folding increases surface area, more surface area means more neuronsWhy is brain folding directly correlated with the capability of complex interactions?atoms < molecules < organelles < cells < tissues < organs < organ systems < organismList the hierarchy of complexity from atoms to organisms.- muscles (some people have genetic mutations that give them one extra or less muscle)
- number of vertebrae (some people have fusion surgeries to merge them together)
- number of organs
- left/right reversal of organization (situs inversus)What are some examples of anatomical variation?- genetics
- environmentWhat two factors affect variation?- dosage (variation for different individuals)
- not al procedures and histology slides will be identical (need trained professionals who understand the science behind variation)Why is considering anatomical variation important for the medical field?HomeostasisMaintaining stability in a dynamic environmentHippocrates_____________ noticed the body's ability to self-restorerange (ex. 7.35-7.45 blood pH)Internal conditions are not always a specific value, instead they are a __________ of values.vitalHaving a correct pH is _________ to survival.98.5 - 98.6 degreesWhat is the average internal body temperature?- help keep variable close to set point
- body senses changes
- body reverses effects of changesWhy are negative feedback mechanisms important to maintain homeostasis?Nerve____________ cells in the brain monitor blood temperature.- If too hot → vasodilation (widening of blood vessels)
- Still too hot → sweating mechanism
- If too cold → vasoconstriction
- Still too cold → shivering (muscle activity to generate heat)Explain the negative feedback mechanisms in maintaining body heat.- receptor detects the change
- the integration center is where a decision is being made (in medulla)
- effector is the structure that does the work that's responding to the change (doing the job to restore homeostasis)In feedback mechanisms, what are the roles of:
- receptor
- integration center
- effectorPositive Feedback MechanismFeedback mechanism that amplifies change in the same direction?Fevers can be harmful if the temperature is too far away from the set pointWhat is an example of a harmful positive feedback mechanism?- During childbirth the uterus is contracting
- Those contractions are pushing the fetus downwards into the cervix, causing dilation
- Tissue in the cervix detecting the stretching happening and sends the information to the brain
- Brain releases oxytocin
- Oxytocin stimulates more contractionsExplain positive feedback in childbirth:- Chemical Concentration
- Electrical Charge
- Pressure
- TemperatureGradients and flow represent differences in:down (move from high to low pressure/temperature)Movements occur _________ a gradient
