COM 1 Cytology week 5

Question 1

What does the retina develop from

Answer 1

Optic cup

Question 2

Name the 2 layers of the retina

Answer 2

-Outer pigmented layer
-Inner Neural layer

Question 3

Explain the sructure of the retina pigmented layer of the retina:
-What cells it made out of
-What it contains

Answer 3

• Made of cuboidal pr columnar cells
  -It contains , gap junctions, secondary lysosomes, peroxisomes smooth ER , phagocytic vacuoles

Question 4

What are the functions of the retina pigmented layer ( outer layer)

Answer 4

• Absorb light
  -Froms blood retina barrier
  -Involved in phagocytosis
  -Secretes ATP, growth factors

Question 5

What is the structure of the Neural retina layer

Answer 5

• Contains nine distinct layers, including neuronal and glial cells

Question 6

What does the Outer nuclear layer of the neural retina contain

Answer 6

• Photoreceptor cell bodies

Question 7

What does the Inner nuclear layer of the neural retina layer contains

Answer 7

• Contains the nuclei of bipolar, amacrine and horizontal cells

Question 8

What does the Ganglionic layer of the neural retina contain

Answer 8

• Ganglion cells

Question 9

Between the first 3 layers of the neural retina Name the 2 plexiform layers

Answer 9

• Outer plexiform layer
  -Inner plexiform layer

Question 10

What does the outer plexiform layer in the neural retina layer contain

Answer 10

• Contains axons from photoreceptors and dendrotes

Question 11

What does the inner plexiform layer in the neural retina contain

Answer 11

• Contains axons and dendrites

Question 12

What are Muller cells

Answer 12

They are elongated glial cells that support renal function

Question 13

What are the functions of Muller cells

Answer 13

-Remove waste
-regulate ion/water balance
-help maintain the blood retina barrier

Question 14

What do Muller cells form

Answer 14

They from the Outer Limiting Layer (OLL) and the Inner Limiting Membrane ( ILM)

Question 15

Why can conditions like head trauma cause the pigmented epithelium and photoreceptor layer of the retina to seperate ?
+ What does this seperation cause

Answer 15

• As the pigmenetd epithelium and photoreceptor layers are not firmly joined
• They create intervening space

Question 16

What are the consequences of Retinal Detachment

Answer 16

• Causes the photoreceptor cells to loose access to the metabolic support provided by the pigmented epithelium,
  -This leads to the photoreceptors eventually dying

Question 17

What are rod cells highly sensitive to + what does this allow

Answer 17

Highly sensitive to light. , allowing vision in low light

Question 18

Explain the structure of rod cells

Answer 18

They are thin and elongated with 2 segments :
-An outer photosensitive segment and an inner segment for biosynthetic activity

Question 19

What are the discs in rod cells formed by

Answer 19

In-folding of the plasma membrane

Question 20

What do cone cells produce

Answer 20

• They produce color vision in adequtely bright lights

Question 21

Which one is more sensitive rods or cones

Answer 21

Cone cells

Question 22

Explain the difference between the 3dierent types of cones

Answer 22

-They each have different iodospin pigment sensitive to red blue or green avelenghts

