Biology Chapter 10: Homeostasis (3 Stars)

Question 1

The _______ system serves many functions, including the regulation of blood pressure, blood osmolarity, acid–base balance, and removal of nitrogenous wastes.

Answer 1

excretory

Question 2

The _____ produces urine, which dumps into the ureter at the renal pelvis. Urine is then collected in the bladder until it is excreted through the urethra.

Answer 2

kidney

Question 3

The kidney contains a cortex and a ______. Each kidney has a hilum, which contains a renal artery, renal vein, and ureter.

Answer 3

medulla

Question 4

The kidney contains a portal system with #____ capillary beds in series.

Answer 4

two

Question 5

Blood from the _____ artery flows into afferent arterioles, which form glomeruli in Bowman’s capsule (the first capillary bed).

Answer 5

renal

Question 6

Blood then flows through the _____ arteriole to the vasa recta, which surround the nephron (the second capillary bed), before leaving the kidney through the renal vein.

Answer 6

efferent

Question 7

The bladder has a muscular lining known as the _____ muscle, which is under parasympathetic control. It also has two muscular sphincters.

Answer 7

detrusor

Question 8

The internal ______ sphincter consists of smooth muscle and is under involuntary (parasympathetic) control.

Answer 8

urethral

Question 9

The external urethral sphincter consists of ______ muscle and is under voluntary control.

Answer 9

skeletal

Question 10

The kidney participates in _____ movement through three processes:

Answer 10

solute

Question 11

Filtration is the movement of solutes from blood to filtrate at _____. The direction and rate of filtration is determined by Starling forces, which account for the hydrostatic and oncotic pressure differentials between the glomerulus and Bowman’s space.

Answer 11

Bowman’s capsule.

Question 12

_____ is the movement of solutes from blood to filtrate anywhere other than Bowman’s capsule.

Answer 12

Secretion

Question 13

____ is the movement of solutes from filtrate to blood.

Answer 13

Reabsorption

Question 14

Each segment of the _____ has a specific function.

Answer 14

nephron

Question 15

The proximal convoluted tubule (PCT) is the site of bulk ______ of glucose, amino acids, soluble vitamins, salt, and water. It is also the site of secretion for hydrogen ions, potassium ions, ammonia, and urea.

Answer 15

reabsorption

Question 16

The descending limb of the loop of Henle is permeable to water but not _______; therefore, as the filtrate moves into the more osmotically concentrated renal medulla, water is reabsorbed from the filtrate. The vasa recta and nephron flow in opposite directions, creating a countercurrent multiplier system that allows maximal reabsorption of water.

Answer 16

salt

Question 17

The ascending limb of the loop of Henle is permeable to salt but not water; therefore, salt is reabsorbed both passively and actively. The _____ segment is in the outer medulla; because salt is actively reabsorbed in this site, the filtrate actually becomes hypotonic compared to the blood.

Answer 17

diluting

Question 18

The distal convoluted tubule (DCT) is responsive to ______ and is a site of salt reabsorption and waste product excretion, like the PCT.

Answer 18

aldosterone

Question 19

The ______ is responsive to both aldosterone and antidiuretic hormone and has variable permeability, which allows reabsorption of the right amount of water depending on the body’s needs.

Answer 19

collecting duct

Question 20

The kidney is under hormonal control. When blood pressure (and volume) are low, #____ different hormonal systems are activated.

Answer 20

two

Question 21

Aldosterone is a steroid hormone regulated by the renin–angiotensin– aldosterone system that increases ____ reabsorption in the distal convoluted tubule and collecting duct, thereby increasing water reabsorption. This results in an increased blood volume (and pressure), but no change in blood osmolarity.

Answer 21

sodium

Question 22

Antidiuretic hormone (ADH or vasopressin) is a peptide hormone synthesized by the hypothalamus and released by the posterior pituitary. Its release is stimulated not only by low blood volume but also by high blood osmolarity. It increases the permeability of the collecting duct to water, increasing water reabsorption. This results in an increased blood volume (and pressure) and a _____ blood osmolarity.

Answer 22

decreased

Question 23

The kidney can regulate ____ by selective reabsorption or secretion of bicarbonate or hydrogen ions. Skin

Answer 23

pH

Question 24

The skin acts as a ______ protecting us from the elements and invasion by pathogens.

Answer 24

barrier

Question 25

The ____ is composed of three major layers: the hypodermis (subcutaneous layer), dermis, and epidermis.

Answer 25

skin

Question 26

The epidermis is composed of five layers: the stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum. The stratum basale contains ____ cells that proliferate to form keratinocytes. Keratinocyte nuclei are lost in the stratum granulosum, and many thin layers form in the stratum corneum.

Answer 26

stem

Question 27

_______ produce melanin, which protects the skin from DNA damage caused by ultraviolet radiation; melanin is passed to keratinocytes.

Answer 27

Melanocytes

Question 28

______ cells are special macrophages that serve as antigen-presenting cells in the skin.

Answer 28

Langerhans

Question 29

The dermis is composed of two layers: the papillary layer and the _________

Answer 29

reticular layer.

Question 30

Many sensory cells are located in the ______including Merkel cells (deep pressure and texture), free nerve endings (pain), Meissner’s corpuscles (light touch), Ruffini endings (stretch), and Pacinian corpuscles (deep pressure and vibration).

Answer 30

dermis,

Question 31

The _______ contains fat and connective tissue and connects the skin to the rest of the body.

Answer 31

hypodermis

Question 32

The skin is important for ________, or the maintenance of a constant internal temperature.

Answer 32

thermoregulation

Question 33

Cooling mechanisms include _______, which absorbs heat from the body through evaporation of water from sweat, and vasodilation. Sweat glands are innervated by postganglionic cholinergic sympathetic neurons.

Answer 33

sweating

Question 34

Warming mechanisms include piloerection, in which arrector pili muscles _____, causing hairs to stand on end (trapping a layer of warmed air around the skin), vasoconstriction, shivering, and insulation provided by fat.

Answer 34

contract

Question 35

The _____ also prevents dehydration and salt loss from the body

Answer 35

skin