Lecture 5 Flashcards
What are the 5 body systems?
- skeletal system
- muscular system
- adipose system
- endocrine system
- nervous system
Body systems are influenced by _____ factors.
extrinsic
Skeletal system for embryo:
cartilage model
Primary ossification:
prenatal
Secondary ossification:
postnatal
____ ossify faster, complete earlier.
girls
Scoliosis ratio:
11:1
Length in postnatal growth:
- secondary centres
- epiphyseal, growth, or pressure epiphyses
Diameter in postnatal growth:
appositional
Traction epiphyses:
A secondary centre of ossification forming at the attachment site of a tendon.
When does growth at the epiphyseal plates stop?
- stops at different times for different bones
- all typically close by age 18-19
- closure occurs at younger age in girls
Bone undergoes ______ throughout the ______.
- remodelling
- life span
In the skeletal system in adults, old bone is _____, new bone is _____.
- absorbed
- formed
In adulthood, bone growth _____, fails to keep pace with _____.
- slows
- reabsorption
As we get old, our bones become more _____.
brittle
Hip dysplasia in newborn:
- congenital
- 1 in 100 affected
- acetabulum underdeveloped Cf. head of femur (blood supply to 2nd ossification)
What are the causes of hip dysplasia in newborn?
- large fetus
- 1st pregnancy
- breech swaddling
- 4:1 (female:male)
How can we tell if a baby has hip dysplasia?
- feel for laxity
- asymmetry of bum creases
How do we fix hip dysplasia in a newborn?
- self resolve (6 weeks)
- after 6 weeks, use harness (maximize contact at ball and socket)
Prenatal growth involves _____ and _____.
- hyperplasia
- hypertrophy
Prenatal growth mainly involves _____.
hypertrophy
Muscle growth follows _____ pattern.
sigmoid
Differences between the sexes become marked in ______ (especially in …)
- adolescence
- upper body musculature
Adult muscle is composed of what muscle fibre type?
- type I
- type IIa
- type IIx
At birth, ______% of fibres are undifferentiated.
15-20%
By age ___, distribution of muscle fibre type is similar to adult distributions.
age 1
Loss of muscle mass is minimal until age ____.
50
By age ____, average ____% of muscle mass is lost.
- 80
- 30%
Muscle loss occurs in _____ and _____ of muscle fibres.
- number
- size
Size of muscle fibres usually decreases after the age ____.
70
Do type II fibres undergo greater loss?
unclear
How to test for sarcopenia?
simple quick muscle strength test is sufficient
Sarcopenia:
- flesh deficiency
- loss of muscle tissue as a result of aging
Some fat is needed for…
- energy storage
- insulation
- protection
Fat increases rapidly until age ____, then gradually until age _____.
- 6 months
- 8 years
In adolescence, _____ increase fat more dramatically than ____ do.
- girls
- boys
Fat growth is by _____ and _____.
- hyperplasia (HP)
- hypertrophy (HT)
Body fat distribution changes with _____.
growth
Children have more ____ than ______ fat.
- internal
- subcutaneous
Subcutaneous fat increases from age ____ years until age _____ in boys and girls.
- age 6-7
- age 12-13
Subcutaneous fat continues to increase after age 13 in ____.
girls
Both men and women tend to _____ fat during adulthood, but this is not _____.
- gain
- inevitable
In adulthood, increases in _____ fat are notable, but _______ fat on ____ tends to decrease.
- trunk
- subcutaneous
- limbs
GH is secreted by:
anterior pituitary
GH is necessary for:
normal growth
Deficiency of GH can result it:
growth abnormality
Thyroid hormones are secreted by:
thyroid gland
Thyroid hormones influence:
whole-body growth
One of the THs play a role in:
skeletal growth
Gonadal hormones have influence on:
- growth
- sexual maturation (sex organs)
- secondary sex characteristics
2 types of gonadal hormones:
- androgens
- estrogen
Androgens secreted by:
- testes (boys)
- adrenal glands (boys, girls)
What do androgens do?
- hasten epiphyseal growth plate closure
- promote growth of muscle mass
Estrogen secreted by:
- ovaries (girls)
- adrenal cortex (girls, boys)
What does estrogen do?
- hastens epiphyseal growth plate closure
- promotes accumulation of fat
Too much cortisol puts you at risk for:
cushing’s syndrome
Not enough cortisol puts you at risk for
addison’s disease
In the nervous system, ____ direct its development.
geners
In the nervous system, _____ factors exert influence, especially in the formation of _____ _____.
- extrinsic
- synaptic connections
Prenatal neural development generally includes:
- neuron formation
- differentiation into general type
- migration
Prenatal neural development: once in place, neurons develop an _____ to carry signals to ____, _____, _____, _____
- axon
- neurons
- glands
- organs
- muscles
______ might disturb normal migration and branching.
teratogens
Late in the prenatal period, neurons start to fire _____ _____.
- electrical impulses
- first at random, then forming circuits
In early neural development, experience might play role in _____ _____.
- synaptic proliferation
- strengthening some connections, weakening others
In early neural development, _____ ____ becomes more efficient with experience.
neural network
What did Sur do?
make retinal ganglion cells grow to auditory cortex instead of visual cortex
Cortical arealization:
nerve cells in the auditory cortex behave like those found in the visual cortex
Brain growth increases rapidly after _____.
birth
Postnatal neurological growth involves these factors:
- increase in size of neurons
- prolific branching to form synapses
- increases in glial cell for support and nourishment of neurons
- increases in myelin to insulate axons
Stimulation of learning increases …
number of synaptic connections
Development is normally ______ but in this case ____ ____ first (opposite).
- cephalocaudal
- spinal cord
Myelination of axons allows:
faster conduction of neural impulses
From 15-45 we have ______ while from 45-75 we have _____.
- development (myelination)
- degeneration (demyelination)
Nervous system: aging involves loss of:
- neurons
- dendrites
- synapses
- neurotransmitters
- myelin
One theory of aging suggests that ____ in neural network links cause ____ and therefore _____.
- breaks
- detours
- slowing
Exercise promotes improved ____ function in nervous system in older adults.
cognitive
4 different cognitive tasks:
- executive
- controlled
- spatial
- speed
Systems _____ as they develop and age.
interact
During periods of rapid change, a system might be more sensitive to ____ ____.
extrinsic factors
Extrinsic factors play a _____ role (genetic factors _____ role) as one moves through life.
- greater
- lesser
Model of constraints shows that a system can act as a ___ _____ (during growth) or as a ______ (of aging).
- rate limiter
- accelerator
