Unit 3 Flashcards
Function of bone
- Support
- Movement
- Protection
- Mineral storage
Osteon
Structural unit of bone–a central canal surrounded by concentric circles of bone cells
Osteocytes
Bone cells
Osteoblast
Bone forming cell, mature into osteocytes
Epiphyseal plate
Layer of cartilage separating the shaft and the end of a bone. Cartilage cells in the plate divide, lengthening and increasing the diameter of the bone. Also called the growth plate.
Describe the formation of bone in a fetus.
- A cartilaginous model of the bone is formed.
- Osteoblasts form bone around the shaft of the model.
- The shaft begins to hollow and spongy bone replaces the cartilage.
- Bone begins to form in the center of the ends of the bone.
- Cartilage remains only on the ends of the bone and in the growth plate.
The functional units of compact bone.
Osteons
How does bone grow in childhood?
Cartilage cells in the growth plates divide when signaled by sex hormones and the extra cartilage is replaced with bone.
Where in a bone is fat stored?
Yellow bone marrow
A condition characterized by a decrease in bone density that causes a weakened bone.
Osteoporosis
What holds two bones together at a joint?
Ligaments
Bone is hardened by which two minerals?
Calcium and phosphorus.
Cells that form bones
Osteoblasts
What hormones are involved in bone growth?
Growth hormone signals liver to release growth factor
Thyroid hormone modifies growth hormone activity to regulate proportion of bone growth.
Sex hormones signal division of cartilage cells in growth plates.
What hormones are involved in the cessation of bone growth at puberty?
Sex hormones (testosterone and estrogen)
Where is growth hormone produced? What are the consequences of too much/too little growth hormone?
Growth hormone is produced in the anterior pituitary gland. Too little GH results in dwarfism. Too much GH results in giantism.
Why are people today taller on average than in the 1700s (assuming same genetic background)?
Nutrition
What hormones are involved in regulating plasma calcium concentration? Why is this regulation critical?
Calcitonin and parathyroid hormone.
Because low levels of plasma calcium concentration can lead to osteoporosis.
What is the role of vitamin D in bone health?
Vitamin D ensures efficient absorption of calcium.
Why is daily exposure to sunlight a good thing?
Sunlight allows our bodies to produce vitamin D.
How many calories are in one gram of protein? carbohydrate? fat?
Protein = 4 calories Carbohydrate = 4 calories Fat = 9 calories
How many excess calories does a person have to eat to gain one pound?
3500 calories.
celiac disease
A condition in which ingestion of gluten causes an autoimmune response. Damaging to villi in the digestive tract, which impairs nutrient absorption.
cholera
Bacterial infection in the small intestine resulting in diarrhea.
amoebic dysentery
Inflammation of the intestine causing diarrhea caused by amoeba.
gastric ulsers
A defect in the lining of the stomach
cirrhosis
An excess accumulation of fat around the liver due to excessive alcohol consumption, an excess of fat in the diet, or genetics.
hepatitis
Inflammation of the liver. Most commonly caused by a virus
polyp
A (usually) asymptomatic growth in the lining of the colon which can grow into colon cancer.
colonoscopy
A diagnostic test performed on the colon to look for polyps. Preventative of colon cancer.
BMI
Body Mass Index. Evaluates body weight relative to height.
Healthy: 18.5-25
Overweight: 25-30
Obese: <30
BMR
Basal Metabolic Rate. The minimum amount of energy needed to keep an awake, resting body alive.
What is the difference between a vitamin and a mineral?
A vitamin is an organic compound which is vital to health but needed in minute amounts.
A mineral is an inorganic compound vital to health. There are seven minerals needed in large doses and twelve needed in trace amounts.
What are the water-soluble vitamins?
What are the fat-soluble vitamins?
Water soluble vitamins: C and the various B vitamins
Fat soluble vitamins: A, D, E, K
What happens to excess amino acids in the body?
They are broken down by the liver.
essential amino acid
The nine amino acids which the body can’t synthesize.
essential fatty acid
Fatty acids which cannot be synthesized by the body. Omega-3 and Omega-6
saturated vs unsaturated fat
Unsaturated fats are liquid at room temperature and are usually from plant sources. Are considered healthier than saturated fats.
Saturated fats are solid at room temperature and are most often from animal sources. Supposedly linked to atherosclerosis.
cholesterol
A type of lipid. Essential in structure of cell membrane. Structural basis of the steroid hormones.
complementary proteins
Two sources of proteins that, when consumed together, provide all the essential amino acids.
malabsorption syndrome
A condition in which nutrients are not properly absorbed in the small intestine.
anorexia
A condition in which the person deliberately self-starves.
bulimia
A condition in which the person binge eats then purges by self-induced vomiting, enemas, laxatives, diuretics or excessive exercise.
GMO
Genetically Modified Organisms. Foods that have been genetically altered to produce a preferred trait. Highly controversial in regards to safety of consumption and effects on the environment, especially because few to no long-term safety studies exist.
What can urinalysis measure?
Abnormal constituents such as glucose, red blood cells, white blood cells which may indicate a health issue. Presence of abnormal levels of substances such as proteins. Presence of some drugs.
What are the three major areas of the kidney?
Renal cortex: outer region
Renal medulla: region enclosed by cortex
Renal pelvis: inner chamber
What are the functions of the kidney?
Produce urine Conserve water Regulate pH Stimulate red blood cell production Transform vit D to active form
How does the kidney help to maintain homeostasis?
They maintain salt and water balance by adjusting concentration of the urine.
What cell structure is shared in the lining of the proximal convoluted tubule and the lining of the small intestine? What is the common function of this cell structure?
Microvilli, which assist in absorption of substances.
What percent of the water that is filtered by the glomerulus is reabsorbed?
99%
What percent of the sodium that is filtered by the glomerulus is reabsorbed?
99%
What percent of the glucose that is filtered by the glomerulus is reabsorbed?
100%
How do diuretic medications help reduce blood pressure?
They increase the excretion of water by decreasing the reabsorption of sodium ions.
What are kidney stones?
Crystalized forms of certain substances (calcium, cystine, uric acid) in the kidney which may be painful if they pass through the kidney into the ureter.
What is metabolic waste?
Substances left over from the excretory processes which can’t be used by the body and must be excreted.
Why is electrolyte balance critical?
Because electrolytes are responsible for important bodily functions.
How does ADH affect the nephron and what is the effect of its action?
ADH regulates the amount of water reabsorbed by the collecting ducts. Increase in ADH results in increased water returned to the blood, which results in higher blood pressure.
How are the effects of atrial natriuretic hormone different from those of ADH and aldosterone?
ANH DECREASES the reabsorption of sodium ions. (Decreasing BP)
Aldosterone INCREASES the reabsorption of sodium ions. (Increasing BP)
ADH INCREASES reabsorption of water in the collecting ducts.
How is alcohol metabolized?
70% small intestine
20% stomach
10% excreted directly through urine/breath/sweat
Why does a breath sample indicate whether or not someone has consumed too much alcohol?
Because a portion of consumed alcohol is excreted directly through the breath.
What are the short term effects of heavy alcohol consumption or binge drinking?
Vomiting, impaired respiratory function, unconsciousness, coma.
What are the long term effects of excessive alcohol consumption?
Increased risk of cancer, liver damage, damage to the heart and blood vessels.
What is a possible serious complication of an untreated urinary tract infection?
Kidney infection
What are possible consequences of kidney failure?
Acidosis (decrease in blood pH) Anemia (low red blood cell count) Edema (fluid build up in tissues) Hypertension (high blood pressure) Accumulation of nitrogen waste in blood
May require kidney transplant or dialysis.
ureter (description and function)
Transports urine from the kidneys to the bladder.
urethra (description and function)
Transports urine from the bladder to outside of the body.
kidney (description and function)
Main organs of the urinary system.
