weeks 7-9 Flashcards
4 steps in a negative feedback loop
a stimulus that produces change, a receptor that detects changes in this parameter, a control/integration centre and an effector whcih enacts a response to maintain homeostasis
what is a somatic sensation
our awareness of our external environment
what is a visceral sensation
the sensation of our internal functions
key neurotransmitters/hormones involved in thermoregulation include:
noradrenaline - released by the sympathetic nervous system evoke a fight flight or fear response, activate a class of receptors called adrenergic receptors, adrenaline - secreted by adrenal gland (sympathetic), and the thyroid hormone - secreted by the thyroid gland, (regulated by hypothalamus) and increases energy expenditure. ALL CAN INCREASE ENERGY EXPENDITURE.
when is our internal body temp lowest during the day
while we sleep
how do we exchange heat with the sun
radiation, evaporation, convection, and conduction
what is a pyrogen
something that induces a fever response
what does a pyrogen stimulate
the production of prostaglandin (PGE2), which alters activity in the hypothalamus, leading to an increased internal temperature set point (so body temp is still homeostatically regulated, just at a higher temp than normally seen)
what do ibuprofen and aspirin do
block the production of prostaglandin and therefore reduce inflammation and pain
what is sepsis
an uncontrolled inflammatory response which leads to excessively high temperatures, which can lead to organ damage/failure
what are cognitive symptoms of schizophrenia
impaired working memory, diminished executive function and difficulty focusing
what are the main steps in the overall development of an embryo
rotational cleavage (to form a blastocyst), gastrulation, and then neurulation
what is a blastocyst
one of the primary stages of embryonic development, an outer cell layer, consisting of pluripotent stem cells (able to form all other cells in the body), and filled with a fluid called blastocoel
what are the 3 main germ layers, and when do they form/differentiate
the differentiate from pluripotent stem cells during gastrulation. They are the ectoderm (forms the skin and nervous system), endoderm (the lining of internal organs) and mesoderm (basically anything else, including muscle, blood, and connective tissue etc.)
what is neurulation
a part of the ectoderm specialised to form the neural plate, which which eventually invaginate to form the neural tube, which gives rise to the nervous system (specifically the spinal chord and brain)
what are the 4 key phases of neuron development
genesis of neurons (neural stem cells give rise to neural progenitors, which differentiate to form specific neural cells), outgrowth of axons and dentrites (axons and dendrites grow towards other neural cells), synapse formation and refinement of synaptic connections.
where are neurons formed in the developing embryo and what do they do afterwoods
they are formed in the ventricular proliferative zone (near the inside of the of the neural tube). They then begin to migrate outwards from the neural tube (via radial glial cells), with the oldest neurons forming the innermost layers of the cortex, they are directed to their target through various methods
when do the number of synapses in the brain begin to slowly decline
around 4 years
what is the limbic system
the emotional or affective region of the brain. Consists of structures deep within the cerebral hemispheres.
what part of the brain is the limbic system derived from
the diencephalon
