EXAM 4 Flashcards
Movement of food from one end of digestive tract to another
Propulsion
include a wave of relaxation of circular muscles in front of the mass of food followed by a wave of contraction behind the mass of food
Peristalsis/ waves
lubricate, liquefy, buffer, digest food. contains large amount of h2o that makes digestion and absorption easier.
secretions
secreted along entire digestive tract, lubricates food and lining of tract (protect epithelial cells)
Mucus
secreted by oral cavity, stomach, small intestine, pancreas
Enzymes
the movement of molecules out of digestive tract and into blood vessels or lymphatic system.
Absorption
is the process of removing waste products of digestion from the body
elimination.
where does elimination occur?
large intestine.
Modification of waste occurs, including reabsorption of water & salts.
Creates semi solid waste, called feces which are eliminated by the process of defecation.
what are the 4 major tunics/layers, from inner to outer?
Mucosa
submucosa
Muscularis
serosa/adventitia
which tunic/ layer is epithelium, stratified squamous in mouth, oropharnx, esophagus & anal canal.
Simple columnar in stomach & intestines ?
mucosa
which tunic/layer has connective tissue with nerves, blood & lymphatic vessels, small glands
submucosa
which tunic/layer has muscle, esophagus also has skeletal muscle
muscularis
which tunic/layer includes connective tissue & simple squamous epithelium ?
serosa
a division of the ANS that controls secretions & movement of digestive system.
The enteric nervous system
Oral cavity is lined with what tissue?
stratified squamous epithelium
Labia (lips) are formed by what tissue?
Orbicularis oris muscle & connective tissue
What is the largest muscular organ in oral cavity?
Tongue
What divides the tongue?
Terminal sulcus divides it into , body and root.
There are two different dental arches in the mouth.
Maxillary and mandibular
Each tooth includes
Crown, neck, and root.
Nerves & vessels enter & exit pulp cavity in teeth through
apical foramen
What surrounds pulp cavity? calcified, living, cellular tissue.
Dentin
What protects tooth from abrasion & acids?
Enamel. covers dentin in crown.
What helps anchor tooth and covers dentin in root ?
cementum.
What is a breakdown of enamel by bacterial acids living on sugars from food?
Dental caries. enamel is non living and cannot repair itself so it requires a dental filling.
What may be required to remove pulp?
root canal
Inflammation of gingiva, often due to food accumlation in crevices
Gingivitis, can lead to periodontal disease. May result in tooth loos and halitosis.
What are the muscle involved in mastication?
Temporalis, masseter
3 salivary glands
Parotid, submandibular, and sublingual.
What protects and contain lysozyme, antibodies, and antibacterial to wash bacteria away?
Saliva
Names of sphincter of esophagus
Has an Upper esophageal sphincter, & a lower esophageal sphincter
Structures that food will pass by through the digestive tract
- Oral cavity
- Pharnyx
- Esophagus
- Stomach
- Small intestine, duodenun, jejunum , ilem
- Large intestine , cecum, colon, rectum, anal, canal, anus
In stomach, submucosa & mucosa are folded into ?
Rugae, which disappear as stomach volume increases
What phase use peristaltic waves to move food down esophagus to stomach?
Esophageal phase
in stomach, mucosa lining is simple columnar epithelium that forms invaginations called
gastric pits, which are openings for gastric glands that secrete acids.
IN stomach, there are 5 types of stomach epithelial cells called
- surface mucous cells - on surface around gastric pits, produce alkaline mucous, protects stomach wall from acid.
- Mucous neck cells- produce mucous, deepest portions of gastric pit near openings to gastric glands.
- Parietal cells- produce HCI & intrinsic factor
- Chief cells- produce pepsinogen & gastric lipase
- Enteroendocrine cells- produce regulatory hormones that influence secretion or motility.
Once food enters stomach, it is mixed with stomach secretions to form what?
Chyme
What do secretions include?
