Physiology Flashcards
1
Q
Definition of a hormone?
A
A substance secreted by living cells in trace amounts, transported to a distance site where it is used to regulate or initiate reactions.
2
Q
How do steroid and thyroid hormones travel in the blood?
A
Bound to plasma proteins
3
Q
What does the response to a hormone mostly rely on?
A
Depending on receptor number
4
Q
What are the two lobes of the pituitary called, their separate functions?
A
Anterior pituitary - adenohypohysis - part of the gut
Posterior pituitary - neurohypohysis - part of the CNS
5
Q
Two hormones the posterior pituitary secretes? Where are they synthesised?
A
ADH and oxytocin - synthesised in the hypothalamus (SON and PVN)
6
Q
What does oxytocin do and what causes it’s release and what inhibits it’s release?
A
Causes uterine contraction and milk let down
stimulated by stretch of the cervix and suckling
Inhibited by stress and alcohol
7
Q
What does ADH do and what causes it’s release and what inhibits it’s release?
A
Causes water reabsorption in the kidney by insertion of aquaporins
Stimulated by high plasma osmotic pressure, low blood volume and stress
Inhibited by alcohol
8
Q
What does lack of ADH cause?
A
Diabetes insipidus (high flow of dilute urine)
9
Q
What can cause lack of ADH?
A
Whiplash injury to the tract
Pituitary tumour
Local damage to hypothalamus
10
Q
What does over-secretion of ADH (SIADH) cause?
A
Low flow of concentrated urine
Water is retained
Cells become over-hydrated
Plasma [Na+] falls
Fatigue
Confusion
11
Q
Common causes of SIADH?
A
Carcinoma
12
Q
Diagnosis of SIADH
A
Presence of high urine [Na+] and low plasma osmolarity
13
Q
Treatment of SIADH?
A
Fluid restriction and very slow NaCl infusion.6
14
Q
What hormones does the anterior pituitary secrete?
A
Thyroid stimulating hormone
Adrenocorticotrophic hormone
Growth hormone
FSH
LH (leuteinising hormone)
Prolactin
15
Q
What is the anterior pituitary stimulation test?
A
ACTH and GH stimulated by injecting insulin
TSH and prolactin stimulated by TRH injection
LH and FSH stimulated by GnRH
16
Q
What inhibits growth hormone?
A
Somatostatin
High blood glucose
Chronic stress
17
Q
Actions of GH?
A
Fasting state:
- Gluconeogenic AA taken up and converted to glucose
- Mobilises fat to FFA
- Powerfully anti-insulin in action
Insulin Concentrations High:
- Stimulates AA uptake
- Stimulates protein synthesis largely via IGFs
18
Q
GH stimulated by?
A
Low blood glucose concentration
High plasma AA concentration
19
Q
Results of lack of GH?
A
In adults, disordered metabolism but other systems compensate
In children causes failure to grow
20
Q
Causes of lack of growth hormone in children?
A
Chronic stress e.g. bullying/parental divorce
Treatment of asthma or IBD causing high plasma cortisol
21
Q
Tests for GH?
A
Stimulation: give insulin then glucose
Suppression: Glucose tolerance test
22
Q
Three areas of the adrenal cortex and the hormones they produce?
A
Zona Glomerulosa: Mineralocorticoid
Zona fasciculata: Glucocorticoid
Zona reticularis: Sex steroid production
23
Q
Results of excess GH?
A
Children: Gigantism
Adults: acromegaly
Diabetes mellitus and heart disease risk
24
Q
What can cause primary under-production in the adrenal cortex?
A
TB/HIV
Addison’s disease (inherent disorder of the adrenal cortex)
25
Excess mineralocorticoid production can cause what?
Conn syndrome
26
How do you differentiate between ACTH dependent causes of cushings?
Low dose dexamethasone suppression test - diagnoses cushings
High dose test:
> 50% suppression of following 9am cortisol - corticotroph/pituitary tumour ('cushings disease')
27
Two types of under-production of the adrenal cortex?
Primary: Entire cortex affected
Secondary: Hypopituitarism, loss of ACTH
28
Cushing syndrome symptoms and signs? (get some)
```
Moon face
Weight gain with central obesity
Hypertension
Diabetes
Depression
Hypogonadism
Osteoporosis
Poor wound healing
Acne
```
29
Diagnosing glucocorticoid excess?
Midnight/bedtime cortisol levels
24hr urinary free cortisol
30
Medical treatment for cushings?
Block cortisol production: metyrapone, ketoconazole
31
Pituitary tumour treatment?
