psych of childbirth midterm 1

skeletal muscles

attached to the bones and help us move around. can be voluntarily controlled

smooth muscles

found in most internal organs including the digestive system, bladder, and blood vessels. cannot be voluntarily controlled

skeletal muscles

attached to the bones and help us move around. can be voluntarily controlled

smooth muscles

found in most internal organs including the digestive system, bladder, and blood vessels. cannot be voluntarily controlled

peripheral nervous system

cranial and spinal nerves that spread throughout the body. includes the autonomic and somatic nervous systems

autonomic nervous system

part of the PNS that controls motor innvervation of smooth muscle, cardiac muscle, and glands

somatic nervous system

part of the PNS that controls motor innervation of all skeletal muscles

sympathetic nervous system

division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations ("fight or flight")

parasympathetic nervous system

division of the autonomic nervous system that calms the body, conserving its energy

myometrium

muscular middle layer of the uterus - smooth muscle

myocytes

smooth muscle fibers located within the myometrium

motor denervation of the uterus

process where the nerves responsible for controlling uterine muscle contractions (motor nerves) are reduced, leading to a decrease in the ability to control uterine contractions

endometrium

inner lining of the uterus, contains glands and tiny blood vessels

sensory denervation of the myometrium

causes a loss of sensory nerve input, allows for the uterus to stretch and increase in strength throughout pregnancy

common explanations for labor pain

stretching of the cervix, contraction of uterine muscle

stage 1 of labor

uterus contracts and stretches the cervix to open to approximately 10 cm diameter

stage 2 of labor

the baby passes through the birth canal and is born - the time between full dilation and the baby

stage 3 of labor

the placenta is birthed - hardest and most important stage arguably

post-partum stage of labor

uterus contracts in order to return to its original shape

benefits of normal labor pain

guides the birthing person through the process, focuses mental and physical resources towards birthing, can regulate the strength of contractions

villi of the placenta

some of the fetus's blood vessels are contained within these tiny hairlike projections

intervillous space

the part of the placenta where the mother's blood passes through, surrounding the villi

placental membrane

thin membrane that separates the mother's blood in the intervillous space from the fetus's blood in the villi

oxytocin

a hormone released by the pituitary gland that stimulates uterine contractions during labor

oxytocics

drugs that induce labor at term by increasing the strength and frequency of uterine contractions

pituitrin

pituitary extract that causes uterine contractions ("synthetic oxytocin")

endogenous oxytocin

synthesized in the hypothalamus, stored and secreted by the posterior pituitary gland - can act as both a neurotransmitter and a hormone

sensations associated with oxytocin production

security, relaxation, warmth

stage of labor with the highest oxytocin peak

third stage-- birthing of the placenta

myometrial activity during labor

myocytes become more interconnected, creates conditions for spontaneous organization of synchronized activity

nociception

the sensory process that produces the nerve signals that trigger pain

placebo analgesia

positive expectations of pain reduction may reduce sensations of physical pain

mechanisms of placebo analgesia

increase in endogenous opioids

nocebo analgesia

when negative expectations increase pain sensations

mechanisms of nocebo analgesia

anxiety: cholecystokinin (CCK), an anxiety-producing hormone that facilitates pain transmission

stress: the hypothalamic-pituitary-adrenal axis (HPA) releases cortisol, suppresses immune system

nucleus accumbens suppresses endogenous opioids

expectation: dorsolateral prefrontal cortex

ascending (afferent) nociceptive signals

enter brain through the spinal cord and are distributed through different pathways-- one to the thalamus, one to the amygdala, one to the cerebellum

interoception

thalamus sends projections to the posterior insula, anterior cingulate cortex (ACC), somatosensory cortex

molding during labor

softness of the baby's cranial bones that allows it to fit more easily through the pelvis

vitamin K injection for newborns

serves as a coagulant to prevent bleeding in the baby. some vitamin K comes from the placenta, but may not be enough

erythromycin ointment

administered to newborns to prevent eye infection from passing through the birth canal. used to be mandated for all newborns in BC

Early conceptions of the uterus

caused literally every single problem a woman could have; related to hysteria

fundus

top part of the uterus where contractions are initiated and are the strongest

corpus

uterine body; largest subdivision of the uterus, below fundus

cervix

lowermost portion of the uterus

isthmus

transition zone between uterine body and cervix

layers of the uterus

endometrium, myometrium, perimetrium

perimetrium

outer connective tissue of uterus

in late pregnancy, muscle fibres form an interlacing network __________ _______ the fundus

transversally across

in late pregnancy, muscle fibres form an interlacing network ________ _______ anterior and posterior of the uterus

obliquely down

in late pregnancy, muscle fibres form an interlacing network ________ _________ the lower segment of the uterus

transversally across

the dominant narrative in the media regarding birth is...

medicalized birth

the alternative narrative in the media regarding birth is...

physiological (normal, natural) birth

what is the key part of the international confederation of midwives (ICM)'s definition of physiological (normal) birth?

the labour must start, continue, and complete without intervention

how does the media's dominant portrayal of birth impact real life?

the predominant portrayal is overall negative and is hyper-medicalized, so those who view the media may conform to medicalized norms based on what they have seen

how does the media's alternative portrayal of birth impact real life?