Mucus- viscous alkaline; protects stomach wall from acidic chyme & digestive enzymes
Intrinsic factor - by parietal cells, binds with Vit B12, making it more readily absorbed by ileum.
HCI- by parietal cells- makes stomach acidic
Digestive enzymes- such as pepsinogen & gastric lipase by chief cells.
What does HCI do?
Kills bacteria
denaturing proteins so proteolytic enzymes can reach internal peptide bonds
provides optimal pH for activation & function of pepsin
stops carbohydrate digestion (inactivates salivary amylase)
What do chief cells secrete?
Pepsinogen
Where is pepsinogen packed & released?
Into the lumen of stomach via exocytosis.
HCI & previously formed pepsin molecules convert pepsinogen to what?
pepsin
When is pepsin most effective ?
effective at low pH levels.
Muscular contractions
mixing waves - occur every 20 sec, more fluid part pushed from body to stomach towards pyloric sphincter.
Peristaltic waves- less frequent, more powerful. Can force liquified chyme towards & through pyloric sphincter.
Small intestine include
Duodenum - shortest, secretions from liver & pancreas enter here. Functions in absorption of nutrients & water.
Jejunum- absorption of nutrients & water
Iluem
2 small projections of duodenum
minor duodenal papilla- opening of accessory pancreatic duct
Major duodenal papilla - common opening of bile duct & pancreatic duct
Ileum contains lymphatic nodules called
Peyer’s patches.
initiate immune responses against ingested microorganisms.
Ileum connects to large intestine at
Ileocecal junction
** Ring of smooth muscle, ileocecal ileocecal sphincter ,& valve, ileocecal valve achieve one-way movement of
contents
ileum
histology of small intestine
circular folds- formed by mucosa & submucosa
vili- projections of mucosa
microvilli- cytoplasmic extensions of epithelial cells
epithelial cell are produced within tubular invaginations of the mucosa.
Absorptive & goblet cells migrate to surface of villi
granular & endocrine cells remain in bottom of gland.
submucosa of duodenum contains tubular brunner’s glands or duodenal glands. protective:secrete alkaline fluuid that contains mucin.
examples of hormones release by duodenum include;
Secretin
released is stimulated by acidic chyme entering duodenum
secretory effects- decreases gastric secretions & stimulates pancreatic & bile secretions high in HCO3
motility effects- decreases gastric motility
Cholecystokinin (CCK)
Release is stimulated by fatty acids & peptides in duodenum
Secretory effects- stimulates pancreatic secretions high in digestive enzymes & release of bile into duodenum
Motility effects- strongly decreases gastric motility.
Enzymes of small intestine
Enzyme: many bound to absorptive cell microvilli membranes called brush border enzymes.
include:
disaccharidases- break down disaccharidases into monosaccharides.
peptidases- hydrolyze peptide bonds between small chains of amino acids
large surface area brings enzymes into contact with chyme.
after breakdown ,small molecules are absorbed through microvilli
then molecules enter circulatory or lymphatic systems.
movement in small intetsine
segmental contractions- mix
Peristaltic contractions- primary propel.
distension of small intestine, as well as chemical content of chyme, increase smooth muscle contractions.
Relaxation of ileocecal sphincter allows chyme to pass into large intestine.
In large intestine, chyme is converted into
feces (poop).
involves absorption of water, vitamins & salts, secretion of mucus, microorganisms.
begins at ileocecal junction, cecum, colon, rectum, anal canal.
Proximal end of large intestine.
sac that extend inferioly below iliocecal junction.
Cecum.
vermiform appendix is attached to cecum
colon of large intestine has 4 parts.
Ascending colon
, transverse colon ,
descending colon,
sigmoid colon
Small lipid-filled connective tissue pouches called omental appendages, are attached, along the outside of the colon.
One important function is synthesis of ?? which is then absorbed in the large intestine
Vitamin K
Segmental mixing movements are infrequent and peristaltic waves move chyme through ascending colon.
