Exam 4 Flashcards
What are the 4 tissue layers of the digestive tract, from innermost to outermost?
Mucosa, submucosa, muscularis externa, serosa
What is the mucosa layer of the digestive tract?
The innermost, it lines the lumen and contains MALT for lymphatic function and capillaries for absorption
What is the submucosa layer of the digestive tract?
Loose connective tissue containing blood vessels, lymphatic vessels, and nerves. Mucus-secreting glands dump mucus into the lumen
What are the layers of the muscularis externa of the digestive tract?
Inner circular layer and outer longitudinal layer
What is the inner circular layer of the muscularis externa?
Contains sphincters which regulate the passage of material through the tract
What is the outer longitudinal layer of the muscularis externa?
Motility propels food and residue through the tract
What is the serosa layer of the digestive tract?
Outermost. Areolar tissue
What are dentition?
Teeth
What are the regions of the tooth?
Crown, root, neck (and root canal)
What is the crown of a tooth?
The portion above the gum
What is the root of a tooth?
The portion below the gum
What is the neck of a tooth?
The point where the crown, root, and gum meet
What is a root canal?
A canal leading from the roots to the pulp cavity in the crown
What are the extrinsic salivary glands?
Parotid, submandibular, and sublingual
Components of saliva?
97-99.5% water, salivary amylase, lingual lipase, lysozyme, and IgA
What does salivary amylase do?
It’s an enzyme that begins starch digestion in the mouth
What does lingual lipase do?
Digests fat
What do lysozyme and IgA do?
Enzymes that kill bacteria
What is the blood sugar between and after a meal?
Between - hypoglycemic
After- hyperglycemic
What is the uvula?
Protrusion of the soft palate hanging in the back of the throat
What is the epiglottis?
A flap which covers the trachea during swallowing so food doesn’t enter the airway
What are pharyngeal tonsils?
AKA the adenoids
What are gastric pits?
Filled with parietal cells which produce hydrochloric acid (or HCl) for converting pepsinogen into pepsin, which digests proteins, and intrinsic factor, for absorbing vitamin B12
What is the pathway of G cells of the stomach?
G cells stimulate chief cells, food comes to stomach, elevated pH comes to gastric pits, stimulates G cells as stomach stretches out
Difference between ingestion and digestion?
Ingestion is the intake of food, digestion is the mechanical and chemical breakdown of food into a form usable by the body
What is the difference between mechanical and chemical digestion?
Mechanical physically breaks food down, chemical degrades molecular structure and follows mechanical digestion
What are the 3 main macromolecules?
Carbs, proteins, and fats
What do carbs break down into?
Monosaccharides
What do proteins break down into?
Amino acids
What do fats break down into?
Monoglycerides and fatty acids
What has to be done to polysaccharides?
They have to be broken down into monosaccharides
What are the 3 phases of the gastric process?
Cephalic phase, gastric phase, and intestinal phase
What happens during the cephalic phase of the gastric process?
The stomach controlled by the brain - responds to sight, smell, taste, and thought of food using acetylcholine
What happens during the gastric phase of the gastric process?
Swallowed food and semi-digested protein activate gastric activity because food stretches the stomach
What happens during the intestinal phase of the gastric process?
The stomach controlled by the small intestine. Duodenum responds to arriving chyme and moderates gastric activity via hormones and nervous reflexes
What sphincter separates the large intestine and small intestine?
The ileocecal sphincter
Parts of the large intestine?
Ascending, transverse, and descending
Purpose of HCl?
Converts pepsinogen to pepsin, which comes from chief cells
What do chief cells secrete?
Pepsinogen and intrinsic factor
What does a lack of intrinsic factor cause?
Pernicious anemia
Different regions of the stomach?
Cardia, near tube leading in. Fundus, at top of stomach. Body, the majority. Pyloris, at bottom of stomach
What is mastication?
Chewing
Difference between hard and soft palate?
Hard is anterior. Soft is posterior, contains uvula, and helps retain food in mouth
Digestive organs?
