New Biology Flashcards
Nares
In the nose. Has vibrissae (nasal hairs) to filter air
order of air
nasal, pharynx, larynx, bronchi, bronchioles
pharyx
air and food. food goes to the esophagus, air goes to lungs.
larynx
also called the glottis- (covered by the epiglottis) - has 2 vocal cords and to the trachea and into the bronchi
pleurae
surround each lung
visceral pleura - inner
parietal pleura- outer
interpleural space
contains a thin layer of fluid - lubricates the two pleura
inhalation
involves external intercostal muscles, intrTHROACIC VOLUME INCREASES
negative pressure breathign
air flows from high pressure to low pressure
exhalation
use internal intercostal muscles and abdominal muscles, which appose teh external and pull the rib cage down.
surfactant prevents the complete collapse of alveoli during exhalation by reducing surface tension at the alveolar surface
total lung capacity
the max volume of air in the lungs when one inhales - 6 to 7 liters
residual volume
the volume of air remaining in the lungs when one exhales completely
vital capacity
the difference between min and max volume of air in the lungs (TLC-RV)
Tidal volume
the volume of air inhaled or exhaled in a normal breath
expiratory reserve volume
the volume of additional air that can ve forcibly exhaled after a normal exhalation
inspirator reserve volyme
the volume of additional air that can be forcible inhaled after a normal inhalation
ventilation is controlled by the
medulla oblongata - ventilation center
neurons contain chemoreceptors sensitize to CO2
CO2 rise
hypercarbia/hypercapnia- resp rate will also rise so more CO2 is exhaled , causing CO2 levels to fall in the blood
hypoxia
low O2 conditions
capilarries bring deoxy blood from the pulmonary arteries
to the lungs (from teh R ventricle)
oxygenated blood returns to the LA of the heart via the
pulmonary veins
driving force of gas exchange
pressure differences in gas
blood has low partial pressure of oxygen and a high partial pressure of
CO2- NO ENERGY REQUIERD
in high altitude can
breathe more rapidly to avoid hypoxia, hemoglobin would decrease CO2 contcentration in the environment by decreasing the unloading of oxygen into the tissues- can make more RBC to increase oxygen (vascularization)
capillaries contract
less blood can pass through them. conserving thermal energy
immune in lungs
nasal cavity (vibrissae), macrophages (engulf and digest pantogens), IgA antibodies, mast cells, lysozyme- attack bacteria
bicarb buffer system
CO2 + H20 = H2CO3= H+ + HCO3-
body wants a pH of 7.35-7.45
when the pH is lower
hydrogen ion is higher, academia, increase respiratory rate, also increase in CO2 (but increasing breathing will blow off more CO2)
review RV and TLC
PLS
allergic reactions
mast cells (has to do with antibodies)
the information received from the dendrites is transmitted through teh ell body before it reaches the
axon hillock- integrates the incoming signals and transmit them to action potentials for the axon
myelin sheath
maintains electrical signal within one neuron and increases speed of conduction
oliogodenrocutes
myelin in CNS
Schwann cells
myelin in PNS
exposed areas of axon between myelin sheaths
nodes of ranvier (when it hops from node to node- salutary conduction)
glial cells/neuroglia
supporting role cells in nervous system
astrocute
nourish neurons adn form the BBB which control transmission of solutes from the blood into the nervous tissue
endymal cells
line the ventricles of the brain and produce cebrospinal fluid, which support the brain and serves as a shock absorber
microglia
phagocytic cells that ingest and break down waste products and pathogens in CNS
postsynaptic neuron may receive information from several different presyantic neurons, some are inhibitory adn some excitatory
additive effect of many signals- summation
temporal summation
many signals are integrated during a short period of time. ex a number of small excitatory signals at the same moment will bring it to threshold
spatial summation
advice effects are based on the number and location of the incoming signals. directly on the soma will cause more hyperpol or depol
resting
potassium is inside and sodium is outside
when membrane potential reaches +35
sodium channels are inactivated (top of depol to resting again). are closed before teh cell reaches threshold, and open during threshold to +35.
