q

Recombination Within Genes

A

Creates a greenlike/redlike hybrid

214
Q

Color Blindness

A

Typically due to nonhomologous recombination (losing the green opsin gene means they can’t see green)

Only takes a small change in AAs of rhodopsin receptor to make a difference in absorbance

215
Q

Tetrochromad

A

Possibility of a hybrid that can supposedly see more colors

216
Q

Amplification of Light

A
  1. Photon puts the cell into hyperpolarization
  2. All proteins are activated
  3. Sodium channels close
  4. Rod cell membrane is hyperpolarized by 1mV
217
Q

Three Tunic Layers

A

Outer (sclera and cornea)
Middle (uvea, choroid, iris, ciliary body)
Inner (retina)

218
Q

Layers of the Cornea

A 
Corneal epithelium
Bowman's layer (hemidesmosomes)
Stroma
Descemet's membrane
Corneal epithelium
219
Q

Point between cornea and sclera:

A

Limbus

220
Q

What part of the eye is responsible for focus?

A

Zonule fibers adjusting the lens

221
Q

Detachment of the Retina

A

Separation of the two layers of the retina caused by trauma, vascular disease, metabolic disorders, and aging

222
Q

Anterior and Posterior Chambers

A

Anterior: between the cornea and iris
Posterior: between the iris and lens

Both contain aqueous humor (fluid-like)

223
Q

Canal of Schlemm

A

Goes all the way around the iris but fluid only percolates into the trabecular meshwork

224
Q

Glaucoma

A

Obstruction of aqueous humor (usually at the Canal of Schlemm) causes increase in intraocular pressure

Produces pain and nausea

225
Q

Cataracts

A

Happens when the major proteins in the lens become insoluble (also happens with glucose)

Results from aging and diabetes

226
Q

Red Eye

A

Subconjunctival hemorrhage and conjunctivitis

227
Q

Footplate of the Stapes

A

Responsible for vibrations on the oval window which tells the brain there are sound waves coming through and how strong/frequent they are

228
Q

Olfactory Receptors are GPCRs, what is the sequence of events once activated?

A

Create cAMP and open the ion channel for sodium and calcium influx

if the odorant persists for a while, sensitivity of the channel is reduced and ions reduced

229
Q

How do we change the perceived smell?

A

By changing the odorant concentration (think of the citrus/grapefruit example)

230
Q

Pathway of the Olfactory Neurons

A

Neurons –> glomeruli –> post-synaptic cells which include mitral and tufted cells as well as periglomerular cells

231
Q

What do periglomerular cells secrete?

A

GABA (inhibitory)

232
Q

How are other smells prevented?

A

The odorant producing the stronger stimulation will suppress the input from other glomeruli

233
Q

Entorhinal Cortex

A

Projects to the hippocampus for memory formation

234
Q

Piriform Cortex

A

Projects to lateral hypothalamus, important for appetite

Projects to medial hypothalamus, identifies flavor of food

235
Q

Umami stimuli activate:

A

Metabotropic receptor activated by glutamate

236
Q

If the object is far away….

A

Less refraction is required to bend the light

237
Q

If the object is nearby…

A

More refraction is required to bend the light

238
Q

First site where refraction occurs (and most of it too)

A

Cornea

239
Q

What structure in the eye allows for variable refraction?

A

Lens

240
Q

Near response from the ciliary muscles, suspensory ligaments, and lens: (accommodation reaction)

A

Ciliary muscles: contracts
Suspensory ligament: becomes slack
Lens: thicker and curved

241
Q

Far response from the ciliary muscles, suspensory ligaments, and lens:

A

Ciliary muscles: relaxes
Suspensory ligament: becomes taut
Lens: decreased curvature

242
Q

Refractive Power at Life Stages (diopters)

A

Kids: 20 diopters
Young adults: 10 diopters
Elderly: 1 diopter

243
Q

Three Parts of the Near Vision Response

A

Contraction of ciliary muscles
Convergence of eyes to the point of focus
Constriction of the pupil

244
Q

Visual inputs are provided by these structures:

A 
Lateral geniculate body
Primary visual cortex (V1)
V2
V4
Inferior temporal cortex
Parietal/frontal cortex
245
Q

Functions of the Lateral Geniculate Body

A

Control motion of the eye
Control focusing
Identify major elements in our vision
Identify motion

246
Q

Parts of the Primary Visual Cortex

A

6 Layers that control muscle response and tells the eyes what to focus on

Columns that have various jobs but related to columns nearby
- this is split into upper/lower quadrant of macula (cones, larger) and upper/lower quadrants of retina (rods)

247
Q

Major Job of V2 in Vision

A

Identify disparities in visual images presented by both eyes for depth perception

248
Q

Major Job of V4

A

Complete processing of color inputs

249
Q

Concentration of Perilymph (in scala vestibuli and tympani)

A

Most similar to CSF: high Na, low K

250
Q

Concentration of Endolymph (scala media)

A

High in K, low in Na

251
Q

Impedance Matching

A

Sound waves go from air to liquid (done by ossicles)

252
Q

High Frequency (short wavelength) sounds maximal where?

