Biology 2 Flashcards
What is embriology
the study of the development of a unicellular zygote into a complete multicellular organism
What are the steps of early development of vertebrates
fertilization
cleavage
gastriculation
What is fertilization
when an egg is entered into by a sperm
What is the window for fertilization for the egg
it can be fertilized between 12 and 24 hours after ovulation
where does fertilization occur
in the lateral, widest part of the oviduct or fallopian tube
What happens if more than one egg is fertilized
fraternal twins may be conceived
What is cleavage
early rapid mitotic division
what does cleavage do
leads to an increase in cell number without a corresponding growth in cell protoplasm (volume is constant)
What are the benefits of more cells to less cytoplasm created by cleavage
in increases the gas and nutrient exchange
What is an indeterminate cleavage
a cleavage that results in cell that maintain the ability to develop into a complete organism
what is a result of indeterminate cleavage
identical twins
What is a determinate cleavage
a cleavage that results in cell who have different pathways that are determined at an early developmental stage
What is differentiation (embryology)
the specialization of cells that occurs during development
When does the first complete cleavage of the zygot occur
32 hours after fertilization
when does the 2nd and third cleavage of the zygote occue
60 and 72 hours after fertilization
how many cells does the embryo have after the first 3 cleavages
8
when does the zygote enter the uterus
after the third cleavage (72 hours)
What is the zygote called when it gets to the uterus
embryo
What is it called when the embryo continues to divide until a solid ball of cells forms
a Morula
What is blastulation
when the morula develops a fluid filled cavity called the blastocoel
What is it called when the morula becomes a hollow sphere of cells
a blastula
when does gastriculation occur
when the blastula has implanted in the uterine wall
What is gastriculation
when the blastula’s cells migrate to form a three layered structure called the gastrula.
What are the three layers of the gastrula called
Ectoderm
Endoderm
Mesoderm
What does the ectoderm turn into
The Integument,
the lens of the eye,
the retina, and
the nervous system
What is the integument
epidermis, hair, nails, epithelium of the nose, mouth and anal canal
What does the Endoderm turn into
epithelial linings of the digestive and respiratory tracts, parts of the liver pancreas thyroid bladder lininig
What does the mesoderm turn into
musculoskeletal system circulatory system excretory system goands connective tissue portions of the digestive and respiratory organs
What are the two types of early developent
external
internal placnetal
inter nonplacental
What are some examples of external development
fish eggs in water
reptile, bird eggs on land
What is different between the fertilization of fish eggs in water and reptile/bird eggs on land
fish eggs are fertilized externally
bird/reptile eggs are fertilized internally and then the egg is laid
How does a fish egg survive
the embryo develops within the egg feeding on the nutrients stored in the yolk
What is the purpose of the egg shell
to protect the developing embryo
What are the parts of an egg
Chorion
Allantois
Amnion
yolk Sac
What is the chorion of an egg, and what does it do
it is the lining on the inside of the shell, it permits gas exchange
What is the Allantois of an egg and what does it do
a saclike structure involved in respiration and excretion, it contains numerous blood vessels to transport O2, CO2, water, salt and nitrogenous waste
What is the amnion of an egg and what does it do
a membrane that encloses the amniotic fluid which provides an aquoeus environment that protects the develooping embryo from shock
What is the yolk sac of the egg and what does it do
it encloses the yolk, blood vessles in the yolk sac trasfer food to the developing embryo
What is a case of nonplacental internal development
marsupials and some tropical fish.
What happens wwith nonplacental internal development
the exchange of food and oxygen between the mother and young is limited so offspring may be born very young
What happens in placental internal development
the fetus receives oxygen and nutrients from it’s mother through a specialized circulatory system.
What does the placental circulatory system do besides deliver oxygen and nutrients to the fetus
it removes carbon dioxide and metabolic waste products
What are the two key components of the placental circulatory system
the placenta and the umbilical cord
When do the placenta and the umbilical cord develop
the first few weeks following fertilization
How does gas exchange to the fetus work
gas exchange happens across the placenta, the fetal lungs aren’t functional until birth
What four extraembryonic membranes turn into the placenta and the placenta
Amnion,
Chorion
Allantois
Yolk Sac
What is the amnion and what does it do
it is a thin tough membrane containing amnionic fluid.
What does amnionic fluid do
acts as a shock absorber of external pressure and localized pressure from contractions during labor
where does placental formation begin
with the chorion
What is the chorion
a membrane that surrounds the amnion
What is the allantois
a membrane that develops as an outpocket of the gut
What come of the allantois
the allantoic wall blood vessels develop and enlarge turning into the umbilical vessels.
What is the yolk sac
the site of early development of the blood vessels, is associated with the umbilical vessels
What is labor
a series of strong uterine contractions
What happens in the first stage of labor
Cervix thins and dialates
the amnionic sac ruptures releasing it’s fluids
relatively mild contractions
What happens in the second stage of labor
rapid contractions
birth of the baby
cutting of the umbilical cord
What happens in the third stage of labor
placenta and umbilical cord are expelled
What is the pupal stage of arthropods
when maturation is suspended in a temporary state. (like when a butterfly is in it’s cacoon)
When is differentiation of cells complete
when all organs of an organism reach adult form
What are the parts of a plant embryo
epicotyl cotyledons hypocotyl endosperm seed coat
What is the epicotyl
the precursor of the upper stem and leaves
What is the cotyledons
the seed leaves
how many seeds leaves do dicots have, and monocots
two for dicots
one for monocots
what is the hypocotyl
this develops into the lower stem and root
What is the endosperm
the endosperm grows and feeds the embryo
what happens to the endosperm in dicots
in dicots the endosperm is absorbed by the cotyledon
What is the seed coat
develops to form the outer covering of the ovule.
