SUGER: Week 3 Flashcards
1
Q
Is the kidney retro or intraperitoneal
A
It is retroperitoneal
2
Q
What vertebral levels does the kdiney extend from and to
A
From T12 to L3
3
Q
What is the apex of the renal pyramids known as
A
Renal papilla
4
Q
What is the role of the renal papilla
A
Connects to the minor calyx
5
Q
What is the role of the minor calyx
A
Collects urine from the renal pyramids
6
Q
Describe the path of urine through the kidney structures
A
Renal pyramids -> Minor calyx -> major calyx -> Renal pelvis -> ureter -> bladder
7
Q
What is the renal hilum
A
Gateway to the kidney
8
Q
Where are medullary rays located
A
In the cortex leading into the medulla
9
Q
What provides the striated appearance of the cortex
A
The medullary rays
10
Q
What are the ureters made of
A
Smooth Muscle
11
Q
How does the ureter move urine from the kidneys to the bladder
A
Via peristalsis
12
Q
What is the blood supply of the ureter
A
Upper - Renal arteries
Middle - Common iliac arteries + Gonadal arteries
Lower - Internal iliac arteries
13
Q
What is the nerve supply of the ureter
A
Testicular nerve plexus
Renal nerve plexus
Hypogastric nerve plexus
14
Q
Where is the urinary bladder located
A
In the pelvic cavity
15
Q
Where is the median umbilical ligament located
A
At the apex of the bladder extending to the umbilicus
16
Q
What is the name of the muscle that is contained within the bladder
A
Detrusor muscle
17
Q
How many sphincters does the male bladder have
A
Two: external and internal
18
Q
What is the blood supply of the bladder
A
Males: Inferior Vesical artery
Females: Vaginal Artery
19
Q
What are the inferior vesical artery and vaginal artery branches of
A
The internal iliac artery
20
Q
What is the sympathetic nerve supply of the bladder
A
Superior + Inferior hypogastric plexuses
21
Q
What does the trigone of the bladder consist of
A
2 Ureteric orifices
1 Internal urethral orifice
Mucosal flaps allow unidirectional movement of urine
22
Q
What are the different parts of the male prostate and what epithelium are they lined by
A
Preprostatic - Transitional
Prostatic - Transitional
Membranous - Pseudostratified columnar
Spongy urethra - Proximally pseudostratified and distally stratified squamous epithelium
23
Q
What is the difference in the glands present in the urethra in males and females
A
Males have bulbourethral glands
Females have bartholin glands
24
Q
What structure do the collecting ducts drain urine into
A
The renal pelvis
25
What structure do the ureter move alongside to the bladder
Psoas major
26
Are ureters retro or intraperitoneal
Retroperitoneal
27
Describe the pathway of the ureters into the bladder
1. Move along psoas major muscles
2. Crosses pelvic brim + enters pelvic cavity
3. Runs down lateral pelvic walls
4. Enters ureteric orifices via one-way valves
28
What consists of the renal corpuscle
Glomerulus
Endothelial cells
Bowman's capsule
29
What is the role of the renal corpuscle
Filters blood plasma
30
What does the difference in diameter of the afferent and efferent arterioles achieve
Allows a huge + constant hydrostatic pressure along the glomerulus
31
What are the glomerulus supported by (cell-wise)
Mesangial cells
32
Three role of mesangial cells
1. Contract smooth muscle walls of afferent arterioles to reduce GFR
2. Structural support for capillaries
3. Phagocytosis of glomerular basement membrane breakdown products
33
Where are principal cells found
DCT and collecting ducts
34
Role of principal cells
Changes balance of Na+ and K+ in filtrate
35
What mediates the action of the principal cells
Aldosterone
36
What does an increase in aldosterone cause in the principal cells
Causes an increased Na+ channel expression on apical membrane
Causes increased Na+/K+ ATPase on basolateral (3Na out and 2K in)
37
Apart from the kidneys, where else does aldosterone have an effect at
At the salivary glands + Gut (absorption of Na+ and secretion of K+)
38
Describe the structure of the male spermatic duct from the testicles to the epididymis
1. Convoluted seminiferous tubules
2. Straight seminiferous tubules
3. Rete Testis
4. Efferent ductules
5. Epididymis
39
Where are leydig cells found
Between the seminiferous tubules
40
Role of leydig cells
Produce testosterone
41
Where does meiosis in males take place
Seminiferous tubules
42
What are the seminiferous tubules lined by
Stratified epithelium, sertolli cells and germ lines - Germinal epithelium
43
What is the chromatin in germinal cells called
Spermatogonia
44
What do spermatogonia develop into before entering the testis-blood barrier
Spermatocytes
45
Role of sertolli cells
Nurse cells that develop nurturing developing sperm
46
How long does sperm production take place
64 Days
NOTE: A wave of maturation moves down the tubules until the sperm reaches the blood-testis barrier