absolute refractory period
no amount of stimulation can cause another AP to ocurduring depol
relative refractory period
greater than normal stimulation to cause an AP because membrane is more negative in repo
AP traveling down axon and imitate NT release
impulse propgation
increased length of the axon
higher resistance and slower conditoin
greater cross sectional area
faster propagation due to deceased resistance (key over length of axon)
increase frequency of firing
not strength of AP (al the same no matter the stimulus)
sensory neurons
afferent neurons- transmit sensory rec to spinal cord sn dbrain
motor neurons
efferent - trsansmi motor information from the brain to the spinal cord to muscles and glands.
interneurons
most numerous and located in teh brain adn spinal cord and linked to reflexive behavior
spinal cord
cerical, thoracic, lumbar and sacral, protected yb teh vertebral column
white matter on outside of cord, grey is within iy
sensory neurons bring information to the
peripherally and enter on the dorsal side of the spinal cord, motor neurons hit the spinal cord ventrally and on the side closet to the front of the body
how many spinal nerves
31
how many cranial nerves
12
somatic NS
sensory and motor neurons distributed throughout the skin, joints and muscles
ANS
regulates heart rate, respiration, digestion and gland secretion- involtaty muscles associated with may internal organs and glands
controls body temperature
preganglionic nebros and postganglionic neuron- neurons to transit message sto the spinal cord
reflexies
interneurons in the spinal cord can send motor signals instead of waiting for the brain to
monosynaptic reflex arx
a single synapse between the sensory neuron that receives the stimulus and the motor neuron that responds to it.
knee jerk reflex- protection
polysyantic reflex arc
one interferon between the sensory adn motor
withdrawal relfex- like when stepping on a nail- both need to withdraw and maintain balance so two different action
nerves may carry more than one type of information (sensory or motor)
tracts can only carry one type of information- collection of neurons
NT used in ganglia of both sympathand para
ACh
dorsal root ganglion
contains the cell bodies of sensory neurons only. loss of sensation If cut
catalysts
do not impact the thermodynamics of a reaction (delta H) or the equlilbrium position (constant). instead, they help the reaction proceed at a much faster rate through lowering teh activation energy, increasing rate of reaction,
catalysts are seen in both reactants and products
true
catalysts are pH and temperature sentizie
optimal at certain ranges
enzyme specificity
a given enzyme will only catalyze a single reaction with specific substrates
oxidoreductase
catalyze oxidation reduction reactions- transfer of electrons between biological molecules
often use a cofactor like NAD+ or NADP+
electron donor- reductant and electron acceptor is oxidant.
OILRIG
oxidation is losing electrons, reduction is gaining electrons
transferases
catalyze the movement of a functional group from one molecule to another
moving amino groups create different molecules
kinases!!- transfer phosphate groups, from ATP, to another mc
hydrolases
catalyze teh breaking of a compound into 2 molecules using the addition of water.
phosphatase- clears the phosphate group from another molecule
also peptidases, nucleases, lipase- break down proteins, NA and lipids
lyases
catalyze the cleave of a single molecule into 2 products. do not need water as a substrate and not oxidation reduction reactions. can also catalyze the reverse (2 molecules into a single molecule)
isomerases
catalyze the rearrangement of bonds within a molecule - can be oxioreductases, transferases or lyases
ligases
catalyze the addition or synthesis reactions between large similar molecules - NA repair and synthesis. often needs ATP. smaller molecule synthesis are generally accomplished through lyases.
endergonic reaction
requires energy input (G>0), take energy in as they proceed
exergonic
energy is given off (G<0), release egerngy out as they proceed. sponteous
enzymes do not alter the overall free energy change for the reaction or the equilibrium of a reaction
instead they alter the rate (kinetics) at which the reaction occurs. how quickly reaction can get to equiilbiurm, but no equilibrium itself.
catalysts lower activation energy
make it easier for the sublate to reach transition atto.
THE FORMATION OF THE enzyme substrate complex in the active site I the key catalytic activity of the enzyme
reduces AE
active site
location within the enzyme where the vibrate is held during a chemical reaction
lock and key
enzymes active sitr (lock) is already in the appropriate conformation for the substrate (key) to bind.
induced fit model
more accepted than lock and key. both the substrate and active site changes in conformation. sub induces change in enzyme. interaction requires energy so endergonic. when releases, exergonic, no energy required. the shape of the active site becomes truly complementary only after the substrate begins binding to the enzyme
cofactors and coenzymes
small molecule that bind to teh active site of an enzyme and participate in the catalysis of the reaction, carrying charge through ionization, protonation or deprotonation.
enzymes with co factors
haloenzymes
necessary for enzymes function: prosthetic groups
enzymes without co factors
apoenzymes
saturation
reaches a maximum - all active sites are occupied and b max is reached (working as fast as it can). only way to increase v max is to increase enzyme concentration (to handle the increase in substrate levels)
Michaelis mention equation
describes how the rate of the reaction (v) depends on teh concentration of both the enzyme and substrate to form product.