what makes up the seed
the seed coat and the embryo inside
What combines to form the fruit of a plant
the ovary walls, the base of the flower, and other consolidated pistil components
What is the purpose of the fruit
the fruit serves as a method of seed dispersal (air, water, animals)
Where is the seed released from
the seed is released from the ovary, and it will germinate under the proper conditions
What is growth in higher plants restricted to
embryonic (undifferentiated) cells called meristem cells
What do meristems do in plant development
they eventually undergo reproduction and elongate and differentiate into different cell types
What are the two types of meristems
Apical Meristems
Lateral Meristems
What are apical meristems
apical meristems are found in the tips of roots and stems, growth only occurs at these points
What are Lateral meristems
tissue found between the xylem and phloem. they allow for growth in diameter and can differentiate into new xylem and phloem cells
What is another name for lateral meristems
lateral meristems are also called cambium
When are lateral meristems of cambium active and non active
non active in monocots (grasses) or herbacious dicots (alfalfa)
Active in woody dicots like oaks
What is circulation in plants called
translocation
what is the primary organ of transport in the plant
the stem
what run up and down the stem
vascular bundles
What is found at the center of the stem
the fibrovascular bundle
What is in the fibrovascular bundle at the center of the stem
Xylem, phloem and cambium cells
What is the Xylem
thick walled, often hollow cells inside the vascular bundle at the center of the stem
What does the Xylem do
carry water and minerals up the plant and their thick walls gives the plant rigid support
What is the outer layer of the xylem called
the sapwood, and it is alive
What are the two types of Xylem cells that have been differentiated
vessel cells and tracheids
how does the xylem make water rise up the stem (3 things)
transpiration pull
capillary action
root pressure
How does transpiration pull contribute to the vertical movement of water up the xylem
as water evaporates from the leaves of plants a vacuum is created that pulls water up the stem
how does capillary action contribute to the vertical movement of water up the xylem
any liquid in a thin tube will rise due to the surface tension of the liquid and interactions between the liquid and the tube
how does root pressure contribute to the vertical movement of water up the xylem
water that enters the root exerts pressure that pushes water up the stem
What is the Phloem
thin-walled cells on the outside of the vascular bundle
What do the cells of the Phloem do
they transport nutrients (carbs) down the stem.
What are the two types of phloem cells
sieve tube cells
companion cells
Are phloem cells living
yep
What is the cambium
undifferentiated cells that are actively dividing that are found between the phloem and the xylem. they are responsible for the lateral growth of plants
What can the cambium cells becoe
either phloem cells or xylem cells
What are the layers of the stem from outside to inside
epidermis (outer bark) cortex phloem cambium xylem, pith
What is the pith
tissue involved in storage of nutrients and plant support
What are the functions of the roots of plants
absorb materials through root hairs
anchor the plant
(some provide energy storage reserves)
What plants roots’ provide a storage for energy reserves
carrots and turnips
What are root hairs
specialized cells of the root epidermis that increase surface area for absorption of water and minerals from the soil
What are the layers of the root
epidermis cortex phloem cambium xylem pith
What is circulation like in protozoans
movement of gas and nutrients in protozoans is accomplished by simple diffusion within the cell
What is circulation like in Cnidarians
have body walls that are two cells thick, all cell are in direct contact with either the internal or external environment so there is not need for a circulatory system
What are Cnidarians
hydra
What is circulation like in Arthropods
they have open circulatory systems in which blood is in direct contact with body tissues.
The circulation is caused by body movements
Blood flows through a dorsal vessel and into the sinuses where exchange occurs
What is a open circulatory system
blood is in direct contact with the body tissues
what is a closed circulatory system
blood is confined to vessels to deliver materials to cells that aren’t in direct contact with the external environment
What is circulation like in Annelids
- a closed circulatory system
- blood moves toward the head in the dorsal vessel by the main hearts coordinated contractions
- there are 5 pairs of vessels called aortic loops that connect the dorsal to the ventral vessel and function as additional pumps
- blood travels away from the head through the ventral vessel.
What are annelids
Earthworms
Do annelids (earthworms) have HGB
nope, they have HGB like pigment dissolved in aqueous solution.
