Midterm 1 Flashcards
homeostasis is the ability of the body to
quickly restore changed conditions to normal
when an individuals physiology changes as a result of chronic exposure to an environment
acclimatization
oxytocin is a hormone that is released in response to cervical dilation. It in turn causes more uterine contractions that will further dilate the cervix. Which type of feedback loop does oxytocin trigger?
positive feedback
the largest carbohydrate molecules are called polysaccharides because they are composed of ___ molecules bonded with one another
simple sugar
the chemical bonding behavior of an atom is directly determined by the
number and arrangement of electrons
antioxidants are good for you because they help prevent the formation of
free radicals
a molecule referred to as highly soluble is
very likely to dissolve in water
a free radical is a
molecule with an impaired/missing electron
human experiments can be difficult to interpret because of
variability, psychological factors, many forms human studies can take, ethical consideration (all of the above)
systems in the body that prevent large changes in pH is known as
buffering
silicon has an atomic number of 14; therefore, it has ___ electrons in its outermost electron shell
4
as water freezes
it’s molecules move further apart
why is water considered a polar molecule
it’s electrons are closer to oxygen because of oxygens high electronegativity
in regard to lipids, which is most likely for the term “unsaturated” is to refer to
the presence of double bonds between adjacent carbon atoms in a fatty acid
proteins are made up of these molecules
amino acids
the reaction rates of many chemical reactions that occur in the body are controlled by special protein molecules called
enzymes
lipids are hydrophobic and do not usually dissolve in water. because blood is water based, the lipid cholesterol is combined with ___ so that it can be transported by blood
hydrophilic molecules
starch is a polysaccharide and used as energy storage by plants. ___ is also a polysaccharide and used for energy storage, but in animals
glycogen
the most important energy-transferring compound in cells is a nucleotide known as
adenosine triphosphate (ATP)
a nucleotide consists of a
5 carbon sugar, a nitrogenous base, and a phosphate group
when it comes to proteins, why is the flu so dangerous?
if your body overheats too much, proteins cannot function causing body heat to continuously rise
the brain and spinal cord together compose the
central nervous system
isotopes of the same element differ by having different numbers of
neutrons
the term polar is used to describe molecules because
there are at least two distinct ends of the molecule regarding electron position and the resulting charge
which body fluid compartment contains high levels of K+, large anions and proteins
intercellular fluid only
which of the following statements about the Na+/K+ pump is false
it transports Na+ and K+ in a 1:1 ratio
the resting membrane potential in a typical nerve cell is approximately
-70mV
which of the following is NOT involved in creating the testing potential of a neuron
resting membrane permeability for sodium ions greater than potassium ions
gated channels for sodium ions may include
mechanical gates which respond to pressure, chemical gated which respond to ligands, voltage gated which respond to electrical signals (all answers are correct)
going to -50 mV from resting potential
depolarization
going to -90 mV from resting potential
hyperpolarization
going to +30 mV from resting potential
depolarization
going to -70 mV from -90 mV
repolarization
any change in the membrane potential value other than 0 mV regardless of the relationship to resting potential
electrical polarization
membrane protein pores that are essentially always open are called
leaky channels
autonomic motor neurons are subdivided into the
sympathetic and parasympathetic divisions
why are hydrochloride acid, potassium chloride, and salt considered strong electrolytes
They have high electronegativity and dissolve easily in water
how does the hypothalamus connect/communicate with the anterior pituitary gland
it’s connected through the hypophyseal portal system where releasing hormones go from the hypothalamus to the anterior pituitary got hormone to actually be sent
a type of cellular communication in which a cells secretions bind to receptors on neighboring cells is called
paracrine communication
each of the following hormones is an amino acid derivative EXCEPT one, identify the exception
thyroid stimulating hormone
T/F, steroid hormones are lipophobic molecules that interact with receptors on the cell surface
False
site of vasopressin synthesis
hypothalamus
when adenyl cyclase is activated
cAMP is formed
This enzyme breaks down cAMP
Phosphodiesterase (PDE)
Which of the following are not functions of thyroid hormones
body temp regulation, production of proteins, regulation of calcium levels, impact sympathetic nervous system sensitivity (all of the above are thyroid hormone functions)
thryrotropin (TSH); anterior pituitary
stimulation of thyroid hormone production
prolactin; anterior pituitary
milk production
corticotropin (ACTH); anterior pituitary
cortisol release
follicle-stimulating hormone (FSH); anterior pituitary
egg or sperm production; sex hormone production
epinephrine production and function
suprarenal medulla, fight-or-flight response
androgens production and function
zona reticularis, sex drive in females/ sperm production, secondary sex characteristics in males
aldosterone production and function
zona glomerulosa, Na+ and K+ homeostasis
cortisol production and function
zona fasciculata, stress response
norepinephrine production and function
suprarenal medulla, fight-or-flight response
what part of the brain is located in the myelencephalon
medulla oblongata
dexamethasone is a drug used to suppress the secretion of ACTH from the anterior pituitary gland. 2 patients w hypertension of cortisol are given dexamethasone. anika’s cortisol secretion level falls to normal after the medication but bonnie’s cortisol secretion remains elevated. which patient has primary hypercortisolism, also known as cushing’s syndrome?
ACTH comes from the pituitary but bonnies problem comes from the adrenal gland which is why it wasnt fixed.
what causes a goiter
an enlarged thyroid gland from low levels of iodine
what does the parathyroid gland monitor
calcium levels
the nernst equation predicts
the membrane potential resulting from permeability to a single ion
the concentration of sodium inside the average human cell is 15 mM. The extracellular concentration is 145 mM. Solve the Nernst equation for sodium
log 61/1 (145/15)
receptors are not direct and work through second messenger systems are called ___ receptors
metabotropic
Graded Potentials
change in potential due to stimulus binding and opening channels (Ca + K); up and down not all or nothing
calcium is important in the synapse because it
signals the exocytosis of the neurotransmitter
what is the correct sequence involved in transmission at the cholinergic synapse?
AP depolarizers the axon terminal at the presynaptic, calcium ions enter the axon terminal, acetylcholine is released from storage vesicles by exocytosis, acetylcholine binds to receptors on postsynaptic membrane, chem reg ion channels on the postsynaptic membrane are activated
tetrodotoxin is a toxin that blocks voltage-gated sodium channels. what effect does this substance have on the functions of neurons
the neuron is not able to propagate action potentials (it’s blocked so can’t function)
rising phase
voltage gated sodium channels open rapidly (A)
falling phase
sodium voltage channels inactive and potassium voltage gated channels begin to open; more K channels are open ad more potassium leaves the cell (C)
pre action potential resting phase
sodium and potassium voltage gated channels close (B)
post action potential resting phase
sodium potassium pump is active to restore resting potential (E)
undershoot
some voltage K channels remain open, sodium channels closed, potassium leaves cell (D)
a person struggles with low metabolism, excessive growth, low bone density, and diabetes insipidus. If you were to look for a common cause, where in the body would you check first?
The thyroid