E + S= ES = E + P
1st = : k1- can also ES dissociate back into E + S (k-1)
2nd =: k cat
also
v = v max S/ Km + S
when reaction rate is equal to half of v max, Km= S
Km
substrate concentration at whi half of the enzymes active sites are full - Michralis constant
can be a measure of affinity
higher kM= lower affinity for its substrate because it requires a higher substrate concentration to be half saturated
v max
represents max enzyme velocity and is measured in moles of enzymes per second.
kcat
measures the number of substrate molecules turned over, or converted to products per enzyme molecule per seconds
a large k cat (high turneover) or a small Km (high substrate affinity)
will result in a higher catalytic efficiency, which indicate a more efficient enzume
lineweaever Burk plotdd
x interecept: -1/Km
y intercept: 1/vmax
cooperatively
many subunits adn active sites
think of it like a party- the more people come, the more the atmosphere becomes relaxed and appealing, as the party dies down, more people are encouraged to leave so the hosts can clean up.
sigmoidal curve
substate binding happens more quickly as more active sites are occupied (in contrast to as suvrate binding decreases more binding from happening- saturation)
hills coeffeiecnet
greater than 1= positive cooperative binding , after 1 ligand bound, the affinity of the enzyme for further ligands increases
less than 1, negatively cooperative binding- after one ligand is bound, the affinity of the enzyme for further ligands decreases
=1, te enzyme does not exhibit cooperative binding
enzymes are specific during
temperature, pH (especially at high temperatures = enzymes fail), salinity
reversible inhibiation
competition, noncomp , mixed and uncomp
comp inihibtion
occupancy of the active sites . substrates cannot access enzymes binding sites if there is an inibbitro in the wy,
can be overcome by adding more substrates so that the substrate to inhibitor ratio is higher, more likely to bind substrate instead of inhibitor
does not alter v max, but increases Km (sub needs to be higher to reach half of the v max)
noncomp ini=hibition
inhibitors bind to allergic sites on the active sites- which induce a change in enzyme conformation. cannot be overcame by adding more sublate, decreases v max (less available enzyme to interact but does not affect Km (any copies of the enzyme that are still active maintain the same affinity for their substate)
mixed inhibition
inhibitor can bind to either the enzyme or the enzyme sub complex but with diff affinity
bind to allergic
uncomp inhibitor
bind only to the enzyme substrate complex and locks the substrate to the enzyme, preventing th release. increase affinity for the enzyme and substrate
bind at allosteric site
lower Km adn Vmax
irreversible inhibition
not easily overcome or reversed
allosteric enzyms
many binding sites
regular the availability of the active site and the active site
enzymes in human body work best at what temp
37 degrees C
enzymes speciicity
determined by teh 3D active site shape
perioxiomses
contain hydrogen periods
breakdown long chain FA via beta oxidation
microfilaments
actin with ATP and myosin to help in muscle contraction
protect the cell
play a role in cytokinesis with teh cleavage dirrpw
microtubuiles
tubular proteins
provide pathways which motor proteins like kinesis and dyne carry vesicles
cilia and flagella
centrioles in centriomes do the mitotic spindle
intermediate filmaents
cell to cell adhesion or maintenance of overall integrity of cell skelton
keratin, desmin, lamins
binary fission
asexual reproduction seen with prok
epithelial tissue
lining
connecie tissue
bone cartilage, tendons, blood to form ECF
facultative anaroebes
can use O2 if present, or if not thats ok too
bacteria
plasmids
carry genes that help with antitbioic resistance
also carry virulence facet, increase pathogenicity
bacteria genetic recombination
transofmrtion, conjugation and transfuction
transformation
integration of foreign genetic material into host genome
conjugation
mating two cells from a conjugation bridge that transfers genetic material sex pili make the bridge ` donor male and recipient female must have sex factors, f factor
transfuction
requires a vector- virus that carries genetic material from 1 bacterium to another
single stranded viral RNA may be positive or negative sense
positive= genome may be directly translated to functional proteins by ribosomes of the hot cell negative= RNA acts as a template for synthesis of a completmenatyr stanrf, which is then used to make the proteins
lytic cycle
involves the reproduction of viruses using a host cell to manufacture more viruses; the viruses then burst out of the cell.