Mouth, pharynx, esophagus, stomach, small intestine, large intestine
Accessory organs of the digestive system?
Teeth, tongue, salivary glands, liver, gallbladder, pancreas
Function of mouth?
Ingestion and chewing and chemical/mechanical digestion
Function of pharynx?
Allows entrance of air from nasal cavity to larynx where swallowing occurs
What is deglutition?
Swallowing
Function of the esophagus?
Brings food into stomach
Function of stomach?
Mechanically break up food particles (using oblique muscle), liquefy food and begin chemical digestion of protein and fat
What is chyme?
Soupy or pasty mixture of semi-digested food in the stomach
Regions of the small intestine?
Duodenum - top
Jejunum - middle
Ileum - bottom
Function of small intestine?
Chemical digestion and nutrient absorption
What is peristalsis?
Movement of contents towards colon
What is segmentation?
Churning and mixing for digestion
Function of large intestine?
Water reabsorption. Squeezes it out to turn the remnants into feces
What are haustral contractions?
Every 30m, they squeeze water out of chyme
What are mass movements?
Occurring 1-3 times a day, peristaltic waves moving food toward the rectum
Teeth function?
Mechanically digest food
Tongue function and makeup?
Manipulation of food. Nonkeratinized stratified squamous epithelium
Salivary glands function?
Helps digest starches and fats and kill bacteria
Liver functions?
Stores food. Breaks down stored glycogen to release glucose into blood between meals. Synthesizes bile. Secretes albumin, lipoproteins, clotting factors, and angiotensinogen into blood
Gallbladder functions?
Stores and concentrates bile
What does bile do?
Aid in fat digestion and absorption
Pancreas function?
Acini release a secretion into the pancreatic duct which is enzymes which digest starch and fat
What is ingestion?
Intake of food
What is digestion?
Mechanical and chemical digestion of food into a form usable by the body
What is absorption?
Uptake of nutrient molecules into epithelial cells of digestive tract, and then blood and lymph. Moves food from the outside of the body to the inside of the body
What is compaction?
Absorbing water and consolidating indigestible residue into feces
What is defecation?
Elimination of feces
What is the lesser omentum?
It attaches the stomach to the liver
What is the greater omentum?
It covers the small intestines like an apron
What nutrients do not require digestion?
Vitamins, free amino acids, minerals, cholesterol, water
A 38-year-old male is upset about his low sperm count and visits a “practitioner” who commonly advertises his miracle cures of sterility. The practitioner is a quack who treats conditions of low sperm count with mega doses of testosterone. Although his patients experience a huge surge in libido, their sperm count is even lower after hormone treatment. Explain the surge in libido and the lower sperm count.
1) Sperm is produced when gonadotropin hormone-releasing hormone stimulates the anterior pituitary to secrete FSH and LH. 2) While it is true that testosterone is a part of the process of sperm production, FSH and LH are also needed in this process. 3) Therefore, prescribing only testosterone will not serve to raise sperm count. 4) It will, however, raise libido as described when on its’ own as this is a function of testosterone. 5) This excess testosterone also reduces the secretion of gonadotropin hormone-releasing hormone, inhibiting the release of FSH and LH, and therefore preventing the production of sperm.
Explain how the 28-day birth-control pill works. How does the pill affect the female menstrual cycle and how does it affect the hormones of the reproductive system?
1) Birth controls have progesterone and estradiol which are taken for 21 days, followed by 1 week of placebo pills with no hormones. 2) The placebo pills trigger breakthrough bleeding due to the drop in hormones. 3) Having higher levels of estrogen and progesterone for 21 days due to the hormonal pills overrides the hormonal cycling that occurs naturally during the menstrual cycle. 4) The pills suppress release of FSH and LH, making the body believe the woman is pregnant and therefore suppressing the menstrual cycle. 5) This prevents ovulation, preventing menstruation as well
Pathway of sperm?
Seminiferous tubules -> epididymis -> vas deferens -> ejaculatory duct -> urethra -> penis
4 divisions of intercourse?
