Human Development Flashcards
Difference between:
a) Exocrine and endocrine glands
b) Exocrine and endocrine secretions
a) Exocrine - secrete via duct, Endocrine - direct into circulation
b) Exocrine - Outwith body, Endocrine - within body
Describe action and give example:
a) Paracrine
b) Autocrine
c) Neurocrine
d) Endocrine
e) Neuroendocrine
a) Acts on cell close by e.g. His from mast cells
b) Acts on same cell e.g. interleukins
c) Electrical signal passed on via synapse e.g. NT
d) Produce 1 prt body, travel in blood e.g. insulin
e) Elec signal passed on via circulation e.g. dopa inhibition of prolactin release
What is the difference between alpha and beta chain in glycoprotein hormones?
Alpha - Species specific
Beta - Hormone specific
What glycoprotein hormone is released from placenta?
Human Chorionic Gonadotropin
Function and example of:
a) Mineralocorticoid
b) Glucocorticoid
c) Sex steroid
a) Affect H20 + electrolyte balance e.g. aldosterone
b) A’’ carb + protein metabolism e.g. cortisol
c) Sexual characteristics e.g. oestr, testos
What types of hormones circulate in :
a) Free form?
b) Bound form?
a) Catecholamines, proteins/peptides
b) Thyroid + steroid hormones
What 2 types of hormones are stored in secretory granules/vesicles?
(How released)
Catecholamines + Peptides
Release via exocytosis, triggered by Ca2+
What are the 5 types of hormone release? + example
Pulsatile - episodic release e.g. LH/FSH hourly release
Circadian - based 24hr cycle e.g cortisol
Diurnal - synchronised to day/night cycle more animals
Infradian - Longer than 24hr cycle e.g. menstrual cycle
Seasonal - More animal e.g. prolactin
What types of hormones are:
a) Hydrophilic?
b) Lipophilic?
How does this affect binding to plasma proteins?
a) Catecholamines + Peptides
b) Thyroid + Steroid hormones
Hydrophilic x bind, lipophilic binds
How many parts does the pit. gland have?
What are they made up of?
Ant lobe (Adenohypophysis) - Pars distalis + tuberalis Neuro-intermediate lobe - Pars intermedia + nervosa Post lobe (neurohypophysis) - Pars nervosa + infundibulum
What is another name for pit. gland?
Hypophysis
Which part of the pit gland is not well developed in man?
Neuro intermediate lobe
What is the growth hormone inhibiting hormone?
Somatostatin
What is the:
a) Releasing hormone
b) Inhibitory factor/hormone
of prolactin?
a) TRH
b) Dopamine
What is the main cell type of ant pit?
What do they produce?
Somatotrophs
Growth hormones
What hormone suppresses menstrual cycle in lactating mother?
Prolactin
Via what receptors does dopamine inhibit prolactin?
How would you treat them in hyperprolactinemia?
D2 receptors
Selective D2 agonists e.g. bromocriptine, cabergoline
What types of somatostatin analogues work better on:
a) Type 2 somatostatin receptor
b) Type 5 somatostatin receptor
Which one is better?
a) Octreotide + Lanreotide
b) Pasireotide
Type 5, pasireotide
What carrier molecule is associated with:
a) Oxytocin?
b) ADH?
a) Neurophysin I
b) Neurophysin II
What happens to colloid space in:
a) Underactive thyroid?
b) Overactive thyroid?
a) Large colloid spaces
b) Little/no colloid spaces also hyperplasia of follicular cells
What happens to fetus if thyroid hormones are not properly delivered?
Cretinism
What is a goitrogen?
Substances disrupt production of thyroid hormones by interfering with iodine uptake in thyroid gland
Increase TSH secretion to form goitre
What is the additional effect of propylthiouracil?
Prevents peripheral conversion of T4 to T3
How much of the bodies iodine is found in the thyroid gland?
60-65%
What defines iodine deficiency?
Less than 50 micrograms a day
Where are adrenal glands located and shape?
On top of kidneys
RHS - pyramidal
LHS - oval shape
What are the layers of the kidney from outside to in?
Zona glomerulosa
Zona fasciculata
Zona reticularis
What does the medulla of the adrenal gland produce?
What percentage?
Adrenaline - 80%
Noradrenaline - 20%
What does the zona glomerulosa produce?
What enzyme does it lack and why?
Mineralocorticoids e.g. aldosterone
17-alpha hydroxylase, x produce cortisol
What does the zona fasciculata produce?
What enzyme does it lack and why?
Glucocorticoid e.g. cortisol
Aldosterone synthase, x produce aldosterone
What does the zona reticularis produce?
What enzyme does it lack and why?
Adrenal androgens eg. androstenedione, DHEA (a little cortisol)
Aldosterone synthase
What are all steroid hormones derived from?