lyosegenic cycle
nvolves the incorporation of the viral genome into the host cell genome, infecting it from within.
interphase
G1, S, G2
longest part of the cell cycle
cells that dont divide spend their time in
G0
euchchromatin
less condensed form- DNA must be available for RNA polymerase so that genes can be transcribed.
heterochromatin - condensed and cannot be transcribed
G1
cells create organelles and protein production (mito, rib, ER) while also increasing their size
restriction point- before entering S phase - must contain propercomlment of DNA and pass the checkpoint
S stae
replicate genetic material so that each daughter-in-law cell will ave identical copies. each chromosome ill have two identical chromatids that are bound together by a centromere
46 chrom, 92 chromatids/
twice as much DNA as cells In G1
G2
quality control checkpoint
Mitosis
prophase, metaphase, anaphase, telophase, cytokinesis
p53
repairs DNA between G1 and S checkpoiint
prophase
condensation of the chromatin into chromosomes
metaphase
along chromatomses at teh mataphase/equatorial plate
centrioles on opposite ends of the cell and kinetochore fibers interact with fibers of spindle
anaphase
centromeres split so that each chromatid has its own distinct centromere, and sister chromatids seperate/
telophase
reverse of prophase- spindle disappears, chrom uncoiled cytokinesis occurs- sprat cytoplasms
meiosis 1 involves
homologous chromosomes - generating haploid daughter cells
23 homologous pairs of chrom - one from each parents.
prophase 1 in meoisis
homologous chromsomes come together and intertwine - syanpsis and crossing overing occurs
males are
hemizygous- 1 copy of the Z chrom
cells of leydig secrete
testosterone
sperm is produced in that
seminiferous tulles and the intersistutal cells of Leydig
sperm is nourished by
Sertoli cells
spermatogenssi
formation of haploid sperm through meiosis
occurs in semniferous tubes
ovaries
produce estrogen and progesterone
one egg per month is ovulated
yes
oogenesis
all oogonia have already undergone DNA replication adn are primary oocytes by birth.
GnRH
triggers anterior pit to trigger FSH and LH which triggers the production of other sex hormones
follicular phase
menstrution begins. uterine lining sheds. GnrH increases, FSH and LH increase therefore, ovarian follicles are secreted, produce estrogen, negative feedback on GNRH LH adn FSH
ovulation
estrogen also positive feedbacks (and negative) LH which indices ovulation- releases ovum from ovary in o the abdominal cavity
luteal phase
LH raises the ruptured follicle to form corpus leutuem which secretes progesterone. maintains uterine lining for implantation
menstruction
without implantation, ,levels decline and uterine is shed
development of mature sperm
spermatogonia, 1 spermocyte, 2 spermocyte, speramtid, spermatozoan
spindle attaches to kinetochores
prophase
from the time of birth until ovulation, egg cells are in prophase of meiosis 1 (primary oocyte)
at ovulation, egg has completed meiosis 1 and is in metaphase 2 (secondary oocyte), once sperm penetrates the outer layer f the secondary oocyte and finishes meiosis 2
estrogen
for endometrium development
abdominal cavity is before the
fallipoian tube (and where the egg is released at
nondisjucntion
incorrect segregation of homolog chrom during anaphase 1 or of sister chromatids during anaphase 2
ectoderm
integument- epidermis, hair, nails, epithelial of nose, mouth, lens of eye, nervous system
endoderm
epithelial lining o fthh digestive and respiratory tratcs, liver, pancreas, bladder
mesoderm
musckosletal system, circulatory system, excretory, gonads, adrenal core
the influence of specific group of cells on teh differentiation of another group of cells
induction
eyes are formed between teh induction of the brain adn teh ectoderm
senesence
biological aging
the tissues a particular stem cell can differentiate into are determined by its
potenncy
greatest potency
totient cells- any cell type
pluripotent
three germ cell layers. can differentiate into any cell type besides for the placental structures
multipotent
multiple cells
like in the blood (RBC, WBC, platelets), but not skin cells, neurons, etc.
