Vertebrate Physiology Exam 1 (Ch.1-7)

protein hormone receptors

cell membrane - lipophobic (and most are big) ligand cant enter cell - outer surface receptor - fast response

anchoring junctions

cell to cell or cell to ECM -cell to cell - linked by cadherins -cell to matrix - linked by integrins

tight junctions

claudin and occludin proteins - keep cells together but a key function is to minimize movement of materials between linked cells

organ systems

circulatory digestive endocrine immune integument musculoskeletal nervous reproductive respiratory urinary

environmental physiology

aims to understand the evolution of physiological traits and adaptations (eg ability to maintain body temp)

active transport

carrier mediated transport that required energy and moves molecules against concentration gradient (uses E from ATP) -can be primary (or direct) or secondary (indirect)

proteins

made of peptides which are made of amino acids -20 standard aa, 9 essential aa >100 aa

tissues

made of up a single or many closely related cell types -held together by CAMs

Na+ - glucose transporter

secondary active transporter that is a symporter

cell response is almost always determined at the level of

the receptor (ie, the target tissue)

high energy phosphate molecules

function: energy tranfser molecules -ATP, cyclic AMP (cAMP), NAD, FAD

conformers

unable to maintain homeostasis in the face of certain environmental challenges

organ system integration

"independent systems" (organs) interact

regulation of receptors

# of receptors can be up or down regulated -can occur quite rapidly -excess signal = reduced # receptors (endocytosis) - can cause desensitization to drug -low signal = increase # receptors (exocytosis)

intermediate filaments

(10nm) fibrous proteins (eg keratins and myosin) that provide structure of cell and cell-to-cell interactions

microtubules

(24nm) alpha and beta tubulins that provide structure (rigidity) and changes in cell shape and move materials within cell -role in mitosis (move chromosomes) -largest cytoskeleton fiber

microfilaments

(7nm) chains of actin molecules that attach to membranes (of cells and organelles) and provide structure, support, motility and shape of cell -form network just inside cell membrane and support microvilli

interstitial fluid

(IF) lies between the circulatory system and the cells - is 75% of the ECF volume

testosterone

(T) acts on testes to promote sperm maturation, brain, muscles, and other tissues

g-protein coupled receptors

(g=guanosine nucleotides) most common form of signal transduction - large family of 7 trans-membrane protein complexes -bind many types of ligand - hormones, growth factors, NTs, olfactory signals (odorants)

open channels

(leak channels, pores) - channel proteins with no "gate" -usually open

primary functions of cell membrane

- barrier - can control whats out vs in and what crosses - cell gateway - regulates exchange of materials with environment (primarily ECF) - cell structure and support (and in some cases motility) -signaling - receptors>communication & cell function

cytoplasm contains

- cytosol - intracelleular fluid, dilute liquid - membranous organelles - inclusions (w/o membranes, direct contact w/cytosol) - protein fibers

examples of simple endocrine reflex hormones

-calcitonin and parathyroid hormone (PTH -pancreatic hormone insulin (produced and secreted from β cells of islets of langerhans in pancreas) -hormones of posterior pituitary

Why we study animals

-interested in how animals work -basic physiology is similar among different species, so we can apply what is learned from animals to humans -agricultural needs -must consider ethical use of animals for experiment

molality

1 mole / kg water (add solute and then add 1 L [1 L = 1 kg] of water.. total volume of solution > 1 L)

molarity

1 mole/L solution (add solute then bring to 1 liter, the amount of solute has displaced aome water so - total amount water<1 L)

scientific method in physiology

1. Observation of phenomenon 2. Hypothesis as to how the phenomenon occurs (must be refutable) 3. Predictions based on hypthesis 4. Devise a test (experiment) of predictions - support or fail to support hypothesis (must use controls, must have significant number of subjects to be sure findings have merit <adequate sample size>, in human studies must avoid placebo effect <subjects are blind to their treatment> can also use crossover study in which each subject serves as its own control, avoid experimenter bias <use double blind design>)

novel signal molecules

1. calcium 2. nitric oxide 3. carbon monoxide

cell theory

1. cells are the basic building blocks of animals (plants) 2. cells arise from the division of existing cells 3. cells perform all the functions of a living system 4. homeostasis of an organism is result of coordinated activity of cells

types of local communication

1. direct chemical or electrical signals 2. contact dependent signals 3. diffusion (across extracellular fluid)

two primary examples of g-protein coupled receptors that activate or inhibit an enzyme on intracellular membrane surface

1. g protein coupled adenylyl cyclase - cAMP system 2. g protein phospholipase C (PL-C) system

properties of diffusion

1. net diffusion - from [high] to [low] (molecules move down conc gradient 2. distance particles must travel affects speed of diffusion (rate is proportional to square of distance traveled - slower for longer distances and faster for short distances) 3. diffusion occurs more slowly the nearer to equilibrium (at equilibrium the rate is the same both ways) 4. gradient of electrical force - for molecules (or ions) with net electrical charge, rate and direction of net diffusion 5. molecular size - big molecules slower than small molecules, although influence relatively modest (inverse size:rate) 6. temperature - diffusion rate relates directly to thermal energy (increase heat = increase diffusion) 7. passive process - no outside energy needed 8. can occur across a membrane or in an open system

when g-protein coupled receptors are active they

1. open ion channel 2. activate or inhibit an enzyme on intracellular membrane surface

three general categories of hormones

1. peptide or protein hormones 2. steroid hormones 3. amine-derived hormones

two characteristics of molecules which decide whether or not it can passively diffuse across membrane

