physio exam 1 Flashcards
what is the organization of the body
elements, molecules, cells, tissues, organs, organ systems, organism
what are the basic functions of cells?
obtain food, perform chemical reactions, eliminate waste, synthesize componenets, control exchange of materials, move materials around, respond to environemtn, reprodcution
what are the 4 types of tissues
muscle, epithelial, nervous, and connective
name an examples of different types of tissue working together for a complex function
muscle tissue working with connective tissue resulting in movement
describe muscle tissue
excitable tissues that consists of cells for contracting. 3 types are smooth, skeletal, and cardiac
what are epithelial cells specialized in ?
exchange between cell and environment
*this level of exchange depends on the location of the tissue in the body
what kind of tissue are glands?
epithelial tissue
where is nervous tissue found?
brain, spinal chord, nerves, and sensory organs
what do organs consist of?
two or more types of primary tissue
dynamic steady state
describes the idea of our body’s state constantly changing
what is the mechanisms by which homeostasis occurs?
cells
what must be maintained in the internal environment for optimal cell function
- oxygen and carbon dioxide tensions
2.concentrations of glucose and other metabolites - osmotic pressure
- concentrations of hydrogen, potassium, calcium, and sodium
internal vs external envioronments
internal=fluid surround cells (intracellular and extracellular fluikd)
external= environment that surrounds the organ
what is ECF made up of?
plasma and interstitial fluid
what two stages is ECF transported in?
- circulatory systems
- movement of fluid between blood capillaries and cells
name the two homeostatic control systems
extrinsic and intrinsic
extrinsic initiated outside the organ system
intrinsic is local, inherit to the organ
example of intrinsic homeostatic control systems
falling o2 in muscles directly triggers dilation of loval blood vessels
example of extrinsic homeostatic control system
increase in blood co2 triggers neural response to respiratory system, increase in respiration rate
give an example of a negative feedback loop
you sweat alot so your body increases sodium until regulatory mechanism stops it
give an example of feed forward control system
digestion (the 1st phase)
is steady state always an equal state?
no
describe why the plasma membrane is made of ampipathic molecules
one hydrophobic end and one hydrophilic end
fatty acid tail= hydrophobic
phosphate group=hydrophilic
glycoproteins
membrane proteins have carbohydrates attached on outer surface of plasma membrane only
what does cholesterol do in the plasma membrane and list exaples
contributes to fluidity and stability of cell membrane
steroids, cortisol
what is the primary function of the plasma membrane
establish a region of selective permeability
sphingolipids
make up lipid rafts and have more cholesterol and proteins and phospholipids
caveolae
tiny indentations where lipid rafts exist as flat platforms
what kind of proteins are the ones gathered in lipid rafts
receptor proteins
what allows epithelial layer to be tough but stretch
desmosomes
cadherins
proteins from desmosomes that come from plasma of neighboring cells to interlock neighboring cells
describe gap junctions
-form physical pore
-non selective
-communication junctions
describe tight junctions
-closed junctions
-made up of claudins
-prevent undesirable leaks
paracellular transport
slightly leaky behavior
aquaporins
specific to kidney and gi cells permit rapid movement of water
nuclear pore complex
regulates movement of molecules in and out of the nucleus
VDAC
voltage dependent anion channel
functions as gatekeeper for the entry and exit of mitochondiral metabolites
also key player in mitochondria mediated apoptosis
gated channels
opening and closing of this channel is dependent upon a particular stimulus
voltage gated channel
open or close when the membrane potential reaches a particular threshold value
ligand gated ion channel
stimulated to open when bound to ligand
(ligan is a neurotransmitter)
tunneling nanotubules
form between cells and could provide a direct passage for larger cargo such as signaling molecules
paracrines
local chemical messengers
(autocrines= exert effect on cell which secreted it)
neurotransmitters
short range chemical transmitters
hormones
long range messengers, secreted into blood by endocrine glands
neurohormones
hormones released into blood by neurosecretory neurons, distributed thru blood to distant target cells
cytokines
act locally to regulate immune responses, protein signal molecules secreted by immune cells
eicosanoids
locally acting chemical messengers derived from plasma membrane
hydrophilic hormones
water soluble, cannot cross membrane
ex. peptides
lipophilic hormones
high lipid solubility, can cross membrane
ex, steroid hormones
extracellular messenger binding to receptor initiates intracellular response by either….
- opening or closing channels
- activating second messenger systems (amplification)
what does binding to a g protein coupled receptor activate in intercellular signal transduction?
activates a second messenger system
what properties of particles influence their passage thru the membrane
relative solubility of the particles and size of the particle
what are the two types of unassisted membrane transport
osmosis and diffusion
what are the 3 types of assisted membrane transport
carrier mediated transport, facilitated transport, active transport
give an example of active transport
calcium getting pumped back into muscle via sarcoplasmic reticulum
what are the two forces that control diffusion
concentration gradient and electrical gradient
Ficks law of diffusion
- magnitude of concentration gradient
- permeability of the membrane to the substance
- surface area of the membrane
- molecular weight of the substance
- distance thru which diffusion takes place
what is the difference in charge called
electrical gradient
what establishes membrane potential
ions
what is the electrochemical gradient
the net effect of chemical and electrical gradients on a particular ion
tonicity
effect that the concentrations of nonpenetrating solutes in a solution has on cell volume
osmolarity
measurement of the solute concentration of a solution in terms of its particles per volume
which way does water flow in osmosis
to the area of higher solute concentration
what corrects imbalance of water in membrane during osmosis
hydrostatic pressure
describe carrier mediated transport
assisted, can be active or passive, membrane carrier protiens w morphology that forms binding pocket for solutes
what are characteristics that determine what can be transferred across the membrane in carrier mediated transport
specificity, saturation, competition
what are the types of assisted membrane transport and which ones are active and which are passive
facilitated diffusion (passive)
active transport (active)
vesicular transport (active)
describe facilitated diffusion
substances move down concentration gradient, requires carrier molecules, no energy reqired, how glucose is transferred into cells
describe active transport
moves a substance against concentration gradient, reqires carrier molecule, requires atp
describe secondary active transport
driven by ion concentration gradient established by a primary active transport system, atp not directly used to move molecule, works as symport or antiport carrier
describe vesicular transport
material moved in or out of cell wrapped in membrane, active method of membrane transport
what are the two types of vesicular transport
endocytosis and exocytosis
what is typical mv of cells at rest
about -70 mv but leak channels change this numebr
what does equilibirum potential tell us?