embryo
morula –> bastula–> gastrula
solid ball of cells, hollow center, three germ layers form
sodium is actively transported out of the nephron into teh PCT adn DCT (against gradient)
in the inner medulla, thin ascending limb, sodium passes down its concentration gradient
thick ascending limb
has many mitochondria for ATP for active transport of NA and CL- out of the filtrate
lowest solute concentration
cortex- where PCT and some DCT are found
passage of blood through the kidneys
renal artery–> afferent artery–> glomerulus–> efferent articlole–> vasa recta (around the nephnr tubular) –> renal vein
ADH and aldosterone increases water reabsorption in the kidney
yes
ADH works by
increasing the permeability of the collecting duct to wate
peptide hormone. vasopressin
alcohol adn caffeine inhibit ADH
allows more water to be reabsorbed at collecting ducts (inhibits waTer elimination)
inserts aquaporins into collecting ducts, decreases volume of urine
aldosrerone
stimulates reabsorption of sodium from teh DCT and collecting ducts .decreased blood pressure stimulates the release of renin, which cleaves angiotensin which produces aldosterone adn increase BP
hypothalmus
regulates body temperature
PCT absorbs
glucose, aa, organic molecules, 100% of nutrients, water, ions
DCT absorbs
The role of the early DCT is the absorption of ions, including sodium, chloride and calcium. It is impermeable to water.
excess ACH leads to
parasympathetic- contraction of the bladder, increased sweat glands`
PCT into blood
waste, urea, drugs
DCT absorbs
Na+- regulated by aldosterone
water
descending limb
highly permeable to water, osmosis (water flows out) because blood is more hypertonic (full of salt and solutes)
ascending limb
highly permeable to salt (not water) by ACTIVE TRANSPORT
endocrine signaling involves
the secretion of hormones into the bloodstream. hormones than travel to distant targets where they bind to receptors and induce a change in gene expression or cell function
peptide hormones are composed of
aa and derived from precursor proteins that are cleaved during post translational modification
polar- can’t pass through pm
trigger second messengers when bind to extra cell rec
rapid onset but short lived effects
travel freely in blood stream (without carrier) because water soluable
steroid hormones
derived from chol
minimally polar and can pass through the pm
bind and promote change in cystolic and intranuclear receptor- Horm rec complex binds to DNA, alters transcription of genes
steroid have slow onset but long lived
lipid soluble so need a carrier when in blood
amino acid derived hrmones
modified AA
share with steroid adn peptide hormones
epi,nor
direct hormones
secreted adn act directly on target tissue
insulin released on pancreas causes increased uptake of glucose by muscles
prolactin (stimulates milk production in mammary glands), endorphins (decrease perception of pain), growth hormone,
non endocrine gland
tropic hormones
intermediated needed to act to influence target tissue
GnRH stimulates LH and FSH - stimulate production of testestrone to cause direct changes in bones and hair follicles
FSH, LH, GNRH, ACTH, CRF
endocrine gland
hypothalamus
controls pit through release of paracrine H secretes GnRH (which secretes LH, FSH and GH), TRH, CRG
posterior pit
release oxytocin (uterine contractions during labor) and ADH (increase water reabsorption in collecting ducts of kidney) (synthesized by hypothalamus
thyroid
controller by thyroid stimulating hormone from ant pit
energy production more efficient b T3 and T4
parathyroid glands
raises blood calcium levels (opposite of calcitonin) and increases vitamin D for calcium absorption in the gut
increased CA reabsorption int eh kidneys, increased bone reabsorption and increased absorption of ca in the gut
adrenal glands
located on top of the kidneys
secretes corticosteroids- glucosi, miniera and sex hormones
glucocorticoid steroids
regulate glucose levels and protein metabolism
cortisol and cortisone
increase glucneogensis adn decrease protein synthesis
increases blood sugar when stressed
mineral corticoids
aldosterone! increasing sodium reabsorption in the DCT and collecting duct
also increasing reabsorption of potassium and hydrogen ions
renin angiotensin pathway
cortical sex hromones
androgens and estrogens.
