teas prep Flashcards
Hypothalamus endocrine function
integration between the endocrine and nervous system. produces releasing hormones that stimulate and inhibit hormones that restrict production of several hormones produced by the anterior pituitary.
Pineal gland endocrine function
produces melatonin
pituitary gland endocrine function
releases hormones that regulate growth and development
thyroid endocrine function
controls rate at which body produces energy from nutrients
parathyroid endocrine function
produces parathyroid hormone for regulation of calcium levels in blood
thymus endocrine function
develops t-cells (defend body from pathogens)
adrenal gland endocrine function
creates adrenaline and cortisol
pancreas endocrine function
secretes hormones in charge of blood sugar homeostasis
testes/ ovaries endocrine function
produce hormones that relate to sexual development and reproduction
hormones are
chemical messengers secreted by ductless glands
negative feedback
counteracting. counter active responses that keep homeostasis.
Ex. the release of insulin triggers uptake of glucose into cells, lowering blood glucose levels.
Positive feedback
(more, more, more)
Ex. contractions cause pressure which causes release of more hormones which causes more contractions which causes more pressure.
homeostasis
the maintenance of a constant internal environment. Maintained largely through negative feedback mechanisms
Beta cells of pancreas
secrete insulin and detect levels of glucose. negative feedback
Alpha cells of pancreas
detect blood glucose levels and secrete glucagon if blood glucose levels are too low. negative feedback
glucagon role
stimulates target cells in liver to convert hepatic glucagon into glucose and release that glucose into the blood.
gigantism
can be due to a benign tumor in the pituitary overriding effects of growth-hormone-inhibiting hormone (GHIH).
thyroid hormone plays part in
regulating growth, development and metabolic rate.
hyperthyroidism
malfunction of regulatory feedback loops which lead to overproduction of thyroid hormone (TH).
Melatonin produced by
the pineal gland in the center of the brain. cells of target organs are in the eye, the hypothalamus, and the anterior pituitary.
follicle stimulating hormone (FSH) secreted by
anterior pituitary and stimulates the development of eggs in ovaries and sperm in testes. Also stimulates production of ovaries’ primary hormonal secretion, estrogen.
luteinizing hormone produced by
anterior pituitary and responsible for triggering ovulation in female gonads and production of testosterone in male gonads
testosterone secreted by
the testes (primary hormone) and secreted in small quantities by the adrenal gland in both males and females.
steroid hormones made from
cholesterol and can pass easily through cell membranes because of their lipid composition.
Influence transcription in their target cells
proteins are
molecules composed of amino acids joined by peptide bonds
non steroid hormones are
water soluble and cannot pass between phospholipids of cell membranes. they bind to hormones on the receptors on cell surface and trigger changes in the receptor that signals molecules within the target cell.
thymus gland is larger in
children until about 6 years of age
parathyroid hormone
non-steroid hormone plays role in regulation of plasma calcium levels.
testosterone secreted by
testes and promotes development of male sex characteristics. Small quantities are produced n the adrenal glands in both males and females. Steroid hormone.
estrogen secreted by
ovaries and promotes the development of female sex characteristics. Steroid hormone.
epinephrine secreted by
the adrenal gland and regulates heart rate and blood pressure. Nonsteriod hormone.
follicle stimulating hormone secreted by
anterior pituitary and stimulates the development of eggs in ovaries and sperm in testes. non steroid hormone.
Glucagon secreted by
pancreas and triggers liver to convert hepatic glycogen stores into glucose and release it into the blood to lower blood glucose levels. Nonsteroid hormone.
growth hormone secreted by
the anterior pituitary and stimulates tissue growth. non steroid hormone.
inhibiting hormones secreted by
hypothalamus and restrict the production of certain morons. non steroid hormone.
insulin secreted by
pancreas and is a non steroid hormone that triggers the influx of glucose into cells thus lowering blood glucose levels.
luteinizing hormone secreted by
anterior pituitary and triggers ovulation in ovaries and production of testosterone by testes. non steroid hormone
melatonin secreted by
pineal gland and plays a role in maintaining circadian rhythms. non steroid hormone
oxytocin secreted by
posterior pituitary and stimulates uterine contractions during childbirth and milk ejection. non steroid hormone
parathyroid hormone secreted by
parathyroid and elevates plasma calcium levels. non steroid hormone.
