Exam must knows! Flashcards
2 eg. of functional cells and their functions
- Nerve cells- brain, direct cell communication, release chemical messages directly on to other cells.
- Germ cells- ova/spermatozoo, reproduction, haploid
Homeostasis
the tendency of a living organism to keep its internal environment relatively stable despite changes in the external environment
universal recipient
AB
universal donor
O
GI
2 changes in pregnancy due to progesterone
- Relaxation of lower esophageal sphincter-> heartburn
- Enlarging uterus compresses large intestine
- > flatulence
Peristalsis vs segmentation
- Segmentation occurs in small intestine, peristalsis occurs all the way from oesophagus to large intestine.
- In peristalsis, adjacent segments contract/relax, creating wave of movement.
- In segmentation, non-adjacent segments contract/relax, causing back & forth of food.
Hyperemesis gravidarum
intractable and persistent nausea & vomiting
Why avoid lambing/cat faeces?
Risk of Toxoplasmosis caused by toxoplasma gondii.
Can cause congenital learning difficulties, blindness
Why avoid soft cheese?
Listeriosis caused by bacterium listeria monocytogenes.
Can cause miscarriage, stillbirth
How to take Ferrous Sulphate
With orange juice- vit c enhances absorption of non-haem iron.
Avoid taking with tea as tannin will stop absoprtion.
Inform if any side effects.
Dietary fibre
Indigestible non-starch polysaccharides.
Found in cereal grains, veg, seeds (large amounts)
Fruit & veg (smaller amounts)
What is negative feedback?
Give eg.
A homeostatic process that changes the direction of the stimulus. May increase or decrease stimulus but stimulus is not allowed to continue as it did before.
eg. Regulation of blood sugar levels
2 functions of endocrine system
- Coordinates homeostatic balance
2. Modifies and induces behavioural changes within the individual.
2 hormones from hypothalamus, released by posterior pituitary gland
- Oxytocin
2. ADH- antidiuretic hormone
3 endocrine glands & functions
- Thyroid- metabolism & growth
- Thymus- immune system
- Gonads- sex steroids that affect reproductive cycles & gamete formation
What is a hormone?
Chemical substance secreted by cells that regulate metabolic function of other cells
regulation of HIGH blood sugar levels
Insulin is increased.
It stimulates sugar uptake by cells and glycogen formation in liver which decreases blood sugar. (Hypoglycaemic)
regulation of LOW blood sugar levels
Glucagon is increased.
It stimulates glycogen breakdown and increases blood sugar. (Hyperglycaemic)
What are neurons?
specialised nerve cells that transmit chemical and electrical signals.
2 parts of nervous system
- Peripheral
2. Central
Glial cells
Provide nourishment & support of neurons
2 types of synapse reactions
- Chemical- a neurotransmitter is released from one cell into another
- Electrical- electrical charge of one cell is influenced by the charge in an adjacent cell
Dendrite
Projections of a neuron that receive signals from other neurons
Epidural space
filled with adipose tissue and dense blood vessel network.
Located between dura mater and surrounding bone of vertebrae.
Synapse
gap between the presynaptic cell and the postsynaptic cell where information is traded (nerve impulse)
2 pregnancy changes to Nervous system
- Grey matter shrinks
2. Pituitary gland enlarges
Function of sensory neurons
convert external stimuli from the environment into corresponding internal stimuli
Function of motor neurons
project their axons outside of the CNS to directly or indirectly control muscles
Function of interneurons
relays nerve impulses between the sensory and motor neurons
2 somatic senses
- Thermoreceptors- temperature changes
2. Photoreceptors- light energy
1st line of defence
skin, mucosa
NK cells
2nd line of defence Type of lymphocyte Found in blood and lymph Release cytotoxic enzymes which degrade target cell contents. Target cell undergoes apoptosis.
4 signs of inflammation
- Pain
- Swelling
- Heat
- Redness
Active vs Passive immunity
Active Natural- bacterial/viral infections
Passive Natural- antibodies passed from mother to fetus through placenta/breast milk
Active artificial- vaccine with attenuated pathogens
Passive artificial- injection of gamma globulins for prophylaxis
4 steps of Rhesus incompatibility
- RH+ father
- Rh- mother carrying Rh+ fetus. Rh antigens from fetus circulate in Mother’s blood.
- In response to antigens, Mother produces anti-Rh antibodies.
- If woman becomes pregnant again with a Rh+ fetus, her anti-Rh antibodies will cross placenta and damage fetal red blood cells.
