Chapter 4

Question 1

embryonic period

Answer 1

third to eighth week of pregnancy

Question 2

organogenesis

Answer 2

the process of organ formation in very early development. in humans this is from the first cell divisions until about 10 weeks

Question 3

prenatal development

Answer 3

the development of human individuals before they are born

Question 4

foetus

Answer 4

in human prenatal development, the organism 12 weeks after conception until birth

Question 5

embryo

Answer 5

the developing organism during the period when organs are forming. in humans from first cell divisions until about 10 weeks

Question 6

neonate

Answer 6

an infant less than a month old

Question 7

postnatal development

Answer 7

the development of a human individual after he or she is born, particularly during early infancy

Question 8

axon

Answer 8

the tail-like part of a neuron which transmits impulses (the actual message) away from the cell body

Question 9

synapses

Answer 9

the connections between neurons which enable them to transmit information

Question 10

synaptogenesis

Answer 10

the building of connections (synapses) between nerve cells

Question 11

apoptosis

Answer 11

programmed cell death

Question 12

neurons

Answer 12

nerve cells within central nervous system which transmit information in the form of electro-chemical impulses

Question 13

ectoderm

Answer 13

the outermost of the three primary germ layers of an embryo. the central nervous system and skin, among other structures, develop from ectoderm

Question 14

neural plate

Answer 14

a thickening of endoderm cells that will give rise to the brain

Question 15

neural tube

Answer 15

a hollow structure in the embryo that gives rise to the brain and the spinal column

Question 16

cranial-caudal

Answer 16

the direction beginning with the head end and moving toward the opposite end or feet in humans

Question 17

neurogenesis

Answer 17

the birth of neurons

Question 18

cerebral cortex

Answer 18

the area of the brain is associated with complex tasks such as memory, language, and thoughts and the control and integration of movement and the senses

Question 19

sulci

Answer 19

the deep narrow grooves of the outer surface of the brain

Question 20

gyri

Answer 20

the prominent ridges on the outer surface of the brain

Question 21

myelin

Answer 21

a fatty insulator which prevents leakage of the messages travelling along the nerves, and increases the speed of neural transmission

Question 22

myelination

Answer 22

the process by which myelin is formed around the neurons. myelination begins in the sixth month of life in the foetus but continues throughout childhood

Question 23

term

Answer 23

the end of pregnancy

Question 24

rooting reflex

Answer 24

the reflex that causes newborn babies to respond to one of their cheeks being touched by turning their head in that direction

Question 25

chemosensory system

Answer 25

encompasses both the gustatory and olfactory senses

Question 26

colostrum

Answer 26

the breast fluid that precedes true milk. it is rich in minerals and antibodies, and it helps populate the newborn's gut with 'good' bacteria

Question 27

vestibular system

Answer 27

the sensory system that contributes to balance and spatial orientation

Question 28

preterm

Answer 28

born prematurely. human infants are regarded as preterm if they are born before 38 weeks of pregnancy

Question 29

circadian rhythm

Answer 29

bodily cycles within the body that occur on a 24-hour cycle, such as patterns of sleeping/waking

Question 30

rods and cones

Answer 30

light-sensitive cells found in the retina of the eye which translate light into electrical signals that are then transferred to the brain so that the image can be interpreted

Question 31

trimester

Answer 31

a period of three months. the course of human pregnancy is divided into three trimesters

Question 32

cochlea

Answer 32

the inner ear, a structure encased in bone that contains the receptors for sound

Question 33

transnatal learning

Answer 33

learning that occurs during the prenatal period which is remembered during the postnatal period

Question 34

electroencephalogram

Answer 34

a scalp recording done with electrodes that measures electrical activity produced by neurons. the EEG is often measured when it is time-locked to a stimulus event, producing an event-related potential (ERP)

Question 35

perinatal

Answer 35

the period just before and after birth

Question 36

meiotic cell division

Answer 36

the type of cell division that occurs in sexually reproducing organisms which halves the number of chromosomes in reproductive cells (sperm and ova)

Question 37

DNA methylation

Answer 37

a process with an important role in gene regulation, consisting of the addition of methyl groups to DNA

Question 38

autosomal genetic disorders

Answer 38

disorders resulting from a mutation in a gene in one of the non-sex chromosomes. well-known examples are cystic fibrosis (a receptive type) and achondroplasia (dwarfism, a dominant type)

Question 39

selective serotonin reuptake inhibitor (SSRI)

Answer 39

a class of drugs typically used to treat depression or anxiety

Question 40

developmental programming

Answer 40

the hypothesis that prenatal conditions have detrimental effects on health on health into adulthood

Question 41

ultradian rhythm

Answer 41

rhythms or cycles that repeat in less than a 24-hour period