Biology Exam 3

animals are multicellular and have 4 different tissue types

connection, nervous, muscle, and epithelial

connective tissue

cels loosely arranged in a matrix of etracellular function and other materials secreted by connective tissue cells

• loose - fibrous proteins in soft matrix, packing material, padding, fibroblasts - cells make fibers and extracellular matrix

• dense - matrix is mostly collagen-tough- secreted by fibroblasts, found in tendons and ligaments that connect muscles, bones, and organs

• supporting - firm extracellular tissue, bone, and cartilage

• fluid - cells are surrounded by fluid extracellular matrix-ECM = plasma, blood

nervous tissue

nerve cells are neurons and then supporting cells only appear in neurons

• neurons - transmit electrial signal, 2 projections from cell body

• dendrites - highly branched, short - facilitate transmission of signals from adjacent cells to nerual cell body

• axon - long, carries electrical signal from cell body to other cells

• glia - supporting cells

  • cns - oligodendrocytes

  • pns - schwann cells

muscle tissue

only in animals, functions in movement, pumping of blood, mixing food

• skeletal - connect bones and cause body movement

• cardiac - make up walls, heart, and pump blood

• smooth muscle - lines walls of digestive tract, blood vessels, move food, regulate blood pressure

epithelial tissue

covers outside of body, line inner surface of many organs, form glands, short lived

• esophogus 2-3 days and large intestine 6

• gland - organ that secretes specfic molecules or solutions

• apical side - face environment

• basolateral side - face animal’s interior and connects to connective tissue

Surface area: volume

ratio affects animal physiology

surface area - affects rae of diffusion

volume - determines the rate at which nutrients are used and waste generates

metabolic rate

overall rate of energy consumption

measured by rate of oxygen consumption - mL 02 consumed per hour

basal metabolic rate BMR

rate animal consumes oxygen, while at rest

mass specfic BMR

function of body mass

mL of O2 consumed per gram of body mass per hour

small animals have —- BMR’s than large anddd as the organisms size —— mass specific metabolic rate decreased

higher BMR’s, and as size increases

homeostasis

occurs when the system is optimal, stabile in chemical and physical conditions within organisms cells, tissue, organs//// maintains constant internal conditions— enzymes and other cellular process-diffusion- function best at certain temps, pH, etc

homeostatis steps

1. conform - maintain internal close to environment

2. physiological regulation - expends energyto maintain internal state even when envi fluctuates

3. behavioral regulation - regulates internal state by changing behavior

need to do a little of all

regulation

system is regulating levels/ concentrations kept constant by balancing influx and efflux if it doesn’t match it fails

advantages - lower energy costs, no regulatory system needed, greater ability to tolerate a range of conditions, greater capacity for activity in a range of conditons

disadvantages - less ability to tolerate a range of conditions, energetically expensive, must have evolved regulatory systems, reduced ability to regulate - can only when envi is right

influx

in

efflux

out

set point

normal range of values for controlled variable

sensor

structure senses the environment

integrator

compare incoming sensory info to set point and determines whether response is needed

effector

structure helps restore internal conditions

this alllll maintains

a negative feedback loop, effectors oppose direction of change in internal state

thermoregulator

maintains temp requires balancing heat influx and efflux

PICTURES IN PHOTOS CHECK!!

conduction

direct transfer of heat between two physical bodies in contact with each other

convection

heat exchange between solid and liquid or gas-fluid flow

radiation

transfer heat between 2 bodies not in direct physical contact

evaporation

phase exchange occurs when liquid water becomes gas

metabolism

heat is a byproduct of biochemical activity

endotherm

produces enough heat to warm own tissues

warm themselves due to high basal metabolic rate which leads to move active all time and ATP costly, retain heat-insulation fur and heat,

ectotherm

relies on heat gained from environment

low ATP/food intake so greater ATP supporting reproduction

homeotherm

keeps body temp constant

poikilotherm

allows body to rise and fall on environment

maintain heat/ reducing heat efflux

reduces surface area, increase insulation - trap still air in fur and feathers and being fat if there are no fur/feathers

decrease temperature differential

use torpor - drop in body temp for a week or 2 - or hibernation - long drop in body temp - reduces overall body temp

countercurrent exchange to reduce heat of blood in extremities— IN PHOTOS

asexual reproduction

mitosis, without fusion of gametes, offspring are same as parent

sexual reproductin

meiosis, fusion of gametes

budding

offspring forms wihin or on the parent then breaks free and grows on its own

fission

individual splits into 2 or more descendants

parthenogenesis

female produces an offspring without help from a male —-mitosis, meiosis, or fusion of two products of meiosis

most animals produce

sexually, haploid gametes fuse to form diploid offspring—increase chance that offspring will do well if more variable, increased chance of successful genotype - physical conditions, predator/prey interactions, disease

why some are asexual repro

have the advantage every individual generates offspring, pass 100% of alleles - sexual parents only 50%

daphnia - water flea

spring/summer

• produce diploid female offspring with parthenogenesis - which develop a brood pouch, offspring released when it molts

late summer/fall

• many develop into males which produce sperm by meiosis and females eggs by meiosis - sperm → egg

