Exam 4

aerobic respiration

use of oxygen to help completely catabolize fuel molecules inside cells to create ATP

anaerobic fermentation (lactic acid)

incomplete breakdown of glucose inside cells without oxygen to create 2 molecules of ATP

lactic acid fermentation and Cori cycle

recycling of lactic acid back into glucose by liver cells

lactic acid fermentation and Cori cycle cont

lactic acid from anaerobic tissues is carried by the blood to the liver where it is converted into glucose within liver cells

glycolysis

anaerobic process that converts glucose into two molecules of pyruvic acid. also produces 2 ATP and NADH

citric acid cycle

pyruvic acid loses carbon and breathes out as carbon dioxide, turns into acetyl-CoA. acetyl molecule combines with 4 carbon to turn into citric acid. each acetyl molecule goes through cycle twice, producing CO2, NADH, FADH2, and ATP.

electron transport chain

electron carriers FADH2 and NADH imbedded in inner mitochondrial membrane travel across 4 complexes and give off energy to create ATP. at the fifth complex, electrons are pumped to the outside of the membrane where they combine with oxygen to form H2O

catabolism of lipids

triglycerides are broken down by hydrolysis into 1 glycerol molecule and 3 fatty acids

catabolism of glycerol

glycerol is 3-carbon molecule that converts to pyruvate by enzymes in cytoplasm. if sufficient oxygen is present within cell, pyruvate can be converted to acetyl-CoA and enter citric acid cycle

catabolism of fatty acids

beta-oxidation: chain is broken into 2-carbom acetic acid fragments, which can be converted to acetyl-CoA

how many acetyl-CoA molecules are produced from beta-oxidation of a single 18-carbon fatty acid

9

how many ATP produced from complete beta-oxidation of 18-carbon fatty acid

120

why not just use lipids instead of glucose/carbs?

neurons cannot metabolize fats

energy and nutrient balance during post-absorptive state

digested nutrients are not being absorbed from digestive tract, metabolic activity is focused on mobilizing energy reserves and maintaining normal blood glucose levels

catabolism of proteins

amino acids are used very infrequently for energy due to proteins being more difficult to catabolize, used for building body proteins, and one of the byproducts of protein catabolism is ammonia (toxic)

lipid metabolism during post-absorptive state

cortisol and glucagon stimulate lipid mobilization

cortisol stimulates lipid catabolism in all tissues except neurons

lipids can be converted to ketone bodies by liver cells and released in the blood for energy

gluconeogenesis during post-absorptive state

liver acts to stabilize blood glucose by breaking down glycogen reserves and creating new glucose molecules from amino acids and lipids

this maintains normal blood sugar for neurons to burn energy

protein metabolism during post-absorptive state

cortisol stimulates catabolism of tissue proteins

amino acids can be used by liver cells to make new glucose molecules or converted to ketone bodies and released in the blood for energy

kidney functions

removes substances from the blood to form urine including metabolic waste products, some toxins, excess water, excess hormones, and excess electrolytes

modifies blood chemistry and quality by regulating blood cell production, blood volume, blood pressure, blood pH, and blood electrolyte concentration

urine removal route

renal calyx - renal pelvis - ureter - urinary bladder - urethra - outside of body

nephron function

functional unit of kidney

carry out actual removal of substances from the blood to form urine

concentrate urine by reabsorbing water

1.3 million in kidney

filtration

occurs in renal corpuscle

plasma is filtered from glomerular capillaries through filtration membrane made from podocytes

this membrane surrounds glomerular capillaries and allows plasma to be pushed through

fluid that is filtered into proximal convoluted tubule is called filtrate

reabsorption

substances move from lumen of nephron tubule out into peritubular capillaries

secretion

opposite of reabsorption

substances move from peritubular capillaries into nephron tubules for excretion via urine

substances in the last portion of collecting duct are excreted via ureters, bladder, and urethra