2 types of vaccine & eg
Inactivated- killed microorganisms, may need 2-3 injections eg. tetanus
Live attenuated- full, long lasting response after 1-2 doses eg. MMR
Homologous chromosomes
Pair of chromosomes with same genes but different alleles
Purpose of Meiosis I is to….
separate homologous pairs
Purpose of Meiosis II is to….
separate sister chromatids
eg of numerical chromosome disorder
Downs syndrome
Cell cycle
cycle of stages a cell undergoes to divide and produce new cells
Crossing over
exchange of genetic material between non-sister chromatids of homologous chromosomes
Autosomes
chromosome pairs 1-22
23rd chromosome
sex
Sister chromatids
2 identical copies of the same chromosome attached by centromere
Functions of ovaries
- To produce oocytes that can be fertilised and undergo full development
- To secrete hormones which prepare the reproductive tract for fertilisation
- To establish and support pregnancy
Follicular phase
- After luteal phase, FSH and LH stimulated
- Graafian follicle grows and matures
- Graafian follicle produces oestrogen -> causes surge in LH
- FSH inhibited by oestrogen -> slow growth and then death
- Dominant follicle remaining
- Inhibin secreted
- Forms bulge near surface of ovary for ovulation
Ovulation
- LH matures oocyte and weakens wall of follicle
- Dominant follicle ruptures
- Secondary oocyte discharged into pelvic cavity
- Fimbrae guide to fallopian tube for fertilisation
Luteal phase WITH fertilisation
- Cells of ruptured follicle form corpus luteum -> oestrogen, progesterone, relaxin, inhibin
- This develops endometrium which awaits fertilised oocyte
- Remains until placenta takes over
Luteal phase WITHOUT fertilisation
- Corpus luteum degenerates -> corpus albicans
- Hormones decrease
- Low oestrogen & prpgesterone = hypothalamus produces GnRH
- Anterior pituitary gland -> FSH
- Ovarian cycle starts again
Phases of menstrual cycle and their overlap
- Menstrual phase- beginning of follicular phase
- Proliferative phase- follicular phase & ovulation
- Secretory phase- ovulation & luteal phase
Where is progesterone produced?
Ovaries, placenta, adrenal glands
Where is FSH produced?
Anterior pituitary gland
Where is FSH produced?
Anterior pituitary gland
Corona radiata
outer layer of cumulus cells (1st barrier preventing access to sperm) adjacent to zona pellucida
Cleavage
repeated mitotic cell division of zygote
2 sperm abnormalities
- Teratozoospermia- abnormal morphology
2. Azoospermia- no sperm present within ejaculate
Acrosome reaction
purpose & steps involved
Triggers changes in the sperm membrane which allow sperm-oocyte binding and then fusion.
- Sperm pushes through the corona radiata and binds to zona pellucida.
- Vesicles containing acrosomal enzymes are opened, exposing inner acrosomal membrane.
- Tunnel digested through zona pellucida by acrosin and acrosomal enzymes.
- Sperm propels through the ZP & perivitelline space.
- Sperm head now in contact with oocyte surface membrane.
How is polyspermy prevented?
cortical and zona reactions
Describe the cortical and zona reactions
Cortical granules are deposited in the perivitelline space -> release enzyme to prevent other sperm from penetrating the egg.
Zona pellucida loses its ability to bind to sperm and in turn the acrosome reaction -> changes texture, zona hardening
What happens at the zona pellucida?
- Capacitated sperm loosely and reversibly adhere to surface of ZP.
- Sperm become strongly and irreversibly bound to the ZP.
- Many sperm bind to ZP but only a few permeate into perivitelline space.
- Only 1 will fuse with oocyte plasma membrane.
5 key functions of placenta
- Oxygenation- transfer of oxygen from maternal to fetal circulation
- Protection- infection, some drugs
- Excretion- elimination of waste products
- Nutrition- amino acids, glucose, fatty acids, minerals, water balance
- Endocrine- prostaglandins, hCG, oestrogens, progesterone
2 functions of pelvic girdle
- Supports & protects pelvic organs and some abdominal organs
- Protection & support in pregnancy
3 bones that make up innominate bones
- ilium
- ischium
- pubis
compression of baby’s head in birth stimulates the….
respiratory centre
3 factors that stimulate first breath
- Light
- Sound
- Temperature change
Lochia
Vaginal discharge after birth of baby
eg. of type of lochia
Lochia alba- yellow/white. Serous fluid and leukocytes
2 sources of infection in puerperium
- Genital tract
2. Urinary system
2 hip manoeuvres in NIPE
- Barlow manoeuvre- dislocatable hip
2. Ortolani manoeuvre- dislocated hip
2 ways newborn stabilises blood sugar
- Feeding
2. Catecholamines- stimulate enzymes in liver to convert glycogen to glucose
2 changes to breast in pregnancy
- Areola darkens
2. Montgomery’s tubercles appear or enlarge
Lactogenesis II
onset of copious milk supply about 2-4 days after giving birth
What could delay lactogenesis II?
stressful birth
Prolactin
produces milk
Describe oxytocin reflex & when it is conditioned
- baby suckles -> impulse to brain
- Posterior pituitary gland secretes oxytocin
- Muscle cells around alveoli contract and squeeze milk down to baby
Becomes conditioned to respond to baby’s cues for food- oxytocin released in response to handling baby, thinking about feeding, baby crying.
