|Pre embryonic stage||
Fertilization through 2 to 3 weeks. Germ cel layers are established. Ectoderm, mesoderm, endoderm. Notochord develops, that turns into vertebral column, ribs, sternum, skull.
3-4 weeks through eight weeks. All major organ systems begin. Principal components of the face develop. Humanlike appearance. At seven weeks tastebuds develop. Critical period. Exposure can cause birth defects. drugs infections toxins.
Nine weeks through birth. Genetic and chromosomal factors are what we look at in terms of defects at this age. Vulnerable to injury from the environment such as infections drugs radiation and mechanical compromise. Any change in the fetus can result in malformations of organ systems. Rapid growth and completion of organ differentiation. Head is almost half of the length. Less susceptible to death. Gains substantial weight. Changes are less dramatic then the embryonic state but necessary to prepare it before extrauterine survival.
Tissues:Skin Hair nails lens inner ear teeth enamel pituitary gland. Organ systems: Central nervous system bring spinal cord meninges peripheral nervous system
Tissues: Cartilage, bone, connected tissues, striated/smooth muscles. Organs: Heart, kidneys, gonads, spleen.
Tissues: Digestive/respiratory, eustachian tube, middle your cavity, thyroid/parathyroid. Organs: Liver/ pancreas.
|Fetal Oral Motor Development||
At nine weeks there is mouth and lower face movement. 23 to 24 sucking begins. 24 to 25 rooting reflex begins. 26 to 27 gag reflex. 26 to 29 lungs breathe air with difficulty. 27 to 28 swallow reflex. 28 phasic bite reflex. 32 rooting reflex present. 24 to 26 suck swallow breathing development- can begin oral feeding.
Normal placenta is located in the upper third of the uterus. Placenta previa the placenta is abnormally placed so that it lies over the cervical opening. Abruptio placenta a normally placed placenta becomes partially separated from the uterine wall in the second or third trimester and bleeding results.
Preterm less than 37 weeks. Full term 37 to 42 weeks. Postterm 42 weeks or above.
Macrosomia is more than 4000 grams 8.8 lbs. Normal birth weight 2500-3999 lbs about 7.5 lbs. low birth weight 1500 to less than 2500 g. Very low birth weight less than 1500 g. birth weight is considered one of the most important predictors of an infant's health and survival.
Infant reflexes are general indication of neural maturity and integrity. Neurological impairment present if reflexes persist. Many reflexes assist Infant in feeding. As infant matures reflexes are integrated.
|Neonate 0-1 month||
Moves reflexively. Some Motor reflexes disappear appear. Touch is reflexive bound.
Blink- to flash of light or a puff of air infant blinks- permanent. Babinski- when the side of an infants foot is stroked from the heel to the toes, the toes fan out and the foot twists inward. Disappears around 1 year. Babkin-when an infant is lying on his back and pressure is applied to the palms of both hands it causes the head to turn straight ahead, the mouth to open, and the eyes to close. Disappears around 3 months. Grasping- pressure is applied to the infant's palms and produced by an object like the parent's finger causes the fingers to curl with a strong enough grasp to support the infants own weight. Weakens after 3 months/disappears around5 months.
Moro- The reflex pattern which involves extending the arms and then Bring them rapidly toward the midline While closing the fingers in a grasping action, can be Triggered by several kinds of startling stimuli such as a Sudden loud noise or holding the infant horizontally faced up Then rapidly lowering the baby about 6 inches. Disappears around five months. Rooting- When an infant's cheek is Stroked lightly he turns his head in the direction Of the stroked cheek and opens his mouth to suck the object that stroked the cheek. Disappears around four months. Stepping- when an infant is held above the surface and then lowered until the feet touch the surface, the infant will make stepping movements like walking. Disappears around 3 months. Sucking- when an object such as a nipple or finger is inserted into the infants mouth, rhythmic sucking occurs. Changes into voluntary sucking by 2 months. Tonic neck- an infant placed on his back tends to turn his head to one side and to extend the arm and leg on that side while flexing the limbs on the other side ( like a fencing position). Disappears around 4 months.
The most common cause of severe motor disability in children. CP is characterized by movement and posture disturbance; is non progressive, occurs in developing fetal or infant brain; and is often a companies by coo curing problems with sensation, per elation, cognition, communication, and behavior. Tone or movement abnormalities include spasticity, dystonia, and choreoathetosis (which together are called dyskinesia), and ataxia.