Functions: Produce urine Conserve water Regulate pH Stimulate red blood cell production Transform vit D to active form
bladder (description and function)
Muscular, expandable organ which stores urine.
nephron (description and function)
Microscopic functional units of the kidneys. Consists of renal corpuscle and renal tubule. Three functions: glomerular filtration, tubular reabsorption, tubular secretion
glomerulus (description and function)
A group of capillaries housed within the glomerular (Bowman’s) capsule where fluid is filtered from the blood.
Bowman’s capsule (description and function)
A cuplike structure which houses the glomerulus.
Loop of Henle (description and function)
Middle section of the renal tubule, placed in between the proximal and distal convoluted tubules
collecting duct (description and function)
Collects waste products from distal convoluted tubules in many nephrons and adjusts the concentration of urine by opening/closing aquaporins (water channels) before draining into the renal pelvis.
proximal convoluted tubule
First section of the renal tubule.
Nearest the glomerular capsule.
Contains microvilli which reabsorb useful materials from the filtrate and returns them to the blood.
distal convoluted tubule
Last section of the renal tubule.
Farthest from the glomerular capsule.
Has few microvilli, empties into collecting duct with the distal convoluted tubules of many other nephrons.
tubular reabsorption
Process of collecting water and solutes from the filtrate as it passes through the proximal convoluted tubule and returning these to the blood.
tubular secretion
Process of removal of waste and excess ions from blood by secreting these into the tubules and collecting ducts. Location of pH adjustments.
aquaporins
Water channels within the collecting duct which allow for adjustment of concentration of urine.
diabetes insipidus
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diabetes mellitus
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insulin
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glucagon
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pancreatic islet cells
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What is the effect of insulin?
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What is the effect of glucagon?
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Which hormone (insulin/glucagon) dominates in the fed state?
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What is the primary physiological deficit in type 1 diabetes mellitus?
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What is the primary physiological deficit in type 2 diabetes mellitus?
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How are treatment choices affected by the differences between type 1 & type 2 diabetes?
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Why is blood sugar high in untreated diabetics?
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Why do diabetics often excrete glucose in their urine?
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What is the A1C test and why is it used in diabetics?
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How can you decrease your risk of type 2 diabetes?
Healthy diet and regular exercise.
breech birth
A birth in which the baby comes out bottom first.
parturition
Birth
lactation
The production and ejection of milk from the mammary glands.
prolactin
Hormone which stimulates the production of breast milk. Is stimulated by infant sucking on the breast.
oxytoxin
The hormone released by the posterior pituitary gland that stimulates uterine contractions and milk ejection.
zygote
The first cell of a new individual, resulting from the joining of egg and sperm.
gamete
A reproductive cell which contains one copy of each chromosome (sperm or egg). When combined with another gamete, it becomes a zygote.
oocyte
An immature egg cell which divides from the primary oocyte into the secondary oocyte
spermatocyte
A sperm cell precursor formed in the seminiferous tubules.
seminiferous tubules
Area within testes which produces inhibin, a hormone which inhibits FSH secretion and thereby decreases sperm production and testosterone production.
Leydig cells
Interstitial cells next to the seminiferous tubules which produce testosterone in the presence of LH.
Epidiymis
One of a pair of ducts in which sperm are stored and matured.
vas deferens
One of a pair of ducts that transport sperm from the epididymis to the urethra.
urethra
A tube that transports semen and urine.
prostate gland
A gland that produces alkaline secretions that activate sperm and reduce the acidity of the male and female reproductive systems.
seminal vesicles
Glands that produce secretions that make up the bulk of semen.
bulbourethral glands
Glands that produce secretions just before ejaculation which lubricate and may rinse urine from urethra.
fallopian tubes (oviduct)
Conduct the egg or embryo towards the uterus, usually the site of fertilization.
uterus
The pear-shaped organ which houses and nourishes the developing baby until birth.
vagina
The muscular tube which receives the penis during intercourse, also the birth canal
ovary
One of two glands which produces eggs and sex hormones (estrogen and progesterone)
testis
One of two reproductive organs (gonads) that produces sperm and sex hormones (testosterone)
penis
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follicular phase
Generally days 1-13 of the menstrual cycle.
