Digestion, Urinary System And Transport Flashcards
What response is defecation in infants
Involuntary in response to rectal distension which promotes the relation of external sphincter
When is voluntary control usually achieved
Between 18 months and 3 years
What does not pass through the semi-Permeable membrane into filtrate
Platelets
What plays a vital role in the regulation of blood pressure
The kidneys
Is the Urinary system fully developed and functioning at birth
No
What happens in the cephalic phase of digestion
Gastric juices are secreted and the stomach contacts
What is the purpose of villi
To secrete bile
Found in the small intestine
Like adults, in infants, the stimulation to void the bladder is through the stretch exerted on the bladder wall, what approx volume of urine stimulates this need to void in an infant
15 mls
What is metabolised in the liver
Opiods
How large is a new borns stomach at day 1, 1 week, day 3, 1 month
Day 1 - size of a cherry
Day 3 - size of a walnut
1 week - size of an apricot
1 month - size of a large egg
What is the correct order of the flow of filter are through the structure of the nephron
Bowmans capsule Proximal tubule Loop of henle Distal tubule Collecting ducts
What is GFR
glomerular filtrate rate
What has both exocrine and endocrine functions
The pancreas
Approx how many nephrons are in the human kidney
1000000
What’s the main function of the digestive system
To break down complex food molecules into soluble and readily available nutrients
What digestion process does the digestive system
Physical and chemical digestion
What are the 3 phases that control gastric function
Cephalic
Gastric
Intestinal
What is the gastric function
Act to control gastric secretions
Related to quantity and composition of food in the stomach and duodenum
What happens in the cephalic phase
Conditioned reflex to the sight and smell of food
Parasympathetic nervous stimulation
Increased gastric juice secretion and stomach contraction
What happens in the gastric phase
Stimulated by food in the stomach
Release of hormone gastrin
Increases gastric juice secretion
Increases gastric moment
What happened in the intestinal phase
Initiated as food enters duodenum
hormone secretion
Slows gastric mobility and inhibits gastric juice secretion
Acts to delay emptying of stomach, allows through digestion of both stomach and duodenum
Protective functions
How is nutrition and elimination of waste carried out in utero
By the placenta
What is sterile in utero
The gut
Colonisation with bacteria begins immediately after birth and proceeds rapidly throughout the first days of life
What is colostrum in breast feeding
High density, nutrient rich, low volume feed
Purgative effect of gastrointestinal system
Helps clear meconium from the baby’s gut
What are the key properties in breast milk
High in protein Immunoglobulin A Growth factors Oligosaccharides Enzymes
Why does breast milk colonise the intestine with bacteria
The protect against pathogens such as e.coli
What happens to food it the mouth
Broken down by the teeth
Triggers a nervous reflex that causes salivary glands to deliver a water fluid called saliva
What does saliva do to food
Moistens and lubricates the food with the aid of a slipper substance called mucin, making swallowing easier
What happens when amylase is released
Allows the saliva to start the chemical digestion of starches to begin before it hits the stomach
What do the swallowing reflexes do
Allow the food to be moved from the mouth into the oesophagus and the stomach
What happens when the food is in the stomach
Physical and chemical digestion
Continual churning movement of the muscular walls of the stomach which mixed the food with gastric juice
What does pylori sphincter do
Controls the entry of chyme into the first part of the small intestine called the duodenum
What is diffusion
Moving from a high concentration to a low concentration
Doesn’t require energy
Passive process
What is filtration
Passive process
Doesn’t require energy
Force of pressure of small molecules out into the space around that blood vessel
What’s facilitated diffusion
Substances may not be able to pass the cell membrane (insulin)
allows that molecule through the membrane
Doesn’t require energy
Passive process
What is active transport
Use a molecule that generates energy that allows things to move in the opposite direction
What is osmosis
Has a selective permeable membrane that allows some molecules through that are smaller (water) but both bigger (protein) molecules
What does the hydrostatic and osmotic pressure do
Hydrostatic pressure - Pushes out
Osmotic pressure - Pulling in
To maintain fluid balance
What is phagocytosis
Known as cell eating
How molecules get inside cells through vesicles
Requires energy
What organs make up the renal system
Bladder Ureter Urethra Aorta Inferior vena cava Adrenal gland Adrenal vein Kidney Renal vein Renal artery
What are the functions of the urinary system
Filtration Create urine Reabsorption Secretion Homeostasis