renal corpuscle (glomerular capsule and glomerulus) location

cortex of kidney

proximal convoluted tubule location

cortex of kidney

distal convoluted tubule location

cortex of kidney

nephron loop location

start in cortex, dip into medulla of kidney

collecting ducts location

start in cortex, dip into medulla of kidney

proximal convoluted tubule

reabsorbs most contents of filtrate

reabsorbs 100% of organic nutrients

reabsorbs sodium and chlorine

passive reabsorption of water

secretion of hydrogen, ammonium, and creatinine

descending limb of loop of Henle

15% filtrate reabsorbed

water diffuses out bc medulla very salty

concentrates urine by removing water

wall is very permeable to water

ascending limb of loop of Henle

reabsorption of sodium and chlorine but water CANNOT follow bc of tubule impermeability

vasa recta

special capillaries that control concentration gradient of medulla

distal convoluted tubule and collecting duct

reabsorption is variable due to hormonal control

ADH

makes cells lining distal convoluted tubule and collecting duct more permeable to water to increase reabsorption

aldosterone

increases rate of sodium absorption (therefore chlorine and water) from DCT and collecting duct

ANP

does opposite of ADH and aldosterone

renin-angiotensin system

stimulates increased aldosterone and ADH secretion

nephron secretion

is the opposite process of nephron reabsorption

secreted substances move from peritubular capillaries into lumen of nephron tubules

proximal convoluted tubule secretion

hydrogen, ammonia, creatinine, some drugs and toxins

distal convoluted tubule secretion

hydrogen, ammonia, creatinine, some drugs and toxins

sodium and potassium are secreted depending on aldosterone levels

collecting duct secretion

hydrogen or bicarbonate can be secreted to help maintain proper pH balance

generally more hydrogen, unless in alkalosis

location of juxtaglomerular complex

wedge of cells between glomerulus, distal convoluted tubule cells, and afferent and efferent arterioles

juxtaglomerular complex function

monitor blood pressure and oxygen levels of blood

if oxygen is low, secretes more EPO

if blood pressure is low, secretes more renin

normal pH range

7.35-7.45

acidosis

pH less than 7.35

too many hydrogen ions present in the blood plasma and interstitial fluid

alkalosis

pH greater than 7.45

too few hydrogen ions present in the blood plasma and interstitial fluid

how can kidneys manipulate carbonic acid/bicarb equation to help correct pH

secrete or absorb more hydrogen ions or bicarb ions as necessary

how can lungs manipulate carbonic acid/bicarb equation to help correct pH

lungs can breathe slower/shallower or faster/deeper

exhaling CO2 removes hydrogen ions

compensation

corrections in the body pH by the kidneys and the lungs

acid-base imbalances

respiratory acidosis, respiratory alkalosis, metabolic acidosis, metabolic alkalosis

respiratory acidosis

respiratory system unable to remove CO2

respiratory acidosis correction

kidneys would secrete hydrogen ions at higher rate and reabsorb bicarbonate ions at higher rate

metabolic acidosis

excess production of acidic substances in the body such as lactic acid or ketones

decreased ability of kidneys to eliminate hydrogen ions in urine

loss of large amounts of bicarbonate from body

metabolic acidosis correction

respiratory system would breathe faster/deeper to exhale more CO2 and thus remove excess hydrogen ions

respiratory alkalosis

eliminates too much CO2 from body

metabolic alkalosis

rapid elimination of H ions from body during severe vomiting or overconsumption of alkaline

metabolic alkalosis correction

breathe slower/shallower to exhale less CO2 and generate H

kidneys would reabsorb H at higher rate and secrete bicarb at higher rate

mitosis

produce 2 genetically same daughter cells

meiosis

reduces cell chromosomes by half, produce 4 haploid/gamete cells

oogenesis

one cell with 46 chromosomes goes through mitosis, divides into polar bodies and one daughter cell, then meiosis to polar bodies and one oocyte

oogenesis location

ovarian follicles

spermatogenesis

goes through mitosis and creates identical daughter cells, then meiosis to create 4 haploid

