Development of the ear/ Olfaction

Question 1

What does the ectoderm thicken into originally?

Answer 1

otic placodes

Question 2

Where does the middle ear form from?

Answer 2

an outgrowth of the first pharyngeal pouch (inside of the embryos throat)

Question 3

Where did the external ear space form from?

Answer 3

1st pharyngeal groove (outside of the embryos neck)

Question 4

What makes up the outer ear?

Answer 4

The pinna, Auricular muscles, the ear canal and the ends of the ear drum

Question 5

What is found between the surface ectoderm and surface endoderm?

Answer 5

The tympanic membrane (ear drum)

Question 6

What muscle moves the pinna?

Answer 6

The auricular muscle

Question 7

What are the two canals found in the external ear?

Answer 7

Horizontal and vertical canal

Question 8

What are the three ossicles of the middle ear?

Answer 8

Hammer, anvil and stirrup (malleus, incus and stapes)

Question 9

What is the function of the ossicles in the middle ear?

Answer 9

To transmit and amplify vibrations

Question 10

What are the two labyrinths found in the inner ear?

Answer 10

Membranous and osseous

Question 11

What is the membranous labyrinth?

Answer 11

A series of inter-connected ducts and chambers that are filled with endolymph

Question 12

What is the osseous labyrinth?

Answer 12

Hollow cavity in the temporal bone of the skull

Question 13

What are the two functions of the inner ear?

Answer 13

Hearing via the cochlear and Balance via the vestibular system

Question 14

What do the semi-circular canals detect?

Answer 14

rotations of the head

Question 15

What do the saccule and utricle detect?

Answer 15

accelerations

Question 16

What are the semi-circular canals?

Answer 16

three tiny, fluid-filled tubes that help you keep your balance

Question 17

What is the olfactory system?

Answer 17

System that detects smell/ sense of smell

Question 18

Where is the ear drum formed?

Answer 18

Where the 1st groove and pouch meet

Question 19

Where do ear bones form from?

Answer 19

they develop endochondrally from neural crest cells in between the groove and pouch

Question 20

What adaptations does the pinna have that makes it a good thermoregulator?

Answer 20

Large surface area and good blood supply

Question 21

Which nerve innervates the pinna?

Answer 21

The facial nerve

Question 22

What is the function of cerumen (ear wax) ?

Answer 22

it traps particles that may damage the tympanic membrane

Question 23

What does the tympanic membrane separate?

Answer 23

The external and middle ear

Question 24

What does the tympanic membrane stretch over?

Answer 24

The tympanic ring

Question 25

What is the middle ear housed inside of?

Answer 25

Housed inside the temporal bone of the skull (tympanic bulla)

Question 26

What is the middle ear lined with?

Answer 26

a mucous membrane

Question 27

What are the two compartments of the guttural pouch?

Answer 27

The medial and lateral compartment

Question 28

What does the otic vesicle of the ear form?

Answer 28

The membranous labyrinth

Question 29

Where do the ear bones develop from?

Answer 29

They develop endochondrally from neural crest cells in between the pharyngeal pouch and pharyngeal groove

Question 30

What is the tympanic bulla?

Answer 30

a bulbous expansion of the tympanic bone

Question 31

What is the middle ear lined with?

Answer 31

mucous membrane

Question 32

How does the middle ear communicate with the pharynx?

Answer 32

Via an auditory tube

Question 33

What are some functions of the middle ear?

Answer 33

Equalisation of pressure and gland secretions

Question 34

What is the membranous labyrinth of the inner ear?

Answer 34

A series of inter-connected ducts and chambers, filled with endolymph

Question 35

What is the osseous labyrinth of the inner ear?

Answer 35

A hollow cavity in the temporal bone of the skull

Question 36

What fills the space between the membranous and osseous labyrinth?

Answer 36

Perilymph

Question 37

What is the name of the nerve that sends pressure information from hair cells from the tectorial membrane?

Answer 37

Vestibulocochlear nerve

Question 38

In what animals is the tympanic membrane visible?

Answer 38

Reptiles, they also have no visible pinna

Question 39

What is the name of the nerve that innervates the auricular muscles?

Answer 39

The facial nerve

Question 40

What kind of glands are found in the external ear?

Answer 40

sebaceous and modified apopcrine glands

Question 41

What is the function of cerumen/ earwax?

Answer 41

To trap particles that may damage the tympanic membrane

Question 42

How does the stapes help to transmit vibrations?

Answer 42

It presses against the oval window which compresses perilymph in the scala vestibula, this then transmits pressure waves to the endolymph in the Reissners membrane movement of the endolymph causes pressure on the tectorial membrane inside the cochlear duct which puts pressure on hair cells, sending an impulse through the vestibulacochlear nerve

Question 43

Where is the middle ear housed inside?

Answer 43

It is housed inside the tympanic bulla and lined with a mucous membrane

Question 44

What are some of the functions of the middle ear connecting to the pharynx via the auditory tube?

Answer 44

Pressure equalisation, drainage of gland secretions

Question 45

What compartments is the guttural pouch split into?

Answer 45

medial and lateral compartments