Movements IN large intestine
mass movements occur in
transverse & descending colon ( large intestine)
mass movements must be coordinated with relaxation of anal sphincter so what can occur? parasympathetic reflexes usually coordinate.
defecation
voluntary actions that stimulate a defecation reflex includes a inspiration & forceful contraction of abdominal muscles, forces feces into rectum, stretch in walls initiates reflex
Valsalva Maneuver
In liver, L&R lobe is seperated by
falciform ligament
blood flows into liver via
hepatic portal vein and the hepatic artery
flow of bile
L&R haptic ducts unite into common haptic duct
bile can pass into gallbladder via cystic duct.
cystic duct has 2 way flow of bile… exits gallbladder & enters
common bile duct, which joins pancreatic duct at the hepatopancreatic ampulla
hepatopancreatic ampulla empties into duodenum at the major duodenal papilla.
histology of liver
at porta hepatis, connective tissue capsule sends branches into liver, dividing liver into hexagonal hepatic lobules.
each lobule has a portal triad at each corner & a central vein in the center
central vein collects blood as it leaves lobule.
central veins unite to form hepatic veins which exit liver & empty into inf. vena cava
Histology liver pt 2
hepatic cords, made of hepatocytes, functional cells of the liver, which take up nutrients from portal blood.
nutrients are stored, detoxified, or used to make new compounds, then released into hepatic sinusoids, or into bile canaliculi.
hepatic sinusoids are blood channels in spaces between hepatic cords– lined with endothelial cells and hepatic phagocytic cells called kupffer cells.
bile canaliculus is a cleft lumen in between cells of each cord.
flow of blood & bile through liver
- hepatic artery bring oxygenated blood to liver.
- enters porta hepatis
- branches become part of portal triads
- blood enters haptic sinusoids & supplies O2 to hepatocytes - hepatic portal vein carries nutrient rich deoxygenated blood from digestive tract
- blood is hepatic sinusoids picks up processed molecules & waste products from hepatocytes
- sinusoids empty into central veins
- bile is produced by hepatocytes in hepatic cords.
- hepatic duct branches converge to form left & right hepatic ducts
where is bile made ?
liver.
does not contain digestive enzymes
does neutralize stomach acid & emulsify lipids
components of bile
Alkaline solutions that include:
1. bile salts- emulsify lipids– needed for 2. digestion b lipases
3. bile pigments- green/ yellow/ brown contribute to coloration of feces & urine
4. cholesterol
5. lipids
6. lipid soluble hormones
7. lecithin ( mixture of phospholipids)
Does neutralize stomach acid & empulsify lipids.
storage of nutrients
hepatocytes can store nutrients
glucose: can remove glucose from the blood & store in the form of glycogen
helps maintain blood glucose levels within narrow limits
hepatocytes also store lipids, vitamins, copper,
& iron
storage is usually short term & amount fluctuates daily.
processing of nutrients
hepatocytes can convert some ingested nutrients to those that are needed by the body
liver is a major site of what synthesis ?
cholesterol synthesis
functions to store & concentrate bile
Gallbladder
Gallbladder
contractions of smooth muscle in wall of gallbladder cause bile release into small intestine.
stimulated by hormone cholecystokinin (released by duodenum after a meal high in fatty acids & peptides)
gallstones are insoluble aggregates, often including excess cholestrol.
formed in gallbladder but can pass into & block cystic duct (prevent flow of bile) and possibly the pancreatic duct.
includes endocrine & exocrine functions
pancreas
exocrine secretions (pancreatic juices) flow to
small intestine a converging ducts.
merge into main pancreatic duct.
joins common bile duct at hepatopancreatic ampulla.
empties into duodenum at major duodenal papilla
controlled by hepatopancreatic ampullae sphincter.
components of exocrine secretions/ pancreatic juice.
include:
- aqueous component
- rich in bicarbonte ions (HCO3) which neutralizes chyme
- stops pepsin digestion
- required for pancreatic enzymes to function. - enzymatic component includes:
- Pancreatic proteases (proteins)
- lipases (lipids into fatty acids & monoglycerides)
- amylases (polysaccharides)
- deoxyribonucleases(DNA)
- Ribonucleases(RNA)
Types of mixing & propulsive movements
- Swallowing– moves a bolus from oral cavity to esophagus.