What does the bicarbonate buffering system do
it can accommodate many pH imbalances that may occur in the body
What role does blood play in the buffering system
it acts as a carrier for the crucial gasses and ions used in the system
What is the function of the Cardiovascular system
transport of gasses
transport of nutrients
transport of waste
Where are Amino acids and simple sugars absorbed into the bloodstream
intestinal capillaries
What are the metabolic waste products that are brought into the blood then excreted
urea
water
Co2
What are veins
vessels that travel back to the heart
What causes the differences in the fetal cardiovascular system as opposed to the adult
the fetal system must bypass the lungs
What are the differences between the fetal and adult CDV system
foramen ovale
ductus arteriosus
ductus venosus
What is the foramen ovale in the fetual CDV system
a hole between the right and left atrium of the heart that forces blood to bypass the right ventricle
What is the ductus arteriosus
a connection between the aorta and the pulmonary artery that prevents any blood in the right ventricle from entering the lungs
What is the ductus venosus
moves blood from the umbilical vein to the inferior vena cava of the fetus, it bypasses the liver and takes the blood straight to the developing brain
What does the lymphatic system consist of
lymphatic vessels
lymph
lymph nodes
What does the lymphatic system do
- transports excess lymph to the CDV system to keep body fluid levels constant
- lymph nodes filter the lymph removing and destroying foreign particles and pathogens
What is lymph
interstitial fluid
what is in the lymph nodes
leukocytes
how much blood is in the average human body
4-6 liters
what percent of blood is liquid, what percent is cellular
55 percent liquid
45 percent cells
What is in the blood plasma
nutrients, salts, gases, wastes, hormones, and blood proteins
What are some blood proteins
albumin
fibrinogen
immunoglobins
What are the cellular components of blood
erthythrocytes
leukocytes
platelets
how many HGB molecules can one RBC hold
250 million
What is HGB called when it has O bound
oxyhemoglobin
What are the advantages of the biconcave disk shape of RBC
increased surface area for gas exchange
flexibility to fit through small capillaires
Where are RBC formed
from stem cells in bone marrow (there they lose their nuclei, mitochondria, and other organelles)
why do RBC’s lose all of their organelles in the bone marrow where they are formed
to make more room for HGB
how long do RBC’s last
120 days
Where are RBC’s phagocytized
in the liver and spleen
what is larger leukocytes of RBC’s
WBC’s
what is the function of WBC’s
- phagocytize foreign matter and organisms like bacteria
What are some different kinds of WBC’s
macrophages
lymphocytes
(T and B cells)
What are macrophages
WBC’s that have moved from the blood into the tissues where they can phagocytize pathogens or innitiate an immune response
what do lymphocytes do
they are involved in the immune response
production of antibodies (B cells)
cytolysis or death of infected cells (T cells)
What do B cells do
produce antibodies
What do T cells do
kill infected cells
What are platelets
cell fragments that lack nuclei and are involved in clot formation as a response to tissue injury
How does plateleg plug formation happen
- platelets upon contact with exposed collagen damaged vessel
- they secrete a chemical
- chemical causes them to adhere to one another
- this forms a platelet plug
What do both platelets and damaged tissue release
thromboplastin
What does thromboplastin do (with the aid of its cofactors Ca and Vit. K)
convert inactive plasma protein prothrombin to its active form Thrombin
What does Thrombin do
converts fibrinogen into fibrin
What does fibrin do
threads of fibrin coat the damaged area and trap blood cells to form a clot.
What is the purpose of a clot
prevention of excessive blood loss while the damaged tissue heals itself
What is the fluid left after blood clotting called
serum
Where does prothrombin come from
the liver
What are antigens
things that are foreign to the body
What are the two abilities of the immune system
- distinguish between self and nonself
2. remember nonself entities that it has encountered
What are the two specific defense mechanisms of the immune system
- Humoral immunity
2. Cell mediated immunity
What is humoral immunity
the production of antibodies in response to exposure to antigens
What is cell mediated immunity
cells that combat fungal and viral infection
What are responsible for both humoral and cell mediated immunity
lymphocytes
What is another name for antibodies
immunoglobins (Igs)
Where do antibodies come from
B cells
What do antibodies do
they recognize and bind to specific antigens and trigger the immune system to remove them
What are the two ways that antibodies get rid of antigens
- attract other cells (leukocytes) to phagocytize them
- cause the antigens to agglutinate (clump up) to form large, insoluble complexes that can be easily removed by phagocytic cells
What is active immunity
the production of antibodies during an immune response to antigens
how can active immunity be conferred
by vaccination
what is vaccination
injection of a weakened or inactive form of a particular antigen which stimulates creation of antibodies against that antigen
how long does active immunity take to build up
weeks
What is passive immunity
the transfer of antibodies produced by another individual or organism
How is passive immunity acquired
passively
injection
what is an example of passive passive immunity
when a mother passes antibodies onto the fetus
what is an advantage/disadvantage of passive immunity
it is acquired immediately, but it only lasts as long as the antibodies circulate in the blood
Passive immunity is not very specific either
What is gamma globulin
the fraction of blood containing a wide variety of antibodies
what can gamma globulin be used for
gamma globulin can be used to confer temporary protection against hepatitis and other diseases by passive immunity
how are gamma globulins often applied
by injection
What does cell mediated immunity do differently from humoral immunity
instead of antibodies it uses antigen-specific T-lymphocytes to mediate attacks against foreign material
What do antigen-specific T-lymphocytes use to attack foreign material
Macrophages
Natural Killer Cells
Cytokines
What does Cell-mediated immunity primarily attack
microbes like
viruses
fungi
pathogens
What is transplant rejection
the bodies rejection of a donor’s organ
What causes transplant rejection
Cell-meditaed immunity
What can be done to prevent cell-mediated immunity from causing transplant rejection
immunosuppresing drugs can be used to lower the immune system
What are some nonspecific defense mechanisms of the body
Skin passages with mucous coated epithelia macrophages inflammatory response interferons
How does skin protect the body
it is a physical barrier against bacterial invasion. And pores on the skin secrete sweat which has enzymes that break down bacterial cell walls
how does mucous coated epithelia protect the body
it traps and filters foreign particles
how do macrophages protect the body
Macrophages engulf and destroy foreign particles
How does the inflammartory response protect the body
- activated in response to physical injury
- Injured cells release histamine, increasing blood flow
- Granulocytes attracted to the site phagocytize antigenic material
What does histamine do locally
causes blood vessels to dialate, and increase blood flow to said region
What often accompanies the inflammatory response
a fever often accompanies the inflammatory response
How do interferons protect the body
Interferons are produced by cells under viral attack, they diffuse to other cells to prevent further spread of the virus
What are allergies
allergies are inappopriate immune responses to certain food and pollen. They cause the body to form antibodies and release histamine
What determines the type of blood you have
The antigen/s or lack of anitgens on your RBC
so if you have A blood type you…
have A antigens and Anti-B antibodies
If you have B blood type you have
B antigens and Anti-A antibodies
if you have AB blood type you have
both A and B antigens and neither antibody
if you have 0 blood you have
neither A or B antigens and both A and B antibodies
What happens if you don’t have compatible blood with a transfusion
the antibodies will cause the RBC’s with the wrong antigen to clump up.
what type of blood is the universal acceptor
type AB
What type of blood is the universal donor
type O
What is the Rh factor
the Rh antigen is another RBC antigen that some people have and some don’t
So if you have A+, B+ etc..
you have the Rh antigen
What is a problem with the Rh factor
an Rh- mother may have an Rh+ child
if the Rh+ factor moves across into the mothers circulation she will build up antibodies against it.
if the mother then has an Rh+ child, the antibodies she has produced will cross the placenta and destroy the fetus’ RBC’s
What is the disorder caused by a mismatch of Rh factor between a mother and child
Erythroblastosis fetalis
Can Erythroblastosis fetalis be caused by ABO blood type
nope, because ABO antigens can’t cross the placenta.
