ap bio 4

Mast cells

Mast cells

secrete histamine as part of the inflammatory response causing blood vessels to dilate

Inflammatory response

redness, swelling, heat, and pain; triggers increased activity of phagocytes in the inflamed area

Natural killer cells

part of innate immunity; release chemicals to inhibit spread of viruses and cancer cells

Complement system

involves antimicrobial proteins that work together in a cascade; a complex forms causing water and ions to rush into bacterial cell which makes it swell and burst

Clonal selection

involves a B or T cell undergoing multiple divisions to produce clones; some become short-lived plasma cells that secrete antibodies and others become long-lived memory cells

Adaptive immunity

also called acquired immunity; develops after exposure to microbes or toxins and allows for rapid defense against an antigen that has been encountered before

B cells versus T cells

B cells are part of humoral immunity (things outside the cell) and are important for antibody production; T cells are involved cell-mediated immune response and defend against pathogens and cancer inside cells using cytotoxicity

Helper T cells

release cytokines to stimulate differentiation in B cells and T cells

Passive immunity

transfer of antibodies from one organisms to another; can be naturally acquired if antibodies cross the placenta or during breastfeeding or can be artificially acquired through injections of antibodies

MHC

major histocompatibility complex are host proteins that display antigen fragments on the cell surface; presentation of MHC-antigen complex on a cell surface is crucial for the adaptive immune response to be activated

Vaccination

form of artificially acquired active immunity; some vaccines are given yearly because certain viruses undergo rapid mutation which alters surface proteins in infected host cells

Autoimmune disease

self molecules are treated as non-self

Prostaglandins

local hormones comprised of fatty acids

Hormone

chemical message; same hormone can have different effects on target cells because they have different receptors for the hormone or different signal transduction pathways

Steroid hormone

lipid soluble so they easily cross the phospholipid bilayer

Positive feedback

reinforces a stimulus to produce an even greater response; ex: oxytocin during labor and delivery enhances uterine muscle contractions

Pancreas

has exocrine and endocrine functions; exocrine = digestive enzymes; endocrine = insulin and glucagon to regulate blood sugar levels

Antagonistic hormones

have opposing effects; ex: insulin lowers blood sugar and glucagon raises it; parathyroid hormone raises plasma levels of calcium and calcitonin decreases it

Hypothalamus

makes the hormones secreted by the posterior pituitary

Fight or flight

involves a response from the adrenal medulla which leads to secretion of epinephrine (adrenaline)

Pineal gland

secretes melatonin to regulate our sleep wake cycle

Hormone action

hormones will trigger different responses in different organisms because their structures are different among different species

Somatic nervous system

motor neurons can alter the activity of target cells because signals bind to receptor proteins on skeletal muscles

Sodium-potassium pump

causes sodium ions to move out of the cell and potassium ions to move into the cell

Threshold

the minimum depolarization needed to operate the voltage-gated sodium and potassium channels

Action potentials

move down the length of the axon

Acetylcholine

ligand-gated sodium channel; acetylcholine is released into the junction between a motor neuron and skeletal muscle binds to a sodium channel to open it

Gamma-aminobutyric acid (GABA)

amino acid that operates at most inhibitory synapses in the brain

Myelinated neurons

allows impulse transmission to occur at a faster rate using saltatory conduction; demyelinated fibers have slower impulse transmission; especially abundant in white matter of the brain and white matter of the spinal cord

Antagonistic actions

opposing actions such as what is found in the sympathetic and parasympathetic nervous system

Corpus callosum

allows communication between the left and right hemisphere of the cerebral cortex

Cerebrum

associated with cognitive thought, calculations, and contemplation

Cerebellum

coordination and balance

Medulla oblongata

regulatory centers for the circulatory and respiratory centers

Hypothalamus

regulation of body temperature

Speech

controlled by Wernicke’s and Broca’s regions of the brain

Occipital lobe

responsible for vision

Cerebral cortex

responsible for formation of long-term memories