Excitement, plateau, orgasm, resolution
What happens during excitement of a male?
Vasocongestion, erection of penis, myotonia, increase in heart and respiratory rate and blood pressure, bulbourethral glands secrete their fluid
What does bulbourethral gland fluid do?
Lubricate head of penis and reduce acidic environment of the urethra for sperm to survive
What happens during plateau of males and females?
Respiratory rate heart, rate, and blood pressure stay at their raised levels for a bit before orgasm
What happens during orgasm in males?
Emission and expulsion. Emission propels sperm through ducts and glandular secretions are added, expulsion is semen exiting body
What happens during resolution of males and females?
Body returns to pre-excitement state
Function of male reproductive system?
Produce sperm and hormones to introduce gametes into female reproductive tract
What are gametes?
Sex cells
What is an ovum?
Mature egg
What is an oocyte?
Immature egg
Function of female reproductive system?
Produce eggs, receive sperm, provide for union of gametes, harbors fetus, nourishes offspring
What are the gonads?
Primary sex organs. Testes and ovaries. Produce gametes
What are secondary sex organs?
Organs that are also necessary for reproduction
Male secondary sex organs?
Ducts, glands, penis
Female secondary sex organs?
Uterine tubes, uterus, vagina
What are secondary sex characteristics?
Features that distinguish between sexes and play a role in mate attraction
Male secondary sex characteristics?
Facial hair, coarse and visible body hair, muscular physique
Female secondary sex characteristics?
Distribution of body fat, breast enlargement, hairless skin
Sperm is highly…
Motile
What sperm makes males and females?
Male - Y-carrying sperm
Female - X-carrying sperm
Egg contains..
Nutrients for developing embryo
Stages of a baby?
Zygote -> embryo -> fetus -> birth!!!! -> neonate -> infant -> child
What is a zygote?
A fertilized egg formed from male and female gametes’ combination
What happens to the fetus at 5-6 weeks?
Gonads begin to develop
What happens to fetus at 8-9 weeks?
Y chromosome in males starts making testosterone to stimulate development of male anatomy
What are homologous organs?
Ones that develop from the same embryonic structure in males and females. Ex: clitoris is homologous to the penis
Penis structure
1 corpus spongiosum and 2 corpus cavernosa which fill w/ blood during arousal and account for enlargement and erection
What is the scrotum?
A pouch of skin covering the testes and spermatic cord
What is the spermatic cord?
A bundle of fibrous connective tissue containing the vas deferens, blood and lymphatic vessels, and testicular nerve
What are the testes?
They reside in the scrotum and produce sperm
How does the scrotum regulate temperature and why?
Cremaster muscle, dartos muscle, and pampiniform plexus. Because the testes must be about 2 degrees cooler to produce sperm
How does the cremaster muscle regulate temperature of the scrotum?
In cold, it contracts and is held closer to the body for warmth. In heat, it relaxes and suspends testes further from the body
How does the dartos muscle regulate temperature of the scrotum?
Contracts when cold, wrinkling scrotum, holding testes against warm body. Reduces surface area of scrotum, and therefore, the heat loss
How does the pampiniform plexus muscle regulate temperature of the scrotum?
Network of veins, the blood cools
Structures of testes?
Spermatic cord, epididymis, vas deferens, efferent ductule, rete testis
What produces testosterone?
Interstitial cells of testes
What forms the blood-testis barrier?
Gap junctions between sertoli cells
Components of semen?
Fructose, prostaglandins, proseminogelin, clotting enzyme, serine protease
What do seminal vesicles produce?
60% of semen components. Fructose, prostaglandins, proseminogelin
What does the prostate gland produce?
30% of semen components. Clotting enzyme and serine protease
What does GnRH stimulate release of in both males and females?
FSH and LH
What does FSH do in males?
Spermatogenesis
What does LH do in males?
Stimulate interstitial cells to produce testosterone
What does inhibin do?
Suppress FSH output, reducing sperm production without reducing LH and testosterone secretion
What is mitosis?