What does the endocrine system do
it functions as a means of internal communication, coordinating the activities of the organ systems
What glands secrete hormones directly into the blood stream
endocrine glands
How are exocrine gland secretions transported
they are transported by ducts
What are the two main types of hormones
Steroid
Peptide
What are peptide hormones like structurally
they can be simple short peptides (ADH)
or they can be complex polypeptides (insulin)
how do peptide hormones cause changes in the cell
they bind to specific extracellular receptors on the surface of their target cells and trigger a series of enzymatic reactions in the cell
What is the typical first reaction caused in the cell by a peptide hormone binding to the outside of the cell
ATP to cAMP by the enzyme adenylate cyclase
If peptide hormones are the first messengers, then what is the second messenger
cyclic AMP
What is the cascade effect of hormones
with each step of the process (pep hormone –>cAMP—> other reactions) the hormones effects are amplified
What inactivates cAMP
phosphodiesterase
how long and fast are the effects of peptide hormones
the effects of peptide hormones are fast acting and short lived
What are steroid hormones derived from
cholesterol
How do steroid hormones affect their target cells
because they are lipid soluble they can enter the cell and bind directly to specific intracellular receptors in the cytoplasm
What happens once steroid hormones have bound to their receptor in the cell
the receptor-hormone complex enters the nucleus and directly activates the expression of specific genes by binding to receptors on the chromatin
By what do steroids actually bring about a change
they change mRNA transcription and thus protein synthesis
What determines the specificity of hormonal action
the presence of specific receptors in or on the target cells
What are the adrenal gland
the adrenal medulla
the adrenal cortex
What causes the Adrenal cortex to secrete it’s hormones
ACTH adrenocorticotropic hormone (from ANT. Pit)
What kind of hormones does the Adrenal cortex secrete
steroid hormones called corticosteroids
What are the corticosteroids
glucocorticoids
mineralocorticoids
cortical sex hormones
What are the glucocorticoids
Cortisol and Cortisone
What do glucocorticoids do
- they raise blood glucose levels by promoting the breakdown of proteins and using the products in gluconeogenesis
- they decrease protein synthesis
What is antagonistic to the effects of glucocorticoids
insulin
What is a mineralocorticoid
aldosterone
what does aldosterone do
- aldosterone causes active resorption of sodium and passive absorption of water in the nephron
What is the functional unit of the kidey
the nephron
What does the resorption of sodium and water by aldosterone cause in the body
rise in blood pressure and volume
What does excess production of aldosterone cause
hypertensions due to the excessive water retention
What are the cortical sex hormones
Androgens
What are androgens
male sex hormones
Where are the majority of androgens from
testes in the male, some from the adrenal cortes in females
what can the overproduction of androgens from the adrenal cortex cause in females
women can have masculinizing effects such as facial hair
what kinds of hormones does the adrenal medulla secrete
catecholamines
are catecholamines peptide or steroid formones
peptide
What are the two catecholamines
epinephrine and norepinephrine
What is another name for epinephrine
adrenaline
What does epinephrine do
- increases the conversion of glycogen to glucose in the liver and muscle causing a rise in blood glucose levels and an increased basal metabolic rate
- increases heart rate and contractility of the heart
- cause increased blood supply to the muscles, heart, and brain and decreased blood flow to the kidneys skin and digestive system
- inhibit vegetative functions like digestion
What does norepinephrine do
- increases heart rate and contractility of the heart
- cause increased blood supply to the muscles, heart, and brain and decreased blood flow to the kidneys skin and digestive system
Are epinephrine and norepinephrine also neurotransmitters
yes
How are adrenal hormones controlled
by ACTH from the ant. pit
What controls secretion of glucocorticoids and sex steroids
ACTH
what controls secretion of aldosterone
the renin-angiotensin mechanism
What is another name for the pituitary
hypophysis
what are the lobes of the pituitary
anterior
posterior
intermediate (rudimentary in humans)
What are the two types of hormones secreted by the Ant. Pit
direct and indirect hormones
What are the direct hormones of the Anterior pituitary
Growth hormone (GH) Prolactin Endorphins
What are the indirect (Tropic) hormones of the Anterior pituitary
Adrenocorticotropic hormone (ACTH)
Tyroid-stimulating hormone (TSH)
lutenizing hormone (LH)
Follicle-stimulating hormone (FSH)
What is another name for GH
somatotropin
What does GH do
promotes bone and muscle growth
what does a deficiency of GH in children cause
stunted growth (dwarfism)
What does overproduction of GH in children cause
gigantism
What does overproduction of GH in adults cause
acromegaly
What is acromegaly
acromegaly is a disorder characterized by overgrowth of bone, usually in the skull, jaw, feet, and hands
What does prolactin do
prolactin stimulates milk production and secretion in female mammary glands
what do endorphins do
endorphins are neurotransmitters the behave like opioids relieving pain and producing pleasurable sensations
What does ACTH do
stimulates the adrenal cortex to synthesize and secrete glucocorticoids and sex steroids
What regulates ACTH release
corticotropin-releasing factor (CRF)
What does TSH do
TSH stimulates the thyroid gland to synthesize and release thyroid hormones
What does LH do in females
in females it stimulates ovulation and formation of the corpus luteum
in males in stimulates the interstitial cells of the testes to synthesize testosterone.
