Final Exam Flashcards
alimentary tract
muscular tube from oral cavity to anus
alimentary tract path
oral cavity, pharynx, esophagus, stomach, small intestines, large intestine
Functions of the digestive system
o Ingestion: entering GI tract
o Propulsion: movement of ingested food
o Mechanical digestion: crushing and shearing the food
o Secretion: release of hormones, enzymes, acids, buffers, and salts by GI epithelium and glands
o Chemical digestion: chemical breakdown of food
o Absorption: movement of nutrients across the GI epithelium into blood and lymphatic vessels
o Defecation: excretion of indigestible materials and metabolic wastes via feces
Visceral peritoneum
covers organ same as serosa
parietal peritoneum
lines surface of abdominal cavity
Mesenteries
keep organs in place
lesser omentum
stabilizes stomach
greater omentum
protects abdominal organs
mesentery proper
stabilizes small intestines
falciform ligament
stabilizes liver
mesocolon
stabilizes the large intestines
Layers of tissue in GI
mucosa, submucosa, muscularis externa, and serosa
muscularis externa
made of 2 layers (circular and longitudinal) regulated by myenteric plexus
serosa
visceral peritoneum
submucosa
layer outside the mucosa, contains: glands, connective tissue, blood and lymphatic vessels
Mucosa
inner most layer (has 3 parts-epithelium: columnar with microvilli, lamina propria: and muscularis mucosae)
Peristalsis
muscle contractions that propel food forward
segmentation
mechanical processing by mixing. Not forward movement
anatomy of oral cavity
lined with oral mucosa and contains accessory organs that turn ingested food into bolus (food mixed with our saliva)
functions of oral cavity
sensory analysis, mechanical digestion, lubrication, chemical digestion
there is no nutrient absorption until:
small intestine
Functions of tongue
mechanical processing, assists with chewing and swallowing, and sensory analysis: taste, temperature, and touch, helps you speak
What is mastication
chewing: mechanical digestion which increases overall surface area of food, allowing for better chemical digestion. 32 teeth
Components of saliva
salivary amylase, lysozyme, IgA, Bicarbonate, and water
functions of saliva
moistening and lubricating the oral cavity and its contents. Dissolving chemicals that stimulate taste receptors and provide sensory information, initiating chemical digestion, deter bacterial growth
3 types of salivary glands
parotid glands, sublingual glands, submandibular glands
parotid glands
secrete watery secretion
sublingual glands
watery and mucus secretion
submandibular glands
mucus secretions
Pharynx
shared passageway with respiratory system
Esophagus
uses muscle peristalsis to move bolus and folds function to accommodate large bolus
two sphincters in esophagus and their function
upper esophageal sphincter and gastroesophageal sphincter: prevent back flow
3 phases of swallowing and what happens in each
o Voluntary (oral) phase: tongue forces bolus into oropharynx
o Pharyngeal phase: the bolus enters the oropharynx. Soft palate and epiglottis seal off nasopharynx and larynx, inhibition of respiratory centers. Controlled by swallowing reflex
o Esophageal phase: bolus enters the esophagus. Peristaltic wave pushes the bolus toward the stomach
Functions of stomach
o Storage of food
o Mechanical digestion: bolus becomes chyme
o Chemical digestion
o Production of intrinsic factor: glycoprotein necessary for vitamin b 12
o No absorption of nutrients
What are gastric pits
stomach mucosa forms deep structures
gastric glands
at the base of gastric pits, and contain hormones and gastric juice.
chief cells
secrete gastric lipase and pepsinogen
parietal cells
secrete intrinsic factor and hydrochloric acid
goblet cells
secrete mucosa
mucous neck cells
secrete mucus
G cells
secrete gastrin
hormone gastrin and its effects
stimulates stomach secretions and contractions
Functions of stomach pH
o Kills microorganisms
o Digests plant cell walls and connective tissues in meat
o Activated pepsin
o Optimal pH for digestive enzymes
3 phases of gastric activity and what happens in each
o Cephalic phase: prepares stomach for food. Causes secretion of gastrin and histamine, which results in increased acid secretion and activity of stomach
o Gastric phase: bolus enters stomach and stretches it. Increase in gastrin and histamine. If stomach becomes too acidic, somatostatin released.
o Intestinal phase: chime enters small intestine. Slow and controlled gastric emptying. Increase production of mucus for protection. Gastric inhibitory peptide: released by small intestine and inhibits the stomach. gastrin: simulates stomach.
