# data[].attributes.attachment_link.title
The Brain for Kids | Learn cool facts about the human brain

# data[].attributes.attachment_link.readable_text
Here we provide information about how your child's lungs grow and develop. We explain how lungs develop in the womb and how they continue to grow after birth and through childhood.
On this page:
How lungs grow in the womb

Your child's lungs develop in five stages. The first four stages happen in the womb, and the final stage finishes in late childhood or the early teenage years. The stages of development always happen in the same order, but the exact timings can be different for everyone.

Do babies breathe in the womb?

Before your baby is born, their lungs are filled with fluid. They get oxygen from the mother's blood through the placenta.

The fluid in the womb lets your baby's lungs develop and mature, ready for birth. They will take their first breath of air when they are born.

Stage 1: After conception

The first stage of your baby's lung development usually happens at 3-5 weeks during pregnancy. At five weeks, your baby is just 2mm long, but major organs are already beginning to form.

A lung bud starts developing from a small tube of cells called the foregut (which also goes on to form the gut). This bud separates into two. Later on, the lungs separate from the gut.

These two buds will eventually go on to become your baby's right and left lungs. Your baby will then start to make lung movements in the womb as if they are practising breathing.

Stage 2: Airways begin to form

The second stage of lung development happens between 5-16 weeks during pregnancy. During this time your baby is growing quickly. The major organs are in place by 12 weeks, and at 14 weeks your baby measures 85mm from head to toe.

Your baby's lungs will now start to develop the tree-like structure you see in adult lungs. Each lung bud starts to divide again and again, like the branches of a tree.

At first, they form three buds on the right side - these will become the upper, middle, and lower lobes of the right lung. They only form two buds on the left side - the upper and lower lobes of the left lung. Your baby's right lung will be bigger because the left lung has to share space with the baby's heart. This is the same for almost everyone.

These buds continue to divide throughout this stage. They may divide up to 20 times.

By 16 weeks your baby's lungs have all of their main airways (bronchi) and smaller airways (bronchioles). Cells that will eventually become the tiny air sacs (alveoli) have started to appear at the end of these smaller airways, like buds on trees.

Stage 3: Getting ready to form air sacs and blood vessels

Stage three takes place from 16-26 weeks during pregnancy. Your baby starts to develop the areas where air sacs and blood vessels will form, at the end of the smallest airways. These air sacs will be needed to get oxygen into their blood when they breathe outside the womb.

The cells that will become air sacs carry on developing even after your baby is born. Small blood vessels called capillaries grow close to these cells.

If a baby is born prematurely

A baby born before 32 weeks of pregnancy won't have strong enough lungs to breathe on their own yet. They may be put on a breathing machine to help them breathe. We have more information about babies who are born premature.

Stage 4: Preparing the lungs for breathing

This stage of development begins at 26 weeks and carries on until birth. In this stage, the end of the smallest airways (now called saccules) grow in size. They will eventually develop into early alveoli (air sacs).

The walls of these saccules get thinner to make more room for air in your baby's lungs.

A mixture of fats and proteins begin to form at this stage - these are called surfactants. They help make sure the air sacs expand more easily and won't collapse at the end of each breath out.

Stage 5: Air sac development

Stage five of lung development starts at 32 weeks and continues after birth into childhood. In the last few weeks of pregnancy, the first air sacs (alveoli) develop.

More surfactants (fats and proteins) are produced as the lungs carry on developing. The lungs develop and grow to enable oxygen to get into the blood. This prepares your baby's lungs to breathe outside the womb.

Your baby's first breath

When a foetus (unborn baby) is in the womb, their lungs are filled with fluid, and they get oxygen through the umbilical cord. As soon as your baby is born, they need to start using their lungs to breathe and get oxygen from the air.

Their first breath can take up to 30 seconds after birth. The breath sounds like a gasp as the baby reacts to sudden changes in temperature and environment.

As a baby takes their first breath, the blood vessels around the lungs get wider and the blood flows to the lungs to collect oxygen. The fluid drains and the lungs begin to inflate and work on their own.

How lungs grow after birth

Your baby has around 20-50 million air sacs at birth. This number will increase rapidly until they are two years old.