1. plasma membranes predominantly made up of lipids - solutes must be able to enter the lipid bilayer before it can diffuse across membrane (lipophilicity) 2. the size of molecule influences whether it can or will diffuse across membrane, but influence of a molecules size is secondary to it lipophilicity

antagonism

1. refers to direct competition for a receptor in which another compound acts as antagonist and blocks the hormone from biding and activating cell response 2. used to describe two hormones that act on same system to opposite ends (eg push/pull) (keeps given system within homeostatic limits)

g protein phospholipase C (PL-C) system process

1. signal molecule activates receptor and associated g protein 2. g protein activates phospholipase c (PLC) an amplifier enzyme 3. PLC converts membrane phospholipids into DAG, which remains in membrane, and IP3, which diffuses to cytoplasm 4. DAG activates protein kinase C (PKC) which phosphorylates proteins 5. IP3 causes release of Ca++ from organelles, creating Ca++ signal

process used by cAMP system

1. signal molecule binds to g protein coupled receptor which activates g protein 2. g protein turns on adenylyl cyclase, an amplifier enzyme 3. adenylyl cyclase converts ATP to cyclic AMP 4. cAMP activates protein kinase A 5. protein kinase A phosphorylates other proteins, leading ultimately to cellular response

polypeptide

10-100 aa

prolactin half life

198 aa - half life ~ 20 minutes

oligopeptides

2-9 aa

eicosanoids

20 C fatty acids involved in multiple physiological functions (eg thromboxane involved with blood clotting)

lipids or fats represent about _ lbs of body weight in 154 lb male

24

total yield of catabolism of one glucose molecule

30 or 32 ATP

pH at which most enzymes in humans have optimal activity

7.4 -trypsin and chymotrypsin have optimal pH that is relatively high -amylase has optimal pH that ~ neutral -pepsin has optimal pH thats very low

carbon monoxide

CO - activates cGMP>acts on SM and neural tissues

carbohydrates

CnH2nOn

17β-estradiol

E2 (the primary estrogen) acts on ovary to promote ovarian follicle maturation, brain, breasts, and other tissues

gonadotrophin-releasing hormone

GnRH - produced in hypothalamus>release of gonadotrophins (follicle stimulating hormone FSH and luteinizing hormone LS) ovaries - promote follicle development >estradiol and progesterone production and release testes - promote sperm development as well as testoeetrone production and release

nitric oxide

NO - paracrine or autocrine - NO=endothelial-derived relaxing factor>relaxation of SM in arterioles>dilation of arterioles -activates cGMP -brain neurotransmitter & neuromodulator -over expression>multiple pathologies (neurological, intestinal, immune....)

physiologically, osmolarity and osmolality

OsM and Osm are interchangeable bc decrease in conc of solutes in our bodies displace little water>OsM~Osm

steroid response elements

SREs - regions of promoter DNA sequence at which receptor-steroid complex binds (aided by response element binding proteins) -causes or inhibits gene expression

cadherins

a CAM in which these proteins intertwine w one another across intracellular space -cell to cell anchoring proteins

integrins

a CAM protein that ties to materials within the ECM - can also be involved in signaling -cell to matrix anchoring junctions

dopamine

a neurotransmitter that affect brain processes that control movement (parkinsons), emotional response, and ability to experience pleasure and pain (reward, addiction)

albumin

abundant plasma protein that 1. binds various materials for transport 2. maintains plasma osmotic pressure 3. is made in the liver

citric acid cycle

acyl unit undergoes series of rxns after combining with oxaloacetate which then combines with another acyl unit and goes through cycle again -1 CO2, 3 NADH, 1 FADH2, and 1 ATP released in each cycle

hypocortisolism

addisons disease - decreased CORT - cant use lipid reserves and use glucose too fast

diffusion used for local communication

across extracellular fluid -cytokines, eicosanoids, neuromodulators

autocrine signals

act on same cell that secreted them

allosteric regulators

activate or inhibit - bind away from active site and cause conformational shift in tertiary structure that affects the binding site to allow or inhibit binding with ligand

g protein phospholipase C (PL-C) system

activated PL-C converts membrane phospholipid phosphatidylinositol biphosphate (PIP2)>diacyglycerol (DAG) and inositol triphosphate (IP3) (both are 2nd messengers) -DAG remains in membrane and activates protein kinase C (PK-C) -IP3 moves into the cytosol where it binds with Ca++ channels of ER and Ca++ efflux>cell response

antiport

active transport - molecules cross membrane in opposite directions

symport

active transport - molecules cross membrane in same direction

white fat

adipocytes that contain a single enormous lipid droplet

brown fat

adipocytes that contain multiple lipid droplets - some in adults but more important in infants (cant shiver) and other animals (hibernation)

metabolism

all chemical rxns that occur within an organism -catabolism and anabolism

steroid hormones

all from cholesterol - all have same 4 ring structure with variable side groups -produced from adrenal, gonads, placenta, brain -not stored in vesicles before release (are lipophilic) -response generally longer than protein/peptide hormones but can act rapidly through membrane bound receptors

norepinpehrine

also from adrenal medulla and same stimuli as EPI - vasoconstriction primarily - NE is both neurohormone and neurotransmitter (primary function)

simple endocrine reflex

an endocrine cell directly senses a stimulus>the cell to secrete its hormone (eg decrease in Ca++ sensed by parathyroid cells>secrete parathyroid hormone (PTH)>kindeys>increase reabsorption of Ca++ and produce calcitrol (active vitamin D)>increased gut uptake of Ca++) also acts on bone increase in [Ca++]>parathyroid>decrease PTH (classic example of negative feedback loop -insulin

adipose tissue

an energy store - (insulation) temperature regulation infants and other vertebrates in cold environments(think marine mammals) -white fat and brown fat