3 segments of small intestine
duodenum, jejunum, ileum
what do folds do in the small intestines
Folds increase surface area for absorption
Functions of the small intestine
absorption, propel food forward, completion of chemical digestion
most absorption takes place in
the small intestine
Exocrine cells in the pancreas
secrete pancreatic juice. Delivered to duodenum via the pancreatic duct
pancreatic juice
mixture of enzymes and buffers
pancreatic juice ph and why
7.5-8.8. to balance out the acid from stomach
liver lobules
left, right, caudate, quadrate
what are hepatocytes
liver cells
the direction of blood flow in a lobule
comes in through the portal venule (corners) to the central vein, and will drain into hepatic vein and be taken away from liver. (corners to the center)
7 functions of the liver
Bile production
Nutrient metabolism
Detoxification
Excretion: excretes bilirubin and other substances
Phagocytosis and antigen presentation cells called Kupffer cells
Synthesis of plasma proteins
Absorption and recycling of hormones and antibodies
Bile salts are
the ones that emulsifies lipids (lipids broken into smaller droplets)
bile
(mixture of water, iron, bilirubin, cholesterol, and bile salts)
lipoproteins
how lipids travel around the body
types of lipoproteins, where are they produced, where do they go and what is their composition
Chylomicrons: absorbed/formed in the intestines, goes into lymphatic vessel, which is emptied into blood. Large complexes of triglycerides.
VLDLs: made by liver. Contain lipids and cholesterol. Go to tissues cells that need lipids
LDLs: made by liver. Mainly made of cholesterol. Goes to tissues. “bad cholesterol”
HDLs: returns excess cholesterol to the liver. Removed from tissues. “good cholesterol”
gallbladder functions
stores and concentrates bile
what are gallstones
form as a result of problems with concentrating bile
Large intestine segments
cecum, colon, rectum
Functions of the large intestine
o Absorption of water, electrolytes, bicarbonate and bile salts
o Absorption of vitamins
o Bacteria break down of undigested materials
o Bacteria stimulate the development of the immune system and prevent the growth of pathogenic bacteria
o Production and storage of fecal material
Reproductive functions
o Continuation of species
o Increase genetic diversity through sexual reproduction
o Produce, nourish, store, and transport gametes (reproductive cells)
o Female reproductive system supports and nourishes the developing embryo/fetus
testes
responsible for production of sperm and testosterone
cryptorchidism
one or both testes do not descent by birth.
temp need to be __ in testis
temp needs to be lower in order to produce sperm.
what adjusts distance of testis from body to regulate temp
The cremaster and dartos muscles
Role of scrotal septum
separates testes from one another. Keep infections and tumors isolated
Pampiniform plexus
an extensive network of veins from the testes that surrounds the testicular artery and serves as a countercurrent heat exchanger which removes heat from the descending arterial blood.