A

Closest to the oval window

253
Q

Low Frequency (long wavelengths) is maximal where?

A

Farthest away from oval window, near the helicotrema

254
Q

Actions of the Cochlear Nuclei

A

Ventral: time and pitch
Dorsal: localizes the sound

255
Q

Actions of the Superior Olives

A

Medial: maps intraaural time differences
Lateral: maps intraaural intensity

256
Q

Inferior Colliculus vs Superior Colliculus

A

Inferior: suppresses echoes
Superior: adds vertical height

257
Q

Primary Auditory Cortex Areas

A

Rostral areas: low frequency sounds

Caudal areas: high frequency sounds

258
Q

Anterior Semicircular Canal

A

Maximal motion: falling forward
Muscles activated: superior rectus activated, inferior rectus inhibited
Eye movement: UP

259
Q

Horizontal Semicircular Canal

A

Maximal motion: turning motion
Muscles activated:
- ipsilateral: MR activated, LR inhibited
- contralateral: LR activated, MR inhibited
Eye movement: LEFT AND RIGHT

260
Q

Posterior Semicircular Canal

A

Maximal motion: falling backward
Muscles activated: superior oblique activated
Eye movement: DOWN

261
Q

Utricle Motion

A

Horizontal motion (walking)

262
Q

Saccule Motion

A

Vertical motion (jumping)

263
Q

Action by cortical and cerebellar involvement in reflexes is:

A

To suppress the reflex to allow for voluntary motion

264
Q

What part of the brain controls the set point temperature?

A

Hypothalamus

265
Q

Difference between a feedback and feed-forward system?

A

Feedback: most systems in the body are a negative feedback system

Feed-forward: prevents changes in the controlled variable; happens in the hypothalamus

266
Q

Definition of Thermoreceptors

A

Neurons which change their firing rate in response to changes in local temperature

267
Q

Warm Sensitive Thermoreceptors

A

4 channels: TRP-V1 through 4

Can be activated by vanilloid (found in capsaicin)

Allows Na and Ca influx

268
Q

Cold Sensitive Thermoreceptors

A

2 channels: TRPM8 and TRPA2

Activated by menthol

Allows Na and Ca influx

269
Q

Thermoreceptors are found in:

A

Skin, viscera, and the brain

270
Q

Cutaneous Thermoreceptors

A

These are bimodal = touch and temp sensitive

10x as many cold sensitive than warm

Tells us environmental conditions

271
Q

Gut Thermoreceptors

A

Sense core temps and threats to maintenance

Food ingested may change body temperature

272
Q

Central Thermoreceptors

A

Location: pre-optic and superoptic region of the hypothalamus

3x as many warm sensitive as cold

273
Q

Anterior Division of Hypothalamus

A

HEAT LOSS BEHAVIORS - YOU’RE TOO HOT

Mechanisms: evaporative heat loss, convection, conduction, and radiation

274
Q

Posterior Division of the Hypothalamus

A

HEAT PRODUCTION BEHAVIOR - YOU’RE TOO COLD

Mechanisms: can either be ANS or hormonal, muscular activity, and non-shivering thermogenesis

275
Q

Process of Evaporative Heat Loss

A
  1. Insensible (respiratory) - we can’t control this
  2. Sweating (controlled) - innervated by sympathetics (cholinergic)
    - can either have a low flow rate (concentrated) or a high flow rate (mostly water, happens when very hot)
276
Q

Convection vs Conduction vs Radiation

A

Convection: heat transferred through air molecules
Conduction: heat transferred through touching objects
Radiation: heat transferred through non-touching objects

277
Q

Types of Muscular Activity

A

Shivering: dorsomedial posterior hypothalamus, increased motor neuron excitation

Increase voluntary activity via cortex: jumping and running

278
Q

Types of Non-shivering Thermogenesis

A

Hormonal influence: thyroxin and epinephrine increases heat production, stimulated by cold

Increase food intake: increase metabolism

Brown adipose tissue: mostly in babies, requires exposure to cold and uncoupling protein

279
Q

Challenges for Hypothalamus to Overcome

A

Anaerobic and aerobic metabolism that produce heat

280
Q

Environmental vs Body Temperature

A

Core temperature is the most stable/constant - well regulated
Oral temperature very stable too
Average skin slightly less stable
Hands and feet are very variable

281
Q

With sleep, temperature will:

A

DROP - due to circadian rhythm, whether at night or during the day, set point temperature decreases

282
Q

With exercise, temperature will:

A

INCREASE - increased heat production, set point increases

283
Q

Definition of a Fever

A

CONTROLLED increase in body temperature driven by a set point increase

284
Q

Stages of a Fever

A
  1. Secretion of endotoxins
  2. Increase heat production and decrease heat loss
  3. Body creates new “comfort” temperature
  4. Bug is vanquished - no more endotoxins
  5. Body temp > set point
  6. Body temp = set point
285
Q

Definition of Hyper and Hypothermia

A

UNCONTROLLED - set point remains normal but environmental stresses exceeds body’s ability to regulate temperature

Neuroscience (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions