chapter 19 - birth and development of infant Flashcards
1
Q
what is parturition
A
- birth, when the foetus is expelled from mother at the end of gestation
2
Q
what is labour
A
- sequence of events before birth
3
Q
what are some changes that happen before labour
A
- hormonal: ligaments of pelvis soften, strengthens contractions of uterus
- foetus: head in mothers pelvis, legs crossed, knees drawn up to its abdomen
- cervix: softens, shortens in length, opens a little
4
Q
what happens during the first stage of labour
A
- months 7-9: weak irregular contractions, frequent 30min interval contractions (labour pains)
- dilation of cervix: from onset labour to complete dilation (opening) of the cervix
- labour: lasts for ~8-9hours for first child
- wave like contractions: (kinda like peristalsis), causes uterus to shorten, cervix to open, allows foetus to move more freely into pelvis, head is pushed down
- complete dilation: 10cm, occurs at end of 1st stage
- birth canal: curved passage, uterus, cervix and vagina
5
Q
what happens during the second stage of labour
A
- water breaks: amniotic membrane breaks, triggers stage of expulsion
- stage of expulsion: can last ~20min-2hours, delivery of foetus
- foetus: head stretches the vagina -> contracts abdomen muscles -> contraction of uterus -> push foetus through vagina, head faces towards mothers back
- mother: pulse rate increases, perspiration occurs
- expulsion: foetal head can be pushed out of shape (skull = separated by joints = movement), head delivered first (breathing begins), shoulders turn to fit into bones of pelvis, rotates sideways to face mothers hips
6
Q
what happens during the third stage of labour
A
- umbilical chord: cut and tied, umbilicus (naval) is all that remains
- vernix: baby is covered with a waxy material, this isn’t entirely removed (decreases occurrence of skin infections)
- afterbirth: placenta, amnion, chorion and umbilical chord are expelled
- blood clots: form to prevent blood leakage
7
Q
what are the characteristics of the new born infant
A
- full term: ~50cm, ~3.3kg, head is 1/4 of body length, legs are 1/3 of body length
- can breathe, suck, swallow, see, removes wastes, tastes, smell, hear, turn head, cries to signal help
- reflexes: movements occur automatically in response to a particular stimulus
- e.g. placing something (nipple / dummie) in babies mouth stimulates sucking
8
Q
how does the baby rely on the mother during development
A
- embryo / foetus relies on mother for supply of oxygen and nutrients and removal of wastes and co2, protection against changes in temp, shock and many disease causing organisms
- placenta: lungs, liver and alimentary canal of foetus don’t function, obtain nutrients from placenta
9
Q
exchange and circulation of foetus before birth
A
- foetus -> umbilical arteries -> placenta -> umbilical vein -> foetus
- foetus -> ductus venousus -> inferior vena cava -> right atrium -> ductus arterialises / Forman ovale
10
Q
what are the three bypasses of the foetus
A
- DV: blood vessel that bypasses the liver: partial hepatic vein -> inferior vena cava
- DA: blood vessel that bypasses the lungs: pulmonary artery -> aorta
- FO: opening between two chambers of the heart (blood entering RA goes straight into LA), blood from placenta = highly oxygenated, this increases blood flow
11
Q
what happens to the circulation after birth
A
- new born can no longer rely on mother / placenta for food / oxygen
- DV: closes, allows liver to become a fully functioning organ
- respiratory: stimulated by first breath, lungs begin to function, expansion means blood flow occurs
- DA: decreases due to expansion of lungs, eventually closes
- FO: closes off due to increased blood supply needed for the lungs
- hole in heart: occurs when the FO doesn’t close
12
Q
what happens to the infants heart rate and breathing
A
- B first 2 weeks: babies lungs undergo 45 breaths / minute, after two weeks breathing slows
- HR: high rate of 125/130 (180 beats / min), because more oxygen is needed for increased muscular activity (keep baby warm)
- RBC: #increases to carry extra oxygen to tissues
- WBC: very high count at birth, decreases rapidly by 7th day
13
Q
what changes to the mother occur after childbirth
A
- puerperium: 8 weeks post childbirth
- reproductive organs: (especially uterus) continues to contract, organs return to their non-pregnant state
- flattening of abdomen: contractions and gradual shrivelling of muscle fibres brings about shrinking
- discharge of fluid: from shrinking uterus (mixture of blood / breakdown products of tissues)
- blood volume / pulse: gradually returns to normal, pulse is slower
- emotional changes: postnatal depression, mood swings, adjusting to new situation
- menstruation: begins after 6 months (if breast feeding), within 10 weeks (if not)
14
Q
describe the structure of the breasts
A
- lobes: breast divided into 16-25 sections
- lobules: each lobe is divided into lobules
- alveoli: makes up wall of each lobule, milk secreting region of breast
- fatty tissue: surrounds lobules and lobes
- milk spaces: from lobules, ducts open into wide spaces, spaces serve as reservoirs for milk
- duct: from milk spaces short, straight duct leads to nipple
- nipple: each lobe has its own milk space, 15-25 openings on the nipple
15
Q
what is lactation
A
- the initiation and maintenance of milk secretion and delivery of milk to infant
- hormones: cause changes in breasts, becoming larger in size and oil secreting glands around nipple change, secretes milk 1-2 days after birth
- colostrum: first secretion, watery yellowish-white, contains little to no fat, high content of antibodies
