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223 terms

NLN study guide

anatomy & physiology terms on the new NLN test
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plasma membrane
membrane made up of a double layer of phospholipids and cholesterol and also has proteins embedded. proteins may extend thru entire membrane or only protrude one side. some may also have attached sugar groups. it serves as a barrier and transports substances in and out of cell. externally facing proteins act as receptors
mitochondria
Powerhouse of the cell, organelle that is the site of ATP (energy) production; metabolites are broken down and oxidized and used to attach phosphates to ADP molecules and make ATP
rough ER
sugar groups attached to proteins in cisternae; proteins boud to vesicles for transport to the Golgi apparatus and other sites; external face synthesizes phospholipids
smooth ER
site of lipid and steroid synthesis, lipid metabolism, and drug detox
Golgi apparatus
packages, modifies, and segregates proteins from the cell, inclusion in lysosomes and incorporated into the plasma membrane
peroxisomes
enzymes detox a number of toxic substances; most important catalase breaks down hydrogen peroxide
micortubules
support cell and give it shape; involved in intracelular and cellular movememnts, form centrioles and flagella
microfilaments
involved in muscle contraction and other types of intracellular movements, help form cell cytoskeleton
intermediate filaments
stable cytoskeletal elements, resist mechanical forces acting on cell
centrioles
storage for nutrients, wastes, and cell products
nuclear envelope
separates nucleoplasm from the cytoplasm and regulates passage of substances to and from nucleus
chromatin
granular material visible within the nucleus; consists of DNA tightly coiled around proteins
simple diffusion
kinetic energy; net movement of all molecules from one are of higher concentration to an area of lower concentration along concentration gradient
facilitated diffusion
kinetic energy; same as simple diffusion but the diffusing substance is attached to a lipid soluble membrane carrier protein or moves thru a membrane channel
osmosis
kinetic energy; simple diffusion of water thru a selectively permeable membrane
primary-active transport
transport of substances against a concentration gradient; preformed across plasma membrane by a solute pump directly using ATP hydrolysis
secondary-active transport
co-transport of 2 solutes across membrane; energy is supplied indirectly by ion gradient created by primary active transport; symporters move transported substances in the same direction; antiporters move transported substances across the membrane
pinocytosis
plasma membrane sinks beneath an external fluid droplet containing small solutes; membrane edges fuse, forming a fluid filled vesicle
phagocytosis
"cell eating" an external particle is surrounded by a "seizing foot" and becomes enclosed in a vesicle
exocytosis
secretion or ejection of substances from a cell; substance is enclosed in a membranous vesicle which fuses with the plasma membrane and ruptures, releasing substances to exterior
sodium-potassium pump
uses an enzyme call Na+-K+ATPase; regulate the Na and K that are inside and outside the cell; needed for excitability of cells; works continuously; releases Na out of the cell and takes in K; need ATP
channels
intramebranous proteins that transport substances like ions and water thru the plasma membrane
cell-life cycle
series of changes a celll goes thru from the time it is formed until it reproduces
interphase
the period of the cell cycle during which the nucleus is not undergoing division, typically occurring between mitotic or meiotic divisions
mitosis
process by which the nucleus and duplicated chromosomes of a cell divide and are evenly distributed, forming two daughter nuclei
cytokinesis
division of the cytoplasm during cell division
RNA
single stranded; can leave the cell; part of protein syntheis by forming chains of amino acids
amino acids
consists of codons of mRNA in chains that form proteins
glycolipid
lipids with attached sugar group found outside plasma membrane; make up the end of Glycocalyx
primary germ layers
make up four primary tissues
ectoderm
forms the nervous tissue
mesoderm
forms the muscle and connective tissue
endoderm
forms epithelium
stratum basale
deepest epidermal layer; attached to the dermis layer, also called stratum germintivum; highly mitotic; single row of stem cells
stratum spinosum
several layers of cells thick, prickly cells
stratum granulosum
3-5 cells thick, process of keratinization is beginning; keratohyaline granules in cells help produce keratin in upper layers and lamellated granules contain water resistant glycolipid
stratum lucidum
thin translucent layer found in thick skin like palms and heels; 2-3 cells thick of flat clear keratinocytes
stratum corneum
outermost layer of skin; 20-30 cells thick; provides a durable outercoat of body that protects inner cells
dermis
