Kin 477 Exam 2

A loss of 1% of bone mass occurs each year, starting as early as the mid-_____________. a. 20's b. 40's c. 50's d. 30's

a. 20's

Muscle mass increases until age 13 in girls and accounts for _____% of their body weight. Select one: a. 45 b. 35 c. 30 d. 54

a. 45

The increase in girth in the long bones is called ____________ growth. Select one: a. appositional b. primary c. hypertrophy d. secondary

a. appositional

What proportion of muscle fibers are undifferentiated at birth? Select one: a. 15% b. 30% c. 25% d. 20%

a. 15%

During childhood, subcutaneous fat increases faster than visceral fat Select one: True False

False

Hyperplasia is an increase in the relative size of an individual cell Select one: True False

False

In infancy, childhood, and adolescence, muscle growth is by both hyperplasia and hypertrophy. Select one: True False

False

In the prenatal period, neurons proliferate at a rate of 100,000 per minute. Select one: True False

False

Development of the Adipose System

Early Development we don't see a lot of adipose tissue until about the 8 month premature babies aren't really born with mush adipose tissue Rapid increase during the first 6 postnatal months. Gradual increase until age 8 in both boys and girls. increase in number of fat tissue (hyperplasia) hypertrophy doesn't happen until adolescnce Adolescence hyperplasia happens here to In boys, adipose tissue increases gradually through adolescence. Girls experience a more dramatic increase. • they typically have 30 LBS of fat weight • men have 22 LBA Men 22 lbs. of fat weight and women 30 lbs. men have he weight above the waist women below the waist Subcutaneous vs. Visceral Fat Gender differences in fat distribution body composition: insulation how young can kids really benefit from certain types of exercise programs there was a program where some children had a physical program and they found that they had a less subcutaneous levels of fat than those who weren't part of this program

About one-third of adolescents begin their growth spurt within a year of average for her gender. Select one: True False

False

Older Adulthood

Muscle Mass Additional 30% of mass is lost by age 80 By very old age, 50% of muscle mass can be lost Muscle Fibers 35% loss in number of fibers Size decreases in the 70's slow twitch size are maintined more than the fast twich fibers they are better at endurance activity rather than fast because fast twitch muscles are slower Muscle Strength By age 65, 45% of strength is lost Mass vs. Strength Loss of strength is greater than that of muscle mass Resistance Training Moderate and high intensity training improved strength in men over 65. Need to be sufficient length to see hypertrophy. can see muscle hypertrophy still happen left 80% of rev max 4 times a week the rate that we loose this depends on our body weight, strength and the activities that we do

When does ossification of the skeleton begin? Select one: a. Prenatal b. postnatal

Prenatal

look at chart of sigmoid curve

Rapid deceleration at beginning then plateau then rapid acceleration: the initiation of growth spurt or age uptake • for a girl it was 9 years (2 yrs biological more mature than boys) (11.5 to 12) • boys at 11 (13.5 to 14) at 16 and 18 we see the slight change in height really big peak around 5 years of age but a child is not going to through puberty at 5 years of age but it is not uncommon to see a little peak right before our age of take off but not as intense as in puberty • age of take off 10.5 • 13.5 peak velocity • early mature • short as an adult

In infancy, childhood, and adolescence, adipose tissue growth is by both hyperplasia and hypertrophy. Select one: True False

True

A newborn infant's brain is 25% the size of an adult brain. Select one: True False

True

Active older adults gain less fat than their sedentary peers. Select one: True False

True

Body fat redistributes with aging, and both men and women typically have an increase in internal fat as they move through middle adulthood and into older adulthood. Select one: True False

True

On average, boys mature two years later than girls Select one: True False

True

Using the velocity curve you created for the male, at what age did he experience his age at take off? Select one: a. 10.5 years b. 12.5 years c. 7.5 years d. 4.5 years

a. 10.5 years

Using the velocity curve you created for the female, at what age did she experience her age at take off? Select one: a. 10.5 years b. 8.5 years c. 4.5 years d. 13.5 years

a. 10.5 years

_______________ refers to the area(s) in in the midportion of the shafts of long bones where bone cells are formed so that the cartilage-model bones of the fetal skeleton begin ossifying, from the center outward, to form bone shafts. a. primary ossification b. appositional growth c. secondary ossification

a. primary ossification

Between the ages of 20 and 50, the average woman gains how many pounds of fat? Select one: a. 31 b. 26 c. 36 d. 18

b. 26

By age 4, the brain in _____% of its adult weight. Select one: a. 70 b. 80 c. 60 d. 90

b. 80

Differentiation is Select one: a. direction of growth proceeding from the body toward the extremities b. the process wherein cells become specialized, forming specific tissues and organs c. increase in the relative size of an individual cell d. direction of growth proceeding from the body toward the extremities e. increase in the absolute number of cells

b. the process wherein cells become specialized, forming specific tissues and organs