By the time your child is three, their lungs look like a mini version of adult lungs. The airways and lungs expand in size as your child grows taller, filling their rib cage.

When will my child's lungs be fully grown?

Your child's lungs get bigger as they grow. All their airways and air sacs increase in size and volume. Volume is the amount of air your child's lungs can hold.

The exact size and volume of the lungs will vary from child to child. There is evidence to say that new air sacs keep developing throughout childhood and into the teenage years. Fully grown, adult lungs have around 300 million air sacs.

Looking after your child's lungs

It's important to look after your baby's lung health while the lungs are still developing.

Some lung problems can be caused by genetics or premature birth, and other problems can be caused by passive smoking, diet, and pollution. We have lots more information about the risks to children's lungs, as well as how to protect children's lungs.

# data[].attributes.attachment_link.title
How children's lungs grow - British Lung Foundation

# data[].attributes.attachment_link.description
Here we provide information about how your child's lungs grow and develop. We explain how lungs develop in the womb and how they continue to grow after birth and through childhood. On this page: Your child's lungs develop in five stages.

# data[].attributes.attachment_link.readable_text
Alternative names for growth hormone

Somatotropin; GH; human growth hormone; HGH

What is growth hormone?

Growth hormone is released into the bloodstream from the anterior pituitary gland. The pituitary gland also produces other hormones that have different functions from growth hormone.

Growth hormone acts on many parts of the body to promote growth in children. Once the growth plates in the bones (epiphyses) have fused growth hormone does not increase height. In adults, it does not cause growth but it helps to maintain normal body structure and metabolism, including helping to keep blood glucose levels within set levels.

How is growth hormone controlled?

Growth hormone release is not continuous; it is released in a number of 'bursts' or pulses every three to five hours. This release is controlled by two other hormones that are released from the hypothalamus (a part of the brain): growth hormone-releasing hormone, which stimulates the pituitary to release growth hormone, and somatostatin, which inhibits that release.

Growth hormone levels are increased by sleep, stress, exercise and low glucose levels in the blood. They also increase around the time of puberty. Growth hormone release is lowered in pregnancy and if the brain senses high levels of growth hormone or insulin-like growth factors already in the blood.

What happens if I have too much growth hormone?

Not surprisingly, too much growth hormone causes too much growth.

In adults, excessive growth hormone for a long period of time produces a condition known as acromegaly, in which patients have swelling of the hands and feet and altered facial features. These patients also have organ enlargement and serious functional disorders such as high blood pressure, diabetes and heart disease. Over 99% of cases are due to benign tumours of the pituitary gland, which produce growth hormone. This condition is more common after middle-age when growth is complete so affected individuals do not get any taller.

Very rarely, increased growth hormone levels can occur in children before they reach their final height, which can lead to excessive growth of long bones, resulting in the child being abnormally tall. This is commonly known as gigantism (a very large increase in height).

Overproduction of growth hormone is diagnosed by giving a sugary drink and measuring the growth hormone level over the next few hours. The sugar should cause growth hormone production to reduce. However, this does not happen in acromegaly.

What happens if I have too little growth hormone?

Too little growth hormone (deficiency) results in poor growth in children. In adults, it causes a reduced sense of wellbeing, increased fat, increased risk of heart disease and weak heart, muscles and bones. The condition may be present from birth where the cause can be unknown, genetic or due to injury to the pituitary gland (during development or at birth).

Growth hormone deficiency may also develop in adults due to brain injury, a pituitary tumour or damage to the pituitary gland (for example, after brain surgery or radiotherapy for cancer treatment). The main treatment is to replace the growth hormone using injections - either once a day or several times a week.

In the past, growth hormone treatment was stopped at the end of growth. It is now clear that growth hormone contributes to both bone mass and muscle mass reaching the best possible level, as well as reducing fat mass during development to an adult. The specialist is therefore likely to discuss the benefits of continuing growth hormone after growth has completed until age 25 to make sure bone and muscle mass reach the best possible level. Additionally, growth hormone has been linked to a sensation of wellbeing, specifically energy levels. There is evidence that 30-50% of adults with growth hormone deficiency feel tired to a level that impairs their wellbeing. These adults may benefit from lifelong treatment with growth hormone. Taking growth hormone when adult will not result in increased height.