Trans-sphenoidal hypophysectomy +/- radiotherapy
32
Causes of hypoadrenalism?
TB/AIDS
Addison's disease
Metastatic tumour
Lymphoma
33
Clinical features of hypoadrenalism?
```
Tiredness
Weakness
Weight loss
postural hypotension
hypoglycaemia
```
34
Diagnosis of hypoadrenalism?
Short synacthen test - Give ACTH and measure cortisol later
35
Treatment for hypoadrenalism?
Hydrocortisone lifelong
36
What is endocrine hypertension?
Hypertension caused by demonstrable hormone excess
37
What is Conn syndrome? symptoms?
Primary hyperaldosteronism
Few symptoms, hypokalaemia, weakness, lethargy, headaches
38
Classic presentation of Conns syndrome?
Young, severe hypertension, high sodium, low potassium
39
Where do spironolactone and eplerenone act?
Mineralocorticoid receptor in distal convoluted tubule, they antagonise the MR receptor.
40
Two examples of catecholamines?
Adrenaline
Noradrenaline
41
What is a phaeochromocytoma?
Tumour of the adrenal medulla, secreting catecholamines (adrenaline and noradrenaline)
42
Actions of catecholamines?
acts on α and β adrenoreceptors
alertness, anxiety, agitation
Pupil dilatation
Bronchodilation
Increased glucagon and decreased insulin
Increased renin release in the kidney
43
Treatment of phaeochromocytoma?
Surgery or α and β blocker (phenoxybenzamine or propranolol)
44
How do the adrenals regulate the stress response?
Catecholamines prepare for flight or fight
Glucocorticoids and mineralocorticoids 'raise the alarm'
45
What does the cortex and medulla of the adrenals secrete ?
Cortex - steroid hormones, glucocorticoids, mineralocorticoids, sex hormones
medulla (part of the SNS) secretes catecholamines
46
What type of hormone is cortisol? Where does it act?
Glucocorticoid receptor very strongly
Mineralocorticoid receptor weakly
47
11β-HSD 1 and 2 actions?
2 prevents flooding of mineralocorticoid receptors by cortisol (converts it to cortisone)
1 amplifies glucocorticoid action
48
Steps of cortisol synthesis?
Hypothalamus affects the pituitary through CRF and ADH
Pituitary releases more ACTH in response to the above two
ACTH stimulates cortisol production
49
What is the HPA axis?
The classic negative feedback system functioning in between the hypothalamus, pituitary and the adrenals
50
Actions of cortisol?
Catabolic:
- Stimulates protein breakdown in muscle bone e.t.c.
Anabolic:
- Increases gluconeogenesis
- Decreases glucose and AA utilisation
- Increases glycogen synthesis
Maintains fluid volume in the CV system
Immunosuppression and anti-inflammatory effects
51
What type of hormone is aldosterone? What are it's main actions?
Mineralocorticoid
Promotes sodium reabsorption in the distal convoluted tubule
52
Main hormonal system that regulates aldosterone production?
RAAS pathway
53
What is DHEA, when is it secreted in the adrenals?
A sex steroid large amount secreted at birth and then stops till 7-8 where more is secreted.
54
What cells are in the adrenal medulla?
chromaffin cells - like specialised postganglionic cells without axons
55
How are catecholamines released, in response to what?
In response to stimulation of splanchnics causes exocytosis of secretory granules of
56
What exactly is cushings syndrome?
Causes
Cortisol excess (not that is not cushings disease)
Primary cause - ACTH independent e.g. adrenal tunour (this is cushings disease)
Secondary cause - ACTH-independent e.g. excess ACTH e.g. secretion from pituitary tumour
Prolonged corticosteroid treatment
57
What exactly is addison's disease and it's causes?
Glucocorticoid/mineralocorticoid deficiency
Primary cause - adrenal damage or auto-immunity
Secondary - pituitary dysfunction leading to low ACTH
58
Features of addison's disease?
Progressive weakness and weight loss
Low plasma glucose and sodium, high Potassium
Dehydration
59
What is different in the fetal adrenal gland? What does this area do?
Has a large inner fetal area that makes DHEA, which is used as a precursor to produce oestrogens by plancenta
60
What is congenital adrenal hyperplasia? Most common type?
Congenital enzyme deficiencies, most common by far is 21-hydroxylase
causes excess sex steroids but decreased gluco/mineralocorticoids
61
Examples of hormones that regulate blood pressure?
Ang II
Aldosterone
Cortisol
Adrenaline/Noradrenaline
Calcium
GH
62
Common causes of Conn syndrome?