47
What is the role of the renin-angiotensin system
Maintain + regulate blood pressure
48
Describe the renin-angiotensin system
1. Renin is produced by juxtaglomerular cells as PRORENIN
2. Renin is released by juxtaglomerular cells when there is a DECREASED arterial pressure.
3. Intrinsic reactions cleave prorenin to renin
4. Renin acts on angiotensiongen -> angiotensin I (loses 2 AA)
5. Angiotensin -> angiotensin II by ACE enzymes in the lung endothelium by losing 2AA
49
Where is angiotensin I converted to angiotensin II
Mostly the lungs but also kidneys too
50
Angiotensin I vs Angiotensin II
Angiotensin I is a WEAK vasoconstrictor
Angiotensin II is a STRONG vasoconstrictor
51
How long does angiotensin II last in the blood vessels
apprx 30 mins because it is de-activated very quickly by angiotensinase
52
How does angiotensin II affect the blood pressure
Vasoconstriction
| Decreased excretion of Na and H20 by kidneys
53
What is the result of a decreased excretion of Na by the kidneys
Increased ECF volume
54
Angiotensin II afefct in veins vs arterioles
Veins do not constrict as much as arterioles - increases TOTAL PERIPHERAL RESISTANCE
55
What two ways does angiotensin act in the body
1. Acts directly on kidneys to cause salt and water retention
2. Causes adrenal glands to secrete aldosterone which increases Na and H20 reabsorption by kidney tubules
56
Explain the direct-acting nature of angiotensin II
Constricts arterioles to reduce pressure in peritubular capillaries + increase pressure gradient from tubules to capillaries (more-rebasorption)
57
How does the RAAS system function when salt intake varies
1. Large intake of salt increases ECF volume + arterial pressure
2. Increased arterial pressure causes increased blood flow through the kidneys
3. Increased blood flow lowers renin secretion so less Na+ is retained.
58
What are the two components of the aicd-base buffer system at the kidneys
- A weak acid (H2CO3)
- bicarbonate salt (NaHCO3)
Check book
59
Is the phosphate buffer system important in ICF or ECF
ICF regulation
60
What are the main components of the phosphate buffer system
HPO42-
| H2PO4
61
How will adding a strong acid like HCL affect the phosphate buffer system
HCL will react with NaHPO4 to give NaCl + NaH2PO4
So HCL (strong acid) is replaced by a slightly stronger weak acid, minimising change in pH
62
How does adding a strong base like NaOH affect the phosphate buffer system
NaOH will react with NaH2PO4 -> H20 + Na2HPO4
A strong base is replaced by a slightly stronger weak base minimising change in Ph
63
How does the phosphate buffer system affect bicarbonate levels in the blood
Production of new HCO3- ions which increase net amount of plasma HCO3-
64
When does the phosphate buffer system take place
When all the HCO3- have combined with H+ and we have an excess of H+ still left
65
Describe the phosphate buffer system
Check book
66
Define a base
Proton acceptor
67
Define an acid
Proton donator
68
Define Base Excess
Quantity of acid required to return plasma pH to normal
69
Define standard base excess
Quantity of acid that requires to return ECF to normal pH
70
Define acidemia
Low pH
71
Define alkalemia
High pH
72
Formula for pH
-log10(H+)
73
What is the anion gap
The difference between measured cation + measured anions in the plasma or urine
74
Why do we calculate an anion gap
To identify the cause of metabolic acidosis
75
Formula for the anion gap
([Na+] + [K+}) - ([Cl-]+[HCO3-])
76
What is the normal range for the anion gap
10 - 16
77
What does a wide anion gap suggest
Renal Failure
78
What does a narrow anion gap suggest
Renal tubular acidosis
79
At what part of the nephron does the phosphate buffer system take place at
PCT
80
How does the phosphate buffer system affect plasma HCO3 levels
Increases it
81
Other than the phosphate buffer system, how else can we produce new bicarbonate ions
The ammonia buffer system
82
Describe the ammonia buffer system
Check book
83
What is glutamine broken down into
NH3 + alpha ketogluturate
