Week 6 Flashcards
What makes up the urine produced by the kidneys?
Removal, from circulating blood, of excess water & electrolytes, & tonic, metabolic waste products such as urea & creatinine
How do the kidneys monitor and effect acid/base balance?
Excreting H+ during acidosis, or bicarbonate ions during alkalosis
What does the secretion of renin by the kidneys do?
Indirectly raises blood pressure
How often is blood filtered and “cleaned”?
Upto 60x per day
What secretes erythropoietin?
Kidneys
What is the fat surrounding the kidneys called?
Pararenal/nephric fat
What overlies the hilum of the right kidney?
2nd part of the duodenum
Why do the kidneys move with respiration?
Because they are related to the diaphragm
What are the 5 parts to a kidney nephron?
- Renal corpuscle (glomerulus)
- Proximal convoluted tubule
- Loop of Henle
- Distal convoluted tubule
- Collecting ducts
Describe the 2 functions of a nephron?
- Ultrafiltration- 180litres filtrate/24hr
2. Reabsorption- 1.5litres urine/24hr
Where are the nephrons located in the kidney?
Renal pyramids
What forms the renal pelvis?
Minor calyces converge on major calyces, which themselves form the renal pelvis that tucks into the sinus of the kidney
What is the blood supply of the kidneys?
- Renal arteries from aorta at L1,2
- Accessory, extrahilar arteries from aorta
- Gonadal
- Common & internal iliac
- Uterine, vaginal
- Vesicle
What are the vascular structures entering the renal hilum from anterior to posterior?
Vein –> Artery –> Pelvis of Ureter
What does the left renal vein receive?
Suprarenal & gonadal veins
Why is surgery difficult in the right kidney?
IVC is to the right of the midline, so the right renal vein is short
How many segmental arteries does the renal artery divide into?
5
What does the segmental artery give off?
Lobar arteries, one for each renal pyramid
What does the lobar arteries give off before entering the renal substance?
2 or 3 interlobar arteries, which run toward the cortex on each side of the renal pyramid
What do the interloper arteries give off at the junction of the cortex and the medulla?
Arcuate arteries, which arch over the bases of the pyramids
What do the arcuate arteries give off?
Several interlobular arteries that ascend in the cortex
What do the afferent glomerular arterioles arise from and what do they supply?
- Arise as branches of the interlobular arteries
- Supply renal corpuscle
What is the nerve supply of the kidney?
T12 & L1
Where does the referred pain of the kidneys go to?
Back & lumbar region, as well as loin to groin
What do afferents in the vagus cause?
Nausea & vomiting associated with pain
Describe the ureter?
- Muscular tube that transports urine to bladder
- Retroperitoneal
Where are the 3 narrowings in the ureter?
- Pelvi-ureteric junction
- Crossing the pelvic brim
- Passing through the bladder wall
What do the ureters cross?
Bifurcation of the common iliac artery
What should the ureters overlie according to anatomy books?
Lumbar transverse processes
What does IVU stand for?
Intravenous urogram
What 2 structures does the ureter lie between in the male pelvis?
Vas deferens & seminal vesicle
Describe the relationship between the ureter and structures in the female pelvis?
Posterior to ovary, inferior to uterine artery, passing cervix & lateral fornix of vagina
What lies in the lateral wall of the ureter (medial) in the pelvis?
- Internal iliac vessels & branches
- Lumbosacral trunk
- SI joint, ischial spine
What vascular supply should you perseveres during surgery?
Renal & Inferior vesicle branches
What is the lymph drainage of the ureter?
Para-aortic & iliac nodes
Describe how the ureters pass through the bladder wall?
Obliquely, creating flap valve that prevents urine backflow
What forces the ureters closed?
Pressure of urine in the full bladder
How would you describe pain of ureteric calculi?
Colicy due to peristaltic waves
What aids bladder emptying?
Raised intra-abdominal pressure
What is the epithelial lining of the ureter/bladder?
Transitional/Urothelium which is urine-proof & allows distension
Describe the different muscles of the ureter & their purpose?
- Smooth & involuntary, controlled by autonomic, particularly parasympathetic
- External sphincter is striated & voluntary
What is the nerve supple of the ureter?
- “Pacemakers” in renal calyces
- Segmentally T10, 11, 12, L1, S2, 3, 4 from aortic, renal & pelvic plexuses
Where does referred pain of the ureter go?
T11 & L2, loin to groin & scrotum/labia
What is the bladders detrusor muscle nerve supply?
Parasympathetic S2, 3, 4
What is the bladder neck/urethral opening like in the male?
Preprostatic, internal sphincter (sympathetic) to prevent semen back flowing into the bladder
What is the bladder neck/urethral opening like in the female?