Aldosterone producing tumour (adrenal adenoma)
Micro/macro-nodular disease
63
Examples of thyroid hormones?
Thyroxine
Triodothyronine
(Thyro)calcitonin
64
What element do thyroid hormones contain (and is therefore required for synthesis)
Iodine
65
How are thyroid hormones synthesised?
Iodine uptake from blood into follicle cell
Transported to colloid surface
inserted into tyrosines
Couple together to form thyronines
66
What does TSH (thyrotrophin) stimulate?
Iodine uptake/oxygenation
T3/T4 release
Causes secretion and gland growth
67
What is TBG?
Thyroxine binding globulin, binds thyroid hormones with very high affinity
68
Actions of thyroid hormone, where do they act?
Acts in intracellular receptors and DNA
Raised BMR
Raises number of adrenergic beta receptors in tissues and therefore increase sympathetic function
69
Thyroid hormone excess (hyperthyroidism) symptoms?
Weight loss
Heat intolerance
Sweating
tremor
Lid retraction and staring eyes
high heart rate
Diarrhoea
70
Causes of hyperthyroidism?
Graves disease (Gland diffusely enlarged)
Toxic nodules
71
Hyperthyroidism treatment?
Surgery + replacement T4
Radioiodine + replacement T4
Antithyroid + replacement T4
72
Hypothyroidism symptoms?
Cold intolerance
Low heart rate
Constipation
Weight gain
Loss of interest in life
73
What is Myxoedema?
Hypothyroidism
74
Where is TSH secreted from, what controls it's secretion?
Secreted from anterior pituitary
Controlled by hypothalamic TRH
75
What is T4 and T3?
T4 is prohormone, T3 is active
They are thyroid hormones
76
What is hashimoto's thyroid disease?
T cell infiltrate within the thyroid
Presence of autoantibodies to thyroglobulin and thyroid peroxidase
Leads to hypothyroidism
77
Which gender is more likely to acquire an autoimmune disease?
female in most cases apart from UC and diabetes
78
What is graves disease, clinical manifestation?
Autoimmune thyroid disorder, causing hyperthyroidism autoantibodies against TSH receptor and thyroglobulin:
- Tremor
- Heat intolerance
- Sweating
- Anxiety
- Weight loss
- Palpitations
79
Common issues in diabetes?
Retinopathy
Neuropathy
Macrovascular and cerebrovascular disease
Foot ulcers (possible amputations)
80
Diagnosis of diabetes with glucose tests?
2-hour plasma glucose: >7.8 - 11.1
Fasting plasma glucose: >6.1 - 7
81
HbA1c level for diabetes diagnosis?
>6.5
82
4 main classifications of diabetes?
Type 1
Type 2
Secondary
Gestational
83
Type 1 diabetes pathogenesis?
T-cell mediated autoimmune destruction of β-cells in the pancreas
84
Type 1 diabetes aetiology/triggers?
Mostly genetic, however other environmental factors also considered such as bacterial/viral and perinatal factors
85
Presentation of type 1 diabetes?
Increased thirst (polydipsia)
Polyuria
Nocturia
Drowsiness/dehydration
86
Causes of secondary diabetes?
Pancreatic disease (e.g. pancreatitis)
Endocrine disease (e.g. acromegaly)
Drugs and chemicals (e.g. Diuretics glucocorticoids)
87
What cells secrete insulin and glucagon? Where?
Alpha cells - glucagon
| Beat cells - Insulin
88
Process of events that lead to the release of insulin?
Glucose taken up by beta cells, metabolised to form ATP
Increased ATP causes cascade leading to exocytosis of the insulin containing vesicles
89
Insulin receptor's effects when insulin is bound?
Increased glucose transport by moving transporters to cell surface
Increased protein and fat synthesis
Increased Glucose synthesis
Growth and gene expression
90
What breaks down insulin?
Mostly the liver, by insulinase
91
Insulins effect on the livers release of glucose?
Decreases it
92
Effects of insulin on the liver?
Inhibits glycogenolysis
Stimulates glycogen synthesis
Stimulates glucose uptake
Stimulates glycolysis
Indirectly inhibits gluconeogenesis, inhibits fatty acid mobilisation from adipose tissue
93
What are the 4 glucose transport proteins?
GLUT 1: basal glucose uptake
GLUT2: pancreatic beta cells
GLUT3: basal glucose uptake
GLUT4: insulin sensitive (the only one)
94
What does insulin do to GLUT 4 receptors?