what direction membrane potential is going to change
what is the nernst equation and why is it limited?
calculates the membrane potential for one cell but this is limited bc multiple ions make up the membrane potential
what is the goldman hodgkin kats equation
extension of nernst equation that includes other elements and is how we arrived at -70 mv as resting membrane potential
what is the difference between efferent and afferent neurons?
efferent= send signals out of cns
afferent= send sensor signals to cns
interneurons
found entirely in cns and deal with higher mental functions associated with the mind
what are the 4 major types of glial cells
- astrocytes
- oligodendrocytes
- microglia
- ependymal cells
describe astrocytes
main glue of cns, guide neurons during fetal brain development, aid in establishment of blood brain barrier, help transfer nutrients from blood to the neurons, important in repair of brain injuries and in neural scar formation, take up and degrade locally released NTs, take up excess K from the brain ECF, enhance synaptic formation, communicate w neurons via chemical signals, clear toxins from the brain via glymphatic systems
describe communication in astrocytes
signals pass thru the ecf thru gap junctions, gliotransmitters, have receptors for glutamate causing influx of ca2 which triggers release of atp
glymphatic system
brain not supplied by normal lymphatic system, allows for exchange of solutes between CSF and ISF (aquaporins)
oligodendrocytes
form insulating myelin sheaths around axons in CNS, increase signal transmission speeds
*schwann cells in pns
microglia
immune defense cells of the cns, when resting release nerve growth factor which promotes neurons and other glial cells to thrive, when activated they become swollen and migrate to areas of injury or infection
what neurodegenerative disease may be contributed to overactive microglia
alzheimers
ependymal cells
line internal fluid filled cavities of the cns, in ventricles of brain help form csf, act as neural stem cells for new glial cells and neurons in the hippocampus
gliomas
glial cells that form into brain tumors bc they are mitotic
meningiomas
tumors that originate in the meninges of cns
what happens when you hit threshold
action potential happens in that section of neurons
what are the 4 gated channels
voltage, ligand, mechanical, thermal
what are the two kinds of potential change
graded potentials and action potentials
graded potentials
short distance signals, their influence can lead to action potential in nerve cells; typically do not involve sodium/potassium channels
action potentials
serve as long distance signals, all or nothing, involve voltage gated channels, absolute strength that never weakens
what/ how does the concentration gradient get restore after being disrupted by action potentials?
sodium is pumped into the ecf and potassium is pumped into the icf
what is the axon hillock?
the neurons triggering zone
axon terminals
release neurotransmitters that simultaneously influence post synaptic cells, output zone of the neuron
continuous conduction
conduction in unmyelinated fibers, action potential spreads along entire axonal membrane
saltatory conduction
rapid conduction in myelinated fibers, impulse jumps to exposed membrane between myelin sheaths
pg 21 of lecture 2
what are the major functions of the cerebral cortex?
sensory perception, voluntary movement,language, personality and emotions, memory, decision making
what are the major functions of the basal ganglia?
motor control, production of stereotyped automatic movements, enabling of cognitive, executive, and emotional behaviors
what are the major functions of the thalamus
relay of sensory info to the cerebrum, relay motor info from cerebellum and basal ganglia to cerebrum, part of limbic system emotion and memory, activation of cerebral cortex conciousness system
what are the major functions of the hypothalamus
regulates temp, thirst, food intake, fluid balance, and biological rhytms
relay station between nervous and endocrine systems, sex drive, emotions and behavior patterns, sleep wake cycle
what are the major functions of the brainstem?
-origin of most peripheral nerves
-control centers for cardiovascular, respiratory, and digestive regulation
-regulation of muscle reflexes for posture and equilibrium
-some control sleep wake cycle
-integration of synpatic input from spinal chord
-activation of cerebral cortex
list the meninges of the brain superficial to deep
dura mater, arachnoid mater, pia mater
what would happen if we did not have csf in our skull?
brain would hit the skull and become damaged
what is the csf fluid primarily synthesized by?
choroid plexuses
where does csf enter and where does it drain?
enters subarachnoid space and flows thru the meninges and then drains thru small openings in the 4th ventricle
what are areas without BBB called and what is the purpose of them?
circumventricular organs, several located near hypothalamus and this allows it to sample blood and make adjustments
where does nearly all of the blood to the anterior pitutiary go thru? and what does it bypass
goes thru hypothalamus and bypasses general circulation (second part of hypothalamic hypophyseal portal system)
hypothalamic-hypophyseal portal system
connects brain to anterior pituitary system, made up of 2 capillary beds
what is neurohypothysis?
hypothalamus interconnected w posterior pituitary
wehre do neurons originate in hypothalamic hypophyseal portal systems?
originate in supraoptic and paraventricular nuclei and terminate in posterior pituitary
what is the release of hypophyseal hormones controlled by?
controlled by regulatory hypothalamic hormones for adenohypophysis and neuroendocrine reflex for neurohypophysis
melanocortin system (which is in arcuate nucleus)
critical neural system underlying the control of body weight and other functions
