Bldg blocks of growth (ch 5) Flashcards
Endocrine glands
secrete hormones directly into the blood stream
Pituitary gland
master endocrine gland and triggers the release of hormones from all other endocrine glands
- produces growth hormone
- Regulates growth from birth through adolescence; triggers adolescent growth spurt
Thyroid gland
influences physical growth and development of central nervous system
- produces activating hormones
- Signal other endocrine glands such as ovaries and testes to secrete hormones
Testes
Responsible for development of male reproductive system during prenatal period
- produces testosterone
- directs male sexual development during adolescence
Ovaries
Responsible for regulating menstrual cycle
- Produces estrogen and progesterone
- estrogen directs female sexual development during adolescence
Adrenal glands
Play a supportive role in the development of muscle and bones
- produces adrenal androgens
- contributes to sexual motivation
Common features of a neuron
- Dendrites
- Long axon of neuron
- Synapse: Tiny gap where axon of one neuron makes connection with another neuron
Dendrites:
branchy, bushy dendrites receive signals from other neurons
Long axon of neuron:
transmits signal to other neurons
Synapse:
Tiny gap where axon of one neuron makes connection with another neuron
Critical or sensitive period:
time when development proceeds most rapidly, occurs during late prenatal period and early infancy
Lateralization:
important feature of the developing organization of brain
- AKA asymmetry and specialization of functions
- Functions of two hemispheres diverge
Left hemisphere
controls right side of body
- adept at sequential (step by step) processing needed for analytic reasoning and language processing
- Thinking
Right hemisphere
- controls left side of body
- skilled at simultaneous processing of information needed for understanding spatial information and processing visual-motor information as well as the emotional content of information
- Emotional
The aging brain - some processes
- Decrease in brain weight and volume
- Transmission of signals by atrophied neurons is less effective
- Declines in levels of neurotransmitters
- Formation of senile plaques
- Reduced blood flow to the brain
Plasticity and growth make up for degeneration in the brain until people are in their …
70s and 80s
Principles of Growth - Three principles
- Cephalocaudal
- Proximodistal
- Orthogenic
Cephalocaudal:
growth occurs in a head-to-tail direction
- early motor development follows this principle
- eg can lift heads before they can sit
Proximodistal:
from center outward to the extremities
- activities in trunk mastered before fine gross motor skills
Orthogenic:
Development starts globally and undifferentiated and moves toward increasing differentiation and hierarchical integration
- able to make a global response before a discriminated one
Milestones of brain development (weight changes)
- At birth, brain weighs 25 percent of adult weight
- By age 2, the brain weighs 75 percent of its adult weight
- By age 5, brain weighs 90 percent of its adult weight
Dynamic systems theory explains motor developments
- A “self-ogranizing” process in which children use the sensory feedback they receive when they try difference movements to modify their motor behavior in adaptive ways
- When children learn to walk, learning takes into account their biomechanical properties and characteristics of the environment they must navigate
2 months - gross motor milestone
Lifts head up when lying on stomach
3 mos - gross motor milestone
Rolls over from stomach to back; holds head steady when being carried
4 mos - gross motor milestone
Grasps a cube or other small object
5 mos - gross motor milestone
Sits without support toward end of month
6 mos - gross motor milestone
Stands holding on to something
7 mos - gross motor milestone
Rolls over from back to stomach and may begin to crawl or creep; shows thumb opposition
8 mos - gross motor milestone
Pulls self up to standing position
9 mos - gross motor milestone
Walks holding on to furniture; bangs two objects together
10 mos - gross motor milestone
Plays clapping games (eg pat-a-cake)
11 mos - gross motor milestone
Stands alone
12 mos - gross motor milestone
Walks well alone; drinks from a cup
Leading cause of infant death
congenital malformations, incl
- heart defects
- spinal bifida
- Down syndrome
- cleft palate
Second leading cause of infant death
complications of prematurity
1/3 of infant death
Leading cause of death in children
Accidents
- car crashes
In childhood, cephalocaudal and proximodistal principles prevail - true or false?
True
Obesity rates have ____ over the past 30 years and are especially high among _____
Tripled;
minorities
Adolescent growth spurt triggered by -
increase in level of growth hormones
Increased production in ____ contributes to ____ in adolescents
adrenal androgens;
secondary sex characteristics of pubic/axillary hair
Increased production of _____ is primarily responsible for secondary sex characteristics and sexual maturation
Gonadal hormones
Tanner scale
Used to measure progression thru five stages of sexual maturity
Advantages of early dev for boys
- judged to be socially competent, attractive, and self-assured
Disadvantages of early dev for boys
- increased risk of earlier involvement in substance use and problem bx such as bullying, delinquency
Late maturation for boys has…
more negative side effects -
- more anxious
- less secure
- more behavioral and adjustment problems
- lower achievement test scores
Positive effects of late maturation for boys
- less likely to use alcohol
early dev for girls is usually
more disadvantageous
- subject of ridicule, higher level of bodily dissatisfaction
- earlier engagement in sexual activities
- higher levels of depression
Adv/disadv of late dev for girls
Adv - good school performance
Dis - some anxiety
Early versus late dev – which groups are likely to find adolescence particularly disruptive?
Early-maturing girls
Late maturing boys
Percentage of adolescents in poor physical shape
33% or 1/3
Leading cause of deaths among teens
Unintentional injuries and violence
__ of 4 high schoolers report occasional heavy or binge drinking
1 (of 4)
Signs of aging noticeable by
age 40
Middle-aged spread
extra weight
- associated with slower metabolism and insufficient physical exercise
Healthcare cost of obesity
147 billion
Good predictor of disability and ability to fxn in later life
Handgrip strength in middle age
All older ppl report poor physiological functioning
FALSE
Men w higher levels of testosterone tend to be more:
- sexually active
- aggressive
Avg age for menopause
avg = 51 range = 45-54
In 2002, a large study found that HRT (hormone replacement therapy) was associated with…
increased risk for breast cancer, heart attack, and stroke
Andropause is characterized by
decreasing levels of testosterone and sx’s such as:
- low libido
- fatigue and lack of energy
- erection probs
- memory probs
- loss of pubic hair
Osteoporosis
loss of minerals
results in easily fractured bones
Osteoarthritis
results from gradual deterioration of cartilage that cushions bones from rubbing together
- most common complain among older adults
Results from the nun study
level of education affected longevity and health
- nuns who were physically and mentally active lived longer and were healthier than less active nuns