Bladder neck above the pelvic floor, pressure of pelvic organs & levator ani contribute to urinary continence
What happens to the peritoneum as the bladder distends?
It pushes upwards, above & behind so that the bladder then lies directly behind the anterior abdominal wall
Describe the urethra of the female?
- External sphincter of striated muscle inferior to bladder neck
- Embedded in anterior vaginal wall
- Opens in vulva as an antero-posterior slit immediately anterior to vagina
List the 4 parts of the male urethra?
- Preprostatic at bladder neck (position of smooth internal sphincter)
- Prostatic
- Membranous, surrounded by striated external sphincter
- Spongy/Penile Urethra
What is the arterial supply of the bladder & urethra?
Branches of internal iliac- sup & inf vesicle, internal pudendal
What is the venous supply of the bladder & urethra?
Vesical (& prostatic) plexuses converging on internal pudendal & internal iliac veins
What is the lymph supply of the bladder & urethra?
Internal & external iliac nodes
What communication in the urethra can facilitate tumour spread?
Prostate & valveless veins of vertebral plexuses (Batson)
What is the nerve supply of the bladder & urethra?
- Somatic motor for striated muscle
- Autonomic (sympathetic & parasympathetic)
- Sensatiosn from S2, 3, 4, Pudendal nerve, Sympathetic & parasympathetic Pelvic Plexus
Describe the 3 stages of Micturition/Urination?
- STORAGE: parasympathetic to detrusor “switched off” bladder to relax & fill
- “FULL”, CAUSES DESIRE TO MICTURATE: afferents (sensory) to spinal cord, the “M” centre in pons stimulates preganglionic parasympathetic neurones at S2,3,4
- VOID: 1y neurones stimulate 2y neurones in bladder wall ganglia, causing detrusor contraction. Simultaneous relaxation of external urethral sphincter via pudendal nerve & contraction of abdominal wall
What is the usual volume of urine in a male bladder?
What volume causes pain?
- 400ml norm
- 500ml pain in lower abdomen & perineum
How is Substance Use disorder classified by the DSM-V?
According to type of substance ie. alcohol, opiates, stimulants & sedatives
Describe & give examples of depressant substances?
Drugs that dampen down the CNS (alcohol, opioids, benzodiazepines)
Describe & give examples of stimulant substances?
Have excitatory effects on CNS (cocaine, amphetamine, nicotine, caffeine, ecstasy)
Give examples of hallucinogen substances?
- Cannabis
- LSD
- Mushrooms
- Solvents
What are the acute signs of alcohol use?
- Smell
- Slurred speech
- Flushing skin
- Disinhibition
- Tremor
- Agitation
- Mints/perfume
What are the acute signs of cannabis use?
- Bloodshot eyes
- Brown fingers
- Drowsiness/slowed down
- Smell
- Lack of focus/concentration
What are the acute signs of stimulant use?
- Agitation
- Pressure of speech
- Lack of focus/concentration
- Mood fluctuation
What are the acute signs of opiate use?
- Gauching
- “Pinned” pupils
- Signs of injecting
- Brown fingers
- Flu like symptoms (withdrawal)
What are the acute signs of sedatives?
- Drowsiness
- Slurred speech
- Poor memory/recollection
What are the 3 key policies in Scotland for substance use?
- The Road to Recovery
- Hidden Harm
- Changing Scotland’s Relationship with Alcohol
What 3 substances have a high >20% addiction potential?
- Heroin
- Methadone
- Nicotine
What 6 substances have a moderate 10-20% addiction potential?
- Amphetamines
- Ecstasy
- Cocaine
- Alcohol
- Cannabis
- Benzodiazepines
What 2 substances have a low 5-10% addiction potential?
- Inhalants
- Steroids
What are the 6 different models of addiction?
- Moral models
- Disease models
- Biological/Medical models
- Personality models
- Behavioural models
- Biopsychosocial models
Describe Moral Models?
- Addiction seen as wilful violations of societal rules & norms, human weakness
- Individual is primary causal factor
- Treatment: moral persuasion, imprisonment or spiritual guidance
- Church, law enforcement & courts are “agents of change”
Describe Dispositional Disease Models?
- Primary causal factor is individual
- “Disease” of addiction is irreversible but can be arrested via total abstinence
- Benevolent model for individual & corporate organisations
- AA & NA subscribe in part to this model
Describe Biological/Medical Models?
- Genetic & physiological processes in determining addiction, primary causal factor is individual
- Identify unique biological conditions which contribute to addiction ie. disorder of brain function
- Consider pharmacology of substance
- Agent of change is medical
What is the evidence supporting Medical Model?