Last reviewed: Feb 2018

# data[].attributes.attachment_link.description
Somatotropin; GH; human growth hormone; HGH Growth hormone is released into the bloodstream from the anterior pituitary gland. The pituitary gland also produces other hormones that have different functions from growth hormone. Growth hormone acts on many parts of the body to promote growth in children.

# data[].attributes.attachment_link.title
Human development -- Britannica Online Encyclopedia

# data[].attributes.body
Easier

# data[].attributes.attachment_link.keywords[]
human growth and developmentdefinitionin the context of the physical development of children

# data[].attributes.attachment_link.keywords[]
growth refers to the increase in the size of a child

# data[].attributes.attachment_link.keywords[]
and development refers to the process by which the child develops his or her psychomotor skills.descriptiongrowththe period of human growth from birth to adolescence is commonly divided into the following stages:

# data[].attributes.attachment_link.title
Human Growth and Development | Encyclopedia.com

# data[].attributes.attachment_link.description
Human growth and developmentDefinitionIn the context of the physical development of children, growth refers to the increase in the size of a child, and development refers to the process by which the child develops his or her psychomotor skills.DescriptionGrowthThe period of human growth from birth to adolescence is commonly divided into the following stages: Source for information on Human Growth and Development: Gale Encyclopedia of Nursing and Allied Health dictionary.

# data[].attributes.attachment_link.title
What makes muscles grow? - Jeffrey Siegel

# data[].attributes.body
Easier: Text to Speech

# data[].attributes.attachment_link.readable_text
You know vitamins and minerals are good for you. But what does your body really need? And is it possible to get too much of a good thing?

What Are Vitamins and Minerals?

Your body needs vitamins and minerals to work properly. You get them from the foods you eat every day.

Vitamins fall into two categories: fat soluble and water soluble (pronounced: SAHL-yuh-bul):

The fat-soluble vitamins - A, D, E, and K - dissolve in fat and are stored in your body.

The water-soluble vitamins - C and the B-complex vitamins (such as vitamins B6, B12, niacin, riboflavin, and folate) - dissolve in water. Your body can't store these vitamins. Any B or C vitamins that your body doesn't use travels through the bloodstream and is lost (mostly when you pee). So you need a fresh supply of these vitamins every day.

Vitamins are organic substances, which means they're made by plants or animals. Minerals are inorganic elements that come from soil and water, and are absorbed by plants or eaten by animals. Your body needs larger amounts of some minerals, such as calcium, to grow and stay healthy. Other minerals like chromium, copper, iodine, iron, selenium, and zinc are called trace minerals because you need only very small amounts of them.

What Do Vitamins and Minerals Do?

Vitamins and minerals boost the immune system, support normal growth and development, and help cells and organs do their jobs. For example, you've probably heard that carrots are good for your eyes. It's true! Carrots are full of substances called carotenoids (pronounced: kuh-RAH-teh-noydz) that your body converts into vitamin A, which helps prevent eye problems.

Vitamin K helps blood to clot, so cuts and scrapes stop bleeding quickly. You'll find vitamin K in green leafy vegetables, broccoli, and soybeans. And to have strong bones, you need to eat foods such as milk, yogurt, and green leafy vegetables, which are rich in the mineral calcium.

How Do I Get the Vitamins and Minerals I Need?

Eating well now is especially important because the body needs a variety of vitamins and minerals to grow and stay healthy.

Eating a mix of foods is the best way to get all the vitamins and minerals you need each day. Fruits and vegetables, whole grains, low-fat dairy products, lean meats, fish, and poultry are the best choices for getting the nutrients your body needs.

When deciding what to eat, check food labels and pick items that are high in vitamins and minerals. For example, when choosing drinks, you'll find that a glass of milk is a good source of vitamin D, calcium, phosphorous, and potassium. A glass of soda, on the other hand, doesn't have any vitamins or minerals.

You can also satisfy your taste buds without sacrificing nutrition while dining out: vegetable pizzas or fajitas, sandwiches with lean cuts of meat, fresh salads, and baked potatoes are just a few delicious, nutritious choices.

