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Digestive & Urinary system Jessika Lee P.1 - Coggle Diagram
Digestive & Urinary system Jessika Lee P.1
Major functions of digestive system
take in food
break it down into nutrient molecules
absorb molecules into bloodstream
rid body of any indigestible remains
Digestive processes
ingestion: eating
Propulsion: movement of food through alimentary canal
Mechanical breakdown: includes chewing, mixing food with saliva, churring food in stomach, segmentation
Digestion: series of catabolic stepts that involves enzymes that break down complex food molecules into chemical building blocks
Absorption: passage of digested fragments from lumen of GI tract into blood or lymph
Defaciton: elimination of indigestible substances via anus in form of feces
Major organs of digestive system
organs fall into 2 groups:
Alimentary canal
continuous muscular tube that runs from the mouth to anus
digests food: breaks down into smaller fragments
Absorbs fragments through lining into blood
organs: mouth, pharynx, esophagus, stomach, small intestine, large intestine, anus
Accessory organs:
teeth, gallbladder, tongue, digestive glands: produce secretions that help breakdown food, salivary glands, liver, pancreas
mouth is where food us chewed and mixed with enzyme- containing saliva that begins process of digestion, and swallowing process is initiated
associated organs: mouth, tongue, saliving glands, teeth
Mouth ( oral cavity)
oral orifice us anterior opening
Walls of mouth lined with stratified squamous epithelium
Lips and cheeks
lip composed of fleshy orbicularis oris muscle
cheeks: composed of buccinator muscles
hard palate: formed by palatine bones and palatine processes of maxilla with a midline ridge calle raphe
soft palate: fold formed mostly of skeletal muscle
closes off nasopharynx during swallowing
Tongue
occupies floor of mouth
Functions: gripping, repositioning, mixing of food during chewing
formation of bulus, mixture of food and saliva
initiation of swallowing speech and taste
The pharynx
food passes from mouth into oropharynx and then into larypharonyx
allows passage of food, fluids, and air
external muscle layers consists of two skeletal muscle layers
The esophagus
flat muscular tube that runs from laryngopharynx to stomach
is collapsed when not involved in food propulsion
Stomach
temporary storage tank that starts chemical breakdown of protein digestion
converts blood of food to paste-like chyme
empty stomach has 50 ml volume but can expand to 4l
liver: digestive function is production of bile
bile: fat emulsifier
gallbladder: chief function us storage of bile
pancreas: supplies most of enzymes needed to digest chime, as well as bicarbonate to neutralize stomach acid
The liver
largest gland in the body
consists of 4 primary lobes: right, left, caudale, quandrate
Gallbladder
thin-walled muscular sac on ventral surface of liver
functions to store and concentrate bile by absorbing water and ions
pancreas
exocrine function: productive pancreatic juice
Endocrine function: secretion of insulin and glucagon by pancreatic juices
Major functions of urinary system
uterus: transport urine from kidneys to urinary bladder
urinary bladder: temporary storage reservoir for urine
urethra: transports urine out of body
kidneys a major excretory organ, maintain body's internal environment
Major organs of urinary system
Kidneys maintain body's internal environment
regulares total water volume and total solute concentration in water
regulating ion concentration in ECF
excretes metabolic wastes, toxins, drugs
3 distinct regions: renal cortex, renal medulla, renal pelvis
renal cortex: granular opening superficial region
Renal medulla: deep to cortex, composed of cone-shaped medullary pyramids
renal pelvis: funnel- shaped tube continuous with ureter
Urethra: muscular tube that drains urinary bladder
Urinary bladder: muscular sac for temporary storage of urine
retroperitoneal, on pelvic floor posterior to pubix symbysis
males: prostate inferior ro bladder neck
Females: anterior ro vagina and uterus
urine storage capacity
collapses when empty
rugae appears
expands and rises during filling without rises in internal pressure
Digestive enzymes
Proteases: breaks down proteins, secreted in inactive form to prevent self digestion
Amylase breaks down carbohydrates, made in mouth and pancreas
