SUGER 2 Flashcards
Label this including layers of the epidermis
for layers of the epidermis it’s Come Lets Get Sun Burned
Difference between Pacinian Corpuscle and Meissner’s Corpuscle
name 7 functions of the skin?
- Barrier: to trauma, light, pathogens etc
- Sensation
- Temporature: blood flow, erection of hairs, release of sweat
- Immunity: specialised langerhans cells
- Permits movement and growth: elastic and recoil properties
- Excretion: waste products like urea removed by sweat
- Endocrine: synthesis of vitamin D
why does the right kidney lie lower?
it is pushed down by the liver on the right
at what vertebral level are the kidneys found?
T12-13
what does the Wolffian duct form?
- Vas deferens
- Epididymis
- Seminal vesicles
- Ejaculatory duct
what is the uteric bud?
it is a bud from the mesonephric duct. it forms the the ureters, caleces and collecting ducts
what are the 3 embryological kidneys?
- Pronephros
- dissapears at the 4th week
- Mesonephros
- gives the mesonephric duct
- dissapears at the 2nd month gestation
- Metanephros
- develops in pelvis then moves into the abdomen
- functions at 12 weeks
- permanent
what are the 4 functions of the kidneys?
- Gluconeogenesis
- Hormone production
- Waste removal
- Water/acid-base/ion balance
what happens to osmolarity as you go further into the medulla?
it increases so in the loop of henle water is forced out of the lumen and is reabsorbed
What are the actions of angiotensin II other than in producing aldosterone
- it increases sympathetic activity
- it shares functions with aldosterone
- it causes tubular Na+ and Cl- reabsorption and K+ excretion in the kidney. Thereby causing H20 reabsortion
- It causes arteriolar vasoconstriction
- it causes the posterior pirtuitary to produce ADH
what two things cause ADH release?
- Increased plasma osmolality detected by hypothalamic osmoreceptors
- Angiotensin II
what is the symopathetic nerve supply to the bladder?
Hypogastric
what is the parasympathetic nerve supply to the bladder
pelvic nerve
what nerve conducts voluntary control to the bladder?
Pudendal nerve
where is bicarbonate reabsorbed in the kidneys?
mostly in the proximal conveluted tubule
what happens to store urine?
- this is sympathetic
- the internal urethra sphincter contracts
- the detrusor muscle is relaxed
- this is mediated by the hypogastric nerve
what is the volume of the bladder and at what point is the need to void felt?
the volume of the bladder is 300-400ml and the need to void is felt at 150ml
Voiding
- This is parasympathetic
- the internal urethral sphincter relaxes
- the bladder neck funnels
- the detrusor contracts
- pudendal nerve controls voluntary external urethral sphincter
summarise the venous drainage of the thyroid gland
Superior and middle veins drain into the internal jugular
Inferior vein drains into the brachiocephalic vein
which glucose transporter does insulin cause to mobilise to the cell surface and which one causes insulin to enter the B cells in the islets of langerhans
- Insulin causes GLUT4 to move to plasma membrane
- Glucose enters the B cells in the islets via GLUT2
what are the tubes in the testis called
seminiferous tubules
when does spermatogenesis begin and how long does the process take to complete?
it begins at puberty and it takes 64 days to complete the process
describe 6 stages of reproduction following pre-implantation
- Fertilization (day 1)
- sperm penetrates zona pellucida and gametes fuse forming a zygote
- Cleavage (day 2-3)
- ooplasm divides into two equal halves and successive cleavages increase cell no.
- Compaction (day 4)
- cells flatten and tight junctions form
- Cavitation and differentiation (day 5)
- fluid filled cavity expands, forming a blastocyst
- Expansion (day 5-6)
- the cavity expand further and the diameter of the blastocyst increases
- Hatching (day 6+)
- due to blastocyst expansion + enzymes the embryo hatches from the zona pellucida
- this is essential for implantation
6 stages of implantation
- Apposition ~9 days after fertilization
- The hatched blastocyst orientates via embryonic pole and synchronises with the receptive endometrium
- Attachment
- Endometrial epithelial cells and trophoblastic cells express integrins which connect to one another
- Differentiation of trophoblast
- it becomes a syncitiotrophoblast
- Invasion
- enzymes degrade the basal lamina
- Decidual reaction
- the stromal cells next to the blastocyst differentiate
- Maternal recognition
- secretion of IL-2 prevents antigenic rejection of the embryo
Human chorionic gonadotrophin
increases from day 7-8 (implantation)
then decreases once the placenta is established
roles: support the corpus luteum, interact with the endometrium and stimulate oestrogen production by the ovaries
Oestrogen in pregnancy
it is produced by the ovaries throughout pregnancy
roles: to regulate progesterone levels, prepare the uterus for the foetus and to prepare the breasts for feeding
Progesterone in pregancy
heightened throughout pregnancy
firstly produced by the corpus luteum and then by the placenta
roles: prevents contraction of the uterus, builds up the uterine lining to prevent miscarriage
Prolactin
increases at the end of pregnancy when oestrogen and progesterone drop
produced by the anterior pituitary (inhibited by dopamine)
roles: production of milk and prevention of ovulation
Relaxin
High early in pregnancy and then again late in pregancy
produced by the ovary and the placenta
roles: limit uterine activity, soften the cervix and contribute to uterine ripening
Oxytocin
secreted throughout pregnancy but skyrockets at the end
Produced by the posterior pituitary
roles: uterine contractions, triggers caring reproductive behaviours
Prostaglandins
PGF2 alpha is the main one
Produced by the uterus
Has a role in initiating the labour by making uterine tissues more receptive to oxytocin
Also produced in response to the baby’s head pushing on the cervix
Stages of Labour
- Latant phase
- Little cervical dilation
- Active phase
- From when stronger contractions start to full dilation
- Full dilation > foetal expulsion
- Placental expulsion
- Post-partum phase
parturition hormones positive feedback can you draw the diagram?