may create pressures - the notion of a "good birth" is pushed and people generally only post about idyllic births; the expectations absorbed may create pressure

information

sensory data we obtain with its context and meanings

knowledge

inferences we draw and theories we construct from our interpretations of the information we have; purpose is to enable action

2 ways that new information can fail to change our knowledge

1: low credibility 2: acceptable credibility, but clashes with pre-existing knowledge (information is retained but not integrated)

differences in contractions between non-pregnant and pregnant uterus

non-pregnant uterus contracts all the time spontaneously; pregnant uterus only contracts during labour and orgasm (and postpartum period)

uterine quiescence

during pregnancy, no spontaneous contractions of uterus (lasts until approx. 37 weeks) (small contractions, but highly localized and not synchronized)

contractions during late pregnancy

occur ~37 weeks, spontaneous and ongoing, "practice" (Braxton-Hicks)

innervation

the connections between nerves and tissues; the ability of a nerve to influence tissue and vice versa

motor innervation (non-pregnant uterus)

neural fibres exit spinal cord, innervating all pelvic cavity organs - neurons grouped based on whether they are sympathetic or parasympathetic, and exit through different levels of the spinal cord

sensory innervation (non-pregnant uterus)

carry visceral sensations - sensory neurons grouped based on which location/organ they originate from, and enter through different levels of spinal cord

types of visceral sensations

distension/stretch, inflammation, ischemia (reduced oxygen supply to tissue)

what causes uterine motor denervation?

ovarian hormones

what 2 physical phenomena contribute to the motor denervation of the uterus?

hypertrophy of uterine myocytes (leading to ratio differences) and dramatic decrease in the number of nerve fibres

what hormone primarily causes contractions?

oxytocin

what happens in the myometrium during denervation?

autonomic nerve fibres decrease

what happens in the endometrium during denervation?

releases hormones

what are the problems with hypothesized reasons for labour pain?

stretch receptors disappear in myometrium during pregnancy and in cervix at onset of labour - no feeling of stretch; muscle fibres in cervix almost completely replaced by connective tissue

what is considered "active labour?"

regular, frequent contractions

Cervix during pregnancy

shortens (effaces) - holds baby in; becomes thin when time comes to dilate

alternative explanations for labour pain

vasoconstriction of uterine blood vessels; release of chemicals from muscle exertion; inflammation; ischemia

what causes muscle pain during exertion?

increase in the concentration of metabolite combinations

what is the vasoconstriction of uterine blood vessels?

contractions reduce blood flow to uterus and baby - compression of blood vessels, hypoxia

pain leads to the release of

endogenous opioids

what were some early medications used for pain relief?

opium, morphine, codeine, heroin (all opiate family); cocaine as a local anesthetic

early epidurals utilized

cocaine, lidocaine, morphine

______ is the most common local anesthetic in epidurals, and _________ is the most common opioid

bupivacaine, fentanyl

the most effective administration of morphine is...

epidural, not IV. it is more effective in combo with bupivacaine

to work, local anesthetics...

must cross the spinal cord - they bind to sodium channels on neurons

local anesthetic has a greater effect on ______ neurons

more active. order of impact: autonomic, temperature, pain, touch, pressure, vibration, prioception, motor

opioids bind to...

opioid receptors (duh). depresses CNS

components of pain

sensory and emotional

sensory pain component

discriminatory component that enables sensory modalities to identify location and intensity of a stimulus - primary and secondary cortexes

emotional pain component

subjectively experience discomfort and drives us to do something to mitigate it - anterior cingulate cortex and insula

what cognitive factors impact pain perception?

stress/depression (increases), calm/optimism (decreases), distress/anxiety, attention paid to the pain (!!!!)

nociceptive nerve fibres have __________

free nerve endings, composed of axons

relationship between myelin and pain

greater diameter of nerve fibres and thicker myelin sheath = faster conduction of impulses (ie faster/acute pain)

A delta nerve fibres

fast, acute pain sensations

C fibres

slower, longer persisting pain (non-myelinated)

gate-control theory of pain

signals arriving from pain receptors in the body can be stopped, or gated, to make it harder for nociceptive impulses to get through

CNS levels that can act as gates for pain

spinal cord, brain stem (including midbrain and medulla oblongata), brain (including prefrontal cortex)

visceral pain

nociceptors in internal organs, sensitive to distension/ischemia/inflammation, low density of sensory interaction and divergence of visceral input onto CNS (more vague pain)

during birth, uterine myocytes...

become excitable and interconnected - creates conditions for spontaneous synchronized activity (contractions)

context-induced positive expectation and context-induced conditioning activates

endogenous opioid and endocannabanoid systems

________ reduces placebo analgesia with anti-opioid action

cholecystokinin (CCK)

descending pain modulating network involves

dorsolateral prefrontal cortex (DLPFC), rostral anterior cingulate cortex (rACC), periaqueductal grey (PAG)

hyperalgesia

anticipation of pain, attention on impending pain, involves CCK, increases perception of pain

stress-induced analgesia

pain reduction due to shifting attention to an environmental stressor and away from pain, involves activation of endogenous opioid system

interacting systems of pain perception

noxious sensory input, social cultural, conceptual judgement, emotional motivational