What does the corpus luteum do
secretes progesterone and estrogen
what does LH do in males
in males in stimulates the interstitial cells of the testes to synthesize testosterone.
What does FSH do in females
causes maturation of the ovarian follicles
What do the ovarian follicles do
secrete estrogen
what does FSH do in males
stimulates maturation of the seminiferous tubules and sperm production
What is another name for the posterior pituitary
the neurohypophysis
What does the posterior pituitary do
it stores, does not synthesize the peptide hormones Oxytocin and ADH
what kind of hormones are ADH and Oxytocin
peptide hormones
Where are oxytocin and ADH produced
the neurosecretory cells of the hypothalamus
When is oxytocin released
during childbirth
what does Oxytocin do
increases the strength and frequency of uterine muscle contractions
Is oxytocin ran by a positive or a negative feedback system
positive
oxytocin stimulates contraction
contaction stiumlates oxytocin release
What besides contractions causes oxytocin release
sucking by a baby
What does ADH do
it increases the permeability of the collecting duct in the nephron to water.
this promotes water reabsorption
decreasing blood osmolarity by increasing blood volume
When is ADH secreted
- when plasma osmolarity increases and is sensed by the hypothalamus osmoreceptors.
- when blood volume decreases and is sensed by the baroreceptors in the circulatory system
What does the hypothalamus do
it receives neural transmissions from other parts of the brain and peripheral nerves, which trigger specific responses from the neurosecretory cells
what do the neurosecretory cells of the hypothalamus do , and how
- regulate pituitary gland secretions
- negative feedback systems
- through the actions of inhibiting and releasing hormones
how does the hypothalamus influence the anterior pituaitary
it’s hormones stimulate or inhibit the release of the anterior pituitary hormones
What does GnRH
stimulates the anterior pituitary to secrete LH and FSH
how do hypothalamal hormones get to the ant pit
through the hypothalamic-hypophyseal portal system (capillaries that run straight from one to the other)
What does ACTH-RF do
causes the anterior pituitary to release ACTH
How does the hypothalamus interact with the posterior pituitary
the neurosecretory cells in the hypothalamus synthesize and transport oxytocin and ADH to the posterior pit for storage
What is the thyroid like
it’s a bi lobed structure located on the ventral side of the trachea.
what does the thyroid secrete
thyroxine (T4)
triiodothyronine (T3)
calcitonin
What are the thyroid hormones
thyroxine and triiodothyronine
From where do the tyroid hormones come
iodination of the AA tyrosine
What do the thyroid hormones do
aid in growth and neurological development in children
increase the rate of metabolism
What is hypothyroidism
when the thyroid isn’t secreting enough thyroxine and triiodothyronine
What does hypothyroidism lead to
slowed heart and respiratory rate
fatigue
cold intolerance
weight gain
What is cretinism
hypothyroidism in newborn infants
What are the symptoms of cretinism
mental retardation and short stature
What is hyperthyroidism
oversecretion of the thyroid hormones
What does hyperthyroidism lead to
increased metabolic rate feelings of excessive warmth profuse sweating palpitations weight loss protruding eyes
What can happen in both hyper and hypothyroidism
the thyroid may often enlarge, forming a goiter
What does calcitonin do
decreases plasma CA2+ levels by inhibiting its release from the bone.
What regulates calcitonin secretion
plasma calcium levels
What has antagonistic actions to calcitonin
the parathyroid hormone
What kind of gland is the pancreas
it’s both an exocrine and endocrine organ
what does the pancreas secrete exocrinically
the cells that secrete digestive enzymes into the small intestine via a series of ducts
how does the pancreas act endocrinically
the islets of langerhans, which are composed of alpha and beta cells.
What do the beta cells of the pancreas produce and secrete
insulin
what do the alpha cells of the pancreas produce and secrete
glucagon
what does glucagon do
stimulates protein and fat degradation
conversion of glycogen to glucose
stimulate gluconeogenesis
What is the result of the actions of glucagon
increase in blood sugar
What causes glucagon to be released
low blood sugar levels
What does insulin do
stimulates the uptake of glucose into the muscle and adipose cells
stimulates the storage of glucose as glycogen in the muscle and liver
stimulates the synthesis of fats from glucose
stimulate the uptake of amino acids
What is the result of the actions of insulin
decrease blood sugar levels
What hormones cause the increase of blood sugar
glucagon
glucocorticoids (cortisol and cortisone)
GH
epinephrine
What is the underproduction or insensitivity of insulin lead to
diabetes mellitus (characterized by high blood glucose)
What are the parathyroid glands like
they are four small, pea shaped structures on the back of the thyroid gland
What do parathyroid glands do
the synthesize and secrete parathyroid hormone (PTH)
what does parathyroid hormone do
increases plasma Calcium concentration by increasing bone resorption and decreasing calcium excretion in the kidneys
What is a side effect of parathyroid hormone action
phosphate is bound to calcium in the bone so phosphate is also increased with calcium levels.
how does the parathyroid compensate for the increase in phosphate it causes
it causes the kidneys to increase phosphate excretion
How do the kidneys act hormonally
they produce renin
What causes the kidneys to produce renin
when blood volume falls
what does renin do
in converts plasma protein angtiontensinogen to angiotensin 1
What happens to angiotensin 1
it is converted into angiotensin 2
what does angiotensin 2 do
stimulates the release of aldosterone by the adrenal cortex
what does aldosterone do
aldosterone causes active resorption of sodium and passive absorption of water in the nephron.