Makes them fuse with the membrane
95
Insulins effect on the lipid metabolism in the liver?
Increased lipoprotein synthesis
Reduced β-oxidation
Reduced ketogenesis
96
Effects of insulin on protein metabolism?
Stimulates protein biosynthesis in muscle
Reduces AA release from muscle
97
Effects of insulin?
```
Glucose and aa uptake
Increased protein synthesis
Triglyceride synthesis
Increased glycogenesis
Inhibits lipolysis
Inhibits gluconeogenesis
Inhibits ketone bodies
Inhibits glycogenolysis
```
98
Anabolic and Catabolic meanings?
Anabolic is building up, catabolic breaking down.
99
Examples of anabolic hormones?
Insulin
GH
Thyroid (low Conc)
100
Examples of catabolic hormones?
Glucagon
Catecholamines
Cortisol
Thyroid (high Conc)
101
Effects of glucagon?
Increased glycogenolysis
Increased gluconeogenesis
Increased ketone body formation
Increased lipolysis (weak)
102
Main control of glucagon release?
Reduced glucose
Fatty acids inhibit
Insulin inhibits
Catecholamines
103
Mechanism of glucagon's action?
Plasma membrane receptor
Activated Adenylyl cyclase
Activates cAMP-dependent protein kinase
Substrate phosphorylation
104
What increases and decreases glucagon secretion?
Increases:
- Low plasma glucose
- Raised plasma amino acids
- CCK
- PNS and SNS
Decreases:
- High plasma glucose
- Insulin
- Energy substrates
105
Catabolic and anabolic effects of GH?
Anabolic effects:
- Protein synthesis, AA uptake
Catabolic effects:
- Lipolysis
- Glycogenolysis
- Reduced glucose utilisation
106
Effects of somatomedins (IGFs)
Anabolic effects:
- Growth
- Cell division
- Protein synthesis
- Glucose utilisation
107
Changes in early starvation?
And Late starvation
KB produced and used by brain and body
Late:
- Brain adapts to using KB
- Muscles switch to using FA
108
What is graves opthalmology?
Accumulation of hyaluronan, CAGs and collagen in perioccular space, infiltrate with CD4 T cells and B cells
109
Symptoms of graves opthalmology?
Proptosis (bulging of eye)
Oedema of the conjunctiva (chemosis)
Eye-lid retraction
110
Thyroid hormone changes in hyperthyroidism?
T4 increase and TSH decrease
111
Clinical signs of hypothyroidism?
Slow pulse
Carpal tunnel
Myopathy
Ataxia
112
Biochemical changes in thyroid hormones in hypothyroidism?
Decreased T4 increased TSH
113
Main functions of the testes? and of the ovaries?
Testes :
- Produce sperm
- Produce testosterone
Overies:
- Mature oocytes
- Produce oestrogen
114
What is the hypothalamic-pituitary-testis axis, explain it?
GnRH produced in the hypothalamus cause the secretion of LH and FSH in the pituitary which go on to stimulate the production of testosterone in the testes
115
Pubertal and mature response of the hypothalamic-pituitary-gonadal axis?
Pulsatile secretion of GnRH about every 90mins
116
Function of leydig cells?
Produce testosterone
117
Effects of GnRH on males and females?
Males:
- LH stimulated, producing testosterone
- FSH stimulated, stimulating spermatogenesis
Females:
- LH stimulates ovulation
- FSH stimulates follicular development
118
Wide ranging effects of oestrogen?
Fallopian tubes contractility
Cervix mucus consistency
Behavioural, reduced appetite
Fluid retention in kidney
119
Wide ranging effects of progesterone?
Development of breasts
Mucus consistency in cervix
Increased appetite
increased body temperature
120
Phases of the ovulatory cycle?
Pre-antral: Primordial to pre-antral follicle
- gets ready to respond to LH and FSH
Antral: forms antral follicle, responding to LH and FSH
Pre-ovulatory phase: occurs when there is lots of Lh and LH receptors on granulosa cells, causes oocyte to complete first meiotic division
Ovulatory: LH surge causes follicle rupture onto ovary surface
Follicular phase: low oestrogen exerts negative feedback on LH/FSH, high oestrogen exerts positive feedback, inhibit exerts negative feedback on FSH
Luteal phase: collapsed follicle becomes corpus luteum (dependent on LH) Granulosa cells secrete progesterone, thecal cells secrete oestrogen
If fertilisation does not occur: corpus luteum regresses to corpus albicans
If fertilisation does occur hCH is released and corpus luteum is maintained
121
Stages of spermatogenesis?