spermatogenesis location

seminiferous tubules of testes

division of cytoplasm during oogenesis is unequal

acts as nutrient source for pre-embryo

fertilization location

fallopian tube

testicles location

inside scrotum, produce sperm and testosterone

testosterone production

Leydig’s cells surrounding seminiferous tubules in testes

ejaculatory duct

tube that delivers sperm from vas deferens to seminal fluid from seminal glands into urethra

normal ejaculation

2-5 mL (20-100 million sperm per mL)

dartos muscle

layer of smooth muscle under skin of scrotum that contracts and shrinks scrotum to pull testes closer to the body

cremaster muscle

same function as dartos muscle

sperm formation

lose cytoplasm

develop head, midpiece, tail (flagellum)

develops acrosome (enzyme cap for fertilization)

fertilization

sperm penetrates egg

23 chromosomes from sperm combine with 23 from egg to form zygote

erection

sensory and psychic stimuli trigger parasympathetic nervous system

blood flow to corpora cavernosa and spongiosum increases, increase in hydrostatic pressure causes penis to become erect

emission

discharge of semen into urethra (stimulated by parasympathetic)

ejaculation

forceful expulsion of semen from urethra

caused by rhythmic contractions of smooth muscle in urethra wall and skeletal muscle around base of penis

male reproductive gonadotropin-releasing hormone (Gn-RH)

released from hypothalamus and stimulates secretion of luteinizing hormone and follicle stimulating hormone from pituitary

male reproductive luteinizing hormone

causes interstitial cells of testes to secrete testosterone

male reproductive follicle stimulating hormone

promotes spermatogenesis within seminiferous tubules

effects of testosterone

promotes development and maintenance of male reproductive organs, secondary sex characteristics

promotes spermatogenesis

inhibits GnRH, LH, and FSH through negative feedback

stimulates male sex drive

female reproductive system

ovaries, fallopian tubes, uterus, vagina, external genitalia, mammary glands

ovaries

outer portion is made of dense connective tissue and contains developing follicles (each follicle contains single oocyte that will divide by meiosis)

follicle development

begins during fetal development

developing fetus can possess up to 5 million oogonia (cells that undergo meiosis to form egg)

by birth, many oogonia have degenerated and those remaining have started meiosis (primary oocytes)

about 2 million oocytes at birth

primary oocytes

surrounded by a single layer of flat cells called primordial follicles

by puberty, about 350,000 primordial follicles remain, only 400 will continue to develop

what hormone stimulates follicles to develop

follicle stimulating hormone from anterior pituitary gland

stages of follicle development

primordial follicle - primary follicle - secondary follicle - tertiary follicle - ovulation

ovulation

follicle matures, swells, ruptures, forcing oocyte out into peritoneal cavity

oocyte usually comes into immediate contact with fimbriae that sweep oocyte into fallopian tube

second meiotic division won’t continue unless what happens (ovulation)

sperm fertilizes oocyte

after ovulation

remaining cells of the follicle become corpus luteum which secretes progesterone

progesterone promotes growth and maintenance of inner lining of uterus

if pregnancy occurs

implanted embryo produces human chorionic gonadotropin (HCG) which maintains corpus luteum, allowing it to produce more progesterone, maintaining the endometrium

if pregnancy does not occur

corpus luteum degrades, progesterone decreases, endometrium sloughs

fallopian tubes

one oviduct associated with each ovary

proximal end of tube opens into peritoneal cavity

opening of oviduct surrounded by fimbriae

uterus

size and shape upside down pear

lower portion is cervix

inner cavity connected to vagina via cervical canal

layers of uterine wall

perimetrium - outer layer

myometrium - smooth muscle inner layer

endometrium - lines lumen, simple columnar epithelium, changes in thickness during cycle

2 layers vagina

outer muscular layer - smooth muscle many elastic fibers

inner mucous membrane - stratified squamous epithelium

vestibule

space into which vagina and urethra open

labia minora

thin folds of skin which surround the vestibule

clitoris

erectile tissue possesses high concentration of sensory receptors, becomes erect during arousal

vestibular glands

produce fluid to maintain moistness