what removes the stimulus for renin
increase in blood volume
What are some gastrointestinal hormones
gastrin
secretin
cholecystokinin (CCK)
Bile
What does gastrin do
stimulates the secretion of HCL
What causes gastrin release
ingested food in the stomach
What does secretin do
it simulates the secretion of alkaline bicarbonate from the pancreas to neutralize the acidity of the chyme
where is secretin secreted from
the small intestine
what is chyme
partially digested food from the stomach
What does cholecystokinin (CCK) do
CCK causes the contraction of the gall bladder and release of bile into the small intestine
it also travels to the brain causing the “full” sensation
Where is cholecystokinin released from
the small intestine
what causes CCK to be released
the presence of fats
What does Bile do
it helps in the digestion of fats
What is the pineal gland, and what does it secrete
a tiny structure at the base of the brain that secretes melatonin
What does melatonin do
plays a role in circadian rhythms (physiological cycles lasting 24 hours)
What regulates melatonin secreteion
light and dark cycles in the environment
what did melatonin do in primitive vertabrates
lightens the skin by concentrating pigment granules in melanophores
Where are plant hormones produced
actively growing parts of the plants like meristematic tissues (apical of shoots and roots)
What are the kinds of plant hormones
Auxins Gibberelins Kinins Ethylene Inhibitors Anti-Auxins
What are the three things auxins do
phototropism
geotropism
inhibition of lateral buds
What is phototropism
The tendancy of the shoots of plants to bend towards the light source
How does phototropism occur
the auxins on the sunny side of the plant are reduced by the sunlight, this causes it to grow more slowely than the unshaded side
What is indoleacetic acid
one of the auxins associated with phototropism
What is geotropism
the tendency of portions of plants to grow towards or away from gravity
What is negative geotropism
causes shoots of plants grow upwards away from gravity
what is positive geotropism
causes roots of plants grow towards the pull of gravity
How does negative geotropism work
in a horizontal shoot the auxins will be more concentrated on the lower side of the shoot and will cause it to grow more quickly, turning the plant up
How does positive geotropism work
in horizontal roots the auxins will be more concentrated on the lower side of the root, which will cause it to grow more slowely, causing the root to grow down ward
What do auxins produced in the terminal bud of a plants growing tip do
they inhibit the development of lateral buds
what do auxins do in the roots
initiate the formation of lateral roots, while inhibiting root elongation
What do auxins do for the production of xylem
they stimulate it growing from the cambium
What do gibberelins do for the production of phloem
they stimulate it growing from the cambium
What do gibberelins do
they stimulate rapid stem elongation (in normally short plants)
terminate the dormancy of seeds and buds
What do kinins do (plants)
they promote cell division
What does auxin levels do to the function of kinins
the higher the auxins the higher the level of function in the kinins
What does Ethylene do (plants)
simulates fruit ripening and aging
what is the fancy word for plant again
senescence
What do inhibitors do (plants)
they block cell division
maintain dormancy in lateral buds and seeds of plants
what happens to inhibitors during the cold season
they break down with time and the cold, causing seeds to be active during the next season
What is Abscisic acid
one of the most important plant inhibitors
What are Anit-auxins
hormones that regulate the activities of auxins
What is indoleacetic osidase
an anti auxin that regulates the concentration of indoleacetic acid
What is the functional unit of the nervous system
the neuron
What is the nervous system like for unicellar organisms
they don’t have an organized one,
they respond to touch, heat, light, and chemicals
What is the nervous system like in Cnidaria
they have a simple nervous system called a nerve net with limited centralization
What is the nervous system of the annelida like
they have a primitive CNS, with a defined dorsal nerve and an anterior “Brain”
what makes up the brain of the annelida
fused ganglia (clusters of nerve cell bodies)
What is the nervous system like for arthropoda
brains similar to annelids, but they have more specialized sense organs (compound or simple eyes and tympanum)
What produces myelin in the CNS
oligodendrocytes
What produces myelin in the PNS
Schwann cells
What is the resting potential
the potential difference between the extracellular space and the intracellular space
What is a typical resting membrane potential
-70 mV (the inside is more negative than the outside)
What maintains the negative resting potential
the sodium potassium pump pumping 3Na out while pumping 2 K in
What is the threshold potential
-50 mV, when the voltage gated Na open causing an action potential
What happens when the membrane has been depolarized by voltage gated Na channels
the voltage gated K channels open to repolarize the membrane
What determines the speed of propogation of an action potentila
the diameter of the axon and the myelination
What are effector cells
cells that are post-synaptic
What are the three ways that neurotransmitters can leave the synapse
- degraded by enzymes
- diffusion
- taken back up by uptake carriers
What does curare do to the synapse
curare blocks the postsynaptic ACH receptors so that ACH can’t interact with receptors
What does botulism toxin do to the synapse
botulism toxin prevents the release of ACH from the presynaptic membrane, resulting in paralysis
What does Anticholinesterases do to synapses
They block ACHesterases from degrading AC so that it constantly binds to the post-synaptic receptors.