  • fertilized eggs fall to bttm of lake overwinter in spring eggs hatch as female

the switch is caused by

environmental cues - water quality as crowded, food concentration low, day length = short

need all 3 conditions

gametogenesis

production of male and female gametes

gametes

haploud cell that animals form by meiosis of diploid cells

spermatogenesis

males produce 4 sperms from each diploid spermatogonium celll

oogenesis

females produce only 1 egg-ovum- from each diploid oogonium —other 3 become polar bodies

external fertilization

aquatic environments, large amount of gametes, gametogenesis occurs in response to envi cues like day lengthing and warmer temps, chemical messangers-pheromones - involve coordination

-spawning - selection and localized

broadcasting fertilization - non-selective, pop wide release of gametes

internal fertilization

occurs terrestrial and aquatically, mostly terrestr.

sperm can be packaged into a spermatophore that is left by the male and picked up by the female

-male salamander deposits the spermatophore on the ground and the female picks it up with her cloaca - sperm can be deposited directly in females - humans =copulation

competition that occurs after mating between sperm from different males to fertilize the eggs of the same female —-

in many animals - females mate with multiple males

sperm deposited by a 2nd male may displace sperm stored from earlier matings - 2nd-male adv is widespread but not universal in insects and some others

male w larger testes produce more sperm and increase the odds of successfully fertilizing eggs, female may choose mate order or physically eject sperm from undesireable mates

male genitalia

certain shapes may give them a sperm competitive adv, natural selection that occurs during sperm competition may explain why is it so diverse among insects/spiders, some genera of spider, species are id’d by gentalia shape

seed beetles

males w longer spines on the tip of their genitalia were more succesful in copulating with females

fitness trade-off

compromise between traits,

ex: spermatophore in crickets - which is a packet of sperm surrounded by gelatinous mass, male deposits that on the female genital opening, females eat mass after mating-longer it takes, more sperm from male fertilize eggs — larger spermatophore=more success per mating, it is costly and takes more than 3 hours to make — larger spermatophore=less time spent mating

development can be internal or external

oviparous and can result in either internal or external fert.

vivparous is internal and embryo cont. exchanges material w mother

ovoviviparous - internal but within a yolk-filled egg

animals use 2 main mechanisms to carry messagees to and from control centers

neural signals- action p, neurvous system

• faster, more specficially targeted, short

chemical signal - horomones, endocrine system

• slower, more broad, but longer lasting

crin

seperated

autocrine

act on same cell that secretes them —cytokines

paracrine

diffuse locally and act on nearby cells

endocrine

hormones carried between cells by blood or other body fluids

endocrine system

collection of organs and cells that secrete chemical signals into blood stream —through glands

hormones

chemical signal that circulates through body fluid and affects distant targets, present in low concentratiosn

neural

neurotransmitters, short lived, diffuse a short distance between neurons

neuroendocrine

neurohormones, hormones released from neurons, bc carried by blood or body fluid to act on distant cells

ex: ADH-antidiuretic horomone - regulate water in collecting duct of kidney, produced by hypothalamus

insulin and glucagon

act as paracrine, but also hormone, produced in pancreas,

panacrine - when on nearby pancreatic cells to ensure steady response to changing blood glucose levels

hormone - released into blood controlling concentration of glucose in blood

exocrine

release fluids through ducts into space other than circulatory system

some gland are endocrine, exocrine, or both

exocrine - salivary glands, sweat glands, mammary glands

both - pancreas

endocrine pathway

endocrine cells respond directly to an environmental signal by secreting a hormone

photo

neuroendocrine pathway

info about exteranl condition is gathered and integrated by neurons in CNS, neurons produce a hormone-neurohormone- which acts on effector cells or ——

neuroendocrine to endocrine pathway

info about external is gathered and integrated by neurons in the CNS, which produce hormone- neurohormone- acts on effector cells or stimulates cells in endocrine system to produce hormones

hormone receptors

responses required appropriate receptors — membrane-bound receptors — which activate or de biochemical pathways

hormone class 1 - peptides and polypeptides

chain of amino acids, bind to receptors on plasma membrane - not lipid soluble

hormone 2 - amino acid derivative

ex: epinephrine/adrenaline, thyroid hormones -lipid soluble, generally most not lipid soluble and bind to receptors on surface of target cell

hormone 3 - steroids

lipid soluble bind to receptors inside target cell, target intracellular receptors, ex: estrogen

hormones have 3 major classes^^

key difference in solubility

signal transduction

message must be transduced to insde the cell

target cells w/ same receptor protien may have

different second messenger or enzyme system

same hormone and receptor can give rise to

different response in different target cells

same chemical messengers can trigger

different responses in cells from different organs or cells at different developmental stages

single hormone can exert a variety of effects

triiodothyronine - T3 and thyroxine - T4 are produced by the thryoid gland - stimulate metabolism, promot growth, increase heart rate, and stimulate synthesis of macromolecules/proteins

several different hormones may affect same aspect of physiology

insulin, glucagon, epinephrine all influence glucose levels in the blood

hormones coordinate cells activity in

1. development, growth, and repro

2. response to envi challenge

3. maintain homeostasis

thryoid hormone in amphibian metamorphosis

signal from brain, pituitary gland secretes thryoid-stimulating hormone - TSH, which stimulates thyroid to produce T4, converted to T3 at target tissue, juvenile amph. T3 stimulates growth of new structures-legs

known from an experiement - that it is from thryoid hormone

growth and metamorphosis insects involves

juvenile hormone -JH

ecdysone - ecdysis-molting

high JH+ecdysone surge = larval grwoth - molting

low JH + ecdysone surge = pupation and metamorphosis

short - term = fight or flight

triggered by cns sympathetic nervous system whcih stimulates adrenal gland to release epinephrine

photo - heart-increase cardiac output, blood vessels - increase flow to muscles, heart, brain, liver - increase glucose release, fat cells- increase fat release

longer term - sustained by activity and alertness increase

stress response, driven by cortisol

photo - hypothalamus produces increase in corticotropin releasing hormone through the anterior pituitary - which increased adrenocorticotropic hormone in the adrenal gland which increase cortisol release —- then liver - more conversion of protein to glucose, fat cells - increase release, immune system - decreases

maintaing homeostasis

messages from integrators to effectors are often sent through hormones

ex: blood glucose — too low - not enough fuel for brain —too high - toxic = organ failure

blood glucose homeostasis

eating - rises blood glucose levels - stimulates release of insulin which stimulates effector cells in body to import glucose from blood for storage or metabolism use - blood glucose levels drop

hours after meal - blood glucose levels decline as glucose goes to cellular resp, glucagon - released from pancreas - causes glucose sotring cels in liver to export glucose to blood - -blood glucose levels increase

PHOTOS

water and electrolyte balance— dehydrated

dehydrated - ADH-antidiuretic released by pituitary which increase permeability of kidney’s collecting ducts to water - so waters reabsorbed through urine

ethanol-alcohol —-inhibits release of ADH so large dilute urine, lots of dehydration

water and electrolyte balance - good hydration

aldosterone - released from adrenal cortex when sodium concentrations in body fluids are low, Na+/K+ pumps active- result in increased reabsorp of sodium ions in distal tubules of kidney - adrenal hormones thatfunction in regulating electrolyte balance are called mineralcorticoids

hypersecretion

too much hormone secreted - hyperthryoidism - overheat, weight loss, restlessness

hyposecretion

too little hormone secreted - type 1 diab - lack of insulin so fails to metabolize and store glucose from meals

hyporesponsiveness

too few hormone receptors- type 2 diab - lack insulin recep lead to milder type 1 effects

multi-hormone pathways probs w upstream hormones cause

probs w downstream hormones

negative feedback loops

hormones control effectors that influnce a varibale - value of that variable helps determine amount of hormone released

short-loop feedback - hypothalamic-pituitary axis

levels of downstream have negative effects on levels of upstream - - feedback inhibition

PHOTOS

nervous system does

gather info about exter + intern envi, activates skeletal muscles and endocrine glands, influences activity of smooth muscles in GI tract and arterioles, influences heart rate, integrates info and makes decisions

nerve net

diffuse arrangement of cells

central nervous system

large number of neurons aggregated into clusters- ganglia

cns

brain - higher level decison making + control

brainstem - influences heart, ventilation, digestio

spinal cord - transmit info, some reflexes

pns

all neurons and other components not in CNS

• afferent - sensory = brings sensory to cns

• efferent - motor = carries CNS to effectors

  • somatic ns

  • autonomic ns - symp and parasymp

somatic ns

voluntary response, skeletal muscles=effectors

autonomic ns

involuntary response, smooth, cardiac muscles, and glands =effectors

• sympathetic- fight or flight, increases physical activity, inhibit digestion

• parasympathetic - rest and digest, promote digestion reduce activity

• PHOTOS