Newborns and reflexes

Question 1

What event led to different types of mammals increasing?

Answer 1

The extinction event of the dinosaurs.

Question 2

What does Cretaceous period mean?

Answer 2

Reptiles ruling the earth

Question 3

What is an example of adaptive radiation?

Answer 3

Bc of increased survival rates, organisms diversified + adapted to new/recently vacated ecological niches after the dinos died.

Question 4

True or False

There was not many mammalian species 65 million years ago

Answer 4

True

Question 5

Describe Endothermy as mammalian physiology

Answer 5

Endothermy = warm-blooded, requires high-energy food + thermoregulatory adaptations (fur)

Question 6

Describe Live Births as mammalian physiology

Answer 6

Mammary glands, adaptions for nursing, and protection from predators (parenting) is a consequence of evolutionary adaptations, signalling behaviours (crying)

Question 7

Finish the sentence…

‘Mammalian physiology can be seen as physiological and…’

Answer 7

Behavioural adaptions to survival

Question 8

True or False?

Humans are not primates

Answer 8

False

Question 9

How are human infants advanced compare to other mammals

Answer 9

Compared to cats born with their eyes sealed shut = babies, eyes + ears are not sealed.

Compared to rats with ~25% = babies are born with nearly complete neural cell perforation.

Compared to ungulates (horses) who are faster and marsupials (kangaroos) = babies have moderate rapid locomotor development

Question 10

How are infants altricial (slow-developing) compared to other mammals?

Answer 10

Infants = dependent on mothers up to 4 years

Very extended juvenile life stage = delayed adolescence/ reproductive maturity

Question 11

How do humans compare to chimpanzees in reproduction?

Answer 11

Humans = unusual in having a significant post-reproductive life span (menopause) whereas chimps reproduce throughout their lives

Question 12

Complete the sentence

‘Infants have reflexes linked to …’

Answer 12

Evolutionary primate heritage

Question 13

What sensory capabilities do new borns have?

Answer 13

All the five senses and balance

Question 14

What types of touch can babies feel at birth?

Answer 14

Pain
Pressure
Proprioception = awareness of the movement of the body
Changes in temp

Question 15

How is a baby’s balance at birth?

Answer 15

They have a well-developed vestibular system

Question 16

What types of taste can babies feel at birth?

Answer 16

Salty
Bitter
Sweet
Sour

Question 17

What types of hearing can babies feel at birth?

Answer 17

Lower frequency and their ability to localise sound improves during the first 7 years of life

Question 18

What types of vision can babies have at birth?

Answer 18

Very poor
20/400 at birth
improves to 20/20 at 6 months

Question 19

What does vestigial mean in relation to reflexes?

Answer 19

Some reflexes as evolutionary holdovers. Reflexes exist in the repertoire of newborns, but they have partially or wholly lost their original function.

Question 20

What are some orientating responses within neonatal bhvral repertoires?

Answer 20

Visual tracking
Auditory tracking

Question 21

What are some reflexes within neonatal bhvral repertoires?

Answer 21

Clinging = palmar & plantar grasp, Moro reflex -> human mums don’t have fur
Nursing = rooting, sucking
Locomotion = crawling, stepping

Question 22

What is the rooting reflex?

Answer 22

If you brush the side of the mouth of a new-born. They will turn their head bc they anticipate a nipple/ insert finger or bottle into the mouth, and they will suck

Question 23

What is the Moro reflex?

Answer 23

Help babies cling to their mothers for safety + protection. If they hear a large bang, they will go to their mothers. Disappears @ 6mths

Question 24

What type of phenomena is neonatal relflexes?

Answer 24

A lower brain stem phenomena

Question 25

What is the Babinski reflex?

Answer 25

Function unknown, stroking baby’s foot from toe to heal and whether the toes curl. Can indicate brain damage.

Question 26

Who is Terry Brazelton?

Answer 26

He invented the clinical assessment of newborns. Neonatal Behavioural Assessment Scale ‘Brazelton scale.’

Question 27

Infant chimps have similar reflexes, but how do they differ?

Answer 27

Human brain growth after birth is significantly larger than in chimpanzees.

Humans have additional cells in the brain = glial cell

Uniquely big brains 400g @ birth, 1300 in adult hood

Question 28

What is a glia cell?

Answer 28

Non-neuronal cells in the central nervous system maintain homeostasis, provide structural support, and insulate neuronal axons w/ myelin. Most neurons present @ birth, but glia continue to multiply

Question 29

What is myelination?

Answer 29

Is the production or formation of fatty sheathes around axons. This increases the transmission of action potentials in human brains.

Question 30

What is the speed for myelinated?

Answer 30

~10-100m/second

Question 31

What is the speed for unmyelinated?

Answer 31

~1m/second

Question 32

In the peripheral nervous system, which cells lay down the myelin sheath

Answer 32

Schwann cells

Question 33

In the central nervous system, which cells lay down the myelin sheath

Answer 33

oligodendorcytes

Question 34

What is Synaptogenesis?

Answer 34

The formation of new connections between neurons (new synapses) = no. of axon terminals + dendrites increases in the first and 2nd year of life.

Dendritic growth in Broca’s area support this, showing the no. of cell bodies stay the same but the density of dendritic spines increases

Question 35

What is a synapse?

Answer 35

junctions between the terminal of a neuron + another neuron/muscle/gland cell which nerve impulses pass

Question 36

When does growth peak in the cortices for synaptogenesis

Answer 36

Visual cortex =~12 months
Auditory cortex = ~3 years
Prefrontal cortex = ~3 years

New connections are the most rapidly made in the early life.

Question 37

How does Hubel and Wiesel (1950s) show evidence for critical and sensitive periods in brain development

Answer 37

Found that 80% of neutrons were activated from input from both eyes (binocular).

Sewed one eye of kittens and removed it at 2.5 mths old. Once removed, found kittens were functionally blind from the sewed eye for the rest of their life.

This shows humans need specific stimulation for typical brain development within a specific period - evidence for humans. Cataract surgery = 3-7 years of life for optimal results.

Question 37

How does extreme neglect affect brain development

Answer 37

Child Trauma Academy by Perry, CT of 3 yrs old vs control 3yrs old. Showed brains were smaller.

Children’s Hospital of Michigan = PET scan of 9yrs old Romanian orphan vs control child. Showed reduced glucose (metabolic) activity in prefrontal + temporal regions. Shows an overall change in brain functioning + growth.