dictionary definition of matrix

an environment or material in which something develops; a surrounding medium or structure

basal lamina

an extracellular and acellular matrix of of fibrous proteins, collagen, and glycoproteins that underlie the epithelial cells

glucogenesis

anabolic pathway in which amino acids, glycerol, or lactate to glucose 6-phosphate or glucose -all cells-glucose-6-phosphotase, but only liver and kidneys can convert to glucose

glucocorticoid actions

anti-inflammatory (inhibition of WBCs; the immune system) gluconeogenesis (accelerated rates of glucose synthesis) protein catabolism (glucose-preserving) -effects generally mediate a long-term response to stressor (illness, environmental perurbation, etc) (somewhat opposite of fight or flight response)

receptors in signaling

are a key step that proceeds from signal (aka first messenger or ligand) to the response

vasopressin

antidiurectic hormone (ADH) - regulates water balance by increasing conservation of water ay the collecting ducts of the kidney -release due to multiple inputs that are transduced via the CNS that detect osmotic pressure of blood and blood volume

cortisol (hydrocortisone) and corticosterone

are produced by cells of the adrenal cortex - released in response to ACTH and have many effects

peptide hormone transport

are released from vesicles by exocytosis and move into blood and most are transported free in plasma (not bound to carrier molecule)

lipid rafts

areas within membrane of high [cholesterol] and [sphingolipid] - often associated with cell to cell communication or organizing centers for assembly signal molecules

peripheral proteins

associated or extrinsic - functions such as attachment of cytoskeleton

dynamic equilibrium

at equilibrium, the rate of diffusion id the same both ways

primary level pathologies

at the target gland (eg hypersecretion often due to tumor) or insufficiency (hypsecretion)

covalent modulators

atoms or functional groups that covalently bind with an enzyme to increase or decrease activity (irreversible)

levels of biological organization

atoms>molecules>[cells>tissues>organs>organ systems>organisms]>population of one species>ecosystem of different species>biosphere [ ] = physiology

Osmolarity and Osmolality

based on # of particles in solution (not necessarily # of molecules)

β1 adrenergic receptors

bind both EPI and NE with equal affinity

ligand-gated channel

bind messenger molecule, open ion channel, rapid movement of ions into or out of cell -particularly important and nerve and muscle cells -fastest and simplest

adrenergic receptors

binds more than one ligand - both epinephrine (primarily a neurohormone) and norepinephrine (primarily a neurotransmitter, but also a neurohormone) -aka adrenaline and noradrenaline

lipoproteins

blood transport molecules

cellular response to acute stress

both EPI and NE released- epi binds to α receptors in smooth muscle of gut blood vessels and causes constriction and binds to β2 receptors in smooth muscle of skeletal muscle and cause relaxation and dialiation -fight or flight response

reproductive system

brain, pituitary, gonads (ovaries and uterus;testes and associated ducts)

nervous system

brain, spinal cord, peripheral neurons

endocrine system

brain, thyroid, adrenal, gonads (and much more)

peripheral proteins of lipid bilayer

can be removed without disrupting the integrity of the membrane

competition for receptor binding sites

can have important pharmacological implications - ligand can either bind a receptor and turn it on or turn it off

specificity

can transport one type of molecule (or closely related molecules)

types of muscle tissue

cardiac smooth skeletal

glycolysis

catabolism of glucose - begins with a pair of endergonic rxns and ends with a pair of exergonic rxns -pyruvate final product of glycolysis (can be further metabolized via aerobic or anaerobic respiration)

enzymes

catalyze rxns and lower activation energy - proteins with binding sites for substrates -can be denatured by heat or pH

CAMs

cell adhesion molecules - membrane spanning proteins that form cell junctions and cell adhesion

excitable

cells conduct signals

epithelial tissues

cells line the bodies internal and external surfaces and the glands (exocrine and endocrine)

fibroblasts

cells that synthesize and secrete matrix (including the other 3 connective tissue fibrous proteins)

neurotransmitters

chemicals secreted by neurons that diffuse across a small gap to the target cell

3 types of energy used to do work in physiological systems

chemical transport mechanical

hormones

chemical messengers - usually secreted into the blood but act upon distant target tissues -most are produced by ductless glands, but there are exceptions: neurohormones and secretory cells sprinkled in amongst other cell types (often with para- and autocrine actions) -usually present in very small amounts (eg nanograms or picograms/mL plasma)

neurohormones

chemicals released by neurons into the blood for action at distance targets

types of fibrous proteins within connective tissue matrix

collagen elastin and fibrillin fibronectin fibroblasts

three broad categories of cell-cell junctions

communicating occluding anchoring

nervous system in distance communication

communication with a combination of electrical (down neuron) and chemical (from neuron to adjoining cell)

comparative physiology

compare different species to understand physiological and evolutionary patterns

competitive inhibitors

compete with ligand (substrate) for binding sites (can be reversible or irreversible)

other factors that can influence membrane permeability

concentration gradient, membrane surface area, composition of lipid bilayer

permissiveness

condition in which a hormone required the action of another hormone to be able to exert its full effects -eg reproductive and thyroid hormones required for proper development of reproductive system -h1>upregulation of receptors for h2, upregulation of enzymes

gap junctions

connexins (cylindrical) are primary protein - create cytoplasmic bridge between linked cells (open and close) - allow movement of materials - allows rapid communication of chemical and electrical signals between cells -found mostly in nervous and muscle tissue as well as other cell types

homeostasis

constancy of internal environment -essential for animals to venture into various environments -one part of physiology is determining different adaptations that have evolved in different species that allow homeostasis

phospholipids

contain both hydrophobic and hydrophilic groups (amphipathic)