How much muscle mass is lost by age 50? Select one: a. 20% b. 15% c. 10% d. 5%

c. 10%

On average, at what age do females experience their peak height velocity? Select one: a. 9.5-10 years b. 10.5-11 years c. 11.5-12 years d. 13.5-14 years

c. 11.5-12 years

On average, boys experience their peak height velocity at what age? Select one: a. 12.5-13 years b. 10.5-11 years c. 13.5-14 years d. 11.5-12 years

c. 13.5-14 years

Between the ages of 20 and 50, the average man gains how many pounds of fat? Select one: a. 15 b. 26 c. 18 d. 22

c. 18

The fetal stage occurs in which of the following time periods? Select one: a. birth to 8 weeks old b. conception until birth c. 8 weeks to birth d. conception to 8 weeks

c. 8 weeks to birth

Regarding embryonic development, the 40-week time point is associated with the appearance of which of the following in the fetus? Select one: a. motor activity, scalp hair, trunk size gaining on head size b. formation of head and tail folds c. pink and smooth skin and at least moderate head hair d. increasing development of fat tissue e. beginning of respiratory-like movements

c. pink and smooth skin and at least moderate head hair

Using the velocity curve you created for the male, at what age did he experience his peak height velocity? Select one: a. 5.5 years b. 8.5 years c. 12.5 years d. 10.5 years

c.12.5

Using the velocity curve you created for the female, at what age did she experience her PHV? Select one: a. 5.5 years b. 9.5 years c. 8.5 years d. 11.5 years

d. 11.5 years

What percentage of muscle fibers are lost prior to age 50? Select one: a. 7 b. 10 c. 2 d. 5

d. 5

On average, girls experience their age at take of at what age? a. 10 years b. 8 years c. 11 years d. 9 years

d. 9 years

A teratogen is any drug or chemical agent that causes ____________ development in a fetus upon exposure. Select one: a. normal b. rapid c. stunted d. abnormal

d. abnormal

Extrinsic factors are those influences that have only a negative effect on growth and development. Select one: True False

false

Genetic abnormalities are always inherited. Select one: True False

false

Large viruses cross the placenta barrier Select one: True False

false

• Newborn

neuron are now connected to one another, forming the brian circuit

Skeletal Maturation: • the most accurate way and the hardest one to do • go to the doctor and get an x-ray of your wrist and comparing it to the average • looking at the ossification o cartilage has harden o once bones fuse the bone doesn't grow anymore o they are assigning it a skeletal age o so if you are a 5 year old and your skeleton looks like an 8 year old then you are an early mature

o

• Development of the Nervous System

o 6-7 prenatal month of development • Genes - direct (drive) neural development • Extrinsic factors - influence, especially formation of synaptic connections • Two processes: Synaptogenesis - an increase in neural connections Myelination of axons • allows faster conduction of neural impulses • direction of myelination tends to follow direction of conduction. • need to avoid teratogens to avoid affecting the child

o Postnatal Development

o At birth brain is 25% of adult weight, 80% by age 4. o In 1st year of life, each neuron can establish 1,000 to 100,000 connections. o Huge potential in terms of plasticity o Rapid growth of the early postnatal period makes neurological development very susceptible to extrinsic factors. o Which brain structures are most developed at birth • early on in life the brain as a potential for plasticity • the synaptic connectiosnt hat are getting made are form extrensic influences, their experiences • our lower brain centers are the most developed at birth o our reflexes o our higher brain centers gets developed as we age

• Adulthood

o Bone formation begins to slow, 1% loss of bone mass per year starting in mod 20's. • WE ARE STARTING AT AGE 20 IN OUR CLASS • when we are in childhood and adolescent we are growing new bone faster than we are damaging but when become in our mid 20 we start to loose bone since we aren't growing bones as fast as when we were younger

• Postnatal Development

o Bone growth in length occurs at secondary ossification centers o (epiphyseal plates) at the end of the bone shaft. • end of long bones, the blue teal on the pic • o Fusion of epiphyseal plates of • long bones cause bone length • once the bones fuse the bone will no longer grow in length o to be fixed. o Appositional Bone Growth: o Increase in bone girth • the thickness of bone grows o Early matures and females, ossification starts early, and stop growing at an earlier age

• Resistance Training

o Children as young as 6 or 7 can increase strength, but hypertrophy will not accompany this strength gain. • some one were to get an injury in the growth plate their growth will be stunted so it has to be highly monitored • really low resistance, very light weight, slow progression

• Adulthood and Older Adulthood

o Connections among the neurons are constantly changing • we reroute the response signal o Neurogenesis: The division and propagation of neurons o Slowing of responses • A neural network model o As age advances, more links in the network break, causing the responses time to take longer and longer. o choice reaction time, where there are various stimulus and you have to choose which one to react to, its harder for adults to do, it takes them longer.