releasing hormones secreted by
hypothalamus and stimulates production of certain hormones. non steroid hormone.
thyroid hormone secreted by
thyroid and regulates development and metabolic rate. non steroid hormone
how many bones in the body
206 and 300 in babies
bones contains
living tissue composed of cells, a collagen matrix, and minerals.
osteocytes are
matured bone cells and maintain bone and their thin cellular projections sense physical stresses on bone
osteoblasts are
immature bone cells and make new bone
osteoclasts
break down bone and perform mineral reabsorption by removing calcium form the bone so it can enter the bloodstream
how do neurons use calcium
to communicate with each other and rely upon its presence in extracellular fluid for normal muscle contraction inhibition
hypocalcemia causes
tetany which is involuntary and continuous contraction of skeletal muscles. this is caused by. sufficient deficits in plasma calcium
osteoporosis
too much calcium depleted from bones by osteoclasts which results in weak and brittle bones.
osteoblasts produce
a highly organized collagen matrix to which extracellular hydroxyapatite a calcium phosphate salt) binds too.
collagen protein’s give
bone flexibility, while minerals that encrust those fibers give them strength
Lamellae
mineral- laden collagen matrix in compact bone. Like rings of a tree
lacunae
microscopic pocket between lamellae where bone cells reside
canaliculi
microscopic tunnels transverse to lamellae and allow for communication between lacunae
osteon
grouping of concentric lamellae and contains a central canal within its inner most ring
central (Haversian) canals
passageways for nerves and blood vessels. allow bones to get oxygen and nutrients without being highly vascular
perforating (Volksman) canals
perpendicular and oblique canals carry small arteries throughout bones
compact bone
bone containing densely packed osteons that make up the peripheral layer of bone. make up plates of the skull and periphery of most other bones
spongy bone
type of bone having fewer osteons and therefore lighter than compact (dense) bone
red bone marrow
site of blood formation and plays a role in the immune system
yellow bone marrow
present within medullary cavity of adult long bones primarily composed of adipose tissue (fat)
femur
largest bone in the adult body containing the largest amount of yellow bone marrow
long bones description
have pronounced longitudinal axis, provide mechanical advantage of levers where they articulate with other bones
hinge joint found in
each elbow and knee and allows for flexion and extension of the more distal bone along only one plane
ball and socket joint found in
shoulders and hips and allow for articulation with other bones
short bones found in
wrists and ankles and have a width similar to their height and articulate with gliding joints
flat bones found in
plates of skull and connect with each other at fused joints called sutures
irregular bones
do not fit in other categories
soft tissue includes
cartilage, tendons, ligaments, and periosteum
Periosteum covers
bones
hyaline cartilage
protects bones where they are involved with articulations
cartilage is
the primary structural protein of connective tissue. and protects bone in articulating joints
osteoarthritis
degenerative bone disease causes inflammation and pain of a joint
rheumatoid arthritis
progressive autoimmune disease that causes joint inflammation and pain. Casued by autoimmune reaction
epiphyseal plate
growth plate. epiphyseal line develops when plate area stops producing cartilage indicating termination of growth in long bone
achondroplastic dwarfism
resulting short stature of individuals when epiphyseal plate stops growing as a premature age.
axial skeleton consists of
skull that shields the brain, thoracic cage of ribs and sternum that shelters the heart and lungs, and spinal column where the spinal cord resides.
also plays major role in metabolism and movement
appendicular skeleton
made up of 4 appendages
bones of arms, legs, hands, and feet
smallest bones in the skull
three auditory ossicles in ear
malleus, incus, and stapes
hyoid bone description
point of tongue and larynx attachment. only bones that does not articulate with the rest of the skeleton
vertebral column description
made of 3 groups of similarly shaped bones. The cervical, thoracic, and lumbar vertebrae
atlas description
cervical vertebra 1 on cranial end of vertebral column. has the two flat surfaces on top. allows for nodding yes
axis description
contains vertical projection (dens) that fits into atlas. allows for side to side shaking no motion of head.