nucleolus

contains DNA that controls synthesis of ribosomal RNA

muscle tissue

contractile - force- movement -excitable

glucocorticoids

corticotrpin-releasing hormone (CRH)>adrenoCorticoTropin hormone (ACTH) aka corticotropin>adrenal cortex>glucocoticoid production and secretion

deamination

conversion of amino acid to organic acid + ammonia

g-protein coupled adenylyl cyclase (cAMP) system

converts ATP>cAMP - used by many protein hormones -cAMP is the second messenger -signal is amplified via cascade of events

secondary (indirect) active transport

couples kinetic E of molecule moving down its conc gradient with another molecule that moves against (or up) its conc gradient -cotransport

penicillin

covalently binds with bacterial enzyme thats needed to make bacterial cell wall (is a covalent modulator)

transmembrane proteins

cross lipid bilayer

hypercortisolism

cushings disease - increased CORT - glucose metabolism suppressed at expense of lipid and protein, muscles break down, lipids break down and deposited in face and around midsection while legs and arms thin

steroid hormone receptors

cytosolic or nuclear - lipophilic ligand enters cell - often activates gene - slower response

way to modify signal (hormones)

degredation of hormone -hormones continually being released and broken down - hormone clearing occurs primarily in kidney and liver but also in blood (by non-specific proteolytic enzymes)

formation of lipids

dehydration rxn - joins carboxyl of fatty acid to hydroxyl of glycerol

Berthold

developed science of endocrinology - asked what caused difference between rooster and hen -castrated rooster and saw reductions in comb size, crowing, and sexual and aggressive behaviors -surgical replacement of testes led to restoration of behaviors -removal and replacement (still important)

hypothyroidism

developmental>cretinism (condition noted by retarded nural and muscle development in adult>myxedema (symptoms are decreased metabolism and inability to adjust to cold, loss of hair, decreased vigor, thick skin, decreased mental ability)

steroid hormone transduction

diffuse into membrane and bind to receptors in target tissue cytosolic or nuclear receptor: hormone receptor complex bind DNA at specific sites>gene expression -can dissociate from binding protein and enter cell or whole complex can be taken into cell

communication within close locations can occur by

diffusion

large fluctuation in internal conditions lead to

disruption of cellular, tissue, and organ function

peptide hormones signal transduction

do not cross membrane - act via membrane bound receptors -message is transduced>act via second messenger systems (often cAMP)

nuclear envelope

double membrane that separates nucleus from cytoplasm

receptor-mediated endocytosis

eg clatharin-coated pit-mediated endocytosis and megalin/cubulin-dependent endocytosis - binding of certain ligand to receptor causes endocytosis

non-selective endocytosis

eg pinocytosis - taking in extracellular (interstitial) fluid & the dissolved material within the fluid

elastin and fibrillin

elastin is coiled and fibrillin is sheets - work together to provide elastic connective tissue - very important in lungs, blood vessels, and skin

complex endocrine reflex

endocrine cascades - usually involve trophic and releasing hormones and they include 2 or more hormones - all begin with release of a neurohormone from hypothalamus >anterior pituitary -stimulatory or inhibitory -often modulated by negative feedback loops at multiple levels>down regulate system -direct delivery by portal system ensures a little hormone goes a long way (no dilution)

types of long distance communication

endocrine system nervous system

catabolism

energy released - extract energy from biomolecules while breaking down molecules

primary (or direct) active transport

energy required to move molecules comes directly from ATP -many known as ATPases, often referred to as pumps -sodium-potassium pump

anabolism

energy used - build a product (synthesis of molecules)

phagocytosis

engulfing of foreign body by macrophage or white blood cell

holoenzyme

enzyme + cofactor

end-product inhibition

enzyme activity is inhibited by the amount of end product -can be one step or multiple step process -feedback inhibition

ATP synthase

enzyme in mitochondrial inner membrane that allows H+ to flow through to generate energy to phosphorylate ADP to ATP -portion of energy released as heat -3 H+ required to phosphorylate one ADP molecule

apoenzyme

enzyme w/o cofactor

lipases in lipid catabolism

enzymes that 'cut' tri-glycerides

peptidases

enzymes that convert peptide to amino acids

proteases

enzymes that convert proteins to peptides

gas signal molecules are

ephermeral signals

four major types of tissues

epithelial connective neural muscle

transcytosis

epithelial transport - both endocytosis and exocytosis can play a role

osmotic equilibrium

equal distribution of water throughout the body's compartments

birth control pills are

estrogen agonists designed for longer half lives than endogenous estrogens -many contain progesterone

tamoxifen

estrogen antagonist - decreases likelihood of cancer cell proliferation via stimulation by estradiol (evidence of some forms of breast cancer being estrogen dependent)

Why much physiological research is based on animal studies

ethical issues (can you withhold drug from control group)

developmental physiology

examines how physiological processes unfold during the course of development from embryo to adult (eg what changes occur in respiratory system upon birth - surfactants)

