MCAT Biology - Homeostasis (Excretory and Integumentary Systems)

Approximately 20% of blood that passes through the glomerulus is filtered into what space?

Bowman's

What cup-like structure surrounds the glomerulus?

Bowman's capsule

What is the functional unit of the kidney?

nephron

What layer of the skin consists of loose CT?

papillary layer of the dermis

What are the two layers of the dermis?

papillary, reticular

The renal pelvis narrows to form what structure?

ureter

What is the name of the capillary bed formed from the efferent arterioles?

vasa recta

What two structures create a countercurrent multiplier system?

vasa recta, nephron

Where do all nephrons empty into?

renal pelvis

Name four functions of the excretory system.

BP, blood osmolarity, acid-base balance, nitrogenous waste

If the blood is acidic, the kidneys will excrete more of what?

H+

What does the PCT secrete?

H+, urea, NH3, K+

As part of the renal portal system, the renal artery branches out, passes through the medulla, and enters the cortex as what structure?

afferent arterioles

The DCT responds to what hormone?

aldosterone

The collecting duct responds to what hormone?

aldosterone and ADH

What is reabsorbed in the PCT?

amino acids, glucose, water-soluble vitamins, salts and water

In which layer of the epidermis are melanocytes located?

basale

In which layer of the epidermis do you find stem cells?

basale

In which layer of the epidermis does the proliferation of keratinocytes occur?

basale

The ureter enters into what?

bladder

In which layer of the epidermis can you find several layers of flattened keratinocytes?

corneum

What is the name of the kidney's outermost layer?

cortex

What is the name of the muscular lining of the bladder?

detrusor

What is the name of the thicker part of the loop of Henle which occurs at the transition from inner to outer medulla?

diluting segment

What part receives blood from the glomerulus and then forms a second capillary bed?

efferent arterioles

What are the three functions of the kidney?

filtration, secretion, reasborption

What structure is a highly convoluted capillary tuft that is derived from the afferent arterioles?

glomeruli

What molecules are almost always reabsorbed?

glucose, amino acids, vitamins

In which layer of the epidermis do keratinocytes begin to die and lose their nuclei?

granulosum

Hydrostatic pressure in the glomerulus is ____ than that in Bowman's space, which causes fluid to move into the nephrone.

higher

The osmolarity of blood is ___ than that of Bowman's space, resulting in pressure opposing the movement of fluid into the nephron.

higher

Hydrostatic pressure is ___ than oncotic pressure, so net flow is from ___ to ___.

higher, blood, nephron

At the diluting segment, filtrate becomes hypertonic, isotonic, or hypotonic?

hypotonic

There are two urethral sphincters, which one consists of smooth muscle and is therefore under involuntary control?

internal

Filtrate is ___ to blood.

isotonic

In the PCT, is the filtrate hypertonic, isotonic, or hypotonic?

isotonic

Calluses form from excessive ___ deposition in areas of repeated strain due to friction to provide protection against future damage.

keratin

What is the name of the kidney's inner layer?

medulla

What sensory receptor responds to light touch?

meissner's corpuscles

What cell in the skin is derived from neural crest cells?

melanocytes

What sensory receptor responds to deep pressure and texture sensation?

merkel cells

What is the reflex called in which stretch receptors in the bladder convey to the nervous system that the bladder needs emptying?

micturition

What sensory receptor responds to deep pressure and vibration?

pacinian corpuscles

What three structures enter and exit through the renal hilum?

renal artery, renal vein, ureter

What is the name of the deep slit in the center of the kidney's medial surface?

renal hilum

What sensory receptor responds to stretch?

ruffini endings

What is the ascending loop of Henle permeable to?

salts

The diluting segment is surrounded by larger cells with large amounts of mitochondria to encourage reasborption of what?

sodium, chloride

In which layer of the epidermis do keratinocytes become connected to each other?

spinosum

In which layer of the epidermis is the site for Langerhans cells?

spinosum

Does piloerection help keep you warm or cool?

warm

The DCT is the site of ___.

waste secretion

What is the descending loop of Henle permeable to?

water