Reproduction and Sex organs

homeostasis

negative feedback loops

Information flow

• Sensory receptors

• sensory neurons

• control center

• motor neurons

• effectors

sensory receptors

general vs specific senses

sensory neurons

travel in nerves

control center

spinal cord and brain

motor neurons

travel in nerves

effectors

muscles and glands

negative feedback loops

responds to counteract a change

negative feedback loop: three parts

• sensors/receptor

• integrator/control center

• effector=carry out commands

negative feedback example

blood clotting

childbirth contractions

withdrawal reflex touching a hot stove

positive feedback loop

responds to amplify a change. break in blood vessals→ damaged cell release chem.→ clotting begins→wall cause bleeding

Santiago Ramon y Cajal

fathered modern neuroscience. learned method staining while a prof. in barcelona

Nervous System

withdrawal reflex arc

Nervous System steps

1. Sensory receptors

2. sensory neuron

3. central N.S

4. Motor Neuron

5. effector

Sensory receptors

detects stimulus + converts that energy to an electrical signal. Destined for the central N.S

Sensory Receptors( general vs Special)

general- felt all over the body.

ex)- touch, pressure, temp,pain detected by free nerve endings

Sensory receptors ( general vs special)

special- have dedicated organ in head

ex)- vision, smell, taste, hearing, equilibrium

hearing and equilibrium= mechanic receptors

Sensory neuron

carries info from sensory receptor to Central N.S.

travels in bundles=nerve

nerve

bundle of axons in periphillis

Spinal vs Cranial nerve

Central N.S

spinal cord. Neurons have synapses with motor neurons

Central N.S

spinal cord function-integrate reflexes+ connect spinal nerves to brain( so up or down)

Central N.S

Brain. Function= conscious + subconscious control of skeletal MT. Controls cardiac MT, Smooth MT,+ glands

Central N.S

brainstem=breathing, basic body functions

Central N.S

meninges= three layers of membranes that protect the brain and spinal cord

Motor Neurons

carries “command” info from spinal cords(or brain) to effector. Travel in nerves.

Effector

skeletal MT that contracts to withdraw from pain( or cardiac MT or smooth MT or gland)

Endocrine System

• Tissue= ET specialized for secretion of hormones

  • Hormones= chem.messengers that travel in blood, only bind to their target cells+ deliver signal to do something

• function=3c’s

  • wireless

  • negative feedback loops

  • controlled by the hypothalamus

Hypothalamus

by controlling the pituitary gland secretes growth hormone and oxytocin

growth hormone

skeletal MT + bone tissue(synthesis targets)

Oxytocin

• targets mammary glands(release milk)

• smooth MT of uterus (contract)

thyroid gland

controls metabolism + heat production

Thyroid gland (hypothyroidism)

• underactive

• cause tiredness and weight  gain

• feel cold

  • thyroid gland does not make enough thyroid hormone

Thyroid gland(hyperthyroidism)

• overactive

• weight loss, increased metabolism

• feel hot

• make too much thyroid hormone

adrenal gland

secrete adrenaline

adrenaline

• stimulates sympathetic response( emergencies)

• increase heart rate + beat force

• dilate arterioles in lungs + skeletal MT

• dilate bronchioles to increase ventilation

Pancreas

• secretes 2 hormones to regulate blood glucose levels

• insuline

• glycogen

Insulin

lowers blood glucose levels by stimulating liver + skeletal MT to take up glucose + store it as glycogen

Glucagon

raise blood glucose by stimulating liver to breakdown glycogen+ release glucose into blood

Biological sex

• anatomy of sex organs

• influenced by:

  • chromosomes→ anatomy→ hormones

• Biological male, female, intersex

Anatomy

sex organs= genitalia

genitalia

gonads

Gonads

produce gametes + secrete hormones

gametes for biological male

sperm

Gonads for biological male

testes. sex hormones + estrogen

Sperm

made by the spermatogenesis in the seminiferous tubules

ducts for biological male

• epididymis

• tube

• ejaculated from tail

epididymis

sperm storage, maturation + reabsorption( if necessary)

Male tube

20 ft long, takes 30 days

Glands for biological male

prostate

Vas deferens

travels up thru inguinal canal, behind bladder, merges with the seminal vesticles

Make most of the seminal fluid( includes fructose)

Urethra of biological male

passes prostate( adds more seminal fluid including clotting factors), then thru pelvic floor muscles, then thru penis→ out( at external urethral orifice)

External male genatilia

• scrotum

• penis

penis

• shared organ between urinary + reproductive system

• senstation

• glans(tip) protected by prepuce( foreskin)

• functions-

  • protection

  • immunity

  • sensation

Urinary Tract Infection

Not an STI

Urinary Tract Infection

kidney provides urine→ureter transports urine towards urinary bladder→ urinary bladder temporarily stores urine prior to elimination→ urethra conducts urine to the exterior

Most likely caused by e.coli bacteria

treated with antibiotics

STI

caused by bacteria or viruses

Bacterial STI’s

• gonorrhea

• chlamydia

• syphilis

Viral STI’s

• not alive

• cannot be treated with antibiotics

Viral STI’s

• genital herpes

• genital warts

• HIV

Gonorrhea

• asymptomatic

• puss like discharge

Chlamydia

MOST COMMON

Syphalis=3 stages

• stage 1= chancre(painless sore)