Making 2 diploid (2n) cells w/ 46 chromosomes
What is meiosis?
Making 4 haploid (1n) cells w/ 23 chromosomes
Do males or females use mitosis?
Only males, but both use meiosis
What is spermiogenesis?
Transformation of spermatids into spermatozoa
Sperm production pathway?
Seminiferous tubules -> rete testis -> efferent ductule -> epididymis -> vas deferens -> spermatic cord
Spermatozoon anatomy?
Head and tail
What is in the head of the spermatozoon?
Nucleus and an acrosome, which has enzymes to penetrate the egg
What is in the tail of the spermatozoon?
The midpiece which has mitochondria
What is coitus/copulation?
Sex
Functions of female reproductive system?
Produces and delivers gametes, provides nutrition and safe harbor for fetal development, gives birth, nourishes infant
What is the external genitalia of a female?
AKA the vulva, includes clitoris, labia minora, labia majora, and mons pubis
What is the clitoris?
An erectile sensory organ that has a prepuce (foreskin) covering it
What is the labia minora?
Hairless folds medial to the labia majora
What is the labia majora?
Hairy thick folds lateral to the labia minora
What is the mons pubis?
Fat with hair over the pubic symphysis
Internal genitalia for a female includes?
Ovaries, uterine tubes, uterus, vagina
What are the ovaries?
They receive blood from 2 arteries (ovarian artery and ovarian branch of uterine artery) and cause ovulation
What is ovulation?
Bursting of follicle and release of egg
What are the uterine tubes?
AKA fallopian tubes, site of fertilization of oocyte
Anatomy of the uterus?
Perimetrium - external serosa
Myometrium - medial muscular layer
Endometrium - inner mucosa layer
What is the endometrium?
Site of attachment during pregnancy and forms maternal part of placenta
What do the breasts contain?
Mammary lands and the nipple
What are mammary glands?
Develop during pregnancy and are active in a lactating breast
What are the nipples?
A sensitive region with a lot of blood capillaries and nerves that trigger milk ejection when an infant nurses
What does FSH do in females?
Produce estrogens
What does LH do in females?
Ovulation
How can you remember FSH and LH in men and women?
They’re opposites. FSH makes estrogen in females, LH makes testosterone in males. LH triggers ovulation in females, FSH triggers sperm production in males
What is oogenesis?
Egg production. Haploid gametes are made via meiosis
What does the sexual cycle include?
Ovarian cycle and menstrual cycle
When does the sexual cycle happen?
When not pregnant
What are the stages of the ovarian cycle?
Follicular phase, ovulation, and luteal phase
Go respond to all of the essay questions
Done
What happens during the follicular phase of the ovarian cycle?
Menstruation occurs during the first few days
What happens during the ovulation phase of the ovarian cycle?
The remainder of the follicle becomes the corpus luteum
What happens during the luteal phase of the ovarian cycle?
Endometrium thickens, corpus luteum secretes estrogen and progesterone and prepares for possibility of pregnancy
If pregnant - HCG
If not pregnant - estradiol and progesterone
What are the stages of the menstrual cycle of the sexual cycle?
Premenstrual phase, menstrual phase, proliferative phase, secretory phase
What happens during the premenstrual phase of the menstrual cycle?
Endometrium degenerates and spiral arteries spasmodically contract
What happens during the menstrual phase of the menstrual cycle?
Discharge of menstrual fluid from vagina
What happens during the proliferative phase of the menstrual cycle?
Endometrium rebuilds
What happens during the secretory phase of the menstrual cycle?
Endometrium keeps thickening in response to progesterone from corpus luteum
What happens during excitement of the female?
Uterus stands and vagina dilates, vasocongestion
What happens during the plateau of the female?
Uterus is erected and vagina constricts penis
What happens during orgasm of the female?
Orgasmic platform contracts rhythmically, uterus exhibits peristaltic contractions
What is the menarche?
The woman’s first ever period
What is the gestation period?
Pregnancy, from conception to childbirth
How is birth predicted?