• Older Adulthood

o Continued bone loss o Bones are more brittle and subject to micro-fractures o Extent of bone loss is contributed to extrinsic factors • 3 extrinsic factors for bone loss: hormonal level: • post menopausal women have less estrogen diet: • calcium, women who are in menopausal years take a calcium supplement • Vitamin D Exercise: • mechanical forces to strengthen our bone density o bone thickness • o Osteoporosis: Bone mineral density significantly below the average • female is a smaller body mass she will be a greater risk of developing osteoporosis

• Increase in Mass vs. Strength

o Functional muscle strength increases at a faster rate than we would expect based on muscle mass (neurological factors) • ex: vertical jumping and sprinting • early on in life we are not going to see much muscle development • we don't have those hormonal influences to build muscle size when young • the nervous system does determine the amount of strength that we get in early child hood • like vertical jump, hopping, running • strength in lower extremities • not building muscle like hypertrophy, just nervous system development

Development of the Muscular System • Childhood

o Muscle Mass • At birth, muscle mass will account for 23-25% of weight. • Growth will be predominately through hypertrophy • Muscles will grow as the skeleton grows, occurs through the addition and lengthening of sarcomeres. • Gender differences are minimal, muscle mass will be a slightly greater proportion of body weight in males . o Muscle Fiber Type • 15% are undifferentiated at birth • experience that a child gets in the first year in life will ebe the 15 % • By 1 year, proportions are similar to that in adulthood. • o Muscle Strength • Boys and girls will have similar strength levels until they are 13 years old.

• Impact of Exercise: Maintains level of blood flow to the brain.

o Stimulates neurogenesis o Promotes synaptic connections

So how do neurons make connections?

o Windows of Opportunity - times when certain parts of the brain can learn new information more easily than at other times. • this window is right open • the older we get the window starts to shut • they have higher plasticity at and earlier age • the window never shuts because we can learn at any age but its harder to learn o For example: • sight: prenatal to 3-4 months (shapes, colors, different brightness)) • vision: prenatal to age 2 years (visual activity, baby can only se about 11 inches but they need to ability to see or an accurate sharpness to their vision) • language: prenatal to 5 years (start getting wired for language during prenatal development, like moms have headphones on their belly, they also get wired to the voices as well) they need to attain a certain amount of words by 5 years of age doesn't mean they cant learn but past that age it gets harder • gross motor skill: birth to 5 years the farther we get away from 5 yrs the harder it is to attain proficiency so need to have these synaptic connections as much as possible • fine motor skills: birth to 9 years • these synaptic connections can change through out life • the more you use them the stronger they are the less you use them the weaker the connections are

• Influenced by genetic and extrinsic factors

o conception to 8 weeks: embryonic development o 8 weeks till they are born: fetal development, they take human shape

• Universality vs. Variability

o in chart you see universal development: appearance, internal development and the age. o prenatal development is very precise, all universal o the things that give variability will be some ones length and weight, when we are born we are all born different sizes.

• Name 3 anthropometric measures

o limb length o circumferences of limbs o Height o bones

• What kind of constraint does physical growth represent?

o structural constraint: physical constrain o based on a persons unique structural constraints you make the environment more suitable for them and how you can body those things to met those things o this is an individual constraint

• Example: Prenatal Growth (Table 4.1)

o talks about landmarks on embryonic and fetal growth o length and weight averages o internal development and what organ systems are developing in that point o our genes are making it predictable of development

Prenatal Extrinsic Influence: Fetal Alcohol Syndrome

re different than genetic because they are avoidable • example would be fetal alcohol syndrome • the mom can avoid this from happening • anything that crosses the placenta and causes abnormal development in the fetus is what we would call a teratogen o the mom and the baby's bloodstream doesn't mingle but what ever goes into the moms blood stream can diffuse into baby's because they are so close to each other. • any condition that the baby is born with its called a congenital defect, they can also be found later in life ( they had it at birth but didn't get diagnosed later in life they found a whole in a heart). • look at chart on pg. 59 • pollution can be another exrensic factor • also having too much pressure in the abdominal area • also have a lot of babies like twins, triplets. o a lot of time twins are born early o there isn't that much room in there its too crowded or too much pressure. o premature babies, you add all that time to the motor milestones, you develop later but catch up at three years.

