Exam 1 Flashcards
Hyperplasia
Making more cells, cells are dividing
General cells
Hypertrophy
Makes cells bigger.
This can be different for different cells depending on time (muscles)
Accresion
Accumulation of stuff between cells. (Matrix)
Maturation
Process of maturing/mature state
Rate of maturation is measured over time. Genetically programmed, naturally occurring
Development
Depends on growth, maturation, etc. Increases the capacity to perform (Not all tissues grow at same rate) Cognitive, social, emotional, motor. Changes that occur over time as the result of maturation
Time frame for embryo, fetus, and infancy
Week 2-8
Week 9- birth
Birth- 2 years (walking and talking)
Scammons curve
Not all tissues in the body grow at the same rate. Lymphoid tall curve. Brain and head reach plateau . General is S curve. Reproductive lower and gets high in puberty
1st week of birth
Oocyte cells enters Fallopian tube and fertilizes with sperm. This matures into a zygote. Creates 2,4,8 cell stages and then create a morula. And then ball hallows into blastocysts. Starts to attach itself to endometrium layer of uterus. Implantation
2nd week of birth
Periods of twos
2nd week: inner cell mass change into two layers of cells. The epiblast and the hypoblast. Then end up with two cavities. The bigger cavity is the yolk sac in contact with hypoblast cells. The other cavity is amniotic cavity in contact with epiblast cells. (This becomes dorsal region). Epiblast are bigger than hypoblast cells.
Teratogens
Anything that might cause maldevelopment.
Teratogen susceptibility
Week 1-2: not susceptible to teratogens.
Week 3-8: heart and CNS develop first. Teratogens cause major congenital anomoties. Starve blood supply to developing limbs.
week 12-38: functional defects & minor congenital anomoties.
Organs that are not developing are not susceptible. As organs become more developed less sensitive to teratogens
3rd week of birth (period of threes)
Gastrulation: 3 layers, ectoderm, mesoderm, endoderm. Susceptible to teratogens. Miss your period and mom knows she’s pregnant.
Develop notochord, primitive streak, neural tube.
Prenatal development
Conception to birth. CNS and heart start to develop. Major congenital anomoties.
Week 3 period of threes.
3 layer embryo. Gastrulation of endoderm, mesoderm, ectoderm. They give rise to everything in us. They form primitive streak, notochord, and neural tube.
Primitive streak
Create mesoblast cells. That create epiblast cells. Streak sends signals to cells. When mesoblast cells destroy hypoblast cells they turn into endoderm cells. And middle cells turn into mesoderm cells. And putter surface turn into ectoderm cells
Mesoblast cells turn into
Muscle, bone,
Endoderm cells develop into what
The linings of our guts
Primitive streak signals gastrulation
Layers of cells start to fold underneath and create three layers of cells. All create neural plate that will become CNS
Ectoderm forms?
Becomes epidermis, skin
Notochord stops at oropharyngeal membrane
Leaves area for cells to get signaled by heart signals.
Notochord signals neural tube to form
Neural tube forms from ectoderm. And folds into tube and eventually punches of from ectoderm and becomes separate. Neural crest is also formed that become spinal ganglia.
Neural tube closes at what age?
Starts 4th week and fully formed in 5th week. Opened on both sides still on 4th week. End of 4th week/ start of 5th week it closes.
Somites
Mesoderm cells on the side of the notochord that clump up and form Somites. Future vertebrae
4th week of birth
Neural tube is formed. Embryo is undergoing folding on the sides to create the gut. (Picture your two arms touching like giving someone a hug) outside layer is ectoderm cells and inside endoderm. When two sides meet they pinch off yolk sac that becomes midgut. Start forming major organs, but functioning does not start. NOTOCHORD IS STILL OPEN AT ENDS
CNS derives from why tissue
Ectoderm
Skeletal muscle comes from which tissue
Mesoderm
Growth
Change in size
Head to tail folding occurs when
4th week. Head and tail start to form. Neural tube is fused but not at the ends. More Somites are also added. Teratogens might effect fusing of notochord to close. (Spinal Bifida)
Week 5
Neural tube has fused close on both ends. Upper limb bud forms first and Lowe limb bud then forms.
Fetal period
Keep developing organs and start getting these organs to function. Get baby to the size where it can survive a harsh environment, Gravity.
Heart starts beating at which week?
Week 3.
Cerebral cortex
Conscious, memory, little voice your hear inside your head, decision making.Thin layer of cells
2 major cells in CNS
Neurons-transmit dance of electrical signals between synapses (developed between inner and outer layer of neural tube.
Glial cells-nonneuronal cells, make synaptic contact with neurons.
Neuron
Has all components of a cell in cell body, dendrites (meant to receive info), has axon( flow of info), atonal terminals. Sodium channels between junction of cell body and axon that allow signal to pass through.
Myelin
Speeds up communication of action potential. Signal can jump from node to nose and speed up signal even further.