strong, flexible connective tissue; papillary layer is areolar connective tissue; reticular layer is coarse irregular dense fibrous connective tissue
hair
produced by a hair follicle consists of heavily keratinized cells; has a central medulla, cortex, and outer cuticle, root and shaft portions
nails
scale-like modifications of skin; nail matrix is constantly growing
rule of nines
divides body into 11 areas each counting for 9% of the body to calculate how much of the body has been burned
first degree burns
results in redness, swelling, and pain; tends to heal in 2-3 days without special attention; only affects epidermis
second degree burns
affects epidermis and top half of dermis; results in blisters; skin regeneration occurs with little to no scarring in 3-4 weeks
third degree burns
full thickness burns; appears grey-white; cherry red or blackened; initally little to edema; since nerve endings have been destroyed there is no pain; skin grafts usually needed
rotation
the turning of a bone on its own axis
flexion
reduces the angle of the joint
extension
increases the angle of the joint
abduction
to move away from middle line of body
adduction
to move towards middle line of body
circumduction
movement of a body part so that it outlines a cone in space
supination
turning backward
pronation
turning forward
dorsiflexion
pointing outwards
plantar flexion
flexion of wrist or ankle
inversion
foot turns medially
eversion
sole facing laterally
protraction
jutting out of jaw
retraction
pulling jaw back
depression
moving elevated body part inferiorly
opposition
touching thumbs to tips of fingers of same hand
plane joints
allow only short axial gliding movements
pivot joint
uniaxial rotation of one bone across its own axis
condyloid joint
allows flexion and dorsiflexion, adduction and abduction and circumduction
saddle joints
found in fingers
muscle contraction
calcium ions released after a nerve signal and binds with troponin and triggers tropomyosin to shift, exposing the actin filaments active sites. myosin binds with available sites of actin forming cross-bridges. myosin heads release ADP and used phosphate from ATP used as energy and moves toward midpoint sarcomere, pulling actin with it (power-stroke) Z discs pulled together and H zones get smaller, sarcomeres shorten
fetal blood flow thru heart valves
placenta delivers oxygen rich blood to the veins leading to the heart and throughout the fetal body; arteries carry oxygen low blood out of the body to the placenta
diastole
period of cardiac cycle when either artia or ventricles are resting
systole
period of cardiac cycle when either atria or ventricles are contracting
purkinje fibers
modified ventricular muscle fibers of the conduction system of the heart
SA node
specialized myocardial cells in the wall of the right atrium; pacemaker of the heart
AV node
specialized mass of conducting cells located at the atrioventricular junction of the heart
bundle of his
bundle of specialized fibers that conduct impulses from the AV node to the right and left ventricles; also called atrioventricular bundle
P wave
atrial depolarization
QRS
ventricular depolarization and atrial re-polarization
ST interval
entire ventricles are depolarized
T wave
ventricular re-polarization begins
neutrophils
phagocytize bacteria
platelets
fragments of megakaryocytes; needed in coagulation of blood
eosinophils
kill parasitic worms; complex role in allergy and asthma
basophils
release histamine and other mediators of inflammation; contain herapin, an anticoagulant
lymphocytes
mount immune response by direct cell attack or via antibodies
monocytes
phagocytosis; develop into macrophages in the tissues
erythropoietin
EPO; hormone released from the kidneys to stimulate RBC production
albumin
60% of plasma proteins; produced by liver; main contributor to osmotic pressure
globulins
30% of plasma proteins; alpha and beta- bind to ions, lipids, and fat soluble vitamins; gamma- antibodies released by plasma cells during immune response
fibrinogen
4% of plasma proteins; produced by liver, forms threads of blood clots
coagulation
phase 1- prothrombin activator formed; phase 2- prothrombin activator converts prothrombin into thrombin (enzyme); phase 3- thrombin catalyzes fibrinogen molecules into a fibrin mesh that traps blood cells and effectively seals the hole until blood vessel is repaired
blood pressure maintenance
depends on cardiac output, peripheral resistance, and blood volume, vasomotor center regulates cardiac output and blood vessel diameter; baroreceptors detect changes in blood vessel diameter
physiological response to exercise
increases respiratory pump, activity of muscular pump, and sympathetic venoconstriction- increases venous return- increases end diastolic volume- increases stroke volume- increases cardiac output
hyperventilation
an increased depth and rate of breathing greater than demanded by the body needs
hypoventilation
Reduction in the volume of air that enters the lung for gas exchange; oxygen exchange insufficient to meet metabolic demands of the body