Stage 1: mitotic proliferation
- spermatogonium
- Diploid spermatogonia
- Primary spermatocytes
2: meiotic division
- Secondary spermatocytes
- Haploid spermatids
3: differentiation
- differentiating spermatids
- Mature sperm cells emerge from residual bodies
122
What is the function of the blood-testes barrier?
Protects sperm from noxious circulating agents and immune response
123
How do sperm move through the male genital tract?
Passively from rete testes to the epididymus by current of fluid
Actively through musculature of the epididymus to the Vas deferens
124
What is capacitation?
Process that occurs naturally in the female genital tract that involves the removal of glycoproteins covering the sperm
125
Where is cut in a vasectomy? Why does this stop the testes filling with fluid?
Vas deferens - Sperm build up behind the cut are removed by phagocytosis
126
What do LH and FSH do in the testes?
LH - stimulates leydig cells to produce testosterone
FSH - acts on sertoli cells to stimulate testicular fluid formation and androgen binding proteins
127
What hormones exert negative feedback on the HPT axis?
Oestradiol and inhibin on FSH
Testosterone on LH and FSH
128
Definition of infertility?
When pregnancy fails to occur after a year, (normally fails in 4/5 cycles)
129
Causes of male infertility?
Pre-testicular:
- Genetic e.g. XXY or hypogonadism
Sperm production/function (oligospermia):
- Mumps
- Chemotherapy/irradiation
- autoimmunological
Sperm delivery:
- Epididymal obstruction
130
Causes of male infertility?
Blocked or damaged tubes - Chlamydia
Ovulatory disorders:
- Absent or irregular cycles
- hyperprolactinaemia (prolactin inhibits GnRH)
- Polycystic ovaries
- Genetic ovarian failure
131
Two reactions that the sperm undergoes before fertilization takes place?
Acrosome reaction
Capacitation
132
The three blocks to polyspermy at fertilisation?
Fast block - Membrane potential changes, ion channels open
Slow block - cortical granules released, increased intracellular Ca2+ ZP3 receptors break down
Juno receptor block
133
What is ICSI
ICSI - intracytoplasmic sperm injection
134
What id PGD and PGS?
Pre-implantation genetic diagnosis/screening
135
Reasons to perform pre-natal testing?
Advanced maternal age
Multiple pregnancy losses (>3)
Known or suspected family history of genetic disorder
Abnormal ultrasound
136
Types of prenatal screening?
Non-invasive: ultrasound
Invasive:
- CVS
- Amniocentesis
137
When would you perform CVS?
Miscarriage risk?
10-13 weeks of pregnancy
2-3%
138
When would you perform Amniocentesis?
Miscarriage risk?
>15 weeks
0.5-1%
139
When can you do an ultrasound to detect abnormalities?
20 weeks
140
Common clinical problems in early and in late pregnancy?
Early pregnancy: Miscarriage/ectopic pregnancy/Mola
Late pregnancy: Intrauterine growth restriction/pre-ecclampsia
141
Where does ectopic pregnancy occur in 95% of cases?
Fallopian tube
142
Classic symptoms of ectopic pregnancy?
Abdominal pain
Amenorrhoea
Vaginal bleeding
143
Intra-abdominal bleeding signs?
Shoulder pain
Urge to defecate
Lightheadedness
144
Ectopic pregnancy risk factors?
Previous ectopic
>40
Smoking
IVF
Previous pelvic inflammatory condition
145
Treatment for ectopic pregnancy?
Surgical salpingotomy
MTX (injection or other administration)
Tubal abortion/regression
146
What is a molar pregnancy?
Unsuccessful pregnancy where there is no/abnormal placental tissue formation, large amounts of HCG
147
What is NIPT?
Non-invasive prenatal testing
Next-gen sequencing technology with high specificity and sensitivity
148
Difference in a screening test and a diagnostic test?
Diagnostic test:
- To account for symptoms or signs
Screening test:
- No prior evidence in the individual
149
Pro's and Con's of screening tests?
Pros:
- early detection - better treatment/early intervention
- Identify people at risk for preventative treatment
- Cost-effectiveness
Cons:
- False positive and negatives
- Invasive tests
- Both cause psychological distress
150
Definition for natural menopause?
12 consecutive months of amenorrhoea
151
Average age of the menopause and duration?
Avg. Age 52
Avg. duration 3 years
152
Menopausal symptoms?