5 basic types of epithelial function

exchange transporting ciliated epithelium protected epithelium secretory epithelium

nervous tissues

excitable electrical chemical -glial cells support

exocrine glands

excretory epithelial glands that have ducts - secrete to outside

endocrine glands

excretory epithelial that are ductless - can be a gland or single cells that secrete hormones into extracellular space and then into circulation (blood stream) -usually act on other cells

in water, membrane bilayers can form

micelle, liposome, or bilayer

ECF

extracellular fluid - is different from cytosol (intracellular fluid <ICF>) -contains 1/3 of total body water by volume

binding proteins

facilitate transport, protect from degredation, increase half life of steroid

lipases

fat digesting enzymes

aerobic respiration

final electron acceptor is O

glycogen catabolism

first step is glycogenolysis - glucose produced - direct conversion of glycogen to glucose 6-phosphate saves the cell one ATP per glucose -liver storage, muscle storage

peoporhormone

first translational product leading to protein/peptide hormone -inactive

fibronectin

forms connections bt cells and matrix -also plays role in blood clotting and wound healing

peptide/protein hormones

from a few to 100s of amino acids - translated by ribosomes, usually at the ER -post translational modification can also create hormones -preprohormone>prohormone>hormone -stored (vesicles) until Ca++ (or other) signal induced exocytosis -water soluble

anterior pituitary

from epithelial tissue from roof of mouth is a true gland

amine-derived hormones

from single aa - most from tyrosine>catecholamines (EPI, NE, DOPA)

epithelial tissue

general function is to protect the internal environment and regulate movement of materials from external to internal (and vice versa) -lines outside of body and tubes connected to outside body -generally underlain by basal lamina (basement membrane)

disaccharides

glucose plus another monosaccharide -sucrose, maltose, lactose

polysaccharides

glucose polymers - all living cells form glucose in the form of a polysaccharide -animals - chitin, glycogen -plants - cellulose, starch -yeast and bacteria - dextran

glycogen anabolism

glucose>glycogen (4 hr supply in liver)

aerobic metabolism of glucose

glycolysis>pyruvate to acyl unit it mitochondrion>Citric acid cycle (Kreb's) cycle>electron transport system

lipogenesis

glycolytic pathway can be important for lipid synthesis

hyperthyroidism

graves disease - autoimmune condition in which ABs against TSH receptors act as agonists>increased production of T3 and T4 - characterized by nervousness, increased heart and metabolic rate, fatigue, exophthalmos (bulging eyes)

β2 adrenergic receptors

have high affinity for EPI

α adrenergic receptors

have high affinity for NE

lipid anchored proteins

have sphingolipid 'tails' inserted into membrane - form lipids rafts

circulatory system

heart, blood vessels, blood

exceptions to ductless gland classical view of hormone secretion

heart, liver, stomach and small intestine, kidney, skin, adipose tissue, placenta

electron transport system

high energy electrons on NADH and FADH2 power proton pumps to establish H+ gradient across mitochondrial membrane [H+] intermembrane space>>>[H+] matrix (lumen) -H+ then move down gradient to power phosphorylation of ADP to ATP

loose connective tissue

highly gelatinous elastic tissue that underlies skin, supports organs and blood vessels -fibroblasts

cell physiology

how do cells function

examples of complex endocrine pathway hormones

hypothalamic-pituitary portal sysytem (hyothalamic neurohormones>anterior pituitary via dedicated blood portal system>anterior pituitary cells) -dopamine, TRH, GnRH, CRH... etc (each from hyptholamus and target cells within the anterior pituitary)

even if results support a hypothesis

hypothesis does not become a fact

oxytocin

in females acts as a neurohormone to induce milk-let down response of mammary gland in response to suckling - also acts in uterus to promote muscle contraction during delivery -is also neurotransmitter (and neuromodulator) that acts on numerous regions of the brain (implicated in influencing social and sexual behaviors as well as maternal) -oxytocin during parturition offers good example of relatively rare positive feedback system

smooth endoplasmic reticulum

in some cells, functions are storage and in others, functions to detoxify materials (liver?)

ECF consists of

interstitial fluid plasma

electrical disequilibrium

intracellular environment is slightly negative compared to extracellular environment - ability of a cell to selectively exclude charged ions and other molecules and use E to pump ions across membranes causes this state of electrical disequilibrium -key in excitable cells -OsM of cytoplasm ~= interstitial ~= plasma ~= 300 OsM (actually ~ 280 OsM)

ICF

intracellular fluid - contains 2/3 of total body water by volume

integral proteins

intrinsic - basically run through the membrane - membrane-spanning (trans-mambrane)

integrin receptors

involved in repair of damaged tissue (blood clotting), immune response, and cell movement (during development) - extracellular component binds to proteins of the extracellular matrix or compounds involved in blood clotting and intracellular component binds to associated proteins (known as anchor proteins) that are attached to cytoskeleton -frequently transfer info from the extracellular matrix

chromatin

is DNA and protein

increase in membrane cholesterol leads to

it becoming less permeable to water (water is polar - lipophobic)

if a cell doesnt have a receptor for signal

it will not respond

ribsoomes

key function is protein synthesis, made up of RNA and proteins -can be free or fixed to cytosolic side of rough ER

urinary system

kidneys, bladder, ducts

exchange epithelium

leaky>rapid movement of materials, primarily gases

receptor enzymes

ligand (cytokines, growth factors, some hormones) binding causes conformation shift that results in enzyme activation on intracellular side of membrane or can be trans membrane integral protein with enzymatic function or trans membrane integral protein thats closely associated with an enzyme -enzymes are either guanylyl cyclase (GTP>cGMP) or protein kinases (ATP>phosphorylates or activates a protein) -bind cytokines, growth factors, some hormones

antagonist

ligand that turns it off or inactivates

agonist

ligand that turns it on or activates

types of transduction systems

ligand-gated channel integrin receptors receptor-enzymes g-protein coupled receptors

eicosanoids used in local communication

lipid-related, primarily inflammation and allergic responses -eg thromboxanes (clotting), prostglandins, and leukotrienes -diffusion

classes if biomolecules

lipids carbohydrates proteins nucleic acids & high energy phosphate compounds

materials that can readily move into and can cross membranes

lipids, lipid related molecules, CO2, O2, H2O

plasma

liquid matrix of blood, is 25% of the ECF volume - substances moving between the plasma and interstitial fluid must cross the leaky exchange epithelium of the capillary wall

seven types of connective tissue

loose connective tissue regular dense connective tissue irregular dense connective tissue adipose tissue blood cartilage bone

connective tissues

loose connective tissues (collagen) dense connective tissues (tendons) adipose tissue cartilage bone blood

respiratory system

lungs, airways

transcription

mRNA created from DNA sequence -RNA polymerase

translation

mRNA into protein by ribosome

protein synthesis

mRNA transcription > mRNA translation > post-translational modification of protein

matrix or ground substance of connective tissue

made up of water and proteoglycans (often gelatinous)

example of push/pull antagonism

maintenance of plasma Ca++ levels is that of calcitonin and PTH (parathyroid hormone)