PCO2
if levels rise the CO2 accumulates in the brain and results in carbonic acid dissociation; the H+ that are released stimulate the chemoreceptors in the brain stem and increase the depth and rate of breath
control of respiration
nerves in the medulla and pons, medulla contains rhythm generating and integrative center; pons smooths out transitions between inspiration and expiration
blood pH
if CO2 levels are high then the pH of the blood drops; if the CO2 levels are low then the pH rises
PO2
O2 sensors that cause the respiratory centers to increase ventilation; significant drops in PO2 needed to increase ventilation
salivary glands
parotid, submandibular, sublingual; secretes saliva (salivary amylase, water, electrolytes, mucin, metabolic wastes)
stomach
different layers of muscle used to digest food; rugae helps grind up food; gastrin released to increase HCl secretion; histamine released to activate parietal cells to release HCl; serotonin released to contract stomach muscles; somatostatin released to inhibit gastric secretions of all products; vasoactive intestinal peptide (VIP) released to inhibit acid secretion; pepsin used to digest proteins
gallbladder
thin-walled muscular sac on the ventral surface of the liver; stores and concentrates bile by absorbing its water and ions; releases bile via the cystic duct that flows into the bile duct
bile
yellow-green solution containing bile salts, bilirubin, cholesterol, fats, phospholipids, and electrolytes
pancreas
under stomach, spleen connected to it; pancreatic islets secrete insulin and glucagon; acini secrete pancreatic juice; zymogen contain digestive enzymes; pancreatic juice neutralizes chyme and has electrolytes, amylase, lipases, nucleases, proteases
CCK (cholecystokinin)
potentiates secretin's actions on organs; also involved in anxiety, pain, memory; inhibits appetite
enzymes that digest proteins
pepsin (stomach); trypsin, chymotrypsin, carboxypeptidase (pancreatic proteases); aminopeptidases, carboxypeptidases, dipeptidases (brush border enzymes)
enzymes that digest nucleic acids
pancreatic ribonucleases and deoxyribonuclease
liver
lobed accessory organ that overlies the stomach; produces bile to help digest fats and serves other metabolic and regulatory functions
hypothalamus
region of the diencephalon forming the floor of the third ventricle of the brain
posterior pituitary gland
hypothalamic-hypophyseal tract; oxytocin and ADH
anterior pituitary gland
hypophyseal portal system; GH, TSH, ACTH, FSH, LH, PRL
growth hormone-GH
produced by somatrophs in the anterior pituitary; stimulates liver, skeletal muscle, bone and carilage to produce insulin-like growth factors, but targets bone and skeletal muscle
thyroid-stimulating hormone-TSH
produced in anterior pituitary; stimulates normal development and secretory activity of the thyroid
andernocorticotropic hormone- ACTH
produced by anterior pituitary; stimulates adrenal cortex to release corticosteroids
follicle-stimulating hormone-FSH
produced by anterior pituitary; stimulates gamete production
luteinizing hormone-LH
produced by anterior pituitary; promotes production of gonadal hormones
prolactin-PRL
produced by anterior pituitary; stimulates milk production
oxytocin
stored in posterior pituitary; stimulates contractions during childbirth and also triggers milk ejection in women producing milk, plays role in sexual arousal and orgasms
antidiuretic hormone-ADH
stored in posterior pituitary; also known as vasopressin; responds to changes in solute concentration in the blood
thyroid hormone-TH
2 related compounds T4 (thyroxine) and T3 (triiodothyronine); produced by thyroid gland; major metabolic hormone; maintains BP, regulates tissue growth, develops skeletal and nervous system, reproductive capabilities
calcitonin
produced in C cells of thyroid gland; inhibits osteoclast activity and release of Ca2+ from bone; stimulates Ca2+ uptake and incorporation into bone matrix
parathyroid hormone-PTH
released by parathyroid gland; stimulates osteoclasts to digest bone matrix; enhances reabsorption of Ca2+ and secretion of phosphate by the kidneys; promotes activation of vitamin D
aldosterone
mineralocorticoid released by the adrenal cortex; stimulates Na+ reabsorption and water retention by the kidneys
cortisol
glucocorticoid released by adrenal cortex; keeps blood sugar levels relatively constant; maintains BP by increasing action of vasoconstrictors; causes gluconeogenesis; promotes rise in blood glucose, fatty acids, and amino acids
androgens (estrogen and testosterone)
gonadocorticoids released by adrenal cortex; contributes to onset of puberty, appearance of sex characteristics, and sex drive
epinephrine and norepinephrine
secreted by adrenal medulla; cause blood glucose levels to rise, blood vessels to constrict, heart to beat faster, blood to be diverted to the brain, heart, and skeletal muscle; epinephrine stimulates metabolic activities, bronchial dilation, and blood flow to skeletal muscles