fibrocartilage located
between vertebrae called intervertebral discs
pectoral girdle made up of
upper region of appendicular skeleton containing the right and left scapula and clavicles
upper limbs consist of
humerus, radius, and ulna
lower limbs consist of
femur, tibia, and fibula
muscles connect to bones with
tendons
prime mover
contracting muscle
antagonists
relaxed muscle
molecule is
an arrangement of two or more atoms bonded together
DNAs main functions
(1) to pass on information it encodes to the next generation (2) it provides the blueprint or recipes for maintaining cellular functions
gene is
a sequence of DNA that is the basic unit of heredity
DNA is
a macromolecule and a polymer made up of monomers linked together in a long chain
polymer is
a substance composed of similar units bonded together
monomer
molecules that can bind to similar or identical molecules to form a polymer. form covalent bonds with each other via dehydration reaction
nucleotides
monomers used to build DNA and RNA
deoxyribonucleotide is
a kind of sugar- highly modified- that is the monomer found in DNA
nitrogenous bases
usually called bases are adenine, thymine, guanine, and cytosine. hydrogen bonded.
DNA double helix is made up of
two polynucleotides wound around each other
DNA backbone made of
altering sugars and phosphates represented rings of a ladder
hydrogen bonds are
a type of non covalent bond
non covalent bond is
a relatively weak bond
adenine pairs with
Thymine
guanine pairs with
cytosine
nucleus
a large organelle within the cell that houses the chromosomes. Primary job is to sequester the DNA into enclosed information
genome
the complete set of genetic information in a cell
humans posses how many pieces of DNA
46 unique pieces of DNA
chromosome
a structure made of protein and one molecule of DNA. Humans posses 23 pairs of chromosomes. one form each parent
DNA stretched out
would be 6 ft long
genes
unit of heredity. sequences of DNA that encode something that the cell can use. encode for proteins or functional RNA molecules like transfer RNA (tRNA) and ribosomal RNA (rRNA). Built from only four nucleotides
eukaryotes
have a nucleus in each cell
purpose of non gene DNA
not clear, some scientists refer to it as junk DNA
mRNA
messenger RNA, a type of RNA that is produced by transcription of DNA
codons
triplets of bases that each code for an amino acid.
if genes are sentences, codons are the words within them.
proteins
polymers built of strings of amino acids. 20 common amino acids make up nearly every protein in nearly every organism on earth
genetic code
set of three-letter combinations of nucleotides called codons. 64 codons that specify the 20 amino acids
sequence of transcription and translation
DNA to RNA to protein
transcription and translation in protein synthesis stages
1st stage- RNA “transcribes”, or copies, DNA instructions to make a protein.
RNA copies from DNA gene
2nd stage- proteins use unwound DNA strand as a template and build complementary strand of mRNA
complementary strand
a molecule of RNA (or strand of DNA) synthesized from a complementary template strand
RNA coding
instead of Thymine base, RNA uses Uracil to make RNA from DNA template
A->U
T->A
where does protein synthesis take place
in ribosome also where translation occurs. “Machine” made of proteins and ribosomal RNA (rRNA)
3 codons give
a specific amino acid
ribosome process
ribosome binds to mRNA and reads each codon.
as codon is read by ribosome the codon is bound by a tRNA (using base parking rule) that has an amino acid hooked.
amino acid is transferred from its tRNA to a growing chain of amino acids held together by peptide bonds that cling to ribosome.
tRNA releases from codon, ribosome reads the b=next codon in line and process repeats
how many possible codons are there
64, each codon encodes for a specific amino acid
mitosis
cell division in eukaryotes that produce two identical daughter cells, each with the same chromosome number as the parent cell
chromatid
one of the two duplicate=s of a chromosome formed during the cell cycle.
pair of duplicates after replication is called sister chromatids
point mutation
simplest. a change in a single nucleotide that affects one codon.
Can change the structure of the completed protein
missense mutation
type of point mutation where an amino acid is changed
silent mutation
type of point mutation where amino acid is not changed
nonsense mutation
type of point mutation where mutation changes amino acid to a “stop”