Where are anticholinesterases used
nerve gases and in the insecticide parathion
What do Anticholinesterases cause
no coordination muscular contractions
What makes up nerves
bundles of axons
What kinds of neurons are sensory neurons
afferent
what kinds of neurons are motor neurons
efferent
What are neuron cell body clustes called PNS and CNS
PNS = ganglia CNS = nuclei
What makes up the outer portion of the brain
gray matter (cell bodies)
What makes up the inner portion of the brain
white matter (axons)
What are the three parts of the brain
forebrain midbrain hindbrain
What are the parts of the forebrain
telencephalon
diencephalon
What are the parts of the telencephalon outside and inside
outside is the cerebral cortex
inside is the olfactory bulb
What are the parts of the diencephalon
The thalamus and the hypothalamus
What is the thalamus
the relay and integration center for the spinal cord and cerebral cortex
What does the hypothalamus do
controls visceral functions(hunger, thirst, sex drive, water balance, blood pressure, temperature regulation
What is another name for the midbrain
the mesencephalon
What does the midbrain do
it is a relay center for visual and auditory impulses
What are the parts of the hindbrain
cerebellum, pons, and medulla
What does the cerebellum do
helps with balance, hand-eye coordination, rapid movement timing
What does the pons do
acts as a relay center between the cortex and the cerebellum
What does the medulla do
controls vital functions
heart rate, breathing, GI activity
what do the midbrain, medulla, and pons make up
the brainstem
What are the layers of the spinal cord
White outer (axons) gray inner (cell bodies)
What is the path of sensory information flow in the spinal cord
- flows in through the dorsal horn
2. exits through the ventral horn
Where are the cell bodies for the sensory neurons located
dorsal root ganglion
What are the two parts of the PNS
somatic and autonomic nervous system
What is the primary sympathetic nervous system neurotransmitter
norepinephrine
what is the primary parasympathetic nervous system neurotransmitter
ACH
What is the thick opaque (white)layer of the eye
sclera
What is the choroid of the eye
Lies beneath the sclera
supplies blood to the retina
dark and pigmented to reduce reflection in the eye
What is the innermost layer of the eye
the retina
what does the retina have
photoreceptors
What is the transparent front of the eye called
cornea
What does the cornea do
it bends and focuses light through the pupil
what causes the Iris to constrict
light
Where is the lens of the eye located
behind the pupil
what controls the focal length of the lens of the eye
the ciliary muscles
What are cones of the eye
photoreceptors that respond to high-intensity illumination and are sensitive to color
what are the rods of the eye
photoreceptors that respond to low-intensity illumination and are important for night vision
How many pigments do the cones have and what do they do
3
they absorb blue, green, and red wavelengths
How many pigments do the rods have and what do they do
1
absorbs a single wavelength
What is the rod pigment called
rhodopsin
If the photoreceptors in the eye are the presynaptic neurons, what are the post-synaptic neurons
Bipolar cells
What is the order of propogation of energy harvested by the photoreceptors in the eye
photoreceptors are depolarized
they pass the action potential to the bipolar cells
they pass the action potential to the ganglion cells
The axons of the ganglion cells form the optic nerves
What is the point in the retina where the optic nerves leaves
the blind spot
What is the area of the retina where there is a high density of cones
the fovea
What is the vitreous humor
a jellylike material that fills the eye and helps it maintain its shape and optical properties
fills the posterior chamber of the eye
What is aqueous humor
fills the anterior chamber of the eye
made by the eye and exits through ducts to join venous blood
What is myopia
nearsightedness, when the image is focused in front of the retina
what is hyperopia
farsightedness, when the image is focusd behind the retina
What is astigmatism
when the cornea is irregularly shaped
what are cataracts
when the lens becomes opaque and light can’t enter the eye = blindness
What is glaucoma
when the outflow of aqueous humor is blocked the pressure in the eye increases which can damage the optic nerve
What are the parts of the outer ear
the auricle
and the auditory canal
What are the parts of the middle ear
the tympanic membrane
the mallus, incus, and stapes
what are the parts of the inner ear
the cochlea
vestibular aparatus
What does the tympanic membrane do
vibrates at the same frequency as the incoming sound
What do the mallus, incus and stapes do
amplify the stimulus and transmit it through the oval window of the cochlea
what does the vestibular apparatus do
helps maintain equilibrium and balance
What happens once the vibration of the ossicles enters the oval window
the fluid of the cochlea moves, this stimulates the hair cells that transduce the pressure into action potentials
where are the hair cells of the inner ear found
in the cochlea on the basilar membrane
What is external respiration
entrance of air into the lungs and the exchange of gasses between the alveoli and the blood
What is internal respiration
the exchange of gas between the blood and the cells and the intracellular processes of respiration
What X-X bond is capable of releasing the most energy per mole when it is broken
C-H
What is the reaction type and name when an H is removed from organic molecules
dehydrogenaion and it is an oxidation reaction
at what step of glycolysis in the former glucose split in two
step 4 (fructose 1,6-diphosphate)
What are the products/substrates in order of glycolysis
Glucose glucose-6-phosphate fructose-6-phosphate fructose-1,6-diphosphate Glyceraldehyde 3-phosphate (Dihydroxyacetone phosphate) 1,3-diphosphoglycerate 3 phosphoglycerate 2 phosphoglycerate phosphoenolpyruvate pyruvate
What are the substrates and products of glycolysis
glucose, 2 ATP
2 Pyruvate, 4ATP, 2 NADH
What is substrate level phosphorylation
when in the synthesis of ATP there is no NADH/FADH2 used, it skips that step
what happens to pyruvate in aerobic situations
it goes onto the CAC
what happens to pyruvate in anaerobic situations
it is reduced to ethanol or lactic acid by fermentation
What is fermentaion
the anaerobic process of glycolysis and the steps to creating ethanol or lactic acid to regenerate NAD+
how many ATP does fermentation produce
2 ATP per molecule
When is ethanol produced in fermentaion
in yeast and some bacteria
When is lactic acid produced in fermentations
in certain fungi, bacteria, and human muscle during strenuous exercise
What are the three stages of cellular respiration
- pyruvate decarboxylation
- Citric acid cycle
- ETC
what happens at pyruvate decarboxylation
pyruvate is converted to Acetyl-CoA
NADH is made
What happens in the CAC
- pyruvate and oxaloacetate join
- 2 CO2’s, 1 ATP, 1 FADH, 3 NADH formed
(4 CO2’s, 2ATP, 2FADH, 6 NADH per glucose)
Where is the ETC located
the inner mitochondrial membrane
What are most of the molecules in the ETC
cytochromes
How many ATP’s are produced per molecule of glucose by substrate level-phophorylation
4 (2 from glycolysis, 2 from CAC)
How many ATP’s are produced per molecule of glucose by oxidative phophorylation
32
28 from 10 NADH
4 from 2 FADH
How many total ATP’s are prduced from one glucose
36 total
Brock style how many ATP’s are produce from one glucose
25 from 10 NADH
3 from 2 FADH
4 ATP
32 total
What is the order of preferred energy source of the body
glucose, other carbs, fats, proteins
How are other carbs used for energy
most of them are broken down to monosaccharides which can then be converted into glucose
How are fats used for energy
Triglycerides are hydrolyzed by lipases to fatty acids and glycerols.
