TTU ZOOL 2403 Final Exam Boros

The kidney...

produces urine

The ureters...

transport urine toward the urinary bladder, smooth muscle tubes, because they are at an angle it prevents back flow of urine, flattens as the bladder is filled with urine

the urinary bladder...

temporarily stores urinne prior to elimination, hollow smooth muscle organ, 1 liter of urine

the urethra...

conducts urine to exterior

process of drinking water

GI tract -> blood -> renal arteries supply kidneys -> become urine

Function of the kidneys P1

excretion- removal of wastes from body fluids in urine

regulation of blood-

- ions control blood Na+, K+, Cl- levels

- pH control blood H+ and HCO3- levels

- pressure and volume control blood fluid volume and thus blood pressure

Functions of the kidneys P2- 3 processes

filtration- of water, ions, nutrients, and waste products from the blood

reabsorption- of most of the water, ions and nutrients back into the blood

excretion- of metabolic wastes into the urine

Where do we constantly lose water?

skin, lungs, and digestive system

How can the kidneys regulate water volume?

because they can concentrate or dilute the urine

Where are the kidneys located and what are they protected by?

either side of the vertebral column, partially protected by the rid cage

Renal cortex

outer portion of the kidney

Renal medulla

inner portion of the kidney that is separated into the renal pyramids and renal columns

Where does the kidney receive blood from

renal artery

Renal artery-

travels between the renal pyramids and renal columns, delivers blood via arterioles to a capillary network called the glomerulus

How does blood exit the kidney?

the renal vein

How many times a day is your entire blood volume filtered through the kidneys?

60 times

What is the kidney composed of?

nephrons and a collecting system

What is a nephron?

where urine production begins, blood is filtered into the nephron

What is the nephron composed of?

renal corpuscle and renal tubule

What is the renal corpuscle composed of?

glomerulus, Bowmans capsule, urinary space

What is the glomerulus?

network of capillaries, receives blood from the Afferent arteriole and blood leaves through the Efferent arteriole

What is Bowmans capsule and what is it composed of?

composed of squamous epithelial cells, sac that surrounds the glomerulus, encloses the urinary space

Where is the urinary space and what does it do?

space between the inner lining of the glomerulus and the outer layer of the capsule, where filtrate collects

Where does filtration of fluid occur?

renal corpuscle

Process of filtration of fluid from blood into the nephron

blood pressure forces H2O and dissolved substances out of the glomerulus into the urinary space, produces a protein free solution called filtrate

three layers of filtration

1. The glomerulus (capillary): endothelial cell layer

2. Middle connective tissue layer

3. Inner lining of the bowman's capsule: epithelial cell layer

What does the glomerular endothelial layer do?

there are pores in this layer that are small enough that they prevent passage of blood cells into the filtrate but they do allow some proteins to get through

What are podocytes?

epithelial cells in the inner lining of Bowmans capsule that surrounds glomerular capillaries

Role of the podocyte layer of the inner lining of Bowman's capsule

filtration slits only allow H2O and dissolved solutes from the blood into the urinary space (no protein in urine)

What leads to kidney disease and kidney failure

the middle connective tissue layer in Bowmans capsule can become clogged with debris

What is the renal tubule?

a long u-shaped tube extending from the cortex into the medulla and back into the cortex. Begins at the renal corpuscle

What is the renal tubule composed of?

proximal convoluted tubule (PCT), loop of henle, distal convoluted tubule (DCT), ends at the collecting duct

What is the wall of the renal tubule composed of?

epithelial cells from squamous to columnar depending on the degree of activity of that portion of the tubule

Functions of the renal tubule

return of filtrate from the nephron back into the blood, reabsorb nutrients from the filtrate and return them to the blood. Reabsorb 90% of water from filtrate

What are pertibular capillaries and vasa recta

the reabsorbed H2O and solutes returns from the filtrate in the tubule. are both are branches of the efferent arteriole (leaves the kidney), drain blood into the venous system and back to the heart

What is the proximal convoluted tubule (PCT)?

the first segment of the renal tubule, 60-70% of the filtrate is reabsorbed here, microvilli increase surface area for reabsorption

What is the loop of henle? What is it composed of?

