NAS2 CHALLENGE LATEST 2026 COMPREHENSIVE EXAM
QUESTIONS AND ANSWERS GRADED A+
✔✔receptor - ✔✔senses environmental stimulus and sends info to control center
✔✔control center - ✔✔hypothalamus
signals effector
✔✔effector - ✔✔responds to stimuli
example: muscle contracting
✔✔negative feedback mechanisms - ✔✔net effect is that the original output of the
system shuts off the original stimulus or reduces the intensity
homeostasis
✔✔negative feedback mechanisms - ✔✔most common form of homeostasis, bringing
people back to normal functioning
✔✔negative feedback mechanisms - ✔✔example of homeostasis: adjustments of blood
pressure, metabolism, body temp
✔✔positive feedback mechanisms - ✔✔form of homeostasis
level of variable changes in same direction as initial change
enhances or accelerates output created by activated stimulus
✔✔positive feedback mechanisms - ✔✔example of type of homeostasis: platelet
aggregation or accumulation in response to injury, child birth
✔✔anatomical position - ✔✔erect position, face forward, arms at side, palms face
forward
used to describe relation to other things
✔✔coronal, sagittal, transverse - ✔✔3 major planes of dissection
✔✔cranial - ✔✔brain body region
✔✔spinal/vertebral - ✔✔spinal cord body region
✔✔thoracic cavity - ✔✔lungs, heart, esophagus, trachea, thymus
✔✔abdominal cavity - ✔✔stomach, liver, spleen, gallbladder, small/large intestines,
kidneys
, ✔✔pleural cavity - ✔✔contains lungs
✔✔pelvic cavity - ✔✔end of large intestines, urinary bladder, reproductive organs
✔✔mediastinum - ✔✔seperates lungs
✔✔pericardial - ✔✔contains heart
✔✔axial - ✔✔head, neck, and trunk of body
✔✔appendicular - ✔✔limbs
✔✔electron - ✔✔negatively charged particle, outer shell
✔✔proton - ✔✔positive, in nucleus
✔✔number of protons - ✔✔number of electrons is equal to the same...
✔✔number of protons - ✔✔atomic number is equal to...
✔✔atomic mass - ✔✔sum of protons and neutrons in the nucleus
the weighted average mass of isotopes of an element, found below the element symbol
✔✔ionic bond - ✔✔chemical bond formed between two ions that are opposite charges,
atom gives up one or more electrons to another atom
✔✔covalent bond - ✔✔sharing electron pairs between atoms
✔✔polar covalent bond - ✔✔pair of electrons unequally shared between two atoms
✔✔nonpolar covalent bond - ✔✔two atoms share a pair of electrons with each other
✔✔hydrogen bond - ✔✔weak bond result of attraction between proton and
electronegative atom of another
✔✔enzymes - ✔✔catalyze chemical reactions by lowering activation energy barriers
and converting substrate molecules to products
✔✔substrate - ✔✔reactant acted upon by an enzyme
enzymes active site binds to this
QUESTIONS AND ANSWERS GRADED A+
✔✔receptor - ✔✔senses environmental stimulus and sends info to control center
✔✔control center - ✔✔hypothalamus
signals effector
✔✔effector - ✔✔responds to stimuli
example: muscle contracting
✔✔negative feedback mechanisms - ✔✔net effect is that the original output of the
system shuts off the original stimulus or reduces the intensity
homeostasis
✔✔negative feedback mechanisms - ✔✔most common form of homeostasis, bringing
people back to normal functioning
✔✔negative feedback mechanisms - ✔✔example of homeostasis: adjustments of blood
pressure, metabolism, body temp
✔✔positive feedback mechanisms - ✔✔form of homeostasis
level of variable changes in same direction as initial change
enhances or accelerates output created by activated stimulus
✔✔positive feedback mechanisms - ✔✔example of type of homeostasis: platelet
aggregation or accumulation in response to injury, child birth
✔✔anatomical position - ✔✔erect position, face forward, arms at side, palms face
forward
used to describe relation to other things
✔✔coronal, sagittal, transverse - ✔✔3 major planes of dissection
✔✔cranial - ✔✔brain body region
✔✔spinal/vertebral - ✔✔spinal cord body region
✔✔thoracic cavity - ✔✔lungs, heart, esophagus, trachea, thymus
✔✔abdominal cavity - ✔✔stomach, liver, spleen, gallbladder, small/large intestines,
kidneys
, ✔✔pleural cavity - ✔✔contains lungs
✔✔pelvic cavity - ✔✔end of large intestines, urinary bladder, reproductive organs
✔✔mediastinum - ✔✔seperates lungs
✔✔pericardial - ✔✔contains heart
✔✔axial - ✔✔head, neck, and trunk of body
✔✔appendicular - ✔✔limbs
✔✔electron - ✔✔negatively charged particle, outer shell
✔✔proton - ✔✔positive, in nucleus
✔✔number of protons - ✔✔number of electrons is equal to the same...
✔✔number of protons - ✔✔atomic number is equal to...
✔✔atomic mass - ✔✔sum of protons and neutrons in the nucleus
the weighted average mass of isotopes of an element, found below the element symbol
✔✔ionic bond - ✔✔chemical bond formed between two ions that are opposite charges,
atom gives up one or more electrons to another atom
✔✔covalent bond - ✔✔sharing electron pairs between atoms
✔✔polar covalent bond - ✔✔pair of electrons unequally shared between two atoms
✔✔nonpolar covalent bond - ✔✔two atoms share a pair of electrons with each other
✔✔hydrogen bond - ✔✔weak bond result of attraction between proton and
electronegative atom of another
✔✔enzymes - ✔✔catalyze chemical reactions by lowering activation energy barriers
and converting substrate molecules to products
✔✔substrate - ✔✔reactant acted upon by an enzyme
enzymes active site binds to this
