Final Flashcards
(141 cards)
1
Q
Fundamental problem of Osmoregulation and Ion Regulation
A
Protein function:
- is affected by ion concentration
- is optimal within a narrow range of inorganic ion concentration
2
Q
What does changes in ion and water content affect?
A
Protein and cell function
3
Q
What is the function of macromolecules affected by?
A
Their aqueous environment
4
Q
When solutes interact with proteins what does that affect?
A
Stability and function
5
Q
What is less inhibitory?
A
Potassium
6
Q
Where does water move from?
A
Low solute concentration to high solute concentration. Across an osmotic gradient
7
Q
Can water be actively pumped?
A
No
8
Q
What does changes in osmolarity cause?
A
A transmembrane osmotic gradient and therefore water moves across the membrane affecting cell volume
9
Q
Osmolarity
A
The measure of solute concentration (number of osmoles per litre)
10
Q
What is a critical problem faced by all cells?
A
Maintenance of a constant volume in the face of extracellular and intracellular osmotic perturbations
11
Q
What does volume perturbations activate?
A
Volume regulatory mechanisms
12
Q
3 types of organic osmolytes:
A
- Carbohydrates
- Amino acids and their derivatives
- Methylamines
13
Q
Perturbing
A
Disrubt metabolism when they are in high concentration or when large shifts in their concentrations occur
14
Q
Compatible (non-perturbing)
A
Do not affect protein function
15
Q
Two strategies animals use to deal with osmotic stress
A
- Osmoconformers
2. Osmoregulators
16
Q
Osmoconformers
A
Body fluids and cells are equal in osmotic pressure to the environment. Mainly found in the oceans
17
Q
Osmoregulators
A
Osmotic pressure of body fluids is homeostatically regulated and usually different from the external environment
18
Q
Role of Osmoregulators:
A
-Maintain extracellular osmolarity and ion composition constant
19
Q
Role of Osmoconformers:
A
-Do not actively control the osmotic conditions but may control extracellular osmolytes
20
Q
What are two types of Osmoconformers?
A
- Stenohaline
- Euryhaline
21
Q
Stenohaline Conformer
A
- Restricted to a narrow range of salinity
- Cannot regulate their osmolytes to compensate
22
Q
Euryhaline Conformer
A
- Tolerant of changes in salinity
- Successful in intertidal zones
- Regulate organic osmolytes in their cells
23
Q
Where are compatible osmolytes conserved?
A
In Osmoconformers
24
Q
What do compatible osmolytes have?
A
Strong selective pressures
25
What are most vertebrates?
Osmoregulators
26
What are sharks? Why?
Osmoconformers because they maintain high concentration of a perturbing osmolytes, urea
27
Osmoregulatory Organs
- Depends on transporting epithelia
- External surfaces (gills, skin)
- Salt glands
- Gut
- Kidneys
28
What are marine osmoregulators?
Hypo-osmotic
29
What are freshwater osmoregulators?
Hyperosmotic
30
Hypo-osmotic osmoregulators
- Have low concentrations of organic osmolytes
| - Marine animals must drink seawater and absorb NaCl to absorb water by creating excess salt in the blood
31
Hyperosmotic osmoregulators
-Cope with the low osmolarity of fresh water
32
Kidney
-Internal organ concerned with osmoregulation
33
Two different mechanisms that lead to primary urine:
- Ultrafiltration
| - Active Secretion
34
3 Regions of the Kidney:
- Renal Cortex--Outer
- Renal Medulla--Inner
- Renal Pelvis--drainage are in center
35
What is the smallest functional unit of the kidney and what does it consist of?
Nephron- Tubule and vascular component
36
What is nephron responsible for?
Formation of urine
37
What are 3 basic nephron processes?
1. Glomerular Filtration
2. Tubular Reabsorption
3. Tubular Secretion
38
Glomerular Filtration
- Separation of plasma fraction of the blood
| - Dived by blood hydrostatic pressure
39
Loop of Henle
- Establishes osmotic gradient in the medulla
| - Reduces the osmotic pressure of the filtrate
40
Distal Convoluted Tubule
- May dilute the filtrate
| - Regulates sodium and potassium in the blood
41
The Collecting Duct
-Permeable to water
42
Nephridia
- Primitive Kidney
| - Filtration-reabsorption systems
43
What might modify ion concentration?