CORT

majority of CORT's actions occur via genomic route, evidence in some animals of a membrane bound 2nd messenger signal amplification mechanism of action -direct infusion of CORT to brain regions>neuronal firing within msec

carrier mediated transport

materials move into cell with aid of carrier protein -facilitated diffusion, active transport -have specificity, competition (and affinity), and saturation

saturation

maximum rate of transport - rate will not increase if you add more ligand

osmotic pressure

measured in atmospheres (atm) or mm or mercury (mmHg) as in other measures of pressure in physiological and physical systems - as water moves across a membrane (in effort to reach equilibrium) it will exert a force on membrane -can be measured as amount of force required to counteract osmosis of water -pure water = 0 atm -180g/L glucose solution has half the osmotic pressure of a 360 g/L solution

receptor proteins

membrane associated proteins external message > internal rxns -bind specific ligand(s)

glycoproteins

membrane structure, signal molecule

endocytosis

membrane surface invaginates and surrounds material to be endocytosed -active - ATP dependent -can be non-selective or selective

cellular makeup

membrane, cytoplasm, nucleus, membranous organelles, inclusions, protein fibers

characteristics of a living system

metabolism responsive to external stimuli movement growth differentiation reproduction

cytoskeleton protein fiber types

microfilaments intermediate filaments microtubules

prohormone

modified preporhormone that is packaged with proteolytic enzymes in secretory vesicles in golgi - further post-trranslational modification may occur within vesicles (inactive aa cut out leading to active hormone) -inactive

co transport

molecules may cross membrane in same direction (symport) or opposite directions (antiport)

synergism

more than additive as the total is greater than the sum of the parts - different hormones interact>enhanced response -eg cortisol, glucagon, and EPI all act to increase blood glucose levels -do not have to act on same target tissue, but have to have same end-point

collagen

most abundant protein of connective tissue (1/3 of total dry weight) - extremely strong and collagen (in part) distinguishes connective tissue (CT) type

gated channel proteins

most are closed except under specific conditions -opened by chemical, electrical, or physical change

calcium as signal molecule

most critical for muscle contraction - channel opening>Ca++ influx - activates a protein -often leads to vesicle exocytosis

adaptation

most organisms are well suited to their environment, this occurs via natural selection and evolution - occurs over generations and has genetic basis

kinetic energy

motion energy - molecules moving due to heat or across membrane

kinesins

motor proteins of axonal transport (- to +)

dyneins

motor proteins of retrograde transport (+ to -)

transporter proteins

move materials across membrane -channel and carrier proteins

exocytosis

move materials too large for channels out of cell (primarily proteins) -some cell types only under certain conditions (eg hormones, neurotransmitters) -others continual - eg goblet cells secrete musuc

ciliated epithelium

movement of materials (eg particles and cells)

mechanical energy

movement of the organism.. muscles

Na+ often used in secondary active transport

moves from [high] extracellular to [low] intracellular -its still considered active transport bc ATP used to pump Na+ back out of cell

types of tissue

muscle nervous epithelial connective tissues

myosin

muscle contract (intermediate filament)

pro-enzymes aka zymogens

must have protein sequence cut out (lysis) to become activated

testicular feminizing syndrome

mutation in androgen receptor>males fail to develop external genetalia

evolution

mutations which enhance an animals survival or fitness will increase in frequency

neurocrines

neural secretions

epinephrine

neurohormone secreted by adrenal medulla in response to fight or flight type stimuli (exercise too) - causes increase in hear trate and force and either vaso dilation or constriction depending on location of smooth muscles -glucose mobilization = gluconeogenesis

nervous tissues contain

neurons and supporting cells

three types of neurocrines

neurotransmitters neurohormones neuromodulators

irregular dense connective tissue

nonaligned collagen fibers - muscle and nerve sheaths -firboblasts

nucleus parts

nuclear envelope necleolus chromatin nuclear pore

nucleic acids and high energy phosphate compounds

nucleotides, DNA, and RNA composed of 1. nitrogenous base (purine or pyrimidine) 2. a 5-C sugar (ribose or deoxyribose) 3. a phosphate group

posterior pituitary

nuerohyophesis - derived from brain neural tissue

pituitary

oft-times referred to as the master gland bc hormones produced there control so many essential downstream functions (arguable that hypothalamus real "master" bc it controls the pituitary) -small gland made up of two types of tissue that merge during development

voltage-gated channels

opened by change in membrane voltage potential

chemically-gate channels

opened by chemicals -example is ligand-gated channel

golgi apparatus

organelle in close proximity to ER from which it receives protein filled vesicles and processes them (post translational modification) and packages them for secretion from cell (secretory vesicles) -also produces lysosomes

lysosomes

organelle produced within golgi that functions as digestive system of cell - enzyme packed vesicle