melatonin
derived from serotonin and released from pineal gland; affects timing of sexual maturation and puberty, day/night cycles, physiological processes that show rhythmic variations
glucagon
released from pancreas; major target is liver; promotes glycogenolysis, gluconeogenesis, and release of glucose to the blood
insulin
released by pancreas; lowers blood glucose levels; enhances glucose transport into fat and muscle cells; part of neural development, learning and memory; inhibits glycogeolysis and gluconeogenesis; increases cellular respiration; glycogenesis; converts glucose to fat
progesterone
maturation of female organs, appearance of female secondary sex characteristics, and breast development and cyclic changes in uterus mucosa
atrial natriuretic peptide-ANP
released by heart; reduces BP, BV, and Na+ concentration in blood 176. Erythropoietin- released by kidneys; signals production of RBCs
renin
released by kidneys; initiates renin-angiotensin mechanism
cholecalciferol
released by skin; precursor to vitamin D
lepton
released by adipose tissue; involved in appetite control and stimulates increased energy expenditure
thymus
releases thymulin, thymopoietins, and thymosins; all involved in normal development of T lymphocytes in immune response
osteocalcin
released by osteoblasts; produces pancreatic beta cells to divide and secrete more insulin, improving glucose handling and reducing body fat
kidney
removes toxins, metabolic wastes, and excess ions from the blood; regulated blood volume, chemical composition and pH; gluconeogenesis
mechanism of urine formation
1. glomerular filtration; 2. tubular reabsorption (returns all glucose, amino acids, 99% of water, salt and other components to the blood; 3. tubular secretion (reverse of reabsorption, selective addition to urine
nephron
structural and functional unit of kidney; consists of glomerulus and renal tubule
urine
95% water, 5% solutes, Na+, K+, PO4(3-), SO4(2-), Ca2+, Mg2+, HCO3-, urea, uric acid, and creatinine
hormonal regulation of male repo. function
GnRH stimulates FSH and LH; FSH stimulates release of androgen-binding protein (ABP) which makes spermatogenic cell receptive to testosterone, LH stimulates release of testosterone which triggers spermatogenesis
hormonal regulation of female repo. function
GnRH stimulates FSH and LH which trigger growth of several follicles and estrogen release, estrogen inhibits LH and FSH; sudden LH surge at day 14 which triggers ovulation and transforms ruptured follicle into corpus luteum which forms inhibin, progesterone, and estrogen; inhibits LH and FSH release, ends luteal activity and inhibits follicle development; days 26-28 corpus luteum degenerates and ovarian hormone levels drop sharply
menstration
days 1-5 menstrual phase: ovarian hormones are at lowest, gonadotropins beginning to rise, stratum functionalis is shed and menstrual flow occurs; days 6-14 proliferative phase: estrogen levels prompt generation of new functional layer, increases synthesis of progesterone receptors in the endothelium, glands enlarge and spiral arteries increase in #; days 15-28 secretory phase: endothelium prepares for implantation of embryo, progesterone causes spiral arteries to form functional layer
conception
the developing of offspring
implantation
completed by the 12th day after ovulation; after conception, cell divides after 36 hours, by 72 hours 16 or more cells, at day 3 or 4 forms a blastocyst that floats for 2-3 days, implantation begins 6-7 days after ovulation and is complete by the 12th day
stages of labor
dilation stage: 6-12 hours, longest part of labor, initial weak contractions, cervix opens 10cm, amnion ruptures and releases amniotic fluid; expulsion stage: strong contractions every 2-3 minutes about 1 min long, urge to push increases, crowning occurs, delivery of infant; placental stage: strong contractions continue and cause detachment of placenta and compression of uterine blood vessels, delivery of afterbirth occurs about 30 min after birth, all placental fragments must be removed to prevent postpartum bleeding
central nervous system- CNS
brain and spinal cord; integrating and command center of the nervous system; interprets sensory input and dictates motor responses based on reflexes, current conditions, and past experiences
peripheral nervous system-PNS
the part of the nervous system outside of the CNS; mainly consists of the nerves that extend from the brain and spinal cord; 2 main divisions: sensory and motor
spinal nerves
carry impulses to and from the spinal cord
cranial nerves
carry impulses to and from the brain
sensory division
part of the PNS; afferent; consists of nerve fibers that convey impulses to the CNS from sensory receptors throughout the body
motor division
part of the CNS; efferent; transmits impulses from the CNS to effector organs (muscles and glands); has to major parts: somatic nervous system and autonomic nervous system
somatic nervous system