Vasomotor symptoms e.g. hot flushes and night sweats
Irregular periods eventually amenorrhoea
Sexual dysfunction
Urinary symptoms
psychological symptoms
153
Urogenital atrophy effects in menopause?
Vaginal atrophy (rise in pH)
Cervical atrophy
Loss of elasticity
Weakening of pelvic floor
Less sensitive to stimulation
154
What causes osteoporosis in menopause?
Lack of E2 causes change in balance of HPG axis leadign to lack of oestrogen and decreased bone density
155
Osteoporosis prevention mechanisms in menopausal women?
Recommended amounts of Calcium and Vit. D
Regular weight bearing exercises
Avoid smoking and excessive alcohol
156
Osteoporosis treatment in menopausal women?
Bisphosphonates for post-menopausal women younger than 65
157
Mechanism for bisphosphonates' actions
Inhibit bone resorption by altering osteoclast function and activity
158
What is given in HRT?
Oestrogen and progesterone for all women with a uterus and only oestrogen for hysterectomised women
Oestrogen alone increases risk of endometrial cancer in women with a uterus
159
Two types of HRT?
Cyclical HRT: Oestrogen throughout with progestin 3 out of 4 weeks to produce bleed
Continuous combined HRT: 'no-bleed' Oestrogen and progesterone throughout
160
Risks and benefits to HRT?
Relieves vasomotor symptoms
Sexual and urogenital symptoms respond well to HRT
Venous thromboembolism, stroke, CHD, breast cancer, ovarian cancer, - increased risk
161
Will a larger maternal size affect the birth size of baby?
Yes
162
What hormone does the growing fetus use to 'signal' it's presence, used for pregnancy tests?
HcG
163
Maternal metabolic changes in pregnancy?
Increase in protein reserves
Increase in fat reserves
Relative insulin resistance leads to increased circulating glucose levels
164
Maternal cardiovascular adaptations in pregnancy?
Oestrogen causes generalised vasodilatation - decreased peripheral resistance
therefore maternal CO increased
165
Maternal renal adaptations in pregnancy?
Blood volume expansion:
- Increased activity in RAAS pathway
- changes in blood osmolality
Increased GFR
166
Why does the hypothalamus not decrease ADH secretion in pregnancy even though blood osmolality decreases significantly?
Hypothalamic osmoreceptors have decreased threshold
167
Maternal respiratory changes in pregnancy?
Tidal volume increased by 40%
Pulmonary blood flow increased by 40%
Increased maternal red cell mass and DPG in red cells - increased O2 carrying capacity
168
How does the fetus utilise IGF's?
Fetal tissue release IGFs in response to raised glucose levels - they stimulate DNA production and cell division
169
What age do you ultrasound the fetus during pregnancy (twice) why?
12 weeks - Date the pregnancy
18-20 weeks - growth and abnormalities
170
Things to avoid eating during pregnancy due to risk of it being toxic to the baby?
Liver or liver-containing products
High dose multivitamin products
Shark, swordfish and limit tuna
171
Micronutrients that should be provided in pregnancy, what they're used for?
Folate/folic acid - DNA synthesis
Vitamin D - regulate calcium and phosphate
Iodine - synthesis of thyroid hormones
172
What can happen if invasion of the cytotrophoblast is poor, formine less capillaries in the placenta?
Pre-ecclampsia
173
What specifically does not cross the placental barrier?
Red cells
Large molecules
Lipophobic molecules (unless transported)
174
What is the synctiotrophoblast?
Barrier that forms over villi in the placenta that prevents certain molecules passing through
175
What can cause impaired placental function?
Reduced maternal blood flow
Too few villi
Too few transport proteins
Maternal illness
176
What drugs do cross the placenta?
Most polypeptides do not - e.g. insulin/cortisol
177
What is hyperemesis gravidarum?
Severe morning sickness, onset around 5-6 weeks
Diagnosis on clinical signs of dehyrdation and ketonuria
178
What are twin-to-twin transfusions?
Artery to vein anastomoses from one umbilical cord to the other, if untreated likely to be lethal
179
Complications associated with pre-ecclampsia?
Seizures 'eclampsia'
Cerebral haemorrhage
Liver damage
Renal failure
180
Main hormone relaxants and stimulants in pregnancy
Relaxants:
- Progesterone
- Relaxin
- NO
Stimulants:
- Oestrogen
- Oxytocin
- Prostaglandins
181
During pregnancy what hormone is in abundance? At term how does the balance change?
Progesterone, at term balance changes to oestrogen
182
During labour what hormones dominate, their roles?