NH3 gains a proton to form NH4+
84
What happens to the alpha keto-gluturate
Give two HCO3- ions
85
Where is some of the NH4+ absorbed
Collecting Ducts
86
How does the mechanism of acid secretion (bicarbonate re-absorption) change along the nephron
At PCT and thick ascending limb of loop of henle - Secondary Active Transport
At DCT and collecting ducts - Primary Active Transport
87
What happens to the proportion of NH4+ during metabolic acidosis
Increases it
88
How is repiratory acidosis caused
Hypoventilation or COPD
89
How is respiratory alkalosis caused
Hypoxia and hyperventilation
90
How is metabolic acidosis caused
Renal Failure or excess H+ secretion
91
How is metabolic alkalosis caused
Vomiting and volume depletion
92
How does metabolic + respiratory acidosis affect the HCO3-/H+ ratio
Decreases it
93
Why does H+ conc. increase in respiratory acidosis
Increased pCO2 levels in ECF - H+ in excess
94
Why does H+ conc. increase in metabolic acidosis
Decreased HCO3- levels in ECF - H+ in excess
95
What happens to NH4+ levels in repiratory and metabolic acidosis
Increases to increase bicarbonate levels again
96
How long does correctin of acidosis take
Days
97
What happens to the HCO3-/H+ ration during alkalosis
It increases
98
How is HCO3- production affected as less H+ is available for the phosphate and ammonia buffer systems
Decreases
99
How is alkalosis corrected at the kidneys
```
Decreased respiration (Increase CO2 levels)
Increased renal HCO3- excretion: Increased ECF conc. causes increased filtration of HCO3- into the tubules and can't be re-absorbed as H+ ions are not present in the cell
```
100
How is acidosis corrected at the kidneys
```
Increased respiration (decrease CO2 levels)
Decreased renal HCO3- secretion
```
101
What are three major roles of the kidneys
Angiotensin II
Erythropoietin
Activation of vitamin D
102
Where is erythropoietin produced
Renal cortex interstitium
103
What is the consequence of incontinence to an individual
1. Societal expectation
2. Taboo subject
3. Significant cause of misery
4. Less quality of life
5. Reduced life-expectancy
104
What are the components of the lower urinary tract
1. Bladder
2. Bladder Neck
3. Prostate Gland
4. Urethra + Urethral sphincter
105
What are three functions of the normal lower urinary tract
1. Prevent leakage of stored urine
2. Low pressure of stored urine
3. Allow rapid voiding and at an appropriate time + Place
106
Define micturition
This is the process by which the urinary bladder empties when it's filled
107
How can I identify the bladder trigone
The trigone is made of smooth mucosa whilst the rest of the bladder has mucosa arranged as rugae
108
How do the ureter pass into the bladder
Obliquely
109
Why do the ureter pass into the bladder obliquely
To allow uni-directional movement of urine
110
What does the urogenital diaphragm consist of
External sphincter of the bladder
111
What is the external sphincter innervated by
Peudendal nerve (supplies motor)
112
Can the micturition process by inhibited
Yes, it can be voluntarily inhibited util it is appropriate to begin voiding
113
Why does pressure in the bladder stay low during storage even though it is filling with urine
Because the bladder has a compliant nature and an increase in bladder tension causes an increase in its radius.
114
Describe the micturition reflex
1. Stretch receptors in the posterior urethra are stimulated when it begins to fill with urine due to the higher pressure in the urine
2. Sensory impulses move down pelvic nerves to S2 + S3 spinal cord segments
3. Parasympathetic fibres carry impulses back to the bladder via pelvic nerves
4. This causes slight contraction of the detrusor muscles
5. If the bladder content isn't voided by then OR the bladder is only partially filled, then the micturition contractions relax again due to detrusor muscles
6. As the bladder fills further, the strength of detrusor muscle contraction eventually increases, pulling the internal sphincter of the bladder open.