Some tubule cells
44
Metanephridia
- Most annelids, mollusks and arthropods
- Osmoregulation and nitrogenous wastes
- Filtrate coelomic fluid
45
What are involved in nitrogen waste excretion?
Osmoregulatory organs
46
What is the problem with nitrogen waste?
- Metabolism of proteins and nucleic acids
| - Produces ammonia
47
Ammonia
- Very soluble in water and toxic at low concentrations
- Easily permeates membranes
- Excretes urea
48
Urea
- Uses energy to create
- Sacrifice less water
- Less toxic that ammonia
49
Why is there a need for a respiratory system?
- Gas Exchange
| - Diffusion of Oxygen
50
Diffusion
A random walk from a region of high concentration to a region of lower partial pressure
51
Total Lung Capacity (TLC)
Maximum amount of air that the lungs can hold
52
Tidal Volume (TV)
Volume of air entering or leaving the lungs during a single breath at rest
53
Functional Residual Capacity (FRC)
Volume of air in the lungs at the end of a normal passive expirations
54
Residual Volume (RV)
Maximum volume of air remaining in the lungs after a maximal expiration
55
Vital Capacity (VC)
Maximum volume of air that can be moved out during a single breath followed by maximal inspiration
56
How is oxygen transported in animals?
Diffusion
57
What do small insects use compared to large ones?
Small- Simple Diffusion
| Large- Ventilation
58
Ventilation
Air movement produced by changing shape of tracheal system (collapse and expansion of air sacs)
59
How do aquatic insects obtain oxygen?
From the air
60
Plastron
- Film of air outside the body held by specialized structures
- Volume is constant
- Functions as a gill
61
Central Controller
Pons, medulla and other parts of the brain
62
Sensors
Chemoreceptors, lung and other receptors
63
Effectors
Respiratory muscles
64
Peripheral Chemoreceptors
The carotid and aortic bodies
65
What do central chemoreceptor cells respond to?
Increases CO2 in arterial blood to increased breathing
66
Where are central chemoreceptors located?
The medulla oblongata
67
What dominates control of breathing is air breathing animals?
CO2
68
What is the major factor controlling breathing in aquatic animals?
Oxygen
69
What is most carbon dioxide transported as?
Bicarbonate ion in the plasma
70
What is most oxygen transported with?
Hemoglobin
71
Why is hemoglobin needed in the blood
As a carrier protein that can transport lots of oxygen at arterial PO2 and release it to the tissue at venous PO2's
72
What is the affinity of hemoglobin for oxygen affected by?
- Temperature
- pH
- CO2
73
What are the components of a circulatory system?
- Fluid
- Pump
- Vessels
74
Open Circulatory Systems
Hemolymph- Moves through vessels that open into extracellular spaces
75
Closed Circulatory System
Blood-pumped from heart
| Capillaries-primary structure
76
Gastrovascular Cavity
- Simplest
- Found in cnidarians
- Water currents
77
What is a closed circulatory system ideal for?
Larger animals
78
Single Circulation Animal
Fish
79
Parallel Circulation Animal
Amphibians
80
Double Circulation Animals
Mammals, birds, crocodiles
81
What does fluid transfer across capillaries depend on?
Hydrostatic pressure and osmotic forces
82
Vertebrate Heart Walls
- Thick, muscular myocardium
| - Sandwiched between endocardium and epicardium
83
What does myocardium consist of?
Interlacing bundles of cardiac muscle fibers arranged spirally
84
What does neurogenic hearts require?
External neural stimulus to beat
85
What kind of cells do myogenic hearts have?
Pacemaker
86
When is an action potential produced?
When the L-type Calcium channels open at threshold
87
What does the P wave represent?
Atrial depolarization
88
What does the QRS complex represent?
Ventricular depolarization and atrial repolarization
89
What does the T wave represent?
Ventricular repolarization
90
What does the PR segment represent?
AV nodal delay
91
What does the ST segment represent?
