Musculoskeletal and Nervous System Development

Podcast Beta

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is a significant factor contributing to the variability in movement abilities during early development?

Hormonal levels

CNS plasticity

Body dimensions and proportionality (correct)

Bone ossification rates

What role do osteoclasts play in bone development?

They regenerate muscle fibres.

They build new bone tissue.

They regulate calcium levels in the bloodstream.

They create the bone marrow cavity. (correct)

Which statement best describes the role of estrogen in skeletal development?

It reduces the likelihood of osteoporosis.

It accelerates muscle fibre development.

It increases bone density.

It initiates growth plate closure. (correct)

Why do children produce less force than adults despite size-normalisation?

They are less skilled at muscle recruitment. Signup and view all the answers

How does the closure of epiphyseal growth plates occur?

Due to high levels of estrogen or testosterone. Signup and view all the answers

What process allows for the increased calcium flow between muscle cells during fibre development?

Myoblast fusion Signup and view all the answers

Which of these factors does NOT contribute to the changes observed in physical capabilities during ageing?

Consistent bone mineral density Signup and view all the answers

Which of the following highlights a critical aspect of musculoskeletal development in early childhood?

Rapid expansion in behavioural repertoire. Signup and view all the answers

What is the primary reason for children's lower capacity for muscular force production?

Fewer Type II muscle fibers Signup and view all the answers

At birth, how much of an adult brain's size does a newborn's brain represent?

25% Signup and view all the answers

What occurs to the number of synapses formed in the cortex during the first year of life?

They double Signup and view all the answers

What critical process primarily guides the maturation of the cerebellum and corticospinal tract?

Experience and activity Signup and view all the answers

Which statement about children's muscle fibers is correct?

They contain a smaller proportion of Type IIX fibers. Signup and view all the answers

During the first year, the cerebellum undergoes what percentage of change compared to the rest of the brain?

More change Signup and view all the answers

What primarily drives the growth of axons and dendrites in infants?

Sensory feedback Signup and view all the answers

What happens to the volume of the cerebellum during the first year of life?

Triples in volume Signup and view all the answers

Which of the following occurs as a result of changes in the visual cortex during early brain development?

Improved vision Signup and view all the answers

What is the significance of synapse elimination in early brain development?

It refines neuronal communication. Signup and view all the answers

What is one of the primary factors contributing to increased reaction time and movement time in older adults?

Reduction of motor units Signup and view all the answers

Which of the following statistics regarding falls in older adults is accurate?

30% of older adults fall at least once each year Signup and view all the answers

What role does resistance training play for older adults?

Increases the rate of force development Signup and view all the answers

How do changes in the vestibular system affect older adults?

Delays postural responses Signup and view all the answers

Which of the following is a potential benefit of aerobic exercise for older adults?

Reduces likelihood of cardiovascular disease Signup and view all the answers

What initiates the neck righting reflex in infants?

Stretching of neck muscles Signup and view all the answers

Which reflex is associated with visual and proprioceptive cues to place the foot on a supporting surface?

Placing reaction Signup and view all the answers

At what age range do infants typically achieve walking alone?

9-18 months Signup and view all the answers

Which of the following reflexes is primarily governed by visual cues?

Optical righting reflex Signup and view all the answers

What is the first type of arm movements observed in infants?

Reflexive grasping Signup and view all the answers

Which phenomenon is described by the head control developing before trunk control in infants?

Cephalocaudal development Signup and view all the answers

What is the primary mechanism that leads to the righting of the thorax in response to body tilt?

Stretch reflexes initiated by neck movements Signup and view all the answers

What key element helps to detect movement disorders in children?

Postural milestone timelines Signup and view all the answers

What aspect of infant movement helps increase voluntary control of limbs?

Exposure to unstructured limb movements Signup and view all the answers

Which reflex involves the foot touching a hard surface, leading to a primitive walking pattern?

Stepping reflex Signup and view all the answers

What is the relationship between reaction time (RT) and age during childhood?

Older children exhibit longer RTs due to their delay in selecting and executing movements. Signup and view all the answers

Why is early childhood considered a critical period for motor learning?

The large number of unrefined corticospinal connections facilitates learning. Signup and view all the answers

What happens to the internal model during the teenage years?