If you're a vegetarian, you'll need to plan carefully for a diet that includes the vitamins and minerals you need. The best sources for the minerals zinc and iron are meats, fish, and poultry. But you can get these from dried beans, seeds, nuts, and leafy green vegetables like kale.

Vitamin B12 is important for making red blood cells and keeping nerves working well. It is found only in animal products. If you don't eat meat, you can get vitamin B12 from eggs, milk and other dairy foods, and fortified breakfast cereals. Vegans (vegetarians who eat no animal products at all, including dairy products) may need to take vitamin B12 supplements.

Should I Take a Supplement?

Lots of people wonder if they should take vitamin or mineral supplements. If your diet includes a wide variety of foods - including whole-grain products, fresh fruits and vegetables, dairy products, nuts, seeds, eggs, and meats - you probably get the vitamins and minerals your body needs.

There are many supplements on the market, and of course their makers want you to buy them. Beware of unproven claims about the benefits of taking more than recommended amounts of any vitamin or mineral. Healthy teens usually don't need supplements if they eat a well-rounded diet.

Check with your doctor before taking vitamin or mineral supplements. Just because something is good for you doesn't mean that more is better. Some vitamins and minerals can cause health problems if you get too much of them.

Talk to your doctor or a dietitian if you're skipping meals, dieting, are a picky eater, or have any concerns about your diet. They can answer your questions and help you create a healthy eating plan that includes the nutrients your body needs.

# data[].attributes.attachment_link.title
Vitamins and Minerals (for Teens) - Nemours KidsHealth

# data[].attributes.attachment_link.description
Vitamins and minerals are nutrients that the body needs to work properly. They boost the immune system, promote normal growth and development, and help cells and organs do their jobs.

# data[].attributes.attachment_link.readable_text
Right now, the bones in your body are undergoing renovation. There are wrecking crews blasting into the bone quarry and carting off debris while an entirely different work crew hauls bags of concrete to the blast site and patches the newly made holes with stronger, newer, better material.

Before we talk about replacing bone with bone, we'd better learn how cartilage turns into bone. When you're floating around in the womb, your developing body is just beginning to take its shape, and it's creating cartilage to do so. Cartilage is a tissue that isn't as hard as bone, but much more flexible and, in some ways, more functional. Cartilage is pretty good stuff to use if you're going to mold a human -- good enough for the finer work, especially, such as your nose or your ear.

A large amount of that fetus cartilage begins transforming into bone, a process called ossification. When ossification occurs, the cartilage (which doesn't have salts or minerals in it) begins to calcify; that is, layers of calcium and phosphate salts begin to accumulate on the cartilage cells. These cells, surrounded by minerals, die off. This leaves small pockets of separation in the soon-to-be-bone cartilage, and tiny blood vessels grow into these cavities. Specialized cells called osteoblasts begin traveling into the developing bone by way of these blood vessels. These cells produce a substance consisting of collagen fibers and they also aid in the collection of calcium, which is deposited along this fibrous substance. (One common analogy for this design is reinforced concrete, which is a grid of metal rods covered with concrete mix.)

After a while, the osteoblasts themselves become part of the mix, turning into lower-functioning osteocytes, sort of a retired version of osteoblasts that continue to putter along but don't stray too far from the blood vessels. This osteocyte network helps form the spongelike lattice of cancellous bone. Cancellous bone isn't soft, but it does look spongy. Its spaces help transfer the stress of external pressures throughout the bone, and these spaces also contain marrow. Little channels called canaliculi run all throughout the calcified portions of the bone, enabling nutrients, gases and waste to make their way through.

But we're not through with the bone-growing process yet.

# data[].attributes.attachment_link.description
­Right now, the bones in your body are undergoing renovation. There are wrecking crews blasting into the bone quarry and carting off debris while an entirely different work crew hauls bags of concrete to the blast site and patches the newly made holes with stronger, newer, better material.

# data[].attributes.attachment_link.readable_text
Much of a baby's body is composed of flexible cartilage, which is much softer than bone. As a baby develops, the cartilage slowly begins to ossify, or turn into bone, by a process known as ossification. Within the center of the bone, cells called osteoblasts slowly turn cartilage into cortical bone. Growth in children, for the most part, occurs at night while they are sleeping.