Galactopoiesis
maintenance of milk supply
Feedback Inhibitor of Lactation
alerts lactocytes to stop making milk once breast is full. Then, when baby feeds, levels of milk and FIL fall and production recommences. Milk removal generates production -> the more milk removed, the more is made.
peak response times for oxytocin and prolactin
oxytocin- 30 secs
prolactin- 30 mins
Influence of relaxin & progesterone on RENAL SYSTEM
- ureters become atonic and dilated
- increase in capacity by up to 300mls
- may result in urinary stasis and risk of infection
Effect of growing uterus on RENAL SYSTEM
1st trimester- uterus enlarges still in pelvis, leads to decreased bladder capacity and increased micturition.
3rd trimester- presenting part in pelvis.
Expanding uterus puts stress on ureters
Why pregnant women prone to UTIs
- Mechanical pressure of enlarging uterus on renal system
- Relaxing effect of progesterone on smooth muscle of urinary tract
Both of these make ureters atonic and dilated causing urinary stasis.
Along with physiologicall immunosuppression of pregnancy.
Respiratory rate (definition, normal parameter, change in pregnancy)
Number of breaths per minute.
Normal- 12 breaths/min
Pregnancy- 15 breaths/min
Maternal respiratory acidosis
- Increase muscle activity, increase in oxygen requirement.
- If contractions occur too frequently with little rest periods, oxygen supply to muscles decreases (ischaemia)
- Tissue hypoxia with an increase in carbon monoxide and decrease in pH.
Causes cerebral palsy, hypoxic ischaemic encephalopathy.
Which hormone prevents uterus from contracting?
progesterone
Define 1st stage of labour
Onset of regular coordinated contractions with progressive effacement + dilatation of cervix as uterine contractions pull entire cervix up.
3 sections of 1st stage
- Latent
- Active
- Transition
2 factors thought to play a role in onset of labour
- MECHANICAL FACTORS- stimulation of uterus + cervix by presenting part and stretching of muscle fibres in uterus, all contribute to contractility.
- PROSTAGLANDINS- levels increase in late pregnancy. Implicated in cervical ripening, contractions, dilatation and membrane rupture. Increase uterine sensitivity to oxytocin.
2 characteristics of Latent phase
- Dilatation- up to 4cm
- Show- cervix ripens, thins, effaces and mucous plug dislodged.
- Cervical ripening- decrease in collagen fibres make it soft + stretchy
Fetal Axis Pressure in active labour
- Significant after waters broken
- Force of contraction transmitted down fetal spine and onto occiput
- Encourages flexion
- Once waters broken, oxygen supply to fetus potentially reduced during a contraction.
Fundal Dominance in active labour
- Contractions start in fundus near a cornuas
- Then spread across and down body of uterus.
- This helps cervix dilate and uterus to expel fetus
2 signs a woman is in Transition
- Loss of control
- Slowing contractions
- Heavy show
- Variable urge to push
Ferguson’s reflex
- fetal head descent onto pelvic floor
- nerve receptors
- oxytocin released
- oxytocin to uterus
- stronger contractions
3rd stage
Period from birth of baby to complete expulsion of the placenta + membranes.
What is involved in active management of 3rd stage?
- Uterotonics
- Cord clamping
- Controlled cord traction
What is important for physiological 3rd stage?
- Calm relaxed environment -> oxytocin
- Skin to skin
- early breastfeeding
Why examine placenta?
- Retention of any products may impede the uterus’ ability to contract. May impede the action of living ligatures to occlude vessel and prevent bleeding.
- Retained product may cause infection
- Vessels- 2 as opposed to 3 may be associated with fetal abnormality
5 features of fetal circulation
- umbilical vein
- ductus venosus
- foramen ovale
- ductus arteriosus
- umbilical arteries
what does compression of baby’s chest result in?
squeezes out lung fluid, then chest expansion which increases the chest capacity and inspiration of air.
Puerperium
6 week period after birth during which the reproductive system returns to a near pre-pregnant state.