- Peristalsis- peristalic waves include a wave of relaxation of circular muscles in front of the mass of food followed by a contraction behind the mass of food.
- Mass movements- contractions that move material in distal large intestine to anus.
Mixing movement of food in a back and forth manner.
- mixing waves - gentle contractions in stomach- churn food with gastric secretions.
- segmental contractions- mix food with digestive secretions in small intestine.
segments of small intestine alternate between contraction & relaxation, spreading material in both directions.
What is the difference between mechanical & chemical digestion ?
Mechanical- chewing breaks large food particles into smaller ones.
mastication & mixing ! (begins process of digestion. Decreases surface area of food. )
Chemical- digestive enzymes break covalent bonds in large organic molecules. enzymatic breakdown.
Ex. Carbs–> monosaccharids
proteins —> amino acids
location for digestion of carbohydrate and major enzymes that digest them
Begins in oral cavity with Salivary amylase
resumes in small intestine with pancreatic amylase
lipid/fat digestion location and major enzymes
lipase enzymes digest lipids into fatty acids & a glycerol
lingual lipase secreted in oral cavity & swallowed with food digest small amount of lipids in stomach.
Gastric Lipase secreted in stomach– also digest small amounts.
most lipids are digested in small intestine by pancreatic lipases.
pancreatic lipases require bile salts.
location for digestion of protein and major enzymes
Digestion of protein begins in stomach with pepsin.
Pancreatic proteases continues protein digestion in small intestine.
digestion is completed by specific peptidases bound to microvilli in small intestine.
anatomy of the kidney
cortex- outer kidney (where fluid from blood begins to be formed into urine)
medulla- inner renal pyramids.
pyramids are made of tubules that process filtrate
pyramids terminate at renal papillar, where urine is passed into a minor calyx
minor calyx, major calyx then renal pelvis
renal pelvis narrows into tube, called the ureter, which take urinary from the kidney to the urinary bladder.
nephron structure
The nephron is the functional unit of the kidney
* ~1 million nephrons/kidney
* Major nephron regions include:
1. Renal corpuscle consisting of:
* Glomerulus- ball of capillaries
* Bowman’s capsule/Glomerular
capsule- surrounds glomerulus, filters
blood
2. Proximal convoluted tubule- returns some
substances to blood
3. Nephron loop (Loop of Henle)- conserves
water & solutes
4. Distal Tubule
* Connects to a collecting duct, which drains
multiple nephrons…
* into a papillary duct, which drains
several collecting ducts, and empties into
a minor calyx
two types of nephrons and the differences between them
Cortical nephrons-
shorter nephron loops,
located mostly in cortex
Juxtamedullary
nephrons- nephron loops
extend deep into medulla 15% of nephrons
locations in the kidney for each part of the nephron
Renal Corpuscle:
Location: Located in the renal cortex, the outer region of the kidney.
Components: The renal corpuscle consists of the glomerulus and Bowman’s capsule.
Proximal Convoluted Tubule (PCT):
Location: The PCT is located in the renal cortex, extending from Bowman’s capsule.
Course: It descends from the renal corpuscle (Bowman’s capsule) and then makes a U-turn to ascend back towards the cortex.
Loop of Henle:
Location: Parts of the loop of Henle are located in both the renal cortex and the renal medulla, the inner region of the kidney.
Descending Limb: Descends from the cortex into the medulla.
Ascending Limb: Ascends from the medulla back into the cortex.
Distal Convoluted Tubule (DCT):
Location: The DCT is located primarily in the renal cortex.