During this process, the ossification center located at the center of the bone slowly turns cartilage to bone. The growth plate of the bone, which is located near top of the bone, tells the cells to extrude themselves by producing more cartilage to lengthen or grow the bone. Slowly, the new cartilage, known as articular cartilage, produced by the growth plate is calcified or turned into bone. As this process continues, the growth plate produces more cartilage, the bones lengthen and the body grows. Later, the cartilage calcifies.

The growth plate is essentially responsible for lengthening or growing the bone. Eventually, the pituitary gland stops producing as much HGH and bone growth slows. During adulthood when growth stops and bones no longer need lengthening, the articular cartilage calcifies.
Learn more about Human Anatomy

# data[].attributes.attachment_link.description
Much of a baby's body is composed of flexible cartilage, which is much softer than bone. As a baby develops, the cartilage slowly begins to ossify, or turn into bone, by a process known as ossification. Within the center of the bone, cells called osteoblasts slowly turn cartilage into cortical bone.

# data[].attributes.attachment_link.readable_text
Most middle schools have sixth, seventh, and eighth graders, which means kids may be as young as 11 or as old as 15 during their years there. Between those ages, kids grow in different ways and at their own pace. You just have to walk into a middle school to see the huge variation in both physical and emotional maturity.

Middle-schoolers are working toward developing certain skills by the time high school rolls around. Learn about the developmental milestones at this age.

As puberty begins, kids go through big physical changes. Growth spurts are common now. And though girls tend to develop earlier than boys, there's a big difference in physical milestones among individual kids.

Still, most middle-schoolers:

Get a little less coordinated as height and weight change quickly

Start showing uneven development in skills like agility, balance, strength, and flexibility (For example, they may be able to run fast, but not gracefully.)

Need more rest since so much energy is being used for growing

Have a difference between body and brain growth; may be more mature physically than cognitively or emotionally

Get better at fine motor and gross motor movements, like those used in team sports

May try to develop strength and endurance because of increased muscle mass (especially boys)

Problem-solving skills and thinking skills develop a lot at this age. Kids may also start to pay more attention to decision making and to organizing ideas, time, and things.

Start to understand concepts like power and influence

Question things and don't take everything at face value

Think about how current actions affect the future and may worry about things like climate change and war

Memorize information more easily

Use flexible thinking, like checking work and changing approaches as needed

Begin developing a worldview and a basic set of values

Want to contribute and make their own money

In middle school, language skills typically develop much more quickly than they did the past few years. You might notice that your child can better understand what people communicate - with or without words.

In middle school, kids often:

Use metaphors, slang, text speak, and other ways of talking

Are interested in having discussions, debates, and arguments (sometimes just for the sake of it)

Start to "get" and pay more attention to body language, tone of voice, and other nonverbal language cues

Go through "what if" scenarios and talk through other ways of solving problems

Continue to build grammar knowledge and vocabulary

Start to use writing to describe personal experiences

Social and emotional milestones

Middle school is a time of major social and emotional growth. Kids may struggle to fit in even while looking for ways to be an individual. And they may not ask for advice as often as before. It's not uncommon for middle-schoolers to do these things:

Bow to peer pressure to be like others

Have experiences with bullying or cyberbullying

Be sensitive to other people's opinions and reactions, and think the whole world is watching them

Develop a sense of pride in accomplishments and awareness of their challenges

Keep secrets (often just having a secret is more important than the secret they're keeping)

Have a better awareness of what's appropriate to say in conversation

Are introspective and moody, and need more privacy

May test out new clothing styles and try on "personalities" while figuring out where they fit in

Keep in mind that middle-schoolers develop at different rates. But when a child this age isn't meeting a number of these milestones or is struggling, it's a good idea for parents and teachers to talk. Parents and caregivers may also want to talk with their child's health care provider.

Key takeaways

Middle-schoolers often start to question adult authority and opinions.

Kids usually become more aware of what's happening in the world and how that affects them.

Kids develop at different rates, especially at this age. But it's a good idea for parents, caregivers, and teachers to talk about any concerns.

# data[].attributes.attachment_link.description
What skills do middle-schoolers develop? Here are typical social, language, and physical developmental milestones for middle-schoolers (grades 6, 7, and 8).

# data[].attributes.body
Don't worry about the questions, just use the reading.