Neurobiology II (Lec 18 - 20)

Question 1

The blood brain barrier forms a layer of protection between the ______ and the ________

Answer 1

Interstitial fluid and the Blood

Question 2

What is the function of blood brain barrier

Answer 2

isolate body’s main control center from potentially harmful substances

Question 3

Tight junctions are stimulated by ______ signals which are secreted by ______

Answer 3

Paracrine signals // Astrocytes

Question 4

Function of Tight Junction ?

Answer 4

prevent solutes from moving between cells ( present in brain capillaries)

Question 5

(T/F) Typical capillaries (outside of CNS) have tight junctions

Answer 5

False. They have “leaky” capillary walls

Question 6

How do hydrophobic molecules move across membranes of typical capillaries

Answer 6

They diffuse across the membranes of endothelial cells

Question 7

How do hydrophilic molecules move across membranes of typical capillaries

Answer 7

They move through “pores” of the capillary

Question 8

How do macromolecules ( proteins) move through gaps

Answer 8

They are actively transported by transcytosis

Question 9

Define Transcytosis

Answer 9

Endocytosis = into the cell // exocytosis = outside of the cell

Question 10

_______ molecules can only cross the blood brain barriers using ______ ( within the CNS)

Answer 10

Hydrophilic using specific transport proteins

Question 11

How do hydrophobic molecules move across membranes within the CNS

Answer 11

they diffuse across endothelial cells

Question 12

(T/F) Transcytosis occurs across capillary endothelial cells in the CNS

Answer 12

False. There is not transcytosis within the CNS

Question 13

How do hydrophilic molecules move across capillary walls in the CNS ? What is the structure responsible for this ?

Answer 13

They move through active transport with specialized protein carriers since there are tight junctions which eliminates pores

Question 14

(T/F) Specific transport proteins must be present in order for hydrophilic molecules to pass through capillary walls in the CNS.

Answer 14

True.

Question 15

An example of molecules with no transport protein is ?

Answer 15

catecholamine

Question 16

Glucose is transported by the specific transport protein

Answer 16

Glut1

Question 17

Three main parts of the brain

Answer 17

Forebrain, brainstem, cerebellum

Question 18

Looking at the cerebrum, the left and right hemispheres are separated by the _________ and connected by a bundle of nerve fibers called the _______

Answer 18

Longitudinal fissure and connected by corpus callosum

Question 19

The cerebrum consists of left and right ________ as well as a deep ________ under the brain

Answer 19

Hemispheres // subcortical nucleui

Question 20

The cerebral hemispheres consists of the ______

Answer 20

Cerebral cortex

Question 21

The cerebral cortex is made up of the outer shell of _______ and inner layer of ________

Answer 21

Gray matter / white matter

Question 22

Gray matter is composed of _______, while white matter is primarily composed of _________

Answer 22

Cell bodies // myelinated fiber tracts

Question 23

An example of the subcortical nuclei is the ______. They are responsible for ______

Answer 23

basal nuclei. They are responsible for modifying movement

Question 24

The cerebral cortex is organized in ____ layers

Answer 24

six layers

Question 25

Convolutions called ____ and _____ are present in the cerebral cortex

Answer 25

gyrus and sulcus

Question 26

Convolutions allow the brain to have a _________ of cerebral cortex to be accommodated within a give _______

Answer 26

greater volume /// given cranial volume

Question 27

(T/F) Sensory information passes through the cortex directly

Answer 27

False. Sensory information does not pass through the cortex directly, but acts as an integration center

Question 28

The cerebral cortex can be divided into which 4 areas ?

Answer 28

Frontal, Occipital, Temporal, Parietal

Question 29

What is topographical organization

Answer 29

Organization according to structure

Question 30

The relative size of body parts on a homunculus corresponds to the _____ devoted to the body part

Answer 30

Relative size of cortical area

Question 31

The central core of the forebrain is formed by the _______ which is composed of the ______ and _____

Answer 31

Diencephalon, which is composed of the thalamus and hypothalamus

Question 32

The ______ is a cluster of cell nuclei

Answer 32

thalamus

Question 33

Function of thalamus ?

