Brain

[trustist-reviewer widget=”TR”]

Each interaction between a baby and the world, (particularly with people baby is bonding with) develops the neural connections and integrates the mind and the body systems – this is the basis of learning.

Pre-birth

• The neural tube forms at 3 weeks and develops into the spine, the spinal cord and the nervous system
• By 4 months gestation the brain structure is in place

The brain of a new born accounts for 10% or his total body weight in contrast with 2% in adults. By the end of the first year an infant’s brain increases in size by about two and a half times. By the end of the 5th year, brain size is three times what it was at birth. At all stages the male brain is slightly larger than the female brain.

 

Brain structure

• The Brain Stem. Involuntary reflexes – heartbeat, respiration, states of sleep and waking. The most active part of a baby’s brain but makes just one tenth of the adult brain.
• The Medulla controls involuntary reflexes, which include the heart and respiration and the states of sleep and being awake.
• The Pons Varoli is the relay station, also responsible for the breathing reflexes.

At birth, the regions of the brain involved with sleeping, waking, feeding and excreting (hind brain and midbrain) are most active. The cortex is the least developed part of the brain. The areas of the brain that are involved with motor development are; the basal ganglia which control both the large subconscious movements of skeletal muscles and the consciously controlled gross movements and the cerebellum which controls balance, coordination, posture and fine motor skills. Parts of the brain that deal with controlled movement, complex thinking and language development (in the cerebral cortex) take the whole of the early years period to develop fully. Development occurs through experiences which lead to a progression of improvements, refinements and adjustments.

Brain development occurs in the following order:

• coordination and balance improve
•  increased skills with voluntary movements
•  improvements in hearing, vision and understanding words
• refinements in attention, memory, creativity, planning and monitoring behaviour

Experiences in the first three years are stored and drawn upon later in life.
The brain is protected by:

• The skull
• The membranes called the meninges
• A selective blood-brain barrier limiting access of materials to the brain tissue
• Floating in cerebrospinal fluid

Neurones carry the electrical impulses in the nervous system

Myelin is a dense, fatty substance essential for electrical impulses to travel. Myelin sheaths begin to form during foetal development and start in the brain before progressing on to the spinal cord and the rest of the body. The sheaths electrically insulate the axon on a neuron and increase the speed of nerve connection. There are gaps between the myelin sheaths and the electrical impulses jump between. This is how the messages travel and pick up speed.

Very little myelin is present at the time of birth with the exception of the nerves involved in swallowing and sucking reflexes. Babies’ responses to stimuli are slow and uncoordinated at first because the process of myelinisation is still in progress.

Myelination of the nerve tracts in the central nervous system is completed by the end of the second year of life, occurring from the head down to the trunk. Parts of the limbs nearest to the trunk develop fine control before the extremities, with fine control of the digits coming later. The development of myelin sheaths in the brain takes much longer and continues right up to adolescence.

All nerves are present at birth and the growth that occurs is in size. This occurs due to their plasticity so they can be constantly remodelled. Motor control develops from head to toe and centre to periphery.

Reflexes are an important aspect of infant development as mechanisms that assist early functions while more integrated structures replace them. The transition from reflex to voluntary activity is a major process that takes place over the first year with a particularly intense period when babies start becoming mobile.

Primitive reflexes are innate patterns of behaviour. All babies are ‘wired up’ with primitive responses required for birth:

• Rooting reflex, stroking a baby’s cheek causes a baby to turn the head in the direction of the touch and open a wide mouth
• Moro reflex causes a baby to throw the arms outwards and then bring them back in again
•  Sucking reflex
• Blinking reflex

Overcoming gravity is one of the first challenges babies overcome. At first, primitive reflexes help maintain infants’ posture while neurological maturation takes place. Over time, postural control and stability become progressively more voluntary and the primitive reflexes become suppressed, allowing new movements to develop. Some primitive reflexes, like the startle reflex, remain with us in adulthood.

Reflexes associated with hands and feet:

• Palmar Reflex –enables babies to have a very strong grip, bending the fingers toward the palm of the hand (up to 4 months). The grasp of a newborn baby is so strong that her whole body can hang in midair with her bent fingers supporting her weight. The Palmar reflex vanishes to be replaced by voluntary grasping after 5-6 months.
• Plantar Reflex – curling of the toes up (birth to 6 months)
• Babinski Reflex – curling of the toes down (3-12months). It is responsible for the extension of thetoes towards crawling. It also inhibits the Plantar
  Reflex.

Locomotive reflexes help with movement:

• Walking reflex – if a baby is held with its feet touching the ground, and moved forwards, she will perform walking movements.
• Stepping reflex – if a baby is held with the front of one leg in contact with an object, it will raise its other leg as if to step onto the object.
• Swimming amphibian reflex – if a baby is immersed in water swimming movement can appear spontaneously in the form of breaststroke kicks. These reflexes normally disappear before 6 months.

Postural reflexes help maintain or regain balance:

 

 

 

 

 

• Landau Reaction Reflex
• Tonic Labyrinthine Prone Reflex – Helps develop muscle tone. It is the basis for head control, balance and posture.
• Asymmetrical Tonic Neck Reflex – Until 4-6 months. This reflex facilitates the birth process, assists breathing and develops homo-lateral movement (same leg same arm movement).
• Symmetrical Tonic Neck Reflex – This reflex is present at birth and reappears just before the baby learns to crawl at 6-9 months. It assists crawling and prepares the baby for upright positions.
• Spinal Gallant Reflex – causes flexion of one hip and extension of the other side of the body. In a spinal prone position if a baby is stroked down one side of the spine the body will curve towards that side. Until 46 months. This reflex assists the birthing process and stimulates movement in the lumbar region. It is connected to the urinary and intestinal functions.
•  Head Righting: – brings a baby up to an upright position, assisting with sitting (appears at 5/6 months).
• Segmental Rolling
• Body righting
• Crawling and Walking

How does this relate to us…

The use of both diagonal and symmetrical stretches in class supports brain development and development of the neural pathways and
to shed their primitive reflexes. We are providing babies with the opportunity to express the stage of development they are
currently at. Yoga and massage have been shown to speed up myelinisation. Relaxation of parents can help babies to access parasympathetic mode as the parent and the baby’s heart beat and breathing regulate each other.