mitochondria

organelle that generates cell energy (ATP) that has two membranes with an intermembrane space (matrix) for protected rxns (concentration gradient across) -have mtDNA w/37 genes that are essential for mitochondrial function -role in steroid synthesis -consume O2 and produce CO2, heat and ATP

peroxisomes

organelles that are produced by ER and self-replication (fission) within cytoplasm - storage vesicles that neutralize toxins and break down fatty acids

coenzymes

organic cofactors that dont alter the binding site but act as carriers for atoms or groups removed from substrate -many are vitamin precursors

biomolecules

organic molecules made up of primarily C, O, and H -N, S, P, Zn, Na, Cl, K, Fe may also be important as trace elements

nuclear pores

regulate movement of material into and out of nucleus

chymotrypsin

pancreatic enzyme that cleaves proteins -starts out a pro-enzyme

regular dense connective tissue

parallel aligned collagen fibers - provides strength and flexibility -tendons (muscle-bone) can't stretch -ligaments (bone-bone) contains elastin = can stretch -fibroblasts

facilitated diffusion

passive carrier mediated transport in which molecules move from area of high conc to area of low conc -net movement ceases when conc inside and outside are equal (dynamic equilibrium)

3 general categories of cell membrane proteins

peripheral integral lipid-anchored

acclimitization

physiological or anatomical change within an individual animal during its lifetime resulting from chronic exposure to certain environmental conditions

melatonin

pineal hormone derived from tryptophan - secreted when dark and inhibited by light -important in setting body rhythms and sleep patterns - sets seasonal (circa-annual) or daily (circadian) rhythms of many animals

competition (and affinity)

prefer one molecule that they are able to transport over another

physical structure of cell membrane

primarily a phospholipid bilayer - is an ampiphile (hydrophobic & lipophobic ends; polar & apolar)

endocrine system in distance communication

primarily blood borne compounds (hormones) that act on cells at a distance

tay-sachs disease

primarily eastern european and jewish descent (also french canadians and cajuns) - lysosomes lack beta hexosaminidase A - an enzyme that breaks down gangliosides (type of fatty acid) associated with nerve cells > ganglioside G >neural failure and cell death -also implicated in rheumatoid arthritis

placenta and steroid production

primarily progesterone

primary, secondary, tertiary, and quaternary structure of proteins

primary - aaa seq. (held together by peptide bond) secondary - coils, beta sheets tertiary - chains fold (some disulfide bridges) quaternary - multiple subunits combine (some disulfide bridges)

adrenal gland and steroid hormones

produces aldosterone, glucocorticoids, and small amount sex steroid hormones

cytoskeleton

protein fibers whose primary function is to provde cellular integrity (strength, support, shape, transport (within cell), cell-to-cell links (stabilization and firm tissue), cellular movement (cell motility)

brain and steroid production

produces small amounts of steroids de novo and converts T to E2 via enzyme aromatase

rough endoplasmic reticulum

protein assembly, modification, & insert into transport vesicles (close association with nucleus - continuous with outer membrane of nucleus) -ribosomes attached

direct chemical or electrical signals

protein family connecxins - direct communication with neighbor via a cytosplasmic bridge -electrical ions, signal chemicals -gap junctions

centrioles

protein fibers that are bundles of microtubules that move chromosomes during mitosis

cilia and flagella

protein fibers that consist of 9 pairs microtubules surrounding central paor - move fluids -have motor proteins (kinesins and dyneins)

microvilli

protein fibers that increase cell surface area for absorption -supported by microfilaments

channel proteins

protein helices span > "hole" in membrane (not necessarily always open and channel #s can be changed rapidly) -very narrow and generally allow only water and ions to pass -can allow passage of anions or cations depending on nature of internal amino acids - or can allow passage of specific ions only -can have "gate"

hormone receptor types

protein hormone receptors steroid hormone receptors

protective epithelium

protein secreting cells filled with membrane-bound secretory granules and extensive RER; steroid-secreting cells contain lipid droplets and extensive SER

protein catabolism

protein>peptide>amino acid>organic acid + ammonia -ammonia (toxic) converted to urea

sodium-potassium pump

pumps 3 Na+ out and 2 K+ into cell for each ATP hydrolyzed

anaerobic catabolism of pyruvate

pyrvuate converted to lactic acid - NADH produced during glycolysis used to convert pyruvate to lactate using lactate dehydrogenase -lactate oxidase will later convert lactate to pyruvate via aerobic respiration -in absence of O2, lactate diffuses out of cell, into bloodstream, and to liver to be converted back into glucose via glucogenesis

passive diffusion

random movement of molecules due to their thermal energy

Ficks law of diffusion

rate of diffusion ~= surface are x conc gradient x membrane permeability

glycolipids

receptors or components within membrane

cytokines

regulatory peptides that mediate cell development, differentiation, and/or immune responses (can also function over long distances) -diffusion

half lives of peptide hormones

relatively short -smaller peptides may only last a few seconds to a few minutes

transduction

relay an external message to the inside of the cell (extra- to intra- cellular communication)

exergonic rxns

release energy bc products have less energy than the reactants

growth hormone

released from pituitary stimulated by GHRH and ihibited by GHIH (somatostatin) (both of hyptothalamic origin)

removal and replacement protocol

removal - should 'eliminate' the hypothesized behavior or phsiological condition replacement - should reinstate the physiological or behavioral condition

endergonic rxns

require net energy input - trap some activation energy in the products, which then have more free energy than the reactants

glucogensesis

required 6 ATP to convert 2 lactate to one molecule of glucose or pyruvate to glucose -occurs in liver and kidneys

