Chapter 3 - Cell function

Question 1

Efferent Signal

Answer 1

(E)fferent - exit the brain

Question 2

Afferent signal

Answer 2

(A)fferent - arrive at the brain

Question 3

Smallest unit of brain function

Answer 3

golgi said it was reticular theory (continuous network of interconnected fibers (neurites) that form a mesh-like structure)

Cajal said neuron was the smallest (correct)

Question 4

Neurons found in the Cerebral Cortex

Answer 4

Pyramidal makes up 2/3 of cerebral cortex

pyramid-shaped cell bodies and are key players in the brain’s neural circuitry

Question 5

Neurons found in the Cerebellum

Answer 5

Purkinje Cells - long branching dendrites

Granule Cells (most abundant in brain) - single dendrite that makes connections with Purkinje cells

Question 6

Internerouns

Answer 6

CNS in spinal cord. go between neurons in spine. involved in processing information, reflexes, and modulation of neuronal circuits.M

Question 7

Motor Neurons

Answer 7

play a crucial role in the nervous system by transmitting signals from the central nervous system (CNS) to muscles and glands, facilitating movement and various bodily functions.

Question 8

name and function of all the glial cells of the PNS

Answer 8

Schwan cells - myelinate the axon of neurons in the PNS

Satellite cells - regulate neurotransmitters in the PNS

Question 9

name and function of all the glial cells of the CNS

Answer 9

oligodendrocytes - myelinate the axons of neurons in the CNS

Ependymal cells - secretes Cerebrospinal fluid (nourishes, waste management, protection)

Microglia - immune response of CNS

Astrocytes - maintain BBB and help in repairs

Question 10

process of fixing a cut neuron in the PNS

Answer 10

if a neuron (PNS) is cut, Schwan cells will form a path for the neuron to reach out to.

when the axon is grown, the Schwan cells for a new myelin sheath

Question 11

What is in the cell nucleus

Answer 11

Chromosomes 46

44 autosomes

2 sex chromosomes

Question 12

Human genome project

Answer 12

completed in 2003

Complete genome of a human
-everything that makes a person
- less than 30,000 genes
(they estimated 100k before)

Question 13

big to small

Answer 13

cell nucleus -> chromosome -> gene -> nitrogenous bases

Question 14

why are nitrogenous bases important in building proteins

Answer 14

nitrogenous base tells what amino acid sequce to build a protein

Question 15

stages of making a protien

Answer 15

amino acid chain ->
B sheet or a helix ->
protein ->
more complex protein (if combined)

Question 16

where does translation happen typically

Answer 16

ER

otherwise at ribosomes that are just chillin in the cytoplasm

Question 17

which base is used instead of thymine

Answer 17

uracil

Question 18

How does protein packaging and transporting work?

Answer 18

Formed in the ER and wrapped up

attched to a motor molecule that moves along a microtuble to be implemented into the membrane or excreted via exocytosis

Question 19

what are channels made of??

Answer 19

proteins

Question 20

what is a wild type?

Answer 20

natural tendacy of a trait (right handedness 90%)

Question 21

What is a Transgenic Technique?

Answer 21

Transgenic organism: genome has been altered (inserting/removing DNA a gene or genes).

Knock-in Technique**
“knocking in” a specific gene precise location. to see what protiens contribute to fur colour in mice

• Done at the embryonic stage, allowing changes to be inherited

Question 22

Why is the Knock-in Technique good?

Answer 22

since our brain is structurally similar across species, we can test what is causing diseases (alzheimer’s, parkinsons)

Question 23

Tay-Sachs Disease

Answer 23

• *Recessive gene
• inherited birth defect
• 4-6 mth after birth gets brain damage
• death by age 5

Question 24

Huntington’s Disease

Answer 24

• motor and cognitive disturbances
• *Dominant gene (chromosome 4)
• dementia for kids

Question 25

What is Apraxia

Answer 25

Neuro disorder is sometimes caused by mutation of the FOXP2 gene.

Results in…
loss of motor function
loss of speech

caused by family members carrying the gene mutation

Question 26

Gene therapy

Answer 26

there are 2 methods of gene therapy

1. Gene augmentation (add/replace)
2. Gene suppression (add/remove to inhibit)

they use can use Viral Vectors to do this or injecting liposomes direclty

Question 27

What example of Gene Therapy did we watch in class

Answer 27

Rhys Evans
born with (SCID) Severe Combined ImmunoDeficiency

Question 28

Potential complications to effective gene therapies

Answer 28

1. Immunotoxicity - T-cells overreact
2. Mutagenesis - alteration of a patient’s DNA in a harmful way
3. heritable changes, meaning the offspring of the treated individual may inherit the modified gene, leading to unintended long-term consequences.

Question 29

Epigenetics

Answer 29

Epigenetic modifications can be influenced by a variety of factors, including development, environmental influences, diet, stress, and exposure to toxins.

Question 30

Epigenetic Drift

Answer 30

Nature vs. Nurture in Twins

Question 31

Epigenetic Mechanisms

Answer 31

Histone Mods:
- Alters chromatin structure (loosening or tightening)(open for transcribing)

DNA Modification:
- Silences gene expression by preventing transcription factor binding (methylation)

mRNA Modification:
- Regulates mRNA stability, translation, and degradation (could prevent translation)

Question 32

How can Stress/Depression effect Epigenetics?

Answer 32

Stress = epigenomic change = changes in behaviour

SLC6A4 (serotonin reuptake)
BDNF (neuron growth & survival)

Question 33

SLC6A4

Answer 33

(serotonin reuptake)

Question 34

BDNF

Answer 34

(neuron growth & survival)

brain derived neurotrophic factor