adrenal medulla
epi, nor (catecholamines)
fight or flight responses
increase glucose, heart rate, dilate bronchi, vasodilation of BV
pancreas
exocrine and endocrine (digestion and insulin, glucagon, somatostatin)
glucagon
increases glucose production by triggering glucogenogenssi and breakdown of protein adn fat
insulin
take ip glucose and store as glycogen
B cells
somatostatin
inhibitor of glucose and glucagon
always inhibitory
leading to decreased insulin and glucagon
pineal gland releases
melatonin which helps regulate circadian rhythms
kidneys secrete
erthyripoeitn- stimulate bone marrow to product RBC in response to low O2 levels
acromegaly
enlargement of small bones in exteemedities and facial structures in adults with too much GH
cretinism
poor neurological and physical development because iodine defificny - swelling of thyroid gland
dopamine secretion blocks
prolactin release
accessory organs of digestion
salivary glands, pancreas, liver, gallbladder
enteric nervous sytem
controls peristalsis
unregulated by parasympth and down regulated in sympath
ADH and vasopressin promote
thrist
glucagon adn gherkin promot
hunger
leptin and cholecytoskinin
promote fullness
stomach has 4 parts
fundus, body, antrum, plyourous
folds called rugae
chief cells secrete
pepsinogen, which is a protease that activated by teh acidic nature of the stomach
mucous cells produce
bicarb rich mucus to protect the stomach
parietal cells
secrete HCL and intrinsic factor, which is needed for vitamin B12 absorption
G cells secrete
gastrin, peptide hormone that increases HCL secretion adn gastric motility
food pass into the duodenum through the
pyloric sphinctor
small intestine
duodena, jejunum and ileum
duodenum
chemical digestion
breakdown maltose, lactose into monosaccharides
peptidases present
secretin
stimulates release of pancreatic juices into the dueonum and slows motility
cholesystokin
stimulates bile release from gallbladder , release of pancreatic juices, and fullnesses
acing cells
in the pancreas, produce pancreatic juices that contain bicarb, amylase and peptidases and lipase
liver syntheizes
bile, which is stored in the gallbladder and secreted into the duenodum directly
bile function
emuslfies fat- making them soluable and increasing their surface area
bile is. made up of
bile salts, pigments (bilirubin) and chol
bilirubin
is the breakdown of HB
liver
produces urea, detoxifies, produces bile, albumin and clotting factors
gallbladder stores and concentrates bile
yes
jejunum and ileum
absorption
lined with vili and lacteal (vessel of lympth system)
lacteal
fat soluable compounds- fats, cool, vitamins, enter
water soluable compounds for digestion
monosaccarides, aa, water, small aa, water enter cap bed
large intestine
absorbs water and salts, forms feces
cecum, cold, rectum
lipase
chemically digests fats
dueonum pH
Ph is 8.5
carboxypeptidase
breaks down proteins in small intestine
skeletal muscle
involved support and movement, propulsion of blood into the venous system and thermoregulation. striated and voluntary, polynucleated
slow twitch fibers
oxidative phosphorlation red fibers
high myoglobin and mito
fast twitch fibers
anaerobic metabolism white fibers
smooth muscle
respiratory, reproduce, CV and digestive system. nonstarter and autonomic control, uninucleated.
cardiac muscle
contractile tissue of the heart. striated and autonomic and uninucleated. shows myogenic (contraction without neural input- same as smooth muscle)
cells are connected with intercalated discs and gap junctions (flow of ions between adjacent cells)
sacromeres
basic contractile unit of started muscle
myosin (thick) and actin (thin)
troponin and tropomyosin
regulate actin myosin interaction and found on actin.
M line (in sarcomere)
M line: located in the middle of the sarcomere
I band
thin filaments
H zone
thick filaments
A band
thick filaments only- constant during contraction
sarcomeres that attach end to end to become
myofibrils
myocyte
muscle cell or fiber
contains many myofibrils
myofibrils are surrounded by
sacroplasmic reticiulum, a ca containing modififed ER and the cell membrane of a myocyte (sacrolemma)
T tubules
connected to teh sarcolemma and allow action potentials to reach all parts of the muscle
muscle contraction begins at teh
neuromuscular junction where motor neuron releases ACh that binds to receptors on the sarcolemma, causing depol. depol spreads to t tubules from sacromella and triggers release of CA ions. CA binds to troponin, causing a shift in tropomyosin and exposure of the myosin binding site on teh actin thin filament. shortening of teh sarcomere occurs as the myosin head binds to the exposed sites on actin, forming cross bridges and pulling teh actin filament along the thick filament which results in a contraction. aka sliding filament model
muscele relaxes when
ACH is degraded by acetylcholinesterase, terminating teh signal and allowing calcium to be brought back into the SR. ATP binds to myosin head and allows it to release from actin.