middle segment of the renal tubule. Composed of a descending limb (fluid flows down into the medulla), and an ascending limb (fluid flows back up into collecting duct))

What does the loop of henle do?

concentrates urine, Na+ and Cl- are pumped out of the ascending limb (back into blood stream)

H20 follows out of the descending limb (back into blood stream)

What is urea?

most abundant organic waste from amino acid breakdown, main solute left in the tubular fluid, hence urine

What is the distal convoluted tubule (DCT)?

last segment of the renal tubule, epithelial cells in the DCT are smaller then in the PCT and do not have microvilli, less active than cells in the PCT, more highly specialized than cells in the PCT. Selective reabsorption in response to hormones, regulate blood pressure & volume and pH

What kind of structure is the juxtaglomerular apparatus?

endocrine structure

What is the juxtaglomerular apparatus composed of?

macula densa (specialized epithelial cells in the DCT), juxtaglomerular cells (specialized smooth muscle cells of the afferent arteriole)

What happens in the DCT when blood pressure and volume are decreased?

if blood pressure is low it is sensed the the juxtaglomerular cells and they release renin (type of hormone) and renin activates angiotensin (another hormone)

What does angiotensin cause? DCT decreased

vasoconstriction and secrets aldosterone (mineralocorticoid hormone) by the adrenal cortex

What does aldosterone cause? DCT decreased

Causes DCT cells to- Na+ and H2O reabsorption. Both are returned to the blood. Increases blood pressure and volume

What happens in the DCT when blood pressure and volume are increased?

the atria of the heart releases atrial natriuretic peptide (ANP hormone).

What does ANP cause? DCT increased

decreases the absorption of Na+ and H2O so that Na+ and H2O increase excretion into the urine which results in low blood pressure and volume

How does the DCT regulate blood pH?

H+ excretion into the forming urine and HCO3- (bicarbonate) production and reabsorption into the blood (buffers the blood)

What do the collecting ducts do?

determine the final urine composition and volume. Converge to empty into a minor calyx which ends at the renal papilla of each renal pyramid

What are hypothalamic neurons?

they are stimulated by low blood pressure or high Na+/Cl- concentration. They release ADH (antidiuretic hormone) which increases H2O absorption at the collecting duct

What is the minor calyx?

Cup like structure surrounding each renal pyramid. It collects urine from each renal pyramid. Several join to form the major calyx

What is the major calyx?

formed by several minor calyx, joins to form the renal pelvis

What does the renal pelvis do?

acts as a funnel to drain urine from the kidney to the ureter

What is urothelium?

AKA transitional epithelium (stratified epithelium), lines the urinary bladder and ureters, composed of cells that are impermeable to water, can rearrange themselves and spread out as the bladder fills with urine

Male urethra is...

7-8 inches long, passes through the prostate gland, and penis, begins at the inferior pole of the bladder

Female urethra is...

1-2 inches long, more prone to frequent infections or urinary bladder than the male

The external urethral sphincter

in both sexes, skeletal muscle that surround the urethra, relaxation micturition permits urination

What are the ovaries?

small almond shaped organs, composed of an outer cortex that contains follicles, and a inner medulla that contains the blood vessels

What is the composition a follicle?

female germ cell oocyte which is surrounded by an epithelium layer

How many chromosomes do humans have?

46 chromosomes

What is mitosis?

somatic cell division, produces two identical daughter cells which also have 46 chromosomes

What is meiosis?

genetic material is exchanged. only occurs in gametes (germ cells) oocytes in females and spermatozoa in males. Meiosis divides chromosomes in half so gametes contain 23 chromosomes

What is a zygote?

fusion of male and female gametes which produces a zygote with 46 chromosomes

What is oogenesis?

begins from oocyte stem cells called oogonia, oogonia undergo mitosis and produce oocytes before birth. Then oocytes undergo meiosis 1 (starts at puberty), meiosis 2 is completed if fertilized

When does meiosis 1 happen?

Occurs at ovulation- starting at puberty

When does meiosis 2 happen?

