Test 4 Flashcards
1
Q
Homeostasis
A
- maintaining an internal cellular environment that is conducive to cellular function
- exchanging with the environment
2
Q
2 Approaches to Homeostasis/Exchanging with the environment
A
- direct
- indirect
3
Q
Direct exchange with the environment
A
- cell uses diffusion/osmosis/carrier mediated transport to exchange with environment
- requires the cell to be close to environment (near body surfaces)
- usually small or have a large surface area
- porifera, platyhelminth, cnidaria
4
Q
Indirect exchange with the environment
A
- involves some mechanism for circulating stuff around body
- 2 approaches
5
Q
What are the two approaches to indirect exchange with environment?
A
- coelomic circulation
- circulatory system
6
Q
Coelomic circulation
A
- use of coelomic fluid to distribute stuff within the body
- negative is that there is no control
- nematodes and echinodermata
7
Q
Circulatory system
A
- hearts, vessels, blood
- more control
- 2 approaches
8
Q
What are the two approaches to a circulatory system?
A
- open
- closed
9
Q
Open circulatory system
A
- fluid leaves the system
- fluid goes into heart through ostia, but cannot leave through ostia
- circulating the coelomic fluid
- arthropoda and mollusca
- direction speed and control (heart rate and which artery)
10
Q
Artery
A
- blood vessel that carries oxygenated blood away from the heart to the body’s tissues and organs
11
Q
Ostia
A
Small one-way openings in the heart that allow coelomic fluid to enter the heart
12
Q
Closed circulatory system
A
- fluid/blood never leaves system unless damaged
- more control
13
Q
Explain how a closed circulatory system works
A
- heart pumps oxygenated blood into arteries, creates a high blood pressure/hydrostatic pressure, and arteries carrie blood away from heart
- Arteries branch into arterioles that contain circular smooth muscles
- arterioles lead the blood into the capillary beds, which allows for exchange of gas, nutrients, and waste
- the deoxygenated blood then goes through the venules
- blood then goes through veins and back to the heart
14
Q
What do the smooth circular muscles do within the arterioles?
A
- allows the arteriole to constrict or dilate
15
Q
What is the function of arterioles?
A
- regulate blood pressure and controls blood flow
16
Q
What is the function of venules?
A
- collects deoxygenated blood from capillary beds and transports it to larger veins
17
Q
Capillaries
A
- sit of exchange
- small and dense
- near well vascularized tissue
- thin celled; lined with simple squamous epithelia
18
Q
Vein function
A
- carries deoxygenated blood back to the heart
19
Q
What direction does blood flow?
A
- from high pressure to low pressure
20
Q
Which has a higher blood pressure: arteries or veins?
A
- arteries
- arteries are closed to heart, so strong hydrostatic force
21
Q
Where does water and dissolved molecules move out of blood at?
A
- in the capillary bed closest to artery through hydrostatic force
22
Q
Where does water and dissolved molecules move into blood at?
A
- in the capillary bed closest to vein through osmosis
- blood is hypertonic to fluid in tissues
23
Q
What are the two forces acting on blood/water?
A
- hydrostatic force
- osmosis
24
Q
Hydrostatic force vs blood/water
A
- from the heart
- pushes water and dissolved molec out of blood
25
Osmosis vs blood/water
- blood is hypertonic to fluid in tissues
- pulls water from tissues into blood
26
Hydrostatic pressure vs volume
- as blood volume decreases, hydrostatic pressure decreases
27
Osmosis vs colume
- osmosis increases as volume decreases
28
Capillary bed and water movement
- as blood enters capillary bed, water is pulled out
- as blood leaves capillary bed, water is drawn in
29
Why is blood pressure higher in arteries than veins?
1. veins are larger, so less volume in larger area = lower pressure
2. veins are elastic
3. not all water is recovered
30
What is the secondary mechanism for pumping blood through veins?
- peristaltic pump
31
Peristalsis
- moves fluids using a series of contractions/compressions and relaxations
32
Peristaltic pump process
- vein is surrounded by muscles
- vein contains unidirectional valve
- muscle contraction/movement squeezes vein and forces blood to move upward
- when muscle rests, blood cannot flow backwards because the valves shut
33
Double circuit circulation
- involves two circuits:
1. pulmonary circuit
2. systematic circuit
- blood passes through the heart twice per circuit
- ensures that oxygenated blood is pumped to the body tissues at high pressures
34
Pulmonary circuit
- deoxygenated blood is pumped from the right atrium to the right ventricle (or ventricle if 3 chambered) then to the pulmonary artery
- once in pulmonary artery it goes through the pulmonary capillary beds where it picks up oxygen and released co2
- returns to the heart through pulmonary veins
35
Systematic circuit
- oxygenated blood is pumped from the left atrium to the left ventricle (or ventricle if 3 chambered) then to the aorta
- blood moves from aorta to the systemic capillary where it delivers the oxygen to the body tissues
- the now deoxygenated blood goes through the vena cava back to the heart
36
What are the two versions of double circuit circulation?
- 3 chambered
- 4 chambered
37
3 chambered heart
- one ventricle
- some fish and reptiles
- amphibians
- delivers moderately oxygenated blood to tissues
- ectothermic
38
4 chambered heart
- 2 ventricles
- some reptiles
- birds
- mammals
- delivers fully oxygenated blood to tissue
- requires a lot of energy
- endothermic
39
Ectothermic
- organism uses the environment to regulate temperature
40
Endothermic
- organism uses metabolism to regulate temperature
41
Lymphatic System
- system of glands (lymph nodes), ducts, and lacteals
functions:
- returns excess fluid from capillary bed to circulatory system
- defense against bacteria and infections
- transports fats from digestive system to the liver
42
What is known as the supplemental circulatory system?
the lymphatic system
43
Lymph nodes function
- filters lymph fluid and fights off bacteria and viruses with its storage of white blood cells
44