Cholesterol
What is an example of an aldosterone antagonist?
Spironolactone
What is affected in these types of hypothyroidism?
a) Tertiary
b) Secondary
c) Primary
d) Resistance
a) Hypo/TRH
b) Pit. gland/TSH
c) Thyroid/T3+T4
d) Periphery/alpha thyroid receptors
Where is the pituitary gland located in the skull?
What is it called?
Sphenoid bone
Pituitary fossa
What structure is located above pit. gland?
Optic chiasm
What would you test for pituitary hypo function?
Measure pituitary hormone and target hormone
What are the 2 ways pituitary tumours can be categorised?
Sub categories?
Size - microadenoma (<10mm)/macroadenoma (>10mm)
Functioning - endocrine syndromes/non-functioning
What are 3 examples of diseases caused by non-functioning macroadenoma of the pit gland?
Cushing’s disease
Acromegaly
Prolactinoma
How are majority of:
a) Macroadenoma of pit gland
b) Microadenoma of pit gland treated?
What is used in regrowth?
a) Surgically (trans-sphenoidal)
b) Medically/Conservatively
Radiotherapy
What type of pit gland tumour can be treated well medically?
Prolactin secreting tumours
When would radio-iodine therapy be avoided in the treatment of hyperthyroidism?
Thyroid eye disease
What % of thyroid nodules are benign?
90%
What is the main type of thyroid cancer? (+ %)
What is the prognosis?
Papillary thyroid cancer, 85%
5 yr survival >98%
What is a pheochromocytoma?
Tumour of adrenal medulla
Meaning of ‘gravidity’ (relation to pregnancy)
No times uterus has been pregnant, inc current pregnancy
Meaning of ‘parity’ (relation to pregnancy)
No babies she has given birth to at 24 weeks or later, born alive/dead
+ superscript of other pregnancies up to
23 weeks (miscarriage, ectopic, TOP)
What blood pressure values are used for hypertension in pregnant women?
140/90 - hypertension
160/110 - severe hypertension
What is pre-eclampsia (PET) in pregnant women?
When does it usually occur?
Raised BP 140/90 + Protein in urine
After 20 weeks
Why should a pregnant women not be on her back more than a min?
Impaired venous return via IVC - supine hypotension
What observation chart is used in obstetrics?
MEOWS
What pregnancy stage is dating scan used?
What fetal measurement is used to calculate expected date of delivery?
11-13 weeks
Crown-rump length of fetus, calculates gestational age
What is the symphyseal- fundal height?
What body parts are included?
Assess growth of fetus + growth of uterus
Pubic symphysis - Fundus (top if uterus)
Cm
What stage of pregnancy is symphyseal- fundal height measured?
What is expected growth?
Every antenatal visit from 24 weeks
Same amount cm as weeks pregnant +/- 2cm
What is the name of the division of the testicles? (anatomically)
What is contained within them?
Lobules
Seminiferous tubules
What 2 types of cells line the seminiferous tubules of the testicles?
What do they do?
Spermatogonial stem cells - gamete (sperm) production
Sertoli cells - support, nutrit, protec, secretory, excretory
How much sperm is produced during spermatogenesis?
How long does the whole process take?
Approx 120 million p/day // 1500/sec
72 days
What is spermiogenesis?
Conversion of spermatid to mature sperm
Becomes longer + thinner, mito go around neck of sperm
What are the names of the different parts during spermatogenesis? (the different cell types)
Spermatogonia, Primary + 2ndary spermatocytes, Primary + 2ndary spermatids, spermatozoa (mature)
What is the structure of a mature sperm cell?
Head - nucleus, acrosome
Neck - mito
Tail
What compartment of the seminiferous tubules are mature sperm cells produced?
Luminal compartment
What comprises the interstitial compartment of the seminiferous tubules of the testicles?
Basal spermatogonial stem cells
Interstitial cells of Leydig
Why are there 2 compartments in the seminiferous tubules of the testicles?
Separates newly formed sperm cells
Protect from immune system from being seen foreign
What cells in seminiferous tubules of the testicles remove degenerate sperm cells?
Sertoli cells
What hormones do the Sertoli cells of the seminiferous tubules of the testicles produce?
Inhibin, ABP (androgen binding protein)
AMH (anti Müllerian hormone), growth factors
What hormone do the interstitial cells of Leydig secrete?
What is it’s actions?
Testosterone, C19
Anabolic, primary + 2ndary sexual character, libido, stimulates sertoli cells + spermatogenesis
What hormones inhibit:
a) FSH
b) LH
production in males?
a) Inhibin
b) Testosterone
What are the 4 stages of sperm transport (to get fertilised)?
Short Descrip
Ejaculation
Cervix - mucous barriers + crypts = sperm resevoir
Uterus + tubes - mild contraction to propel towards egg
Ampullary portion of tube - fertilisation
What is sperm capacitation?