280 days from first day of last menstrual period
Hormones of pregnancy?
Estrogens, HCG (until corpus luteum degenerates), progesterone
How does the fetus move during gestation?
Into a head-down vertex position
What induces labor?
Stretching of the cervix
What can give women a false sense of labor?
Braxton Hicks contractions
What is parturition?
Process of giving birth
Stages of labor?
Dilation, expulsion, placental stage
What happens during the dilation stage of labor?
It lasts 8-24 hours and water breaks and the vagina dilates to up to 10cm
What happens during the expulsion stage of labor?
Lasts up to 30m, the baby crowns (head enters vagina) and is expelled
What happens during the placental stage of labor?
The uterus contracts and the placenta buckles away and is expelled from the uterus
What hormone stimulates spermatogenesis?
FSH and testosterone
What hormone stimulates production of testosterone?
LH
How can you reduce sperm production without reducing LH and testosterone secretion?
Inhibit FSH
What can inhibit GnRH in men and what happens?
Excess testosterone, and therefore FSH and LH get inhibited
What is fertilization?
Sperm and egg unite in fallopian tube to form zygote
What is implantation?
Egg attaches to endometrium
How many spermatids (and sperm) can 1 spermatogonium make?
4
Describe what hormones the hypothalamus makes in men
It makes GnRH, which targets the anterior pituitary to release FSH and LH. LH makes testosterone, and once testosterone levels are high enough, the hypothalamus stops producing GnRH. FSH makes sperm
What would happen if you injected testosterone (as a male)?
You would shut off the hypothalamus (all of its work is done for it) from releasing GnRH to make FSH and LH, decreasing sperm count
What effect does LH have on the corpus luteum?
Stimulates it, increasing progesterone, which prepares the uterus for pregnancy (or gestation - pro, gest)
When does a female produce all of her eggs?
In the womb. Mitosis of eggs stops at birth
How many functional units does 1 germ cell turn into in males vs females?
1 germ cell turns into 4 sperm in males. 1 germ cell turns into 1 functional egg in females
When does the reproductive cycle happen?
When pregnant
What happens at the beginning of the ovarian cycle, and concurrently, at the beginning of the menstrual cycle?
Ovarian - FSH causes follicle to mature and secrete estrogen
Menstrual - estrogen builds endometrium
Where does the menstrual cycle occur?
In the uterus
What happens halfway into the ovarian cycle, and concurrently in the menstrual cycle?
Ovarian - Spike in LH triggers ovulation and release of progesterone
Menstrual - increase in progesterone continues building up endometrium
What happens from halfway to the end of the ovarian cycle, and concurrently in the menstrual cycle?
Ovarian - LH declines and corpus luteum shrinks and stops releasing progesterone
Menstrual - Progesterone drops and endometrium deteriorates. Spiral organs vasoconstrict and shut off blood flow to uterus, which begins to die and cause menstrual cramps. Afterwards, dead tissue is menstruated out
What is responsible for period cramps?
The spiral organs, which vasoconstrict when the endometrium deteriorates and restrict blood flow to the uterus
What phases deteriorate the uterus?
Premenstrual and menstrual
Explain how the 28-day period cycle works.
Hypothalamus secretes GnRh, stimulating release of LH and FSH. FSH causes estrogen synthesis and LH causes ovulation. Ovulation causes corpus luteum to degenerate and secrete progesterone, but once LH declines, it shrinks and stops secreting progesterone, which makes the endometrium degenerate. Which in turn causes spiral organs to shut off blood flow. And then the dead tissue resulting from that is menstruated out
How does birth control work?
The pill contains estrogen and progesterone. The estrogen causes GnRH to stop being secreted, stopping synthesis of FSH so follicle doesn’t mature, decreasing chances of ovulation. The progesterone suppresses LH synthesis, which is also responsible for triggering ovulation
What takes the place of LH in maintaining the endometrium in pregnant women?
HCG
What phases of the menstrual and ovarian cycles overlap?
Idk