7. More APs are fired by pelvic nerves as stretch receptors become more stimulated
8. Pelvic nerve is inhibited if micturition reflex fails to release any urine for a few minutes
115
Describe the voiding phase of micturition
1. Afferent signals are sent to the periaqueductal grey
2. Project to the pontine micturition centre + cerebrum
3. Increased afferent activity causes INCREASED urge to void
4. Voluntary signals to start voiding causes maximal firing from the centre exciting SACRAL PRE-GANGLIONIC NEURONS
5. Neurons cause the bladder wall to contract, increasing intravesical pressure
6. Onuf's nucleus is inhibited which causes relaxation of EXTERNAL URETHRAL SPHINCTER
7. Even when the sphincter is relaxed, the micturition reflex needs to generate a big enough pressure to expel the urine.
116
Where is the micturition reflex centre located
Pons.
117
What type of muscle does the external sphincter consist of
Slow twitch - type 1 muscle fibres
118
What is the external sphincter innervated by
Peudendal nerve (S2-4) which are inihibited to cause the sphincter to relax
119
What is the internal urethral phincter innervated by
Sympathetic - Hypogastric plexus
120
What is the bladder innervated by
Pelvic Splanchnic nerves (parasympathetic)
121
Where is ANP produced
By the atria
122
What does ANP do
Dilates the afferent arterioles and constricts efferent arterioles
This increases GFR which increases blood flow through the vasa recta.
Vasa recta washes out Na and Cl in medullary interstitium which reduces Na re-absorption into the nephrons
Inhibits renin secretion
123
How does Na conc. in blood affect ANP levels
Increases it
124
Following micturition, how is the remaining urine in the urethra expelled
Contraction of the bulbospongiosus muscle
125
How do we expel small quantities of urine even though the micturition reflex is not strong enough to do so
Contraction of abdominal walls which increase pressure applied to the urinary bladder wall.
126
What do primordial germ cells do during embryological development in order to initiate spermatogenesis
They migrate into the testis and form SPERMATOGONIA
127
When do spermatogonia begin to mature
Only once puberty starts
128
Where does sperm maturation take place
In the seminiferous tubules
129
What hormone causes sperm maturation
Gonadotropic hormones
130
At what age does spermatogenesis typically occur at
13
131
Outline the process of spermatogenesis
Check book
132
How is the XY chromosome divided in the sperm
They are separated during meiosis I and placed into separate gametes
Gamete receiving X will form a female
Gamete receiving Y will form a male
133
Where is the nucleus of a sperm found
1. Sperm head
134
Where is the sperm acrosome located
Anterior 2/3 of the head
135
What organelle forms the acrosome
Golgi apparatus
136
What two enzymes are found in the acrosome
1. Hyaluronidase (digest proteoglycans)
| 2. Proteolytic enzymes (digest proteins)
137
Why do we need hyaluronidase and proteolytic enzymes
To allow the sperm to reach the ovum
138
What is found in the tail of the sperm
Axoneme
139
What is the axoneme
Cilia-like structure (central skeleton of II microtubules)
140
What is found in the body of the sperm
Mitochondria
141
What causes the movement of the sperm tail
1. Due to axoneme tubule movement
142
What do leydig cells secrete
Testosterone
143
Where is LH secreted
Anterior pituitary gland
144
What cell does LH activate
Leydig cells
145
What does FSH activate
Sertoli cells
146
What hormone stimulates division of the spermatogonia
Growth Hormone
147
Where is sperm mainly stored
Epididymis
148
How long can sperm be stored for
About a month
149
In what state are sperm stored
Deeply surpassed + Inactivated
150
What do sertoli cells do during ejaculation
They secrete hormones + nutrients which makes sperm motile
151
What pH does ejaculate have to be for optimal activity
Slightly alkaline
152
How does an increase in temperature affect sperm lifespan and why is this the case
Decreases as metabolic activity increases
153
Where do the seminal vesicles empty into
Ejaculatory duct
154
What is the main nutrient by sperm
Fructose
155
Where a prostaglandins produced
Seminal vesicles
156
What is the role of prostaglandins
Aid fertilisation by causing reverse peristalsis in fallopian tubes to assist movement of sperm to ovum
157
What do prostate glands secrete
Calcium, citrate,phosphate ions, profibrinolysin
158
What is the aim of prostatic secretions