lipases breaks down lipids, made in the pancreas
nucleases breaks down nucleic acids
Location of digestion and absorption
Small intestine is major organ of digestion and absorption
subdivisions
duodenum: mostly retroperitoneal; 25.0cm long; curves around head of pancreas
jejunum 2.5 long; attached posteriorly by mesentery
ileum: 3.6 long; attached posteriorly by mesentery joints large intestine at ilococeal valeu
chyme from stomach contains partially digested carbohydrates and proteins and undigested fats
takes 3-6 hours in small intestine to absorb all nutrients and water
motility of the small intestine
segmentation: most common motion of small intestine
initiated by intrinsic pacemaker cells
mixes/ shoves contents toward ileocecal valve
intensity altered by long and short reflexes and hormones
parasympathetic increases motility; sympathetic decreases it
between meals
peristalsis increases, initiate by rise in hormone motility in late intestinal phase
male remnants, bacteria, debris, are moved toward large intestine
complete trip takes 2 hours
ileocecal valve control: gastrin increases motility of ileum
Layers of GI tract
Mucosa
tunic layer that lines lumen
Functions: different layers perform 1 or all 3
secretes mucus, digestive enzymes, hormones
absorbs end products of digestion
protects against infectious disease
Submucosa
consists of areolar connective tissue
contains blood and lymphatic vessels, lymphoid follicles, submucosal nerve plexus that supply surrounding GI tract tissues
abundant amount of elastic tissues, help organs regain shape after storing large meal
3.Muscularis Externa
muscle layer responsible for segmentation and peristalsis
contains inner circular muscle layer and outer longitudinal layers
Circular layers thickens in some areas to form sphincters
Serosa
outermost layer, made up of visceral peritoneum
Disorders
Digestive disorders
Chloe cystitis- inflammation of the gall bladder
causes- diet, inflammation, digestive tumors
symptoms- tender abdomen. sweating, nausea
treatment- medication, fasting, antibiotics
GERD- chronic disease that occurs when the sphincter relaxes
causes- frequent acid re flux, obesity, weakened sphincter
symptoms- chest pain, heart burn, dry cough
treatment- over the counter meds, surgery,
IBD- chronic complex intestinal condition that causes inflammation in digestive tract
causes- unknown, possibly genetics
treatment- medication, diet adjustment, fluid replacement surgery
symptoms- fever, cramping, abdominal pain
peptic ulcers- sores that develop in the lining of the stomach
causes- imbalance in gastric juices, stress, smoking
symptoms- heartburn, severe chest pain, nausea
treatment- lifestyle changes, medication, endoscopic surgery
colon disease- polyps growth
causes- diet, age, heredity
symptoms- asymptomatic, change in bowel movement
treatment- none, surgical removal, diet adjustment
urinary diseases
bladder cancer - cells of the bladder grow abnormally
causes- smoking, radiation, diet
symptoms- back pain, pain when you pass urine, pain in lower abdomen
treatment- medication
UTI- abnormal growth of bacteria
causes- sexually active women, pregnant women, menopausal
symptoms- burning with urination, pain in lower pelvic, cloudy urine
treatments- antibiotic pills, cranberry juice or tablets
Kidney stones- dissolved minerals, salts, and stones
causes- poor bladder emptying, too much calcium in urine
symptoms- sharp, cramping pain in back, burning when urinating, intense need to urinate
treatments- medication, surgery
Nephron anatomy and physiology
Renal corpuscle
glomerular- tuft of capillaries composed of fenestrated endothelium
highly porous capillaries
allows for efficient filtrate formation
Glomerular capsule
cup shaped, hollow structure surrounding glomerulus
consists of 2 layers
parietal layer: simple squamous epithelium
visceral layer: clings to glomerular capillaries; branching epithelial podocytes
structural and functional units that forms urine in the kidneys
1 million m=per kidney
2 main parts: renal capsule, renal tubule
Renal tubule is about 3 cm long
consists of single layer of epithelial cells, region has its own unique histology and function
3 major parts
Proximal convoluted tubule- proximal, closest to renal corpuscle
nephron loop
distal convoluted tubule
distal, farthest from renal corpuscle
distal convoluted tubule drains into collecting duct