Follicle develops due to FSH
Follicle cells produce estrogen.
luteal phase
Generally days 15-28 of the menstrual cycle.
The corpus luteum forms, secretes estrogen and progesterone, then degenerates causing estrogen/progesterone levels to decline.
corpus luteum
Endocrine structure in the ovary formed by the outer sphere of the follicle. Produces estrogen and progesterone. Degrades unless pregnancy is achieved.
endometrium
Lining of the uterus which nourishes embryo if pregnancy occurs. If pregnancy does not occur, it is shed as menstrual flow.
myometrium
Middle layer of uterine wall consisting mostly of smooth muscle.
pap smear
Preventative test to look for signs of abnormal cells in the cervix which may develop into cervical cancer.
HPV
Human papaloma virus, can cause cervical cancer.
gonorrhea
An STD which can cause abnormal discharge, pain during urination or bowel movements, and sterility.
syphilis
An STD which causes cancre at the site of contact, rash, flu like symptoms, lesions on skin and internal organs and eventually blindness, brain damage, heart disease.
chlamydia
An STD which often shows no symptoms, can cause long term reproductive consequences.
capacitation
Next to last step of maturing spermatazoa, happens in the uterus .
zona pellucida
Outer membrane of egg.
monozygotic
Two babies growing from one zygote, identical twins
dizygotic
Two babies growing from two zygotes, fraternal Twins
blastocyst
A ball of cells with an inner fluid-filled cavity which implants into the uterus and develops placenta.
gastrulation
H
ectopic
A pregnancy in which the embryo implants in a location other than the uterus, most often in the Fallopian tubes.
placenta
Functions
- support of fetus (nourishes, carries waste, maintains fluid balance)
- maternal immune suppression
- hormone production
human chorionic gonadotropin
Maintains the corpus luteum until the placenta begins to produce estrogen and progesterone.
What is characteristic of the release of the hormones produced by the anterior pituitary?
All are modified by stimulus from the hypothalamus.
What is characteristic of the target of many (though not all) of the anterior pituitary hormones?
Many of the targets of hormones released by the AP are other endocrine glands.
What controls the production of sperm?
The testes.
What controls the production of testosterone?
The testes.
Why are men with undescended testicles infertile?
The testes do not remain cooler than the rest of the body when they are undescended, and this decreases sperm production.
How can taking androgen supplements result in infertility? What are two other side effects of androgen supplements?
Increased levels of testosterone signal the body to decrease natural testosterone production.
What triggers ovulation?
Maturation of the follicle.
When in the menstrual cycle does ovulation occur?
Roughly 14 days into a 28-day cycle.
Where is estrogen produced?
In the follicle cells and the corpus luteum within the ovaries.
Where is progesterone produced?
In the corpus luteum within the ovaries.
Explain the feedback regulation of the sex steroids.
FSH and LH from anterior pituitary signal release of estrogen and progesterone in the ovaries, which exert negative feedback on in the anterior pituitary, causing FSH and LH levels to decline, which then decreases levels of estrogen and progesterone. This reduces the inhibition on the anterior pituitary beginning the cycle over.
how does hormonal birth control (for women) work?
They contain synthetic forms of estrogen and progesterone which inhibit release of FSH and LH, without which an egg cannot develop.
Which of the non-abstinence methods of birth control is most effective at also preventing STDs?
Condoms.
For which of the STDs is there an effective vaccine?
HPV
What is one physiological change that can indicate that ovulation has occurred?
A raise in basal temperature or a change in cervical fluid.
Where in the female reproductive tract does fertilization occur?
Fallopian tube
Where does implantation of the egg occur?
Uterus
How long after fertilization does implantation occur?
About 6 days.
Explain the concept of critical period in prenatal development.
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Why should pregnant women be sure that their rubella vaccinations are current?
Rubella infection during pregnancy can cause birth defects.
What is the average length of pregnancy counting from the last menstrual period?
Around 40 weeks.
Birth at ___ weeks is considered premature.
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