P1 - Lect 1 - Kinds of Growth Flashcards
What is one of the best indicators of how the people of a country are faring?
size of infants, children, and adults
Humans are neotenous. What does neotenous mean?
retention of fetal or subadult characteristics while achieving sexual maturity.
What are some examples of human features of neoteny?
retention of large brain-to-body ratio, orthognathic facial profile, comparatively hairless, foramen magnum remains under the skull
What is the difference between growth and development?
Growth is change in size. (“we grow”)
Development is change in proportionality and complexity. (“we grow up”)
What is tempo of growth?
how rapidly a child progresses toward maturity
Examples of growth changes in humans.
increase in stature, inc in body wt, inc in dental arch perimeter, inc in the size of the ascending ramus of the mandible
What is an example of negative growth?
separation of digits of hand (Remember, growth is just a change in size, not necessarily always increasing.)
What are examples of developmental changes in humans?
increasingly complex motor skills, dexterity, and character w/ a person’s increasing age, facial width-to-height ratio (round at birth, more oval at adulthood), development of 4 chambered heart
Growth involves dynamic changes in…? (3)
absolute size,
relative size,
position and morphology
The four tissue-specific patterns of growth are? (4)
somatic
lymphoid
reproductive
neural
Growth consists of different kinds of changes, such as changes in..? (4)
kind
number
position
composition
What are changes in kind defined as?
creation of new tissues, structures, or organs where they had not existed previously
What are examples of changes in kind?
change in kind of dentition, onset of secondary sexual characteristics (puberty)
Examples of changes in number?
inc in number of cells in the body,
inc in brain cells,
inc in ossified bones of hand and wrist (19 - birth 46 late childhood, 27 adulthood),
change in cells in lymphoid tissue,
inc in head size (abnormality = hydrocephaly),
L&R frontal bones to fused bone,
L&R hemimandibles to fused mandible
Examples of changes in position?
increasing prominence of mandible and chin (retrognathic to orthognathic);
change in position of diaphragm (C4 descends to T12,
eruption of teeth (formed in basal bone, erupt for occlusion),
ear formation (formed at base of skull at first, then migrate up–Treacher Collins syndrome usu w/ low-set and malformed ears);
formation of tongue (forms betw palatal processes and moves down–failure to do so = cleft palate)
What does micrognathia mean?
small mandible
Symptoms of treacher collins syndrome?
aka mandibulofacial dysostosis;
first pharyngeal arch syndrome
malar hypoplasia (underdevelopment or incomplete development of zygomatic bone)
down-slanting palpebral fissures
lower eyelid deformities
deformed external ear (auricle) –> microtia
When does the bony chin develop in humans?
adolescence
Examples of changes in composition?
cartilage -> bone,
membrane -> bone, (ex. calvarial bones and facial bones are formed thru intramembranous growth)
cranial base is formed through _______ growth.
endochondral (self-initiating, can grow under pressure)
calvarial (skull) bones and facial bones are formed through ___________ growth.
intramembranous (grows under tension, bone resorption under pressure)
occipital bone is formed by what type of growth?
endochondral (at the basal and lateral parts) and intramembranous (at planum occipitale and nuchale [superior portions])
4 categories for rates of growth (change in timing)?
infancy
childhood
adolescence
adulthood
Examples of somatic pattern of growth?
limbs, long bones, facial dimensions (NOT calvarial/skull dimensions)
Somatic growth time table?
0-5 yrs high velocity (infancy) 5-11 constancy of growth 11-16 high velocity (adolescence) 16-35 primarily maintenance 35+ subtle negative velocity
Examples of neural pattern of growth?
-brain and related structures: whole brain cerebellum pons and medulla eyeball pineal gland - head circumference - cervical and thoracic vertebrae
what causes internal hydrocephaly?
overproduction of CSF
obstruction of CSF flow
interference w/ CSF absorption
Examples of reproductive pattern of growth?
onset of secondary sexual characteristics; reproductive organs are a major source of anabolic steroids that modulate growth in adolescence
0-13 yrs - very modest growth
13-20 - high positive velocity
20+ - maintenance
lymphoid pattern of growth?
thymus, peyer’s patches, lymph nodes, lymphoid follicles in appendix, mesenteric lymph nodes, adenoids and tonsils
rapid rise in infancy and early chidhood, then apex near puberty, then decline
0-11 - high positive velocity
12-20 - high negative velocity
20+ - vestigial remnants
What does waldeyer’s ring consist of?
palatine tonsils, adenoids (pharyngeal tonsil), tubal tonsils, and lingual tonsils
adenoid hypertrophy?
aka long face syndrome; occurs when a lot of adenoid tissue blocks facial skeletal growth which may results in a downward slanting chin