Briefly describe spermatogenesis
- much of it occurs in the walls of the seminiferous tubules
- the spermatogonium is stimulated by testosterone produced by the interstitial leydig cells
- it differentiates into diploid a primary spermatocyte
- the primary spermatocyte undergoes meiosis I to become two haploid secondary spermatocytes
- these undergo meiosis II to become 4 haploid spermatids
- the spermatids are supported by the sertoli cells in the wall of the seminiferous tubule to develop into mature sperm cells
- this happens as they travel along the seminiferous tubules and epididymus
give overall timeline of oogenesis
- a woman’s lifetime supply of primary oocytes are created from oogonia by ~20 weeks gestation
- this is 7 million but by birth is already reduced to 2m
- they begin meiosis but are arrested in prophase I for up to 50 years
- from puberty, one primary oocyte a month completes Meiosis I
- it will begin meiosis II but is arrested in metaphase II until fertilization
briefly summarise oogenesis
- at birth: 2mill primary oocytes (2n) arrested at prophase I
- these are in primary follicles
- during menstrual cycle FSH stimulares completion of meiosis I and the formation of secondary oocytes (n) within secondary follicles
- the secondary oocyte is arrested in metaphase II
- on day 14 the secondary follicle ruptures and releases the secondary oocyte into the fibriae
- follicle leftovers remain in the ovary and develop into the corpus luteum
- meiosis will only complete once there is contact with a sperm
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oestrogen production by the follicle
- under stimlulation by LH, the theca cells of the follicle turn cholesterol into androgen
- this androgen is passed to granulosa cells
- granulosa cells, under the influence of FSH then convert the androgen into oestrogen
draw menstrual cycle diagram with sections for:
pituitary hormones
ovarian hormones
endometrium lining
follicle development
briefly summarise the follicular phase of the menstrual cycle
- GnRH is being produced at increasing levels
- In first couple of days FSH secretion is stimulated by low oestrogen to rise
- FSH stimulates development of the follicle
- Oestrogen at low levels inhibits LH secretion
- LH remains low despite high GnRH
- Oestrogen levels begin to rise
- FSH secretion decreases
- Oestrogen reaches a conc high enough to stimulate LH secretion
- Massive spike in LH causes ovulation
briefly summarise the luteal phase of the menstrual cycle
- after ovulation follicle turns to the CL which will release:
- oestrogen - it was always making this
- inhibin
- progesterone
- inhibin stops FSH secretion since we don’t need to stimulate any more follicles
- oestrogen levels begin to drop
- progesterone causes the endometrium lining to build up and inhibits GnRH secretion
- LH and FSH drop
- as the CL degenerates oestrogen, progesterone and inhibin are no longer being produced
- endometrium cannot be maintained –> menstruation
- because progesterone is low, GnRH is high enough (and oestrogen low enough) to allow FSH to be produced and to start the process again.
summarise water distribution in the body
tubuloglomerular feedback
- macula densa of distal tubule detects decreased NaCl
- MD secretes prostaglandins
- prostaglandins cause granular cells to secrete renin
briefly summarise the synthesis of thyroid hormone
- occurs in follicles: sphere of follicular cells surrounding a core of protein rich colloid
- lumen contains thyroglobulin produced by follicular cells from tyrosine
- circulating iodide (I-) is actively cotransported with Na+ ions across basolateral membranes of follicular cells (‘iodide trapping’)
- Na pumped out of the cells by Na+/K+ ATPases
- iodide is transported into the lumen of the follicle
- I- is then converted into atomic iodine by an enzyme called thyroperoxidase (TPO)
- atomic iodine can then be bound to thyroglobulin to form T3 or T4
overall effects of insulin and subpoints for each
- Decreased liver glucose production
- less glycogenolysis
- less gluconeogenesis
- Decreased use of stores
- decreased lipolysis
- decreased ketogenesis
- decreased muscle catabolism
- Increased storage of energy
- Glucose enters cells
- increased triglyceride formation
- increased glycogen formation
- increased muscle metabolism
- Weird one
- K+ enters cells
can you draw the urea cycle?
what is the GFR calculation using a marker
GFR = Um x urine flow rate / Pm
what is henderson hasselbach for blood?
pH = 6.1 + log ([HCO3-] / 0.03 x PaCO2)
bicarbonare reabsorption in the kidney
you can work it out if you just simply remember that H+ is sent into the lumen to collect the HCO3-