Only when fertilization occurs

What is a primordial follicle?

ovary only contains this follicle from birth until puberty, composition: simple squamous epithelium surrounding an oocyte

What is a primary follicle?

at puberty each month about 12 primordial follicles mature into primary follicles in response to FH

What is FSH?

follicle-stimulating hormone

What are granulosa cells?

epithelial cells of a primary follicle, they enlarge, divide and surround the oocyte for protection and form a stratified epithelium. Begin to produce estrogen

What is a secondary follicle?

primary follicles mature into bigger secondary follicles. Epithelial cells continue to produce estrogen and begin to secrete fluid which accumulates in many small cavities between epithelial cells

What is a tertiary follicle?

Each month only 1 of 12 maturing follicles develop into a tertiary follicle. The oocyte bulges into the antrum, separates from the follicle then floats free in the antrum. Produces a lot of estrogen creating an estrogen surge.

What is the antrum?

small cavities between epithelial cells that fuse into a single large cavity of fluid called the ...

What does LH stand for?

luteinizing hormone

What is ovulation?

the release of the oocyte (egg) from this follicle.

estrogen surge leads to LH surge

estrogen surge leads to LH surge

What is the corpus luteum?

an empty tertiary follicle consisting of only epithelial cells after ovulation. The epithelial cells begin to produce progesterone, prepares the uterine lining for pregnancy

What is the corpus albicans?

if fertilization does not occur the corpus luteum degenerates 12 days after ovulation and fills with scar tissue becoming the ...

F.E.L.P

Follicle stimulating hormone, folicular phase, Estrogen, Luteinizing hormone, corpus luteum, Progesterone

FSH causes

follicle maturation

LH causes

ovulation and corpus luteum formation

What is the follicular phase?

primordial through tertiary follicles, stimulated by FSH, estrogen is the primary sex hormone produced by the ovaries during this phase

What is the luteal phase?

corpus lute and albicans formations, LH, progesterone is the primary sex hormone produced by the ovaries during this phase

What are the uterine tubes?

AKA Fallopian tubes, hollow muscular tubes that transport the oocyte from the ovary to the uterus (3-4) days. Tubes are not directly connected to the uterus

Where does fertilization occur?

occurs in the uterine tube near its entrance into the uterus, unfertilized oocytes degenerate

Components and function of the uterus...

the "body" is the largest portion, "cervix" distal end projecting into the vagina

What does the uterus provide?

protection, nutrition, and waste removal for developing fetus

What are the three layers of the uterine wall?

perimetrium, myometrium, endometrium

What is the perimetrium?

outer layer of uterus- epithelium and connective tissue

What is the myometrium?

middle layer of the uterus, thick smooth muscle layer, provides the force to move the fetus out of the uterus into the vagina

What is the endometrium?

inner glandular and vascular layer of the uterus, supports the growing fetus, estrogen and progesterone produced from ovary cause the glands and blood vessels to develop and grow each month. If oocyte is not fertilized then it is sloughed (period)

What is the uterine cycle?

AKA menstrual cycle "period", changes in the endometrium, average 28 days, responds to hormones of the ovarian cycle, 3 phases

what are the menses?

Phase 1 uterine cycle. destruction of the superficial layer of the endometrium, release of blood and tissues, stimulated by decrease in progesterone. 1-7 days, 35-50ml blood

What is the proliferative phase?

Phase 2 uterine cycle. follows menses, repair and regeneration of the endometrium, stimulate by estrogen secreted by the ovarian follicles.

What is the secretory phase?

Phase 3 uterine cycle. Begins at ovulation, secretion by the glands, rapid growth of the arteries, stimulated by progesterone secreted by the ovarian corpus lute, persisting as long as corpus lute does. Preparing for fertilization of the fertilized embryo. Repeats itself back to menses if fertilization does not occur.

What is the vagina?

elastic muscular tube, extends from cervix to vestibule, between the urethra and the recum&anus. Functions as a passageway for menstrual fluids, spermatozoa, and birth canal

What is the clitoris?

erectile tissue (plexus of veins)

What is the labia majora?

external female genitalia that contains adipose tissue, protects inner structures, covered with pubic hair

What is the labia minora?

external female genitalia, medial to the labia majora, not covered with pubic hair

What is the vestibule?

space between the 2 labia minora, contains openings for the urethra and vagina