Mucosa
innermost tissue layer all nutrients must cross it to enter the blood
submucosa
layer of connective tissue containing blood vessels, lymph vessels, and nerves.
muscularis
2 or 3 layers of smooth muscles responsible for mvoement in GI tract
serosa
outermost layer of the GI tract wallconnective tissue that surrounds and protects other layers
Gastrointestinal tract layers
Digestive System Processes
1) Mechanical Processing and Movement
chewing, mixing, and propelling
Digestive System Processes
2) Secretion
fluid, digestive enzymes, hormones, bile, acid, alkali, mucus are secreted into the GI Tract.
Digestive System Processes?
3) Digestion
contents of lumen are broken down into the smallest absorbable units
Digestive System Processes
4) Absorption
through mucosa into blood or lymph vessels
Digestive System Processes
5) Elimination
Undigested material is eliminated form the body
bolus
food chewed into a mass
peristalsis
propels food down the GI tract by wave like muscle contractionsmainly in esophagus
segmentation
mixes food by muscles contracting and relaxingmainly in small intestine
The mouth
begins digestion-teeth- tongue- saliva
swallowing
delivers food to stomachvoluntary phase: tongue pushes bolus of food into pharynxinvoluntary phase: receptors in pharynx stimulated by presence of food
epiglottis
closes opening to trachea
pharynx
common passage way for air, liquid, and foodparticipates in swallowing
esophagus
connects pharynx to stomachmix of smooth and skeletal muscles
hiatal hernia
when the stomach protrudes through the diaphragm
stomach
food storagedigestionregulates food flowdoes not absorb nutrients
chyme
blended food
How long does it take to empty stomach?
2-6 hours
Stomach wall
small intestine
digestion: adds enzymes and bilebreaksdown carbohydrates, protiens and lipids95% of absorption happens here
How long is the small intestine?
about 11 feet
duodenum
area of most digestion
mucosa adaptations to the small intestine
folds covered with villi and microvilli give more surface area
villi of small intestie
contain blood and lacteal capillaries, which take in small water soluble nutrients and lipids, respectivly.
pancreas
secretes digestive enzymes and sodium bicarbonate
liver
produces bile and emulsifies fats
hepatic protal system
carries nutirent rich blood from the digestive tract for processing (in liver)
gallbladder
stores bilesecretions are sent to the duodenum
How long is the large intestine?
5 feet
Large intestine
absorbs some nutrients and watereliminates wasteNO digestion
Colons
feces
indigestible material, bacteria
defecation reflex
due to stretch as feces enter the rectum
diarrhea
often due to bacteria infectiontoo little water is absorbed
constipation
waste remains too long in th large intestine causeing too much water to be absorbed
lactose intolerance
difficulty in digesting lactose in milk productsDoug
diverticulosis
mucosa sacs protrude through layers of the large intestinemay become inflamed or infected
polyps
non cancerous growth from colon mucosaususally removed because they can become cancerous over time, ie. colon cancer
hepatitis
inflammation of the liverMom's friend
gallstones
too much cholesterol in bile
peptic ulcers
open sores in the stomach or small intestine
crohn's disease
inflammatory disorder that damages the intestinal liningLauren
irritable bowel syndrome
abdominal pain, diarrhea, constipationeffects smooth muscle's ability to move feces through colonBecky
anorexia
excessive dieting and exercise leads to lower weight than the idealParis Hilton
bulimia
binge and purgedamage teeth, rupture stomachLindsy Lohan
urinary system
regulates: water levels, nitrogenous and other solute waste
kidneys
principle organ; filters blood to produce urine
renal cortex
outside layer of the kidney
renal medulla
pyramid shaped muscles; inner layer of kidney
renal pelvis
where urin collects after it is formed
ureters
transprot urine to the bladder by peristalsis
urinary bladder
stores urine
how much urine can the bladder hold?