Muscle mass growth follows a sigmoid pattern. Select one: True False

true

Proximal distal growth is the direction of growth proceeding from the body toward the extremities Select one: True False

true

The abnormalities present at birth are called congenital defects Select one: True False

true

The neural network model of aging holds that links in the network of neurons break at random, thus slowing the responses made by older adults. Select one: True False

true

This male matured slightly early compared to the average male. Refer to your velocity curve to answer this question. Select one: True False

true

Physiological Maturation

we can tell some ones maturation form their size or age or both o not a process that we can see • it is difficult to infer maturity form age alone, size alone, or age, and size together

Adulthood

we start gaining fat weight in our 20's The average woman gains 26 lbs. of fat between the ages of 20 and 50, and the average man 18 lbs. fat gets redistributed like subcutaneous fat from the arms moves to the abdominal that's why high levels is dangerous its inevitable that we gain fat Why does total body weight decline after age 50? Body Fat redistribution with aging? Why is this significant?

Skeletal development:

• Early Development of the skeletal system o we start as a cartilage model o 8 weeks fetal development • when we start to look human we start to turn cartilage into bone o 400 ossification centers by birth (primary), o and another 400 after birth. • Primary ossification comes first starts at two months of prenatal development a lot of our bones are ossified but after birth we still have another 400 is ossified • when born the soft spot on head • knee cap, very soft and not ossified • bones on their wrists o Primary Ossification Centers: Areas in the • mid-portion of the shafts of long bones • where bone cells are formed so that the • cartilage-model bones of the fetal skeleton • begin ossifying, from the center outward, to • Form bone shafts.

Weight

• Follows the sigmoid pattern. • Weight is susceptible to extrinsic factors, especially diet and exercise. • Peak weight velocity (PWV) follows PHV by 2.5 to 5 months in boys and 3.5 to 10.5 months in girls (individuals grow up and then fill out).

Adulthood and aging

• Heigt: o decreases in olderadults • complresion of connective tissue between vertebrae ub the spinal column • Weight: o average adult gains weight starting in their 20's • we increase in fat weight and decreasing in muscle mass • so number on the scale declines • it's a generalization

Middle Adulthood

• Muscle Mass o 10% skeletal muscle mass is lost between 20-50 years • Muscle Fibers o 5% loss in # of fibers before age 50 o Fiber size is maintained through age 50 • Muscle Strength o Strength is maintained through the 20's and 30's. o During the 50's, 18-20% of our strength is lost • Mass vs. Strength o Loss of strength is greater than that of muscle mass • Resistance Training o Can maintain or increase strength, which can also increase muscle mass.

Adolescence

• Muscle Mass o Muscle mass increases rapidly in boys until age 17 and accounts for 54% of their body weight. o Muscle mass increases in girls until age 13 and accounts for 45% of their body weight. • Muscle Strength o Boys have a spurt of increased strength at 13 years • hypertrophy in regards to strength training o Girls have a steady increase in adolescence and reach a plateau o Why men are stronger than women o women has 60-80% than a man does o the thing that contributes to the difference would be muscle mass o boys are encouraged to do more and to give more effort o Boys are given very active toys like balls, bats while girls are given dolls • Increase in Mass vs. Strength o Mass and strength will accompany one another • Resistance Training o Hypertrophy will accompany regular strength training

Overall Body Growth:

• Sigmoid (or S-shaped) Pattern o 4 stages of growth o first period of life we double in height o 2nd phase is steady growth o 3rd adolescent, rapid growth again o 4th stage, we dint really grow past 20yrs, we plateau • timing of spurts and steady periods can vary among individuals • timing differs between sexes:

• Neural Connections

• What we expect prenatally: immature neurons; proliferation rate = 250,000/min -- number achieved at birth after pruning ~100 billion; migration followed by axon growth; myelination begins around 16 weeks (fetal); synapses begin to make connections

Primary teeth eruption:

• baby teeth: come in to 3 years • permanent teeth: 6 years to 20 years

How do we assess ( measure and e4valute) physiological maturation?

• the tissue in our body that is advancing • people that are more mature are stronger and more coordinated o Name the 3 methods to asses maturation: • dental maturation • secondary sexual characteristics • skeletal maturation

Prenatal Genetic Influence: Down Syndrome

• we can't avoid when something goes wrong genetically • when one parent passes it down its dominant and when both parents pass it down its recessive • some of the genetic disorder or passed down or random • random mutations can happen at conception, like down syndrome • down syndrome is a result of a random mutation • genetic disorder if severe enough the mom will miscarry o one of those is a mishap in chromosome 18 a lot of times it results in miscarriage o as the mother is older they have a higher chance of having a child with genetic mutations o some one can have a baby with down syndrome at any age but its more common in older mothers

growth with babies

• when they are born baby's head takes ¼ of body size • as adults its 1/8 of our head • that's why our limbs have to grow to give us adult features • baby's have relatively short legs • we get most of our adult height from an increase of trunk length • legs are going to grow from infancy to early adolescence • trunk late adolescence until we are done growing • early matures are going to have shorter legs and longer trunks • late mature's will have log legs and shorter trunks