Seminiferous tubules
coiled inside testes, for sperm production and hormone secretion
Functions of nurse (Sertoli) cells
surround and support the dividing and maturing spermatocytes
Maintain blood-testis barrier
Promote spermatogenesis and spermiogenesis
Secrete inhibin for feedback control
Secrete ABP which concentrates androgens in seminiferous tubules
Secrete MIF which prevents the development of a female reproductive system
Function of interstitial (Leydig) cells
produce androgens (primarily testosterone)
Spermatogenesis
stem cells that initiate spematogenesis (diploid)
Spermiogenesis
sperm maturation (elongate and shed excess cytoplasm. Acrosome develops)
Anatomy of sperm cell
o Head: nucleus and acrosomal cap
o Middle piece: contains mitocondria
o Tail: flagellum
o No other organelles, no energy reserves
Male hormones
o GnRH: stimulates anterior pituitary to release LH and FSH
o LH: stimulates Leydig (interstitial cells) cells to produce testosterone
o FSH: stimulates Sertoli cells and spermatogenesis
o Testosterone
Testosterone functions
Promotes spermatogenesis and functional maturation of sperm
Influences behavior: sexual libido (desire)
Stimulates protein synthesis, muscle growth, RBC production
Establishes and maintains secondary sex characteristics (facial hair, deeper voice, ect)
Maintains accessory reproductive organs and glands
Role of epididymis
sperm maturation and storage, absorbs and recycles damaged and unused sperm
the pathway of sperm through the ducts from epididymis to outside
ductus deferens, ejaculatory duct, prostatic urethra, membranous urethra, spongy urethra
Components of semen
sperm and fluids
Seminal vesicles secretions
produce seminal fluid: 60% of semen volume. Fructose (provides energy), prostaglandins (cause muscle contraction), fibrinogen (semen clotting), and alkaline environment (neutralize acidic male urethra and activates sperm).
Prostate gland
provides 20-30% semen
what is in the secretions of prostate gland
citrate, prostate specific antigen (dissolves sperm clot), seminalplasmin (antimicrobial)
Bulbourethral glands secretions
produces thick, alkaline mucus that lubricates penis tip and neutralizes urine acids
Ovaries: functions
o Produce oocytes, which develop inside follicles in the ovarian cortex
o Produce and secrete sex hormones (estrogen and progesterone) and inhibin
Ovarian cycle: be able to describe the phases
o Follicular phase: vesicular follicle grows and matures and inside the follicle the primary oocyte divides to give rise to secondary oocyte.
o Ovulation: follicle breaks open and the secondary oocyte is released.
o Luteal phase: corpus luteum forms which produces progesterone. If pregnancy corpus luteum stays for a couple months. If no pregnancy corpus luteum becomes corpus albicans and ceases hormone secretion.
Uterine tubes
know that they have peristalsis, cilia and ovulated oocyte enters the tubes and fertilization happens here
why does the duodenum have mucous glands
Protection from acid coming with chyme
large to small cells in small intestine
plicae, villi, microvilli
Bile functions
emulsifies lipids
Uterus: anatomy
o Fundus: broad superior curvature
o Body (corpus): middle portion
o Cervix: cylindrical inferior end
uterus functions
protects and nourishes ovum implant as it develops
uterus Histology (layers)
perimetrium: myometrium: and endometrium
perimetrium
outer layer, extension of parietal peritoneum
myometrium
middle layer, muscular wall
endometrium
inner glandular mucosa (basal: attacjes to myometrium and functional layer: closest to uterine cavity)
Uterine cycle: be able to describe the 3 phases
o Menses: functional layer is lost. Blood and deteriorated tissue shed.
o Proliferative phase: functional layer regrows stimulated by estrogen
o Secretory phase: functional layer at thickest and it produces secretions called uterine milk. Stimulated by progesterone.
which phases of the uterine cycle overlap with which phases of the ovarian cycle
follicular phase overlaps with menses (early) and proliferative phase (late). Luteal phase overlaps with secretory phase
Female hormones
GnRH, LH, FSH, Estrogens, progesterone
FSH in women
stimulates follicular growth and estrogen production by follicular cells
LH in women
know that spike of LH causes ovulation and later LH drives the formation of corpus luteum, which produces progesterone
Estrogen function
stimulate bone and muscle growth, development of secondary sex characteristics, behavior effects on libido, stimulate growth and repair of the endometrium.
They are the dominant hormones prior to ovulation
Progesterone functions
stimulates the secretory phase of the uterine cycle and is the dominant hormone during the luteal phase (after ovulation); secreted by corpus luteum
Function of inhibin
negative feedback loop
Brush border enzymes
maltase, lactase, sucrase