What does the kidney filter
Blood
What helps remove acid from blood
Kidneys
What are the 3 processes of forming urine
Filtration
Selective/tubular reabsorption
Tubular Secretion
What’s the function of the renal artery in the kidney
Transports oxygenated blood from the heart and aorta to the kidney for filtration
What’s the function of the renal vein in the kidney
Transports filtered and deoxygenated blood from the kidney to the posterior vena cava and then the heart
What’s the function of the renal column in the kidney
A passageway located between the renal pyramids found in the medulla and used as a space for blood vessel
What is the function of the nephron in the kidney
The physiological unit of the kidney used for filtration of blood and reabsorption and secretion of materials
What’s the function of the capsule in the kidney
The outer membrane that encloses, supports and protects the kidney
What’s the function of the cortex in the kidney
The outer layer of the kidney that contains most of the nephron; main site of filtration, reabsorption and secretion
What’s the function of the medulla in the kidney
Inner core of the kidney, bottom of nephron goes into this area
Salt, water and urea is reabsorbed
What’s the function of the renal pyramid in the kidney
Helping to concentrate salts and reserve water -plays a role is reabsorption process
What’s the function of the renal papilla in the kidney
Urine gets taken from the nephron and into the you’re ureter
Also in conjunction with the calyx
What’s the function of the calyx in the kidney
A collecting sac that transports urine from the papilla to the renal pelvis
What’s the function of the renal pelvis in the kidney
Collects using from all of the calyces and ends up in the ureter
What’s the function of the ureter in the kidney
Transports urine from the renal pelvis to the bladder
What’s does the afferent arteriole do
Transports arterial blood to the glomerulus for filtration
What does the efferent arteriole do
Transports filtered blood from the glomerulus back to the blood stream
What is the glomerulus
The site for blood filtration
What is the proximal convoluted tubule
Aims to reabsorb useful substances (glucose)
What’s the ascending loop of henle
Where water is reabsorbed
What is the distal convoluted tubule
The end of the nephron
The part it’s going to before it’s collected in the collecting duct
How is glomerular filtration assisted
By the difference between the blood pressure in the glomerulus and the pressure in the capsule
What does the hydrostatic pressure do in the glomerulus
Pushes water out
What does osmotic pressure do in the glomerulus
Pull and filter blood back in
What do the Kidneys do
Increase blood pressure
Play a role in water balance by controlling sodium and reabsorption of salt through the kidneys
What is the difference in adults and children in the urinary system
The glomeruli are smaller in adults
The filtration surface related to body weight is similar
The tubules aren’t fully grown at birth and may not pass in the medulla
What happens to the urinary system with ageing
Decline in urinary function
The bladder shrinks with ageing
Urinary retention is common in males
What are the key roles of the digestive system
Salivary glands Liver Gallbladder Pancreas Mouth Pharynx Oesophagus Stomach Small intestine Large intestine Rectum Anus
What’s the role of the salivary glands
Secrete saliva to moisten food particles, helps bind them and begins chemical digestion of carbohydrates
Saliva dissolves food so they can be tasted and cleanses mouth and teeth
What’s the role of the liver
Carbohydrate metabolism - Maintains concentration of blood glucose
Lipid metabolism- oxidising fatty acids, synthesising lipoproteins, phospholipids and cholesterol
What is the role of the gall bladder
Stored bile between meals, reabsorbs water to concentrate bile and contacts to release bile in the small intestine
What’s the role of the pancreas
Secretion of pancreatic juice
Breaks triglyceride molecule into fatty acids and glycerol
What’s the role of the mouth
Mechanically breaks up solid particles into smaller pieces mixing them with saliva
What’s the role of the pharynx
A cavity posterior to the mouth from which the tubular oesophagus leads to the stomach
Important passageways and muscular walls function swallowing
What’s the role of the oesophagus
Food passageway from the pharynx to the stomach
Goes to the stomach on the abdominal side of the diaphragm
What’s the role of the stomach
Receives food from the oesophagus, mixes food with gastric juice, initiates protein digestion, carries on limited absorption and moves food into the small intestine
What’s the role of the small intestine
Receives chyme from the stomach and secretions from the pancreas and liver
Completes digestion in the nutrients of chyme, absorbs products of digestion and transports the residues to the large intestine
What’s the role of the large intestine
Absorbs water and electrolytes from chyme remaining in the elementary canal
Forms and stored faeces