Cephalocaudal: Head to tail
Proximal-distalfrom: The midline outward
Gross to fine: Gross movement to fine movement
|Integrates 3 systems||
Pyramidal system-involuntary system
Basal Ganglia system
|5 identifiable levels||
1. Cortical level
2. Subcortical level of Basal Ganglia
3. Brain Stem Level
4. Cerebellar level
5. Spinal Level
Motor and Sensory area critical to performance of voluntary movements
You see motor planning, motor programming, and motor execution at this level
The motor strip is bilateral
3 Major Processes:
Neuronal proliferation (1-4 months gestation) the development of the brain
Neuronal migration (3-5 months gestation) the movement and the changes of the cells
Neuronal differentiation (6months to 3rd postnatal years) the differentiation of the cells in the brain
Cell proliferation in forebrain increases dramatically through first half of gestation (20 weeks) continues to 3rd year postnatal.
Peak period is from 2nd to 4th mth gestation
Abnormalities of cell proliferation=diminished number of neurons
Can result in microencephaly and macroencephaly
Mass movement of neurons from the venticular zone to layers of cortex
Associated with development of cerebral convolutions
Results in 6 layer cortex in adults
Abnormalities eventually effect feeding and swallowing
From 6th mth gestation to 3 year postnatal
Axon and dendrite growth, synapse formation, and refinement of neurotransmitters
Neuronal circuits help higher cognitive processes, sensory integration, and motor output
Abnormalities result in seizures and MR
Of the brain stem appears 5 mths gestation
5-6 mths gestation: parts of CN III, IV, VIII, IX, XII myelinated
Extrapyramidal system-damaged have difficulties stopping and starting
Indirect motor System
Influences movement related to posture, automatic movements, skilled voluntary movements
Damage reverts to slower, less automatic and less accurate
Collection of cell bodies outside the pyramidal system. Has to do with movement
Functions as center for control of coordinated movements and affects all stages of speech activity
Results in decomposition of movement or jerky, irregular movements if it is damaged
|Final Common Pathway||
Descending motor pathway of the peripheral nervous system and involves the spinal and cranial nerves
Also known as the lower motor neuron
The last route in the nervous system
Conveys neural information about the interactions of the direct and indirect motor systems to the muscles
The 3 subsystems (Pyramidal, Basal ganglia, and Cerebellar) are transmitted by Cranial and Spinal nerves to activate muscles of the body
III Oculomotor- Innervation of muscles to move the eyeball, pupil, and upper lid
IV Trochlear- Innervation of superior oblique muscle of eye
V Trigeminal- Chewing and sensation to the face
VI Abducens- Abducts eye
VII Facial- Movements of facial muscles, taste, salivary glands
VIII Vestibular acoustic- Equilibrium and hearing
IX Glossopharyngeal- Taste, elevation of palate and Larynx, salivary glands
X Vagus- Taste, swallowing, elevation of palate, phonation, parasympathetic outflow to visceral organs
XI Spinal Accessory- Turning of head and shrugging of shoulders
XII Hypoglossal- Movement of tongue
Speech controlled by different neural mechanisms than the ones needed for non speech tasks
Research found different muscle activity for speech and non speech tasks
Muscle activity in children same as adults with less refinements
|Anatomy and Physiology||
Nasal Cavity- wamrs and cleans air before entering lungs, separated from oral cavity by hard/soft palate
Oral Cavity: includes articulators, mandible/maxilla, hard/soft palate, anterior/ posterior faucial arches
Pharynx: 3 parts-Nasopharynx: closed off by soft palate
Oropharynx: tonsillar pillars to posterior pharyngeal wall
Hypopharynx: tip of epiglottis down to cricopharyngeus muscle.
Larynx: 3 functions, protects the airway, aids in respiration, aids in phonation
Trachea: C shaped cartilagnious rings
Esophagus: muscular tube-remains closed until food travels through it
Posterior portion of the trachea is the anterior wall of the esophagus.
|Differences between pediatric and adult anatomy||
The oral space of the newborn is small
the lower jaw of the newborn is small and somewhat retracted
sucking pads are present in infants
the tongue takes more relative space in the newborn due to the diminished size of the lower jaw and the presence of sucking pads in the cheeks
The tongue is restricted in movement partially because of the restricted intra-oral cavity in which it resides
Newborns are obligatory nose breathers. They do not breathe through their mouths
The epiglottis and soft palate are in approximation in the newborn as a protective mechanism
Newborns often breathe and swallow at the same time
The larynx is higher in the neck of the newborn than in the older infant or adult. This eliminates the need for sophisticated laryngeal closure to protect the airway during swallowing
The Eustachian tube in the infant lies in a horizontal position. It assumes a more vertical angel in the adult.
|First year structural changes||
Enlargement of the oral space
growth of the lower jaw and other bony structures of the face
disappearance of the sucking pads
increased muscle tone and more skilled movement in the tongue
lowering of the larynx
separation of the epiglottis and soft palate
development of more sophisticated movement of the larynx during swallowing (ex. elevation)