Course: It is situated after the loop of Henle, as the tubule returns to the cortex.
Collecting Duct:
Location: The collecting ducts extend from the cortex through the medulla to the renal papilla, which is the tip of the renal pyramid in the medulla.
flow of filtrate through nephron
Filtrate is formed in the renal corpuscle.
Proximal Convoluted Tubule (PCT): Reabsorption of water and nutrients.
Loop of Henle: Concentration gradient established.
Distal Convoluted Tubule (DCT): Further reabsorption and secretion.
Collecting Duct: Final adjustments and concentration of urine.
Urine exits via the ureter, bladder, and urethra.
flow of blood through kidney To Glomerulus:
- Renal artery
- Segmental arteries (not numbered in image- take blood to portions
of kidney) - Interlobar arteries- pass between pyramids
- Arcuate arteries- arch between cortex & medulla
- Cortical radiate arteries- extend into cortex
- Afferent arterioles
- Glomerular Capillaries
flow of blood through kidney Away from Glomerulus:
- Glomerular capillaries
- Efferent arteriole
- Peritubular capillaries- surround proximal convoluted tubules, distal
convoluted tubules & loop of Henle - Vasa Recta- specialized portions of peritubular capillaries that extend deep
into the medulla of kidney & surround nephron loops & collecting ducts - Cortical radiate vein
- Arcuate vein
- Interlobar vein
- Renal vein
FLOW OF BLOOD THROUGH KIDNEY, CONT.
what is filtration?
creates filtrate, occurs in renal corpuscle.
blood pressure in glomerulus forces fluid & small molecules into bowman’s capsule
what is reabsorption ?
movement of H2O & some molecules back from filtrate into pertubular capillaries.
occurs mostly in PCT, nephron loop, collecting duct
what is secretion?
specialized cells transport solutes from blood to filtrate.
some were not initially passed through the filtration membrane
occurs mostly in DCT.
3 pressure that affect filtration
1) Golmerular capillary pressure- pressure inside glomerular capillaries.
outward pressure- pushes fluid out of blood into glomerular capsule.
2) Capsular hydrostatic pressure- pressure from filtrate in capsular space.
inward pressure- opposes filtration.
(STRONGEST PRESSURE)
3)Blood colloid osmotic pressure- osmotic pressure due to high concentration of proteins in plasma.
inward pressure- opposes filtration.
3 structural components of filtration membrane
1) fenestrated capillaries
- most plasma proteins are too large to pass.
2)basement membrane
-negative charged glycoproteins are present on basement membrane & podocytes.
3) podocytes
Characteristics of the filtration membrane that make it suited for filter the blood
selectivity - allows certain substances to pass through based on their size and charge.
porosity-small molecules pass by easily
permeability- preamable to water, ions, amino acids.
4 mechanisms that regulate glomerular filtration rate & how they affect Glomerular Filtration Rate
1) Myogenic mechanism- smooth muscle in walls of afferent & efferent arterioles can detect stretch
2) Tubuloglomerular feedback- matches filtrate flow past macula dense cells to GFR.
3) hormonal regulation- when mean arterial pressure is low, juxtaglomerular cells secrete the anzyme renin.
4) neuronal regulation- if sympathetic NS stimulation is very high, mean arterial pressure can drop
Name of M/F gametes & gonads
gametogenesis is the production of gametes.
F gamete: Ovum (egg)
M gamete: Sperm
GONADS
F gonads: ovaries
M gonads: testes
of chromosomes present in somatic (body) cells and in gametes.
46 chromosomes present in somatic
gametes have 23
stages of meiosis
meiosis- a special type of cell division specialized for producing gametes. reduces chromosome # by half.