muscle cells exhibit an all or none response called a
simple twitch
frequency summation
addition of many simple twitch before the muscle has the opportunity to fully relax
tetanus
simple switches that occur so frequently as to not let the muscle relax at all- more prolonged and stronger contraction
muscle cells have addiotnal energy reserves to reduce oxygen debt and prevent fatigue
creatine phosphate (transfer phosphate group to ADP to form ATP) and myoglobin (heme protein that is a oxygen reserve)
internal and extneral skeltons
endoskeletons and exoskeltons
axial Skelton
consists of structures in the mid line (skull, rib cage, vertebral column)
appendicular skelton
bones in the limbs, pectoral girdle, pelvis
bone is derived
mesoderm
compact bones
provides strength and is dense
spongy or cancellous bones
has lattice like structures consisting of bony spicules known as trabeculae and caivities filled with bone marrow
long bone break down
diaphyses that form metaphases and end in epiphyses (growth plate)
bone is surrounded by a layer of connective tissue called
periosteum
site of attachment of bones to muscle tissues. can differentiate into osteoblasts
bones are attached to muscles by tendons
and to each other by ligaments
osteoblasts
build bnoe
osteoclasts
reabsorb bone
parathyroid hormone
increases resorption of bone, increasing CA and phosphate in blood
vitamin D
ncreases resorption of bone, leading to increased turnover and production of stronger bone
Calcitonin
increases bone formation and decreases CA concentration in the blood
cartildge
firm elastic material secreted by chondrocytes
in areas with more flexibility or cushioning
avascular and not innervated
immovable joints
fused together to form sutures
movable joints
strengthen by ligaments and contain synovial fluid (lubticating motion)
muscles that serve opposite function (one contracts and the other releases)
antagonistic pairs
articular surfaces of the bone are covered with
smooth articular cartilage- stops bones from contacting one another
yellow marrow
adipose tissue
endochondral ossification
replcemnet of cartridge with bones and occurs in long ones
intramembraneous ossifcation
formation of bone from undifferentiated connective tissue cells and occurs in skull
heart is composed of
cardiac muscle and has the pulmonary and systematic cirulation
the atria are separated from teh ventricles by teh
atrioventricular valce (tricupsid on teh R, bicuspid on the L)
the ventricles are separated from teh vasculature from
semilunar valves (pulmonary on R, aortic on L)
the pathway of blood
RA (tricuspid)– RV (pulmonary valve)– pulmonary artery–lungs–pulmon veins–left atrium(mitral valve) –LV (aortic valve)–aorta–arteries–aterioles–capillaries–venules-beins-vena cava-RA
Left side of the heart has more muscle than the right side because of systematic circulation has a much higher resistance and pressure
yes
electrical conduction
SA node (sinoatrial node) and then goes to the AV node (atrioventricular) – bundle of HIS—purkinje fibers
systole
AV valves are closed during ventricular contaction
diastole
hert is relaxed and semilunar valves are closed
CO
HR x SV
arties
elastic, highly muscular, thick
recoil and helps propel blood forward.
away from heart
capillaries
one cell thick walls so RBC travel single file. site for gas and solute exchange
eins
inelastic, thin that transport blood to the heart.. no recoil but can stretch . valves to maintain a one way flow
portal system
blood passes through two capillary beds in a series
heaptic portal system
blood travels from the gut capillary beds to teh liver via the hepatic portal vein
hypophyseal portal system
blood travels from the cap bed in the hypothalamus to the cap bed in the anterior pit
renal portal system
blood travels from the glomerulus to the vasa recta through the efferent artierole
blood
is composed of cells and plasma, aqueous mixture of nutrients, salts and repistaory gases, hormones, blood proteins
erythrocytes RBC
lack mitocoonia, nucleus and organelles have hemoglobin (carries O2)
hematocrit
% of blood composed of RBC
leukocytes WBC
formed in bone marrow
thromobocytes
platelets are cell fragments required from coagulation