- Addiction is about 50% heritable (Sellman, 2010)
- Physiological processes influence vulnerability & behaviour
- Discrete neural circuits involved in different stages of addiction
What are the problems with the medical model?
- Medical treatment effectively reduce harm but are less effective in promoting abstinence
- Treatments do not exist for many addictive behaviours
Describe Personality Models?
- Primary causal factor is individual as addiction due to abnormal personality
- Poor impulse control, low self-esteem, inability to cope with stress, egocentricity, manipulative traits, need for control & power
- Resolution requires restructuring of personality, agent of change is psychiatry
Describe Behavioural Models?
- Conditioning is the process of behaviour modification whereby an individual comes to associate a desired behaviour with a previous unrelated stimuli
- Substance misuse is a learned behaviour, treatment is “relearning new behaviours”
What is the Classical (Pavlovian) Conditioning/ Associated Learning?
Learning by connecting 2 cues, one already elicits a response, the other comes too
What is the Operant (Skinnerian) Conditioning/ Instrumental Learning?
Learning by connecting the consequences of actions with preceding behaviours
Describe the Cognitive Behavioural Model?
- Changes in addictive behaviour occur due to changes in motivation, cognition & appraisal
- Assumption: changing content of cognition & motivation can influence behaviour
Describe controlled/explicit cognitive processing?
- Slow
- Deliberate
- Effortful
- Conscious
- Sequential
Describe automatic/implicit cognitive processing?
- Fast
- Unintentional
- No effort required
- Usually out of awareness
- In parallel
What 2 cognitive processes does addiction influence?
- Attention bias
2. Memory bias
What are the 5 different thinking errors and give examples?
- “Just a treat” - permission giving
- “Only one” - minimisation
- “Haven’t used for a whole week, so why not?” - rationalisation
- “I can use & stay in control” - denial
- “She made me angry so I had to use it” - blaming
Describe the Biopsychosocial Model?
- Concerned with interaction of biological, psycholocial & social factors
- Holistic approach, no factors are dominant
What is Psychological formulation?
Understanding the development & function of substance use for an individual in the context of biopsychosocial model
What is the 3 step methods of assessment?
- Self-report
- Corroboration from other sources
- Objective assessment methods
Describe the 1. Self-report step in assessment?
- Structured clinical interview
- Standard assessment measures (drug, alcohol, cognitive assessment, mental health)
Describe the 3. Objective assessment methods in assessment?
- Drug use: analysis of urine, blood, saliva
- Injecting behaviour: examination of injecting sites
- Dependancy/withdrawal: observation while in withdrawal
- Blood born viruses: blood tests
- General health: full medical history
What are the 6 psychological stages of change (Prochaska & DiClemente)?
- Pre-contemplation
- Contemplation
- Preparation
- Action
- Maintenance
- Relapse
How do kidneys control water excretion?
Changing concentration of ions in the nephron tubule
What is the normal osmolarity of the extracellular fluid when entering the kidney?
300 mOsm/L
What is the osmolarity of extracellular fluid reduced to when it enters the distal convoluted tubule (DCT)?
~ 100 mOsm/L
Why is osmolarilty further reduced in the DCT & collecting ducts?
Reabsorption of sodium chloride
What happens to the DCT & collecting ducts in absence of ADH?
Impermeable to water & tubule fluid becomes more dilute (50 mOsm/L)
What does the failure to reabsorb water & continued reabsorption of ions lead to?
Large volume of dilute urine
What is type of urine is essential for survival?
More concentrated than plasma allowing conservation of water
What is the maximum urine a kidney can make?
1200-1400 mOsm/L which is 3-4x that of plasma
What allows the distal tubules & collecting ducts to become permeable to water?
High level of ADH
What are the 4 factors that contribute to the build up of osmolarity in the medulla?
- Passive absorption of ions in thin ascending limb of Loop of Henle
- Active transport of sodium ions & co-transport of potassium, chloride & other ions out of thick ascending limb of loop of Henle
- Active transport of ions from collecting duct
- Facilitate diffusion of urea from medullary portion of collection ducts into medullary interstitium
What sets up an osmotic imbalance & gradient?
Diffusion of small amounts of water from the medullary tubules into medullary interstitium, far less than reabsorption of ions that occurs there
Describe the different ion transport that can occur in the thin descending limb?
- Impermeable to salt
- Water moves passively
Why does interstitial salt concentration increase as it moves towards hairpin bend?
Both passively & actively moved out of the ascending tubule
Describe the different ion transport that can occur in the thin ascending limb?
- Passive Na+ out of the tubule
- No H2O movement
Describe the different ion transport that can occur in the thick ascending limb?
- Active pumping against Na+ gradient
- No H2O movement
Describe the different ion transport that can occur in the collecting tubule?
H2O can move only if ADH present