Week 15: Development

Question 0

Haploid

Answer 0

Half chromosomes

Question 1

The germinal period

Answer 1

8-10 days after egg and sperm unite and lasts for 2 weeks

Question 2

Diploid

Answer 2

Full set of chromosomes

Question 3

Gametes

Answer 3

Mature reproductive cell (haploid) egg and sperm

Question 4

Zygote

Answer 4

The new cell at conception from the formation of the egg and sperm

Question 5

Cleavage

Answer 5

Cell dividing into 2 then 4 then 8. Occurs 24 hours after fertilization

Question 6

Morula

Answer 6

Spherical mass of divided cells

Question 7

Stem cells

Answer 7

Unspecialized cells

Question 8

Inner cell mass

Answer 8

The inner cells of the morula which will eventually become the embryo

Question 9

Trophoblast

Answer 9

Outer cell lining of the blastocyst and will eventually form a protective layer around the embryo > extra embryonic layer & placenta that transports nutrients, oxygen and metabolizes across the membrane.

Question 10

Blastocyst

Answer 10

Stage that a fertilized egg reaches 5-6 days

Question 11

Neurulation

Answer 11

The process of a neural tube forming within an embryo > formation of the nervous system and the brain and CNS.

Question 12

Neurogenesis

Answer 12

6-7 weeks after conception.

Question 13

Embryonic Period

Answer 13

Eight weeks long and begins as soon as implantation within the uterine wall occurs.

Question 14

Neural migration

Answer 14

Process of the movement, connection and organization of neural cells to form the mature brain.

• genetic instructions
• time & place of neurogenesis
• interactions with glial cells
• chemical genetic and environ signals
• largely unknown!

Question 15

Embryonic development occurs in what directions?

Answer 15

Cephalocaudaul - most intensely at the head and work downwards

Proximodistal - from the centre of the organism outwards

Question 16

Cell apoptosis

Answer 16

Programmed cell death that is a crucial part of development.

THINK: webbed cells between fingers must be reabsorbed in order to have digits instead of a fop appendage.

Question 17

Foetal period

Answer 17

9th week after conception to birth.
Beginning of the foetal period: 30 grams x 4cm (my eraser)

10 weeks: breathing movements to practice muscle for birth not to obtain oxygen

4th month: sleep and wake patterns are detected and large enough for the movements to be noticed

5th month: vestibular system (balance & spatial coordination), responsive to sound, foetal heart beat changes in response to mothers voice, recognizes mothers voice

6th month: 700 grams and 30cm can be premature but obvi better in utero

6-8 month: heartbeat responsive to light stimulation, tastes (show a preference to foods that mom ate while in womb) and movement stops (to facilitate growth of inhibitory neural pathways)

8-9 month: grows 250grams per week until birth

Question 18

Cat in the hat study

Answer 18

• memory in prenatal development
• mom read cat in hat 2 x a day
• after birth baby was given soother that would play cat and hat story or another story read by mom depending on the amount of sucking
• baby adjusted sucking to plays at in hat

Question 19

Teratogen

Answer 19

Alcohol, heavy metal - mercury, some medications.

• the earlier the foetus is exposed the worse the effects
• will affect very mother and foetus differently
• the greater the amount and the longer it is exposed it will have a greater affect.

Question 20

Famous teratogens

Answer 20

Alcohol > Foetal alcohol spectrum disorders

Smoking > lowered IQ and behavioural problems

Medication > Thalidomide was prescribed to mothers and left devastating effects

Diseases > rubella in prenatal infants can cause congenital heart disease, deafness, blindness or mental retardation. Influenza has been correlated with schizophrenia.

Question 21

Reflexes

Answer 21

In infants there are many types of reflexes that are eventually replaced with voluntary behaviours.

Question 22

Explanation for increasing cognitive complexity?

Answer 22

• not the number of neurons since it’s the greatest when we are born (18 weeks after conception)
• complexity of existing neurons: synaptogenesis occurs at a rapid pace after we are born to form all of the synapses we will ever have from birth to age 1.

Question 23

Synaptic plasticity

Answer 23

Neurons can grow or shed connections to other neurons in order to accommodate their own activity levels.

Question 24

Synaptic pruning

Answer 24

The process of selectively eliminating synapses formed during the first year to make it more efficient.

Question 25

Experience-dependant plasticity

Answer 25

Nervous system rewiring itself increasing or decreasing or forming new stronger connections based on its use.

Question 26

Experience-expecting plasticity

Answer 26

Needing an event or critical period to shape a development of the brain. Language critical period. If it is missed the development is lost.

Question 27

Amblyopia

Answer 27

Anna had a mild case

Loss of ability in one eye to see details.

Question 28

Myelination

Answer 28

Formation of myelin sheath (made of glial cells) around axons of neurons to insulate and also to increase the speed at which neurons transmit information

• indicate the age of a brain

Question 29

Executive functioning

Answer 29

Goal-oriented, planning and problem solving behaviour. Behaviour that regulates and controls other behaviour.