Meiosis I- seperates homologous chromosomes
meiosis II - seperates sister chromatids
inheritance of sex chromosomes (X & Y)
It is important for each sex cell to have half the diploid number of
chromosomes because…
* Fertilization- fusion of two gametes
* Restores the diploid # of chromosomes, 46
* Sex of baby is determined by sperm cell that fertilizes ovum
* If the sperm carries an X sex chromosome, baby is female
* If the sperm carries a Y sex chromosome, baby is male
anatomy of male reproductive system
sperm develop in testes & epididymides
Sperm travel into body cavity
through ducta deferentia & join
ducts from seminal vesicles,
forming ampulla
* Extensions of ampullae called
ejaculatory ducts, pass into
prostate
* Empty into urethra
* Urethra begins in
prostate & continues out
of body wall, through
penis
muscles that alter temperature of the testes
Dartos muscle (smooth muscle)
* Dartos muscle contracts in cold temperatures
* Skin becomes firm, wrinkled, reduces in
size
* Cremaster muscles- extensions of abdominal
muscles into scrotum
* Also contract in cold, pull testes nearer body
* Both muscles relax in warmer temps
* Sperm cells are very temperature-sensitive; do
not develop normally if temperature varies
considerably
accessory organs that contribute to semen and the characteristics of their secretions.
seminal vesicles - Secretions are thick, mucous-like, with
several functions, including:
1. Nourishment of sperm cells- fructose, citric
acid, other nutrients
2. Coagulation of semen- secretions contain
fibrinogen (enables weak coagulation of
semen after ejaculation)
3. Movement of sperm cells- prostaglandins
in secretions stimulate uterine
contractions; helps transport sperm
through F reproductive tract
accessory organs that contribute to semen and the characteristics of their secretions pt 2
Prostate gland - ecretes prostatic fluid which empties into prostatic
urethra:
* Thin, milky, alkaline secretion- helps neutralize
acidic urethra & acidic secretions of testes &
vagina
* Secretions also help with coagulation: contain
clotting factors that convert fibrinogen to fibrin
* Creates sticky mass of semen for a few
minutes after ejaculation
* Then, fibrinolysin (also secreted by
prostate) causes mass to dissolve
* Releases sperm to make their way
through female reproductive tract
accessory organs that contribute to semen and the characteristics of their secretions pt 3
Bulbourethral glands -Compound mucous gland- empties into
spongy urethra
* Alkaline, mucous secretion produced &
released just prior to ejaculation
* 2 major functions:
1. Lubrication: lubricates urethra & provides
small amount of lubrication during
intercourse
2. Neutralizing acidity: Neutralizes acidic fluids
of spongy urethra & reduces vaginal acidity
MALE REPRODUCTIVE SYSTEM
ACCESSORY GLANDS
Accessory glands are exocrine glands that secrete
material into ducts of M reproductive tract
* Include:
* Seminal vesicles
* Prostate gland
* Bulbourethral glands
Erectile tissues of the penis
Penis Has 3 columns of erectile tissue
* Erectile tissue is comprised of connective
tissue & smooth muscle with many sinusoids
that become engorged with blood
* Enables erection- penis enlarges &
becomes firm
* 3 Erectile tissue columns are:
* 2 Corpus Cavernosa (dorsal, lateral sides of
penis)
* 1 Corpus Spongiosum (ventral side of penis)
seminal fluids pass through
Epididymis - where they mature and gain motility
ductus deferens -
ejaculatory duct-
urethra -
Descent of the testes & structures that form as testes descend
Between 7-9 months development, testes move through inguinal canals into scrotum, preceded by the process vaginalis
between birth & childhood superior pat of process vaginalis degenerates & inferior part remains as small closed sac called tunica vaginalis - serous membrane that surrounds most of the testis secretes small amount of fluid allows testes to move without friction in scrotum.
stage of spermatogenesis
Spermatogenesis is sperm development.
begins when primary spermatocytes divide
meiosis 1 results in 2 secondary spermatocytes
meiosis II each secondary spermatocyte divides, seperating sister chromatids.
produce spermatids
each spermaid undergoes spermiogensis to form a mature sperm cell
