Biology Flashcards
Adrenal cortex
- releases/synthesizes corticosteroids
ex: glucocorticoids (stimulated by ACTH), mineralocorticoids(stimulated by angiotensin II), androgen, testosterone
Adrenocorticotropic hormone
-synthesized and released in anterior pituitary
- regulated by corticotropin releasing factor (CRF)
- stimulated adrenal gland to release glucocorticoids
Action potential
- sharp change in the membrane potential on a neuron or muscle cell
- caused by a change in selective permeability to Na+ and K+ ions
- gated ion channels
- all or nothing eventA
Acrosome
-large vesicle at the head of a sperm
- contains enzymes to break down the ovum cell membrane to allow for fertilization
Adrenal Medulla
-synthesizes and releases epinephrine and norepinephrine
- causes an increase in metabolic rate and blood glucose
Adaptive Immunity
- form of immunity in response to exposure to pathogens
- consists of humoral and cytotoxic immunity
- compare with : INNATE immunity
Afferent neurons
- carry information from the periphery to the central nervous system
- aka sensory neurons
Aldosterone
- steroid hormone
- produced in the adrenal cortex
- reabsorption of Na+ and water
- excretion of K+ and H+ ions
Allantois
- embryonic membrane
- contains embryo waste products
Alleles
- genes coding for different forms of a given trait
Amino acid - derivative hormones
- synthesized by changing amino acids
- some act as second messengers while others act similar to steroid hormones
Amnion
- innermost extraembryonic membrane
- produces amniotic fluid
Anterior pituitary
-synthesizes vital hormones such as:
–andrenocorticotropic
–follicle stimulating
– lutenizing
– thyroid
– prolactin
– endorphins
– growth hormones
- under control of the hypothalamus
Antidiuretic hormone (ADH)
- peptide hormone also known as VASOPRESSIN
- acts on the collecting duct to increase water reabsorption
- produced by the hypothalamus
- stored in posterior pituitary
Antigen
- bound by an antibody, causing an immune reaction
appendicular skeleton
- pelvis
- pectoral girdles
-limbs
Archenteron
- central cavity in the gastrula stage of embryonic development
- lined by endoderm
- gives rise to adult digestive tract
Arteries
-vessels that carry blood away from heart
- muscular, no valves
Ascending loop of henle
- portion of nephron NOT permeable to water
- filtrate flows up through decreases concentration in interstitium
- NaCl passively then actively removed from filtrate, decreasing filtrate concentration
Atria
- two thin-walled upper chambers of heart
- right atrium: deoxygenated blood from venae cavae
- left atrium : oxygenated blood from the pulmonary veins
Atrioventricular valves
- valves located between the atria and ventricles (tricuspid and mitral valves)
Axial skeleton
- skull
- vertebral column
- ribcage
-hyoid bone
Axon hillock
- portion of neuron connect cell body (soma) to axon
- impulses neuron receives from dendrites are summed at the hillock
- determines if AP will occur
Bacteriophages
- viruses that can only infect bacteria
Bile
-alkaline fluid synthesized in the liver
- stored in gall bladder
- released into duodenum
- aids in emulsification/digestion/absorption of fats
Binary fission
-asexual reproduction
- prokaryotes
- circular DNA replicates the moves to edge of cell,
- cell divides into two daughter cells
Blastulation
- morula develops into a blastula
- fluid filled cavity called blastocoel
Blood antigens
- proteins or sugars found on the erythrocyte cell surface
- antigens to differentiate blood groups : A, B, Rh
- if host is transfused with erythrocytes containing antigens that host does not have:
— immune response + hemolysis
Blood buffer system
- relies on carbonic acid buffer system
- CO2 + H2O (interchange) H2CO3 (interchange) H + HCO-3
- release of carbon dioxide causes increased formation of water… increase in pH (basic)
- increased retention of HCO3- causes pH to rise as well
Carbonic anhydrase
-enzyme
-catalyzes conversion of carbonic acid to carbon dioxide and water
- formation of carbonic acid from CO2 and water
- important in bicarbonate buffer system
Cardiac muscle
- muscle found within heart
- one or two nuclei
- involuntary like smooth
-appears striated like skeletal - can depolarize independent of the nervous system
Cartilage
- firm, elastic translucent connective tissue
- consists of collagenous fibers embedded in chondrin
- produced by cells called chondrocytes
- principal component of embryonic skeletons
-can harden and calcify into bone (ossify)
Catecholamines
- norepinepherine, epinephrine, and dopamine neurotransmitters
- hormones produced by adrenal medulla that play a significant role in sympathetic nervous system
Cell-mediated (cytotoxic) immunity
- branch of immune system in which intracellular pathogens are eliminated by killing host cells
- T cells are primary mediators of cytotoxic immunity
Cell theory
- foundational belief in modern biology
- all living things are composed of cells
- cells are the basic functional unit of life
- all cells arise from preexisting cells
- DNA is genetic material
Central nervous system (CNS)
- brain and spinal cord
centrosome
- portion of cell containing centrioles
Chemical digestion
- enzymatic breakdown of large molecules into smaller molecules
Cholecystokinin
- hormone secreted by duodenum in response to presence of chyme
- CCK stimulates release of bile and pancreatic enzymes into small intenstine
- promotes satiety
Chorion
outermost extraembryonic membrane
- contributes to formation of placenta
Chromatin
- chromosomes in uncoiled state
- chromatin itself is not visible as organized chromosomes under a light microscope
Chyme
- combination of partially digested food and acid that forms in stomach
Codominance
- organism heterozygous for a trait will have phenotype that expresses both alleles in full
- both alleles are dominant
Collecting duct
- portion of nephron permeable to water and ions
- filtrate flows down collecting duct through increaseing concentration of interstitium, filtrate is concentrated
- degree of water reabsorption in collecting duct controlled by hormone ADH
Compact bone
- more dense than spongy bone
- consists of haversian system (osteons)
Conjugation
- temporary joining of two organisms vis a pilus
- genetic material is exchanged
- form of sexual reproduction used by bacteria
Corona Radiata
- outer layer of cells surrounding oocyte
- derived from follicular cells
corpus luteum
- tissue that forms from collapsed ovarian follicle
- produces and secretes progesterone and estrogen
Crossing over
-exchange of genetic material between homologous chromosomes
- prophase I of meiosis
- aids in evolution and genetic diversity by unlinking linked genes
depolarization
- voltage gated Na+ channels open, allowing Na+ to rush into the cell
Dermis
layer of skin beneath the epidermis that is subdivided into papillary layer and reticular layer
- contains sweat glands, sense organs , blood vessels and bulbs of hair follicles
- derived from mesoderm
Descending loop of Henle
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