What happens?
Sperm becomes ‘hyperactivated’, more speed
4 hours after ejaculation
Cholesterol loss + Ca2+ influx
What happens to sperm as it reaches the oocyte?
Interaction of ZP3 protein on oocyte membrane
Acrosome reaction releases enzymes
Facilitates penetration
What enzymes are contained within acrosome of sperm cell?
Hyaluronidase
Acrosin enzymes
How is the oocyte activated after penetration from sperm cells?
Release of cortical granules to block polyspermic penetration
Resumption of meiosis
What factors can affect sperm production?
Excess testost intake
Environ
Air pollution/Smoking
Food chain pollution
What is the mechanism that can affect sperm production?
Free O2 radicals e.g. O2, H2O2, OH
What is the NICE definition of infertility?
Woman of reproductive age who x conceived after 1 year of unprotected sexual intercourse
What 3 factors can affect chances of pregnancy?
Previous pregnancy
Duration less than 3 years
Age less than 30 years
How would you test ovulation?
Midluteal progesterone, 7 days before next expected period
How would you test semen?
Test: concentration, mobility, morphology
How would you test ovarian reserve?
Early follicular FSH
Antral follicle count (AFC) - measuring size of follicles
Anti-Mullerian Hormone (AMH)
Where is AMH produced in females?
When can it be measured (to test for ovarian reserve)?
Produced by granulosa cells from pre-antral + antral follicles
Measured anytime in cycle
What is anovulation?
What are the 3 types?
Ovaries x release oocyte during menstrual cycle
Group I: hypothalamic amenorrhoea/ hypogonadotropic hypogonadism, 20%
Group II: hypothalamic-pituitary-ovarian dysfunction
(predominately polycystic ovary syndrome)
Group III: ovarian insufficiency.
What 3 common drugs are used to treat anovulation?
Clomiphene citrate - selective oest receptor
Letrozole - aromatase inhibitor
Gonadotrophins
What is azoospermia?
What are the 2 types?
Semen present but no sperm
Obstructive - normal spermatogenesis, normal sized testes + FSH levels
Non-obstructive - impaired spermatogenesis, small testes + raised FSH
What are the common causes for the 2 types azoospermia?
Obstructive - post infection/vasectomy, congenital absence of vas deferens
Non-obstructive - testicular failure,
What is the common treatment for azoospermia?
Sperm retrieval
Percutaneous epididymal sperm aspiration (PESA)
Testicular sperm extraction (TESE)
What is ICSI?
Intracytoplasmic Sperm injection
Part of IVF to get sperm ready
When does a fetus acquire legal rights?
At birth
When was Abortion Act established?
What criteria have to be met?
1967
2 registered practitioners of opinion, 1/4 grounds exists
Carried out by Registered medical practitioner
Procedure performed in an approved place
Notified to Chief Medical Officer of DoH
When was the Abortion act amended?
1990
What abortion can be carried out at home?
How many weeks of pregnancy
First 10 weeks
What is ART?
Assisted Reproductive Technologies
e.g. IVF, artificial insemination, surrogacy
What is preimplantation genetic diagnosis(PGD)?
Cell from an embryo at 8-cell stage of development, Around 3-days old, + testing it
In the 1st 5 days of human development, what is formed?
Blastocyst
What is contained in a blastocyst?
Trophoblast layer - embryonic contribution to placenta
Inner cell mass - totipotent cell types
What does the inner cell mass of the blastocyst divide into?
Epiblast - ecto/meso/endoderm, amniotic membrane
Hypoblast - Heuser’s membrane
When is the heart and brain visible in a developing fetus?
Week 2
When does the heart start to beat?
Week 3
What is the embryonic development period in human development? (What weeks)
Weeks 3 -8
Most organs develop
What process leads to the germ layers in human development?
Gastrulation
What organs do the 3 germ layers give rise to?
Ectoderm - epidermis, nervous system
Mesoderm - skeleton, muscle, dermis, kidney, blood
Endoderm - gut, liver, pancreas, lungs
Where do the brain and spinal cord develop on the ectoderm?
On the midline
What is the name of:
a) Anterior
b) Posterior
when looking at fetus?
a) Rostral
b) Caudal
What are 3 examples of endodermal defects?
Lung aplasia - no lungs
Oesophageal atresia/fistula
Omphalocele
What are the 3 divisions of the mesoderm?
Paraxial mesoderm
Intermediate mesoderm
Lateral plate mesoderm - somatic + splanchnic mesoderm
What structures arise from lateral plate mesoderm?
Dermis of skin, Limb Skeleton, Heart, Blood vessels, Blood, connective tissue
Mucosal + muscle layers of gut
What structures arise from intermediate mesoderm?
Kidneys, M + F reproductive systems