Plateau phase
92
What does the TP interval represent?
Passive ventricular filling
93
What do arteries provide?
Rapid passage of blood from the heart to the tissues
94
What do arteries serve as?
Pressure reservoirs
95
What is elastic recoil?
The driving force for continued flow of blood during diastole
96
Arterial Blood Pressure
- The maximum amount of pressure exerted on the arteries (systolic)
- The minimum pressure (diastolic)
97
What is the main driving force of blood flow?
Mean arterial pressure
98
What is mean arterial pressure determined by?
Cardiac output and peripheral resistance
99
Cardiac Output
Measure of blood flow into the arterial system
100
Total Peripheral Resistance (TPR)
Blood vessels provide resistance to flow of blood because of friction between moving blood and wall of vessel
101
What is cardiac output determined by?
Heart rate and stroke volume
102
What is the most important factor controlling TPR?
Radius of arterioles
103
What is the major determinant of resistance to the flow?
The radius of the vessel
104
What do electrical conduction pathways stimulate?
Coordinated contraction of the artia and ventricles
105
What does Ohms Law relate?
Cardiac output, resistance and mean arterial pressure to each other
106
What are the major resistance vessels?
Arterioles
107
What is the thick layer of smooth muscle innervated by?
Sympathetic nerve fibers
108
What does vasoconstriction result from?
Smooth muscle contraction, decreased radius and increased resistance
109
What does vasodilation result from?
Smooth muscle relaxation, increased radius and decreased resistance
110
What is the amount of blood flow received by each organ determined by?
The number and diameter of its arterioles
111
What does extrinsic control include?
Neural and hormonal influences with the sympathetic nervous system dominating
112
What are the main fuels of the digestive system?
Carbohydrates, proteins and fats
113
What are the main fuels broken down into?
Absorbable units (simple sugars, fatty acids and amino acids)
114
Extracellular Digestion
Permits an animal to store and breakdown larger varieties and quantities of food items
115
3 regions of the gut:
1. Foregut
2. Midgut
3. Hindgut
116
Digestive Tract of Vertebrates:
- Mouth
- Pharynx
- Esophagus
- Stomach
- Small Intestine
- Large Intestine
- Anus
117
Swallowing
The process of moving food from the mouth through the esophagus into the stomach
118
2 phases of swallowing reflex:
- Oropharyngeal phase
| - Esophageal phase
119
Foregut
Esophagus
120
Midgut
Stomach
121
Monogastric Stomach Functions:
- Storage of food
- Digestion of proteins
- Formation of chyme
122
What is the forestomach involved in?
Storage and passage of ingested food
123
What is the most important process to occur in the rumen?
Fermentation
124
What does the small intestine have a large surface area for?
Absorption
125
Where does most absorption take place in the small intestine?
In the duodenum and jejunum
126
What is absorbed in the small intestine?
- Fat
- Carbohydrates
- Proteins
- Vitamins
127
Peristalsis
Coordinated Contraction
128
Segmentation
Kneading and mixing
129
Where do endocrine glands secret hormones to ?
The circulatory system
130
Where do exocrine glands secrete digestive enzymes, water and mucus to?
The lumen of the GI tract
131
3 phases of secretion in the stomach:
- Cephalic phase
- Gastric phase
- Intestinal phase
132
Absorption
- Breakdown products of digestion
- Transferred to blood
- Distributed to tissues
133
Nutritional Requirements
- Sources for metabolic energy
- Raw material for growth, repair and production of gametes
- Trace elements
134
Amino Acids
- Used as energy sources
| - Building blocks of proteins
135
Carbohydrates
- Used as sources for energy
- Metabolized as glucose
- Stored as glycogen
- Converted to amino acids and fats
136
Lipids
- Used for energy
| - Suitable to storage
137
Nucleic Acids
-Essential for DNA and RNA
138
Electrolytes
- Have to be taken up
- Metals for enzymes, cofactors
- some in traces
- oxygen transport
139
Vitamins
- Organic substances
| - Requires in small quantities
140
What animals have open circulatory systems?
Invertebrates
141
What animals have closed circulatory systems?
All vertebrates and some invertebrates (cephalopods)