composed of somatic motor nerves fibers that conduct impulses from the CNS to skeletal muscles; often referred to as voluntary nervous system
autonomic nervous system-ANS
consists of visceral motor nerve fibers that regulate activity of smooth and cardiac muscles and glands; also referred to as the involuntary nervous system; has 2 functioning subdivisions: parasympathetic division and sympathetic division
sympathetic division
prepares body for activity or to cope with some stressor; fight or flight response; increased heart rate
parasympathetic division
oversees digestion, elimination, and glandular function; rest and digest; decreased heart rate
multipolar neuron
have 3 or more processes, one axon and the rest dendrites; most common neuron in human body, 99% of neurons; major neuron type in CNS
bipolar neuron
have 2 processes and axon and a dendrite that extend from opposite side of the cell body; rare neurons found in special sense organs
unipolar neuron
single short process that emerges from cell body and divides like a T, a central process that enters the CNS and a peripheral process that is associated with a sensory receptor; found chiefly in the ganglia in the PNS where they function as sensory neurons
reflex arc
reflexes that occur over neural pathways; rapid automatic responses to stimuli
acetocholine-ACh
first neurotransmitter to be identified; released at neuromuscular junctions; synthesized from acetic acid and choline by the enzyme family cholinesterase; enables muscle action, learning and memory
fight or flight response
body provides energy, reflexes, and strength needed to respond to stressors; epinephrine (adrenaline) released, preps body for quick action by triggering: increased breathing to increase O2 levels, increased heartbeats to increase blood flow, muscles tense up for quick movement, pupils dilate and increase light intake for sensitive vision, decreased digestion, and increased blood glucose for increase energy in body
myelin sheath
fatty insulating sheath that surrounds all but smallest nerve fibers; protects and electrically insulates fibers and increases speed of impulse transmission
astrocyte
a type of CNS supporting cell; assists in exchanges between capillaries and neurons
ependymal cells
a type of CNS supporting cell; lines the central cavities of the brain and spinal cord
microglia
a type of CNS supporting cell; can transform into phagocytes in the areas of neural damage or inflammation
oligodendrites
a type of CNS supporting cell that composes myelin sheaths
satelites cells
a type of supporting cell of the PNS; surround neuron cell bodies located in PNS; assists in exchange between capillaries and neurons
schwann cells
a type of supporting cell of the PNS; forms myelin sheaths and is vital to peripheral nerve fiber regeneration
synapse
functional junction between 2 neurons or a neuron and an effector cell
dopamine
influences movement, learning, attention, and emotion; "feeling good" neurotransmitter
serotonin
affects mood, hunger, sleep, and arousal
GABA (gamma-aminobutyric acid)
a major inhibitory neurotransmitter; results in impaired motor control
glutamine
a major excitatory neurotransmitter; involved in memory and learning
endorphins
natural opiates; pain perception; inhibit pain
tachykinins
mediates pain transmission in PNS; also involved in respiratory and cardiovascular controls and mood
somatostatin
often released with GABA; gut-brain peptide hormone; inhibits growth hormone release
adenosine
caffeine, tea, and chocolate stimulate by blocking adenosine receptors; may be involved in sleep-wake cycle and terminating seizures; dilates arterioles, increasing blood flow to heart and other organs
neurotransmitter receptors
either channel-linked receptors or G-protein linked
action potential
large transient depolarization event, including polarity reversal that is conducted along the membrane of a muscle cell or nerve fiber
depolarization
Na+ flows into the cell
repolarization
K+ flows out of the cell
hyperpolarization
caused by K+ continuing to leave the cell
resting state
when no ions are moving in or out of cell
diencephalon
thalamus: sensory impulses ascending to sensory cortex inputs subcortical motor cortex, impulses from lower centers; hypothalamus: important ANS control center, water balance, regulates thirst, hunger, body temp, gastrointestinal activity, and anterior pituitary gland activity; and epithalamus: pineal gland extends from posterior border
brain stem
midbrain: visual and auditory reflex centers, subcortical motor center, pain suppression; pons: conduction area, regulates respiration; medulla oblongata: regulates respiratory rhythm, heart rate, BP, cough, sneeze, vomit, swallow centers in medulla
cerebellum
frontal: reasoning, planning, problem solving, parts of speech, movement, and emotion; parietal: movement, orientation, recognition, perception of stimuli; occipital: visual processing; temporal: perception and recognition of auditory stimuli, memory, and speech
chemoreceptor