How is glycerol used in the production of energy
it is converted into PGAL, which is an intermediate in glycolysis
How are fatty acids used in the production of energy
- they must be activated using 2 ATP’s so it can be taken to the mitochondria
- beta oxidation chops it up into 2 C molecules that are turned into Acetyl-CoA
- The Acetyl-CoA enters the TCA cycle
what is produced in beta oxidation of a saturated fatty acid
1 NADH 1 FADH
When is protein used for energy,
when no other carbs or fats are available
What are the two reactions that activate proteins for energy harvesting
transamination
oxidative deamination
what does oxidative deamination create
Ammonia
What does photosynthesis do
converts water and CO2 into Glucose and oxygen
what is plant storage of glucose
starch
what is the photosynthetic organelles
chloroplasts
how do photosynthetic bacteria work without chloroplasts
they have membranes that function in a similar manner
What are the two reactions of photosynthesis
light reaction and dark reactions
what do light reactions do
convert solar energy into ATP and NADPH
What do dark reactions do
they incorporate CO2 into organic molecules (carbon fixation)
what is another name for the carbon fixation reactions and why
reduction synthesis because carbohydrates are produced by reducing CO2
Where do the light and dark reactions occur
the choloplasts
where actually absorbs the photons of light
chlorophyll in the thylakoid membranes
what is another name for the light reactions of photosynthesis
photolysis
what happens when light strikes the chlorophyll molecule
a P700 molecule is struck and excites electrons to a higher energy level. those electrons can flow in two ways
what are the two ways that the excited electrons can flow in photosynthesis
the cyclic electron flow and the non-cyclic electron flow
what happens in the cyclic electron flow
excited electrons of P700 move along a chain of electron carriers where a series of redox reactions occur which produces ATP, and returns the electrons to P700
what is cyclic photophosphorylation
when ATP is made from the cyclic electron flow
What happens in non-cyclic electron flow
- the electrons from P700 are transfered to NADP+ to make NADPH
- Excited electrons from P680 move to P700 filling P700’s holes and creating ATP
- P680 oxidizes H2O, fills its holes, and two O’s combine to make O2
What are the products of the non-cyclic electron flow
NADPH
ATP
O2
What do the dark reactions do
use NADPH And ATP from the light reactions to reduce CO2 and make carbs
What is the calvin cycle
the process in plants that converts Co2 into PGAL
What happens with the PGAL from the calvin cycle
- it is used
- exported as glucose,
- stored
how many times must the calvin cycle go to produce a 3C PGAL from Co2
3 times
In what 3 ways is the calvin cycle just like the krebs cycle in reverse
- CO2 is fed into the cycle in calvin, in krebs it is released
- FADPH was used in the calvin, NADH was made in krebs
- ATP was used in calvin, ATP is produced in Krebs
What is the product of the calvin cycle
PGAL
what are the steps of the calvin cycle
- CO2 binds to RBP (ribulose biphosphate 5C)
- RBP breaks down to form two 3C PGA’s
- PGA is phosphorylated and reduced (by ATP and NADPH) to PGAL
- most PGAL goes back through the cycle
- 1 PGAL is ready
how many runs through the calvin cycle until you can get a glucose
6,
in six turns of the calvin cycle you get
- 12 PGAL from 6 CO2 and 6 RBP
The 12 PGAL recombine to form 6 RBP and 1 glucose
How does respiration work in protozoa and hydra
since every cell is exposed to the environment gasses simply diffuse through the cell membrane
How does respiration work in annelids
mucus secreted on the external surface of the earthworm provides a moist surface for gas diffusion through the skin. then the circulatory system brings the O2 to the cells, and the CO2 to the surface to be released.
Aquatic annelids use gills or parapodia for gas exchange
how does respiration work in the arthropod phylum (grasshopper)
there are surface openings called spiracles, there are tubes that run from the spiracles to the body cells called trachae. gasses go into the spiracles and down the trachae and can diffuse across into cells directly.
What is the purpose of ventilation
to bring O2 into the blood and get rid of CO2
Where is the respiratory control centers
medulla oblongata
What causes the respiratory control centers to increase firing
increase in the partial pressure of CO2
What is the purpose of pulmonary surfactant
it coats the walls of the alveoli and reduces surface tension
this allows for easier gas exhange, and better compliance
what is lung compliance
elasticity
when does plant respiration occur
day and night
what does plant respiration do
uses oxygen to degrade glucose
how many ATP per glucose is made in plants
36
where do gasses in plants leave from
the stoma of the leaf or the lenticels (openings) of woody stems