Alkaline property which helps neutralise acidic metabolites in seminal fluids released from sperm + acidic conditions of vaginal secretions
159
What epithelium lines the bulbourethral glands
Pseudo stratified columnar epithelium
160
What is the fluid composition of semen
1. 60 % seminal fluid
2. 30% prostatic fluid
3. 10% sperm + bulbourethral fluid
161
What does the sperm have to do in order to get through the cervix
Break down cervical mucous
162
What are type A spermatogonia
Remain outside the blood-testis barrier + produce spermatogonia until they die
163
What are type B spermatogonia
These mature into spermatocytes
164
Why is some testosterone produced during fetal life
To allow descent of the testes
165
How does the SRY gene affect the genital ridge
Causes genital ridge to develop into leydig cells
166
In what part of the body is GnRH released
Hypothalamus
167
What does GnRH cause in the pituitary glands
Secretion of LH and FSH
168
What is the role of FSH in spermatogenesis
The FSH binds to receptors on sertoli cells in the SEMINIFEROUS TUBULES
Causes sertoli cells to grow and produce substances the stimulate maturation (with testosterone)
169
How does testosterone act
Locally by diffusing from interstitial into seminiferous tubules
170
How is FSH levels affected if spermatogenesis FAILS
It will increase
171
What happens if FSH levels are too high
Inhibin is secreted by sertoli cells to stop it
172
What is LH inhibited by
Testosterone
173
How does testosterone inhibit LH
1. Decreased secretion of GnRH
| 2. Acts of anterior pituitary gland
174
Why is meiosis important
1. Prevents polyploidy
2. Increased variation
3. Genetic diversity
4. Chromosomal combinations
175
When does meiosis I start in females
Before 12 weeks in fetus
176
When is meiosis stopped at before puberty begins
Prophase I
177
What happens at puberty to cause meiosis to continue
Increased conc. of LH
178
At what stage is meiosis halted until fertilisation
Metaphase II
179
How many chromosomes are present in polar bodies
23 chromosomes
180
What is the difference between male and female gonads before 6 weeks
None
181
When does sex determination occur embryologically
After 6 weeks
182
What structures form by the paramesonephric duct
1. Fallopian tubes
2. Uterus
3. Upper 2/3 of vagina
183
How many spermatozoa are produced by one spermatocyte
4
184
How many ovum are formed by one egg
1
185
What is the difference in maturation location of the sperm and ovaries
Eggs have one stage in the ovaries and another in the fallopian tubes
Both maturation stages take place in the testis
186
What factors can affect puberty
1. Nutrition
2. Genetics
3. Excersise
4. Leptin
5. Insulin
187
When does puberty take place in males
9-14 (air 12)
188
What are the signs of male puberty
Pubic hair, axillary and facial hair
1st - Testicals enlarged
Spermatogenesis
Odour, mood swings and acne
189
When does puberty take place in females
8-14 (air 11)
190
What are the signs of female puberty
1st = breast development + Menarche
Growth spurt
Pubic and axillary hair
191
When does menarche take place
2.5 years after puberty
192
What structure does the sperm pass through to get to the oocyte
Corona Radiata
193
What structure is the zona pellucid located next to
Corona Radiata
194
What do sperm undergo when they enter the reproductive tract
Capacitation
195
What occurs during capacitation
Destabilisation of sperm acrosome to allow penetration of the egg
Chemical changes that increases sperm motility
196
What happens to the glycoproteins and cholesterol in the plasma membrane of sperm during capacitation
They are more permeable to calcium ions
197
What hormone controls capacitation
FPP
198
Where is FPP produced
Prostate gland
199
How does FPP function
High conc. in male reproductive system keeps sperm inactive
Dilutes in female reproductive tract
200
What happens at the zona pellucida
Sperm binds to corona radiata + enters zona
Binds to ZP3 glycoprotein in zone which bursts the acrosome, releasing enzymes needed to break down zona pellucid
201
What follows penetration of the egg
Cortical Reactions
202
Describe the cortical reactions that take place
1. Granules in the secondary oocyte fuse with the egg cell membrane
2. Granules are released by endocytosis
3. Inactivates sperm binding receptors hardening the zona pellucid
4. Prevents additional sperm from binding to the zona
203
When does meiosis II of the egg start again
Following fertilisation
204
What are pronuclei
These are when there are two nuclei of genetic information which are still surrounded by a membrane and haven't fused yet