ligand may act in _ manner

reversible or irreversible

saturation point

rxn is at its maximum rate, regardless of more enzyme or substrate added

excretory epithelium

secrete materials (often mucous) -can be mixed among other cell types or can be homogenous to form a gland -exocrine glands and endocrine glands

goblet cells

secrete mucus into lumen of hollow organs such as intestine

paracrine signals

secreted by one call and diffuse to adjacent cells

transporting epithelium

selective exchange of non-gaseous materials -can be barrier -microvilli or infolds -tight junctions (move through cell [across membrane] not around) -high in mitochondrion

most healthy membranes are

selectively permeable

cytosol

semi-gelatinous substance that contains dissolved nutrients, ions, waste, insoluble inclusions - suspends organelles

steroid production

signal>activation of enzyme(s) that convert cholesterol to inactive steroid>diffuse out of cell -often travel in blood bound to carrier proteins -can bind nonspecifically to albumin

acclimation

similar to acclimitization but in response to laboratory or experimental conditions

monosaccharides

simple sugars -5 carbons -ribose, deoxyribose -6 carbons -fructose, glucose, galactose

muscolskeletal system

skeletal muscles, bones

muscle tissues

skeletal, cardiac, and smooth

integument system

skin

caveolae

small indentations coated with caveolins (protein type) in membrane - often associated with lipid rafts (the receptors are lipid anchored proteins)

steroid are produced in _ ER

smooth

osmosis

special case of diffusion of water across a membrane

selective endocytosis

specific molecules (eg receptor-ligand complexes) endocytosed (often recycled)

digestive system

stomach, intestines, liver, pancreas, gall bladder

potential energy

stored energy - in the form of a concentration gradient or chemical bonds

4 types of integral proteins

structural enzymes receptors transporters

connective tissue

structural support and physical barrier (protection) - distinguish b/t other tissue types by extensive ECM -matrix or ground substance and fibrous proteins -often highly variable in consistency (bone to blood) -consistency dependent upon ratio of ground substance to fibrous protein (or calcium mineralization within ground substance)

in physiology, _ and _ are highly related

structure and function

physiology

study of living processes - functions of cells, tissues, organs, organisms -includes anatomy and physiology

bone

support function - its dense and hard -fibrous matrix with Ca salts (eg CaCO3) -osteoblasts and osteocytes

cartilage

support function - its light and flexible -trachea, nose, ears, and joint surfaces -has poor blood supply = slow to heal as nutrients and O2 by diffusion -chondroblasts -hyaluronic acid

contact-dependent signals

surface molecules of a cells plasma membrane interact with those of another cell -some of the cell adhesion molecules (CAMs) recently have been found to have signaling abilities -via cytoskeletal links that activate enzymes in adjacent cells

chemical energy

synthesis and breakdown of molecules

limits within living systems exist

temperature moisture chemical composition -true for whole organism and individual cells

gonads and steroid production

testes and ovaries produce sex steroids - androgens (testosterone and dihydrotestosterone), estrogens, progesterins (and some peptide/protein hormones)

induced fit model

the binding site is not an exact match to the ligands (L) shape

differential solute distribution (cell membrane function)

the body compartments are in a state of chemical disequilibrium - the cell membrane is a selectively permeable barrier between the ECF and the ICF

communication for which speed isnt as great of a concern can occur via

the circulatory system (eg endocrine system)

immune system

thymus, spleen, lymph nodes, blood (WBCs)

T3 and T4

thyroid hormones t3 = 3 iodides -increase metabolic activity and increase heat

ultimate goal of every organism

to reproduce and propagate its DNA

dwarfism

too little growth hormone as child

acromegaly

too much growth hormone as adult - lengthening of jaw, coarsening of features, and growth in hands and feet

gigantism

too much growth hormone as child

carrier proteins

transport protein that moves materials across membrane -binds to molecules>conformational change in protein>cross-membrane -never just open like channel and therefore movement across membrane relatively slower

organ

two or more tissues

desmosomes

type of cell to cell anchoring junction that attach to intermediate filaments -strongest cell to cell junction

adherin junction

type of cell to cell anchoring junctions that link actin fibers in adjacent cells

blood

unusual connective tissue, mainly aqueous solution containing ions, gases, and organic molecules

permissive hormone actions

up regulation for a signal as a result of another signal eg hormone a>increased receptors for hormone b

secondary level pathologies

upstream signal problems (excess or insufficient) -hypothalamus or pituitary (tumor,..)

regulators

use biochemical, physiological or behavioral mechanisms to maintain homeostasis

lipids

used for long term storage of energy - contains 2x more energy per gram than carbohydrates -hydrophobic -steroids lipid-related

vesicular transport

used to move many molecules or large molecules -can move in (phagocytosis & endocytosis) or out (exocytosis)

potocytosis

uses caveolae rather than clatherin-coated pits to concentrate and bring receptor-ligand complexes into cell

cofactor

usually inorganic metal ions (some are non-protein organic molecules) - may bind with enzyme and form key component of active site which activates enzyme -Ca2+, Mn2+, Mg2+, Cu2+, Zn2+

neurohormones produced in cell bodies of hypothalamus

vasopressin and oxytocin

aquaporins

water channels -in most cells

living systems exist _ from equilibrium

well away from

transport energy

within and in and out of cell

lipid reserves contain

~100,000 kcal enery -can maintain body function without food for 30-40 days

temp regulation in humans

~37C - anterior hypothalamus/medial preoptic area act as thermostat - thermosensitive nerves near surface of skin send messages to hypothalamus -too hot - hypothalamic induction of vasolidation and sweating to lower temp -too cold - hypothalamic induction of vascoconstriction and shivering to increase temp

EPI:NE

~80:20

types of adrenergic receptors

α, β1, and β2