Stimulants dominate:
Oestrogen:
- Stimulate proteolytic enzymes to dilate cervix
Oxytocin:
- Initiates contractions,
- Stimulates prostaglandin synthesis
Prostaglandins:
- Potentiate contractions induced by oxytocin
183
Stages of labour (parturition)?
Pre-labour:
- 4/5 weeks before
- Braxton hicks contractions
- Increase in uterine activity and change in cervical consistency
Dilation phase:
- Cervical dilation
- Preceded by water breaking
Expulsion stage:
- Uterine contractions and reduction in uterine volume push baby through pelvis
Placental stage:
- Delivery of the placenta 'afterbirth'
184
Uterine changes during pregnancy?
Hypertrophy and hyperplasia of myometrial cells
Increased contractile proteins
Increased numbers of mitochondria and cellular ATP
185
What prostaglandin can be given to initiate labour, what else can be given?
Dinoprostone
Synthetic oxytocin can also be given
186
How are oxytocin receptors affected in labour?
Increased receptor numbers by action of oxytocin
187
Role of fetal cortisol?
Lung surfactant synthesis
Store of glycogen in liver
Synthesis of adrenaline in adrenal medulla
Maturation of islets in pancreas
188
What is fetal distress during labour?
Reduced placental perfusion induced by strong uterine contractions, fetus can switch to anaerobic metabolism leading to acidosis
189
Analgesia during labour?
Inhaled gas&air - entanox
Opioids - pethidine
Local nerve block
Epidural - lignocaine
190
Treatment of post-partum haemorrhage?
Oxytocin - contraction to decrease blood flow
Ergometrine - increases contraction and vasoconstriction
Prostaglandins - e.g. misoprostol - increases uterine tone
191
Drugs used for induction of abortion?
Prostaglandins - Gemeprost (PGE1)
Progesterone receptor antagonists - Mifeprestone
192
Factors that adversely affect fertility?
```
Age
Smoking
Coital frequency
Alcohol
Body weight
NSAIDS
Chemo
```
193
Infertility investigations?
FSH/LH levels
Day 21 progesterone
Rubella/chlamydia status
Semen analysis
194
Fertility treatment options?
Ovulation induction
Intra-uterine insemination
IVF
Intra-cytoplasmic sperm induction
195
Common causes of pre-term labour?
Spontaneous (45%)
Delivery due to maternal or fetal infection (30%
Premature rupture of the membranes (25%)
196
Risk factors of pre-term births?
```
Tobacco use
Previous pre-term
Low BMI
Uterine abnormalities
Congenital uterine abnormalities
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During pregnancy:
- Multiple pregnancy
- Vaginal bleeding
- Systemic inflammation
- Psychological stress/depression
197
What can be detected to predict for pre-term delivery?
Fetal fibronectin
198
What is tocolysis?
Drugs used to delay labour (stops contractions)
199
What drugs are used for tocolysis?
Nifedipine - calcium channel receptor antagonist
Atosiban - oxytocin receptor antagonist
Magnesium
NSAIDS - Indomethecin
Calcium channel blockers
B2 adrenoceptor agonists
200
In preterm labour what are the two general treatments
Delay birth
Mature fetal lung
201
What can you give to mature the fetal lung?
Betamethasone - glucocorticoid steroid, increase the amount of surfactant produced
202
How do NSAIDS work to prolong labour?
Inhibit the production of prostaglandins and:
Reduce uterine contractility
Reduce cervical softening
203
How does Nifedipine work to prolong labour?
Blocks the calcium channel blocker that causes smooth muscle contraction in the uterus
204
How does Ritodrine work to prolong labour?
B2 adrenoceptor agonist - activates intracellular cAMP and causes smooth muscle relaxation
205
Best tocolysis drugs?
Atosiban and nifedipine: less side effects and effective
206
What is surfactant?
Complex mix of phospholipids and surfactant proteins
207
Two main surfactant therapies for the newborn child?
Synthetic surfactants:
Natural surfactants:
208
Particular issues in neonatal physiology (what doesn't work properly?
Immature liver function
Immature kidney function
Immature gut - lacking flora and 'leaky' endothelium
Immature immune system
Immature blood clotting
209
What nutrients can be deficient in breast milk compared to formula?
Vitamin D
Iron
Vitamin K
210
Some conditions that breast milk has been shown to reduce over formula milk?
Short term:
- Otitis media
- Respiratory infections
Long term:
- Incidence if IBD
- Risk of type 2 diabetes/Cardiovascular disease/obesity
211
How does the histology of the breast work from milk producing glands to the nipple?