Question 23

How is Partial colour blindness caused

Answer 23

It is inherited due to mutations in the iodopsin genes

Question 24

What type of partial colour blindness is the most common

Answer 24

Red green colour blindness

Question 25

Why do partial colour blindness affect men more than women

Answer 25

Bcs the gene for cone colour sensitivity are on the x CHROMOSOME

Question 26

WHAT Does the outer segment of Rod cells contain

Answer 26

Stacked membranous discs with rhodopsin

Question 27

Name the 4 specialised areas of the retina

Answer 27

- Optic disc -Fovea Centralis -Macula lutea -Nonvisual photoreceptors

Question 28

What is the optic disc also known as

Answer 28

Blind spot

Question 29

Where is the optic disc located

Answer 29

At the posterior of the retina

Question 30

What does the optic disc lack

Answer 30

Photoreceptors and most retinal layers

Question 31

What is the Fovea Centralis

Answer 31

A specialised retinal area located near the optic disc

Question 32

What does the Fovea Centralis contain + describe its light scatter

Answer 32

Cone cells -It has minimal ight scatter

Question 33

What are Nonvisual photoreceptors + function

Answer 33

A subset of ganglion cells in the retina -They detect changes in light

Question 34

What is Age related Macular Degeneration characterised by

Answer 34

Degenerative changes in the retina , including depigmentation

Question 35

How can age related muscular degeneration be slowed down

Answer 35

By laser surgery to destroy the abnormal retinal capillaries

Question 36

What does age related muscular degeneration cause

Answer 36

Vision loss in the center of the visual field

Question 37

Why does Macula Lutea have a yellow colour

Answer 37

BCS it contains carotenoids

Question 38

What are the membranes of rods and cone cells packed with

Answer 38

- Visual pigments

Question 39

What do visual pigment consist of

Answer 39

A protein(Oisin) and light sensistive chromosphere

Question 40

Explain what causes bleaching

Answer 40

Light induced change in retinal causes the chromosphere t disociate

Question 41

What is conjunctivitis(Pink eye) + what is it caused by

Answer 41

Inflammation of the conjunctiva caused by bacterial / viral infections or allergies.

Question 42

Whatdoes conjunctivitis (pink eye) cause

Answer 42

Mucus discharge and causes a red app

Question 43

Whatdoes conjunctivitis (pink eye) cause

Answer 43

Mucus discharge and causes a red Apperance in the sclera

Question 44

What are styes

Answer 44

Infections near the tarsal gland ducts which lead to painful swelling

Question 45

What does tear fluid contain

Answer 45

Electrolytes, proteins, lysozyme and innate immune protein

Question 46

Name the parts of the ear

Answer 46

- The external ear -The middle ear -The internal ear

Question 47

What is the fucntion of the external ear

Answer 47

Recieves sound waves

Question 48

What is the function of the middle ear

Answer 48

Trasnmists sound from air to fluid in the internal ear

Question 49

What is the function of the internal ear

Answer 49

Transduces fluid movements into nerve impulses

Question 50

In the External ear , what is the Auricle

Answer 50

A funnel shaped cartilage that directs sound waves

Question 51

In the external ear what does sound travel through

Answer 51

- Sound travels through the exeternal acoustic meatus

Question 52

In the external ear what produces earwax

Answer 52

- Ceruminous gland

Question 53

What is the tympanic membrane also known as

Answer 53

Ear drum

Question 54

What is the function of the tympanic membrane

Answer 54

- It vibrates in response to sound waves and transmits energy to the middle ear

Question 55

Where is the Olfactory epithelium located

Answer 55

Roof of the nasal cavity

Question 56

What is the structure of the olfactory epithelium

Answer 56

pseudostratifed

Question 57

Name the major cells types that the olfactory epithelium contaiins

Answer 57

- Olfactory neurons -Supporting cells -Basal cells

Question 58

Explain the structure of the olfactory neurons in the olfactory epithelium

Answer 58

- They are bipolar with dendrites

Question 59

Explain the sturtcure of the supporting cells in the olfacotry epithelium

Answer 59

- Columnar with micorvili

Question 60

Explain the structure of the the basal cells in the olfactory epithelium

Answer 60

- Stem cells that generate olfactory neurons and supporting cells

Question 61

What is the tounge made out of + function

Answer 61

- Made out of striated muscle covered by mucosa, used for manipulating food during chewing and swallowing

Question 62

Name the 3 different papillae in the tounge

Answer 62

- Filifom papillae -Fungiform papillae -Foliate papillae

Question 63

Explain the difference/structure between the 3 differnt papillae in the tounge

Answer 63

Filiform papillae- Numerous, keratinzed, rough texture for food movement Fungiform- less numerous, slightly keratinsed, vascularised -Foliate papillar, has paplpable ridges on each side of the tounge

Question 64

explain the characteristic of vallate papillae + what is it surrounded by

Answer 64

Larges papillae on the tounge -Surrounded by moat like groove

Question 65

Where are tastebuds located

Answer 65

Within stratified epithelium

Question 66

Where are tastebuds not located

Answer 66

filiform papillae

Question 67

What is the structure of taste buds

Answer 67

-ovoid shaoed and contains: -50 to 100 cells that are gustatory cells, stem cells and supporting cells

Question 68

What is the function of tastebuds

Answer 68

They detect general chemical composition of foood