It no longer makes accurate predictions about motor commands. Signup and view all the answers

What is indicated by the correlation between the development of the CNS and movement patterns in childhood?

Efficient movements arise directly from an internal model of body dynamics. Signup and view all the answers

How does a growth spurt affect an individual's internal model of motor control?

It leads to temporary inaccuracies in movement execution. Signup and view all the answers

What happens to neuron density during healthy aging?

Only minor decreases occur in specific regions of the brain. Signup and view all the answers

What is a misconception about aging and neuron function?

Decreases in cognitive function correlate with large-scale neuron density loss. Signup and view all the answers

In the context of childhood motor development, what is the significance of neural pruning?

It enhances the efficiency of movement by refining neural connections. Signup and view all the answers

What is a key factor that affects older children's performance in complex environments?

The general delay in movement selection and execution. Signup and view all the answers

Which statement is true regarding learning complex movements in children?

Simple tasks must be mastered before complex movements can be learned. Signup and view all the answers

Study Notes

Musculoskeletal Development

Changes in body size and proportions significantly impact movement abilities during childhood.
Bone ossification occurs through the breakdown of bone tissue by osteoclasts, forming bone marrow cavities.
Epiphyseal growth plates allow for bone growth after birth, but can be damaged by compressive loads.
Growth plate closure is triggered by high estrogen or testosterone levels, with estrogen playing a critical role in both males and females.
Muscle fiber development involves the fusion of myoblasts, allowing increased calcium flow between cells.
Children's muscles produce less force than adults due to having fewer type II muscle fibers and potentially reduced activation of motor neurons.

Nervous System Development

At birth, the brain is about 25% of adult size but contains as many neurons as an adult brain.
The brain reaches approximately 80% of its adult size by the age of 3.
Neural development proceeds from the brain to the periphery, known as 'cephalocaudally'.
Synapse formation and elimination are critical for refining neural communication and are guided by sensory feedback.
The cerebellum undergoes substantial development in the first year of life.

Midbrain and Cerebral Cortex Reflexes

Righting reflexes help maintain balance against gravity, including:
- Labyrinthine righting reflex: Uses gravity and otolith organs to keep the head level.
- Neck righting reflex: Stretches neck muscles to right the thorax, shoulders, and pelvis.
Optical righting reflex utilizes visual cues to right the head.
Placing reaction involves visual and proprioceptive cues to place the foot on a supporting surface.
Stepping reflex is triggered by the sole of the foot touching a hard surface, mimicking a walking pattern.

Development of Postural and Locomotor Control

Development of postural control follows a cephalocaudal pattern, starting with head control and moving to the trunk and legs.
Milestones in postural development can help identify potential movement disorders.
Unlike many animals, humans are not born able to walk and typically achieve independent walking between 9-18 months.

Development of Arm Movements

Early grasping movements are reflexive.
Initial arm movements are random, allowing for learning arm dynamics.
Voluntary movements gradually increase, with fingers initially moving together and later independently.
Thumb opposition develops over time.

Internal Model Development

Unstructured limb movements allow for the development of an internal model of the body and limb dynamics.
This model is crucial for predicting the effects of motor commands.

Improvements in Information Processing

Reaction times (RTs) are longest in young children and become longer in more complex situations.
Older children show similar sensitivity to complexity as adults but still have longer RTs.
Older children (8+) are capable of handling complex environments but exhibit general delays in movement selection and execution.

The Critical Period for Learning

Early childhood offers a unique opportunity for neural pruning but learning complex movements requires mastery of simpler tasks first.
Teenage growth spurts temporarily disrupt internal models, leading to clumsiness as the brain adjusts to new body dynamics.

Common Motor Changes in Older Adulthood

Neuron density does not decrease significantly with healthy aging, although specific brain areas show some decline.
Reaction times and movement times increase with age, reflecting changes in sensory receptors and a reduction in motor units, particularly fast-twitch fibers.
Reduced signal-to-noise ratio in the vestibular system delays postural responses, increasing the risk of falls.
Exercise, particularly resistance training and sensory training, can help mitigate age-related declines in motor function.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Explore the intricate changes that occur in the musculoskeletal and nervous systems during childhood. This quiz covers bone ossification, muscle fiber development, and brain growth. Understand the critical periods of development and the factors influencing these changes.