UCSD PSYC 2 Quiz 5: Sleep and Circadian Rhythm, and Sex and Reproduction

circadian rhythm

the biological clock; regular bodily rhythms that occur on a 24-hour cycle

zeitgebers

Environmental cues, such as the light-dark cycle, that entrain circadian rhythms

cortisol

stress hormone
-produces at night while asleep

suprachiasmatic nucleus

Located in hypothalamus
-regulates melatonin
-connected to optic nerve -> use light to regulate sleep-wake cycle
-SCN cells also have their own internal clocks and is activated by light
-SCN cells send information to mRNA to synthesize PER and TIM to regulate sleepiness

Sleep-wake cycle

a daily, naturally occurring 25-hour circadian rhythm of sleep and wake states regulated by a biological clock

melatonin

A hormone manufactured by the pineal gland that produces sleepiness.

seasonal affective disorder

SAD
-Long dark cycle causes seasonal depression
-can be treated with bright light to go back to the circadian rhythm

sleep deprivation

lack of sleep
-affect mood, cognitive abilities, hallucinations
-if prolonged, quickly go to REM sleep
-can provide temporary relief from depression by manipulating circadian rhythm

EEG (electroencephalogram)

measure brain activates

EMG (electromyography)

measures muscle tone

EOG (electrooculogram)

measures eye movement

desynchronized EEG

Also called beta activity.
-low amplitude
-lots of messages processed

Synchronized EEG

high amplitude, low frequency
-less information processed

sleep stages

relaxed stage (alpha waves)
stage 1 (early sleep) (hallucinations)
stage 2 (sleep spindles and k-complex- bursts of activity) (sleep talk)
stage 3 (transition phase) (delta waves)
stage 4 (delta waves) (sleepwalk/talk + wet the bed)

REM

paradoxical sleep
-desynchronized beta wave -> feel refreshed and awake
-rapid eye movement, paralysis, penile erection, vaginal secretion, vivid, narrative-like dreams

slow-wave sleep

stages 3 and 4
-deep sleep
-early night

Why do we sleep?

conserve energy, avoid predators, restore body, improve memory

Non-REM dreams

sensations
nightmares -> fear pressure

REM dreams

narrative-like

insomnia

inability to sleep
-melatonin withdraw

sleep apnea

a disorder in which the person stops breathing for brief periods while asleep
-wake up gasping for air
-hypoxia

Narcolepsy

uncontrollable sleep attacks

hypnagogic hallucinations

hallucinations that occur when going to sleep; seen in narcolepsy

REM without atonia

Able to act out dreams

Slow wave sleep disorders

bedwetting, sleep walking, night terrors

endocrine system

release hormones in the capillaries and distribute to blood proteins to travel to the tissues of organs

hormones

chemical messenger
-act on target cells at specific receptors

target cells

cells that have receptors for a particular hormone

function of hormones

alter the function of cells by entering the cell membrane, maintain homeostasis, change genetic activity (gene expression and protein synthesis) by entering the nuclear membrane and binding to chromosomes, regulate metabolic processes such as ATP production, activate or inactivate enzymes, open or close ion channels

Hypothalamus

responsible for the autonomic nervous system and the endocrine system
-produces hormones and releases them to the anterior lobe of the pituitary gland and talks to the adrenal gland

adrenal gland

A pair of endocrine glands that sit just above the kidneys and secrete hormones that help arouse the body in times of stress.

why do we have sex?

-reproduction
-DNA shuffling
-it's fun

steroid hormones

derived from cholesterol

sex hormones

progesterone, estrogen (estradiol), and testosterone

Estradiol

female associated hormone

progesterone

female associated hormone
-maintains the thickness of the lining
-pregnancy hormone

Testosterone

male associated hormone

pituitary gland and ovaries

anterior pituitary gland releases FSH to stimulate the follicle to mature in the ovary during the end of menstruation
In the follicular phase, the follicle is stimulated and becomes large, and the cells around the follicle release estradiol to the anterior
During ovulation, the anterior pituitary gland sends more FSH and LH to increase the follicle to release more estradiol.
After the follicle is released in the fallopian tube, the follicle becomes a corpus luteum which sends progesterone and estradiol

FSH (follicle stimulating hormone)

Secreted by the anterior pituitary and stimulates the gonads to produce sperm and egg.

LH (luteinizing hormone)

Produced by the Anterior lobe of the Pituitary Gland. Targets ovaries and testes to stimulate estrogen secretion and egg maturation
-make sure the follicle goes through ovulation

uterine lining

(menstrual lining) lining of uterus that breaks up and is shed from body during menstruation, also nourishes developing baby during pregnancy

birth control

prevent variation of hormone to occur

fosB

maternal behavior in mice is dependent on the presence of this gene
-when fosB is not expressed -> affects maternal behavior by neglecting the offspring

Oxytocin

A hormone released by the posterior pituitary
helps you bond with people who are part of your group

does hormone cause behavior?

behaviors are influenced by hormones
when testosterone level goes down sexual activity/interest goes down, but does not explain sexual behaviors

Aggression

degrease in progesterone - lactating and bonding decreases
-increase in infanticide
testosterone does not have as much influence

Sexually Dimorphic Nucleus (SDN)

A nucleus in the preoptic area that is much larger in males than in females; first observed in rats; plays a role in male sexual behavior

Critical periods

-3rd trimester of Pregnancy- brain grows/develop
-4th month of Pregnancy- depending on the presence of Y chromosome either go to the left pathway (Mullerian Duct) or the right pathway (Wolffian duct)

Mullerian ducts

Earlier embryonic ducts can develop into female internal genitalia in the absence of testosterone.

Mullerian duct-inhibiting substance

Inhibits the development of ovaries

SRY gene

sex-determining region of the Y chromosome
-initiates internal male gonads

Wolffian ducts

Early embryonic ducts can develop into male internal genitalia under the proper stimulation (testosterone).

gender identity

play a role in size of SDN
-regardless of chromosome, women (both cis and trans) have smaller SDN compared to cis men

Intersex

-XY male with a mutation in the SRY gene
-XX female with SRY gene translocated by Y chromosome
-Presence of testosterone
-absence of androgen receptor