600-1000mL
urethra
carries urine from body; two sphincters
nephrons
funcitonal unit that produces urine1 million per kidney
tubules
filter fluid and reabsorb needed substances
bowman's / glomerular capsule
surrounds a network of capillaries
glomerulus
blood supply of the nephron; contained inside bowman's capsule
glomerular filtration
based on pressure differencefilters water, and small solutes into glomerular capsulefiltrate is formed
tubular reabsorption
returns most of the water and needed solutes back to the blood
tubular secretion proximal tubules
removes other substances form blood back to tubules
Purpose of tubular secretion in proximal tubules
regulation of chemical levels in bodyexcretion of harmful chemicals
what is secreted?
penicillincocainemary janepesticidespreservativesH ionsammonium
dilute urine
excreting excess water when Anti-diuretic hormone is absent and reabsorption of salt without reabsorption of water
concentrated urine
conserving water due to increased anti-diuretic hormone
micturition reflex
as bladder fills, stretching occurs, and sphincters come into play
kidney stones
minerals in urine crystallize in renal pelviscan be surgically removed or crushed with ultrasonic shock waves
Urinary Tract Infection
presence of microbes in urine or an infection in any part of the urinary system
acute and chronic renal failure
conditions that impair kidney functions temporarily
scrotum
sac, regulates temperature of testes
testes
produce sperm and testosterone
penis
conveys urine and spermerectile tissue; functions in sexual intercourse
seminal vesicles
secretes fructose, seminal fluid
prostate gland
secretes watery alkaline fluid; neutralizes acidic vagina
bulbourethral gland
secretes lubricating mucuscleanses urethra
ovaries
release eggssecrete estrogen and progesterone
eggs are also known as...
an oocytes
oviduct is also known as
fallopian tubeuterine tube
fallopian tube
fringed ends to receive eggis not connected to ovary
uterus
the hallow, pear-shaped organ where fertilized egg grows and develops
endometrium
innermost layer of uterussite where fertilized egg implantssloughs off during menstrual flow
myometrium
smooth muscleexpands during pregnancyconstricts during labor
cervix
opening to the uteruspermits sperm to enter the uterusallows the fetus to exit during birth
vagina
organ of sexual intercoursebirth canal
external genitalia
vulva including labia majora and labia minora
clitoris
female erectile tissue
Breasts include
mammary gland100s of milk producing lobules; ducts; adipose tissuelactation
mammary glands
undergo changes due to hormones at puberty, during and after pregnancy
lactation
milk production, estrogen and progesterone influence
How is Sperm made?
in seminiferous tubules it undergoes cell division by mitosis and meosis
Sperm have how many chromosomes
23 (N)half than normal cells
sequence of sperm development
Spermatogonia 2Nprimary spermatocyte 2Nsecondary spermatocyte Nsermatids Nsperm N
sperm
head containing DNAacrosome with enzymes (tip of head)tail with mitochondria
sperm travel
to epididymisto vas (ductus) deferensejaculatory ducturethra
Testosterone
made by interstitial/Leydig cells between seminiferous tubulescontrols growth and function of male reproductive tissuesstimulates aggression, sexual behavior and secondary sexual characteristics
GnRH, LH & FSH hormones
involved in production and secretion of testosterone
Menstrual Cycle
every 28 daysunder hormone controlbegins at puberty
what two cycles are involved with the menstrual cycle
ovarian cycleuterine cycle
how many primary oocytes is a female born with?
about 1 million, which are stored in the ovary
how many eggs are left come time for puberty for a woman?
only 300,000 (most are absorbed)
What happens each month to primary oocytes?
several begin developmentusually only 1 completes this process
Ovarian Cycle
Immature follicle of 1 oocyte develops, FSH and LH increasezona pellucida around oocyteantrum space develops, some estrogen and progesterone secreted2 oocyte and polar body produced, follicle maturesincreased estrogen causes surge of LH, ovulation occurs--> follicle ruptures to realse 2 oocytecorpus luteum formed from follicle