Made up of 15-20 lobes, divided by adipose
The lobes contain alveoli that synthesise and secrete milk
They then drain into lactiferous ducts
Then into the lactiferous sinus
The lactiferous converges on the nipple
212
What hormone inhibits prolactin?
Dopamine
213
What hormone triggers 'let-down' (milk ejection)?
Oxytocin - released during suckling
214
What drugs could be used to first stimulate lactation and also to inhibit lactation?
Stimulate - domperidone, D2 receptor antagonist
Inhibit - D2 receptor agonists - bromocriptin
215
What is colostrum?
They first milk for the first couple of days - low in fats and sugar, but high in protein minerals and vitamins, also contains lots of immunoglobulins
216
What does prolactin inhibit? What is the function of this?
Inhibits GnRH so that LH and FSH are also inhibited, this is supposed to ensure that there cannot be another pregnancy so soon
217
Piaget's stages of development?
The sensori-motor stage (0-2)
The pre-opperational stage (2-7)
The concrete operational stage (7-12)
The formal operational stage (12-19)
218
Interventions to reduce pain and anxiety in children in the medical setting?
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Distraction
Prep information
Play therapy
Hypnosis
Parental involvement
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219
The two different surfactant proteins?
SP-A/B/C and D
220
Causes of short stature in infants?
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Familial short stature
Constitutional delay of growth and puberty
Intra-uterine growth retardation
Chronic disease
Psychosocial deprivation
Dysmorphic syndromes
Endocrine disorders
Skeletal dysplasia
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221
What is constitutional delay of growth and puberty? Treatment?
A condition with poorly understood aetiology that occurs more often in boys with a family history
Therapeutic intervention:
Boys: testosterone
Girls: oestradiol
222
Where is GnRH released from, what are it's actions?
Released from the hypothalamus acts on the pituitary to release LH/FSH
223
Precocious puberty is what? In boys and girls what age?
Early puberty
224
Causes of precocious puberty?
GnRH dependent:
- Idiopathic
- Tumour secreting GnRH
- Chronic inflammation
- Trauma
- Sexual abuse
GnRH Independent:
- Hypothyroidism
- Ovarian cyst
- Cushings
225
Causes of delayed or incomplete puberty?
Hypogonadotrophic states:
- Gonadotrophin deficiency e.g. CNS defects, Kallmann's syndrome
- Congenital adrenal hyperplasia
Hypergonadotrophic states:
- Chromosome abnormalities e.g. turners and Klinefelters
- Gonadal dysgenesis
- Radio/chemotherapy
226
Risk associated with gestational diabetes?
Miscarriage
Congenital malformations
Respiratory distress
Long term risks of: Obesity and Diabetes
227
What diabetes drugs are contra-indicated in pregnancy?
Sulphonylureas apart from glibenclamide
228
Suggested diabetes drugs in pregnancy?
Metformin
glibenclamide - only sulphylurea thats okay
229
Treatment for diabetic ketoacidosis?
Resuscitation fluids: restore circulating volume, clear ketones, correct acidosis/electrolyte balance
Insulin infusion
230
Triad of symptoms in PCOS?
Presence of polycystic ovaries
Signs of hyperandrogenism (hirsutism, acne, clitomegaly)
Oligo/amenorrhoea
231
Why do ovaries become polycystic in PCOS?
Hypothalamic-pituitary-ovary feedback disorder causing 'freezing' of the ovary so that no dominant follicle is selected
232
PMS physical symptoms?
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Swelling
Breast tenderness
Food cravings
Insomnia
Nausea
Sweating
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233
Definition of familial cancer, and hereditary cancer?
Familial: Family history of the same cancer but not clearly dominant or young in onset - includes environmental factors
Hereditary: Young onset, predisposition is uncommon in general population but very common in family
234
Definitions of penetrance and expressivity relating to cancer genetics?
Penetrance - Chance of developing the disease if mutation is present
Expressivity - Disease manifestations may be different
235
Functions of LH?
Formation and maintenance of the corpus luteum
Thinning of the graafian follicles membrane
236
Functions of FSH?
Stimulation of development of follicles
237
When is the proliferative phase of the menstrual cycle?
Begins immediately after the menstrual phase
days 5-14
238
Results of increased oestrogen in the follicular phase (also signs a woman is about to ovulate)?
Thinning of cervical mucus
Thickening of endometrium
239
Functions of progesterone?
Stimulation of oestrogen production
Initiation of secretory phase of endometrium
Inhibit LH and FSH
Increased basal body temperature
