BB1.6: Development Flashcards
Neurulation
- What is it
- When does it occur?
- refers to the folding process in vertebrate embryos, which includes the transformation of the neural plate into the neural tube.
- 3-4 weeks gestational stage…Ectoderm (outermost tissues of embryo) overlying the notochord (rod that supports embryonic body) begins to furrow.
What happens when the ectoderm, during neurulation, begins to furrow
-a neural groove is formed, that is surrounded by two neural folds.
What happens to the neural folds
- The leading edge (outermost) fold becomes the neural crest and the remainder of the furrow (neural fold) closes to form the neural tube, which will becomes the CNS
What does the neural crest form?
-The leading edge of the neural fold form the neural crest, which migrate throughout the body to form different tissues (dorsal root ganglia [cluster of neurons in dorsal part of spine], Melanocytes [pigment produces cells], and caalcitonin producing cells of the thyroid [hormone regulates calcium])
- What does the neural tube form?
- What is the alar plate
- What is a basal plate
- Forms the CNS.
- The neural tube has an alar plate, which differentiates into sensory neurons
- The neural tube has a basal plate, which differentiates into motor neurons
-What happens to the neural tube overtime?
- The neural tube invaginates (be turned inside out or folded back on itself to form a cavity or pouch), itself many times; the embryonic brain begins as three swellings (prosencephalon, mesencephalon, rhombencephalon) which become five swellings (telencephalon, diencephalon, mesencephalon, metencephalon, and myelencephalon), as it becomes the mature brain.
- Where is the fetus attached?
- What attaches the fetus?
- Uterine Wall and Placenta
- Umbilical cord
What is the role of the Placenta?
-To provided food, oxygen, and water to the fetus while also returning water and waste to the mother. Maternal blood supply gives proteins and amino acids need for growth although the embryo will begin to produce them itself.
What external factors can negatively affect the fetus development?
- Viruses and Bacteria
- Pharmaceuticals
- Maternal Malnutrition
- Drugs and Alcohol
- Prenatal X-Rays
-What is a reflex?
-A behavior that occurs in response to a stimuli without higher cognitive input.
Primitive Reflexes (disappear with age)
- Rooting Reflex
- Moro Reflex
- Automatic turning of head in the direction of a stimulus that touches the cheek (nipple for milk)
- Infants react to abrupt movememnts of their heads by flining out their arms, then slowly retracting their arms and crying (prevent falling from tree). Used as a marker of neurological development (when does it disappear?) (Around 4 months is good, A year is too slow and could hint at developmental problems)
Primitive Reflexes (disappear with age)
- The Babinski Reflex
- The Grasping Reflex
- Causes the toes to spread apart automatically when the sole of the foot is stimulated.
- Occurs when the infant closes his or her fingers around an object placed in his or her hand.
Motor Skills
-2 Categories
-Gross Motor Skills and Fine Motor Skills
- What are Gross Motor Skills
- What are Fine Motor Skills
- Incorporate movement from large groups and whole body motion (sitting, crawlng, and walking)
- Involve Smaller muscles of the fingers, toes, and eyes, providing more specific and delicate movements (tracking movements, drawing, catching, and waving).
Social Development
- Infancy (7 months to 1 year)
- 1 year to 2 year
- 2 years
- 3 years
- 5 years
- 6-12years
- TEEN
- Stranger anxiety ( fear of unfamiliar individuals) and Separation anxiety (Fear of being separated from prenatal figure)
- Play style progress from solitary to onlooker (will watch other play and not engage)
- Parallel Play (Play alongside other children but not engage)
- Awareness of gender identity and engages in gender specific play
- Conformity to peers and romantic feelings for others
- Friend circles are same sex without expression of romantic feelings.
- Self-sufficient and have cross-gender relationships