Answer 33

The thalamus relays sensory information directly to the cerebral cortex, except the sense of smell. It filters sensory information therefore is important for directing attention

Question 34

Damage in the thalamus can results in ______, which is _______.

Answer 34

Synesthesia. stimulation of one sensory pathway leads to an involuntary experience of the second sensory pathway

Question 35

Function of Hypothalamus ?

Answer 35

pathways that form the master command of neural and endocrine coordination

Question 36

Brainstem connects the ______ to the _______ and is composed of the (1)______, (2)-_______, (3)________.

Answer 36

Spinal cord to the brain | (1) midbrain (2) pons (3) Medulla oblongata

Question 37

All nerve cells that pass through the _______ , ______ and _______ has to pass through the brainstem

Answer 37

Spinal cord, cerebellum, and forebrain

Question 38

An extremely important part of the brainstem that regulates our sleep wake cycles and consciousness is the _______.

Answer 38

Reticular Formation

Question 39

What is the function of the cerebellum

Answer 39

The cerebellum sits on top of the midbrain and is important for coordinating smooth movements / coordination/ and balance

Question 40

What is the pathway for cerebellum and its relation to other parts of the brain.

Answer 40

The cerebellum receives information about movement status from the sensory area of the cortex, brainstem, and spinal cord. It then transmits the information to the cortex from the thalamus enabling the cortex to modify the movement to be as smooth as possible.

Question 41

The spinal cord is a cylinder of nervous tissue, continuous with the ____________, surrounding by the ___________

Answer 41

lower end of the brain, vertebral column

Question 42

The spinal cord (containing cell bodies and gray matter) ends at the level _____ vertebra in adults

Answer 42

L2

Question 43

The spinal cord is composed of the inner core of _______ and outer core of _______

Answer 43

Gray matter, white matter

Question 44

The spinal cord is divided form superior to inferior into what 5 regions.

Answer 44

Cervical, Thoracic, Lumbar, Sacral, coccygeal

Question 45

What is the cauda equina? It is also called the ______.

Answer 45

the 1/3 end of the spinal cord where no cell bodies are found. It is also called the horse tail.

Question 46

The spinal cord gray matter is composed of ____ and shaped like ______

Answer 46

cell bodies (unmylinated) // the letter H

Question 47

Function of the ventral and dorsal horns

Answer 47

ventral horns are associated with motor neurons | Doral horns are associated with sensory neurons

Question 48

The spinal cord white matter contains ascending & descending bundles. Function ?

Answer 48

Ascending Bundles carry sensory information to the brain (myelinated) Descending Bundles commands motor neurons ( myelinated)

Question 49

Explain Afferent Fibers

Answer 49

Afferent Fibers originate in the periphery and terminate at the dorsal horn.

Question 50

Cell bodies of the afferent fibers are located at the ______

Answer 50

Dorsal Root Ganglia

Question 51

Cell bodies of the Efferent neurons are found at the ______

Answer 51

Spinal Cord ( ventral horns)

Question 52

Function of Efferent neurons

Answer 52

projects axons to the periphery to synapse with effectors

Question 53

What are ventral roots

Answer 53

efferent limb of each spinal nerve that conducts motor impulses

Question 54

What are spinal nerves

Answer 54

union of dorsal and ventral roots and are found in intervertabal formation

Question 55

What does the dorsal column-medial lemniscal pathway relay

Answer 55

Sensory information to the somatosensory cortex

Question 56

Explain the dorsal column-medial lemniscal pathway

Answer 56

1. When you touch a rose pedal, afferent neurons are activated and enter the spinal cord through the dorsal root. This is called First order neurons. 2. First order neurons ascend to the end of the dorsal column nuclei in the medulla oblongata and synapse with second -order neurons 3. Second order neurons pass through the medial lemniscus on the contralateral side and ascend to the thalamus. 4. Third neurons then transmit the information from the thalamus to the somatosensory cortex.