receptor sensitive to various chemicals in solution
mechanoreceptor
receptor sensitive to mechanical pressure such as touch, sounds, or exerted by muscle contraction
nociceptor
receptor sensitive to potentially damaging stimuli that result in pain
osmoreceptor
structure sensitive to osmotic pressure or concentration of solution
photoreceptor
specialized receptor cells that respond to light energy; rods and cones
retina
neural layer of the eyeball; contains photoreceptors
lens
biconvex, transparent, flexible, elastic and avascular; allows precise focusing of light on the retina; cells of lens differentiate into lens fibers that form the bulk of the lens
depth perception
both eyes view the same image from slightly different angles; depth perception results from cortical fusion of the slightly different images
pharyngotympanic tube
connects the middle ear to the nasopharynx; equalizes pressure in the middle ear cavity with the external air pressure
ear bones
malleus, incus, and stapes; transmit vibratory motion of the eardrum to the oval window; causes amplified sound
bony labyrinth
tortuous channels in the temporal bone; vestible, semicircular canals, and cochlea
vestibule
central egg-shaped cavity of the bony labyrinth; saccule is continuous with the cochlear duct; utricle is continuous with the semicircular canals; house equilibrium receptor regions; responds to gravity and changes in the position of the head
semicircular canals
3 canals that each define 2/3 of a circle; membranous semicircular ducts line each canal and communicate with the utricle; ampulla of each canal houses equilibrium receptor region called the crista ampullaris; receptors respond to angular movements of the head
cochlea
spiral, conical, bony chamber; extends from the vestible; coils around bony pillar; contains the cochlear duct, which houses the spiral organ of Corti and ends at cochlear apex
agglutination
clump of foreign cells induced by cross-linking of antigen-antibody complex
antibody
protein molecule released by plasma cell (daughter cell of activated B cell) that binds specifically to antigen; immunoglobulin
antigen
substance tor part of a substance recognized as foreign by immune system, activates immune system, reacts with immune cells
autoimmunity
product of antibodies or effector T cells that attack a person's own tissue
cell-mediated immunity
immunity conferred by activated T cells which directly kill infected or cancerous body cells or cells of foreign grafts and release chemicals that regulate immune response
clonal selection
B or T cells activated by binding with antigen
cytokinesis
small proteins that act as chemical messengers between various parts of the immune system
cytotoxic T cells
effector T cell that directly kills foreign cells, cancer cells, or virus-infected cells by inducing apoptosis
helper T cells
orchestrates cellular immunity by direct contact with other immune cells and releasing chemicals called cytokines, also helps to mediate humoral response by interacting with B cells
humoral immunity
immunity conferred by antibodies present in blood plasma and other body fluids
immune system
a functional system whose components attack foreign substances or prevent their entry into body
killer T cell
effector cell that directly kills foreign, cancer, or virus-infected body cells by inducing apoptosis
Treg cells
population of T cells (CD4) that suppress immune response
T cells
lymphocytes mediate cellular immunity; mature in thymus
B cells
oversee humoral humoral immunity; differentiate into antibody-producing plasma cells; mature in red bone marrow
antibody structure
T or Y shaped monomer of 4 looping linked polypeptide chains; 2 identical H chains and 2 identical L chains
IgM
first antibody released; agglutinating agent; fixes and activates complement
IgA
in mucus and other secretions; helps prevent entry of pathogens
IgD
attached to surface of B cells ; B cell receptor
IgG
75-85% of antibodies in plasma; secondary and late primary responses; crosses placental barrier
IgE
active in some allergies and parasitic infections; causes mast cells and basophils to release histamine
specific immunity
adaptive defense; 3rd line of defense; attacks particular foreign substances; takes longer to react
non-specific immunity
innate defense; 1st and 2nd defense; first line is external body membranes; second is antimicrobial proteins, phagocytes and other body cells; inhibit spread of invaders; inflammation is its most important response
inflammatory response
triggered whenever body tissues are injured by physical trauma, intense heat, irritating chemicals, or infection. prevents spread of damaging agents; disposes of cell debris and pathogens; sets stage for repair
complement fixation
main antibody defense against antigens; several antibodies bind close together in cellular antigen; complement binding sites trigger complement fixation into cell surface; complement triggers cell lysis, amplifies inflammatory response, opsonsization, enlists more defensive agents