Tutorial 9 - Brain & Eyes

Question 1

What is the function of the brain?

Answer 1

CNS receives sensory input and integrates info to form perception and thought (speech and movement, maintain homeostasis)

Question 2

What are the three layers of the meninges?

Answer 2

dura mater
arachnoid mater
pia mater

Question 3

Dura mater

Answer 3

outer, closest to the skull

Question 4

Arachnoid mater

Answer 4

middle layer

Question 5

Pia mater

Answer 5

clings to brain (inner layer)

Question 6

What are the brainstem’s functions?

Answer 6

brainstem is continuous for the spinal cord
- motor and sensory neurons that connect CNS and PNS pass through brainstem
- responsible for involuntary functions of circulatory, digestive, and respiratory systems

Question 7

What are the three components of the brainstem?

Answer 7

1. pons
2. medulla oblongata
3. midbrain

Question 8

What are the three parts of the diencephalon?

Answer 8

1. thalamus
2. hypothalamus
3. epithalamus

Question 9

What are the three main ventricles of the brain?

Answer 9

1. Lateral ventricles
2. Third ventricle
3. Fourth ventricle

Question 10

What are meninges?

Answer 10

Three layers of membrane protecting the CNS and brain

Question 11

What are the functions of the ventricles of the brain?

Answer 11

Ventricles are cavities inside the brain filled with cerebrospinal fluid - site of production of the CSF

• CSF supports the CNS by absorbing impacts and exchanging nutrients/wastes with the bloodstream
• produced in CHOROID PLEXUSES on the ventricle walls
• circulates through ventricles into meninges and spinal cord

Question 12

Where is CSF produced?

Answer 12

In the CHOROID PLEXUSES on the ventricles walls

Question 13

How is blood supplied to the brain?

Answer 13

Supplied through internal carotid and vertebral arteries

Drained through dural venous sinuses and internal jugular vein

Capillary walls and astrocytes surrounding the capillaries form BBB

Question 14

What forms the BBB? What is the function of the BBB?

Answer 14

Formed by capillary walls and surrounding astrocytes

Prevents harmful substances from entering the brain tissue

Question 15

Trace the path of blood TO the brain

Answer 15

Supplied through INTERNAL CAROTID and VERTEBRAL ARTERIES

Question 16

Trace the path of blood FROM the brain

Answer 16

Drained through DURAL VENOUS SINUSES and INTERNAL JUGULAR VEIN

Question 17

What are the three main regions of the brain?

Answer 17

Forebrain
Midbrain
Hindbrain

Question 18

What is the function of the medulla oblongata?

Answer 18

Contains nuclei for cranial nerves

• controls autonomic and involuntary functions such as respiration and heartbeat

Question 19

Which sense is the medulla oblongata NOT responsible for?

Answer 19

Vision

Question 20

What is the function of the pons?

Answer 20

Contains tracts and nuclei that link brain parts together / for cranial nerves

Question 21

What is the function of the midbrain?

Answer 21

Contains nuclei for cranial nerves III (oculomotor) and IV (trochlear)

• contains colliculi which controls visual (superior) and auditory (inferior) reflexes

Question 22

What is the function of the cerebellum?

Answer 22

• subconsciously evaluates body movement and sends signals to the cerebral cortex of the cerebrum to adjust skeletal muscles as needed
• fine tunes body movements and manages balance and posture
• posterior to brainstem and inferior to occipital of cerebrum

Question 23

What are the structural parts of the cerebrum?

Answer 23

Made of 2 lobes, vermis, tracts of white matter (arbor vitae) and cerebellar peduncles
- cerebellar peduncles relay info to other parts of the brain

Question 24

What is the epithalamus made of?

Answer 24

Composed mostly of the pineal gland and related structures

Question 25

What is the function of the hypothalamus?

Answer 25

Regulates autonomic nervous functions and behaviour - produces hormones to influence pituitary gland and regulate endocrine functions

Question 26

What is the function of the thalamus?

Answer 26

- learning and memory - passes sensory info to different regions of cerebral cortex - chooses what info is important enough to go to the cerebral cortex for sensory input

Question 27

What is the function of the pituitary gland?

Answer 27

- functions are activated by hormones from the hypothalamus - hormones from hypothalamus activate hormone secretion by pituitary - hormones drive endocrine functions by targeting glands and tissues

Question 28

What are the functions of the limbic system structures?

Answer 28

Create functional classification of brain - associated with emotions, olfaction, memory

Question 29

What are the functions of the cerebrum?

Answer 29

- higher intellectual functions and conscious thought

Question 30

What is the function of the cerebral cortex

Answer 30

process sensory and motor info (left and right) - outermost part of cerebrum

Question 31

What is the function of the basal ganglia?

Answer 31

Coordinate learned movement - nuclei inside cerebrum that influence body movement and muscle tone

Question 32

What are sulci

Answer 32

Cerebral cortex folds into gyri, which are separated by GROOVES CALLED SULCI

Question 33

What are the two hemispheres of the brain?

Answer 33

Left and right

Question 34

What does the left hemisphere control?

Answer 34

language/calculation

Question 35

What does the right hemisphere control?

Answer 35

visual, emotional, artistic awareness

Question 36

What are the six cerebral cortex areas?

Answer 36

1. Primary motor cortex (M1) 2. Olfactory cortex (O1) 3. Primary auditory cortex (A1) 4. Primary somatosensory cortex (S1) 5. Gustatory cortex (G1) 6. Visual cortex (V1)

Question 37

What are the four lobes of the brain?

Answer 37

1. Parietal 2. Occipital 3. Temporal 4. Frontal

Question 38

Which two lobes are responsible for motor signals?

Answer 38

1. Frontal lobe 2. Temporal lobe

Question 39

Which two lobes are responsible for sensory signals?

Answer 39

1. Parietal lobe 2. Occipital lobe

Question 40

Nasolacrimal duct

Answer 40

final destination for draining tears before they are emptied into the nasal cavity

Question 41

Lacrimal sac

Answer 41

after the lacrimal canaliculi, tears drain into lacrimal sac

Question 42

Lacrimal canaliculi

Answer 42

tears drained from the excretory duct go to the lacrimal canaliculi next

Question 43

Cornea

Answer 43

refract light and projects image onto retina

Question 44

Lens

Answer 44

refract light and projects image onto retina

Question 45

Retina

Answer 45

- back of the eye - contains optic nerve (cranial nerve II) - contains optic disk - contains central retinal vein / central retinal artery - photoreceptors = specialized cells stimulated by light

Question 46

Vitreous humour

Answer 46

fills vitreous cavity - holds retina against choroid

Question 47

Aqueous humour

Answer 47

fills the cavity between cornea and lens

Question 48

Excretory ducts

Answer 48

tears drain through excretory ducts and over eyeball surface to lacrimal canaliculi

Question 49

Optic nerve

Answer 49

conveys visual info to brain

Question 50

Lacrimal glands

Answer 50

secrete lacrimal fluid or tears

Question 51

Sclera: vascular or fibrous tunic?

Answer 51

fibrous tunic

Question 52

Choroid: vascular or fibrous tunic?

Answer 52

vascular tunic

Question 53

Ciliary body: vascular or fibrous tunic?

Answer 53

vascular tunic

Question 54

Iris: vascular or fibrous tunic?

Answer 54

vascular tunic

Question 55

What are rod photoreceptors?

Answer 55

detect light but not colour (intensity)

Question 56

What are cone photoreceptors?

Answer 56

detect bright light and allow for colour vision