• stage 2= body wide rash

• stage 3= skin ulcers, neurological degeneration, death

Gonorrhea and chlamydia can lead to…

Pelvic inflammatory disease

genital herpes

• caused by herpes Synplex virus

• Genital herpes 1= oral

• Genital herpes2= genital

Genital warts

• caused by Human Papilloma Virus

• 150 different strains

HPV vaccine

Gardosil protects against 4 strains of HPV:

2 that protects 90% of genital warts

2 that protects 70% of cervical cancer

HIV( Human immunodeficiency virus)

takes over helper T lymphocytes, leads to acquired immunodeficiency syndrome (AID’s)

Theory of Biological evolution

change in the gene pool of a population over time

microevolution

microevolution

changes accumulate overtime and can lead to large-scale change: macroevolution

Macroevolution examples

• new adaptation appears

• new species appears= speciation

Popular myths

1. Scientists investigate or dispute the potential existence of gods/deities

2. its impossible to be both an evolutionary biologist and a religious believer

3. Humans descended from monkeys

4. Evolution is scientifically controversial

5. Evolution is” just a theory” (not fact)

fact

something known to exist or have happened

3 features of all populations

• genetic variation→ all based on mutation

• competition for limited resorces

• hereditary= mutations are heritable if they arise in gametes

heritable

something that can be inherited

How does a gene pool change over time?

• genetic drift

• gene flow

Genetic drift

change in gene pool of a population due to a random chance

ex) bottleneck effect

ex) bottleneck of northern elephant seals= hunted to almost extinction, only 20 left that repopulated

ex) founder effect in Darwin Finches= got blown away in wind storm

gene flow

change in a gene pool of a population due to migration in/out of that population

homologous structures

are those that derive from the same embryonic structures

homologous structures

1. testis—ovaries 

2. penis— clitoris 

3. nipple— nipple 

biological female anatomy(gonads)

ovaries make eggs + sex hormones= estrogen + progesterone

eggs( in gonads)

• develop in follicles on a cycle(± 28 days)

• 1 egg/cycle(or 2 ) released from follicle= ovulation

bio. female anat.( Ducts)

uterine tube

• “Sucks up” ovulated eggs with ciliated cells 

• typical site for fertilization

• cilia sweep embryo to the uterus 

• ectopic tubal pregnancy 

• tubal ligation 

bio female anat. (Uterus)

where embryo implants + develops fetus

implants

• lining is welcome: glycogen rich mucus + lots of spiral capillaries

• + blood= menses

• endometrium

uterus

• neck= cervix( access thru vagina)

• thick walls of smooth MT— has cervical canal= dilates to 10cm

bio of female anatomy (vagina)

• birth canal

• vaginal orifice= opening 

bio female anatomy external genitalia (vulva)

• labia majora + labia minora= protection

• clitoris homologous to penis, made of 3 erectile bodies →fxn: sensation 

female anatomy externial genetilia( glands)

• accessory glands= lube

• mammary glands= secrete milk 

homologous reproductive structure

structure—Male—female

• gonads—testes—ovaries

• gametes—spermatozoa—ova 

• hormones—testosterone—estrogen 

• erectile organ—penis—clitoris

• glands—seminal vesicle—accessory glands

• —prostate and Cowper glands

• external—penis—clitoris

• genetilia—scrotum—labia majora 

  ---

  ---

contraception

preventing pregnancy

contraception

• IUD(intrauterine device)

• surgical sterilization(male/female)

• birth control implant 

• birth control shot

• birth control pill condom

• sponge'

• transdermal patch 

• emergency contraception

hormonal methods

• suppress ovulation

• thicken cervical mucus

• thin the endometrium

barrier methods

• dont let sperm get past

2 more mechanisms for bio.evol.(sexual selection)

change in gene pool of a pop. over time due to non random mating

ex. sage grouse—lekking

ex. superb lyrebird—song/chirping

ex. peacock spider—dancing 

2 more mechanism for biol. evol.(natural selection)

change in gene pool(allele frequency) of a pop. over time due to environmental selective pressure

*some individuals in a pop. leave more offspring than others= those individuals are more fit 

fitness

measure of an individual’s genetic contribution to the next generation

*focus on heritable characteristics that increase an individual’s ability to survive + reproduce in a particular environment → adaptation

evidence for biol. evol. (4 categories)

1. see evolution in action(artificial selection)

humans are the selectors

ex: dog breeding

ex. crop development

evidence for biol. evol.(4 categories)

1. see evolution in action(resistance)

pop. develops resistance to____

ex. bacteria to antibiotics

ex. viruses to antiviral meds

ex. weeds to herbicides

evidence for biol. evol. (4 categories)

2. homology

results from common ancestry

• anatomic homology

ex. forelimbs of vertebrates

• vestigial structures= reduced or no function

ex; boa hind limbs+ pelvic bones

ex. baleen whale hind limbs

ex. blind mole rats eyes

ex humans(arrector pili muscles(makes hair stand up), tailbone, appendix, palmaris muscle+ calf muscle)

homologous structure

characteristics seen in different species that result from common evolutionary ancestry 

embryological homology

ex. common development patterns

ex. human embryo w/ tail, notochord, pharyngeal gill slits

molecular homology

ex. ATP, proteins, DNA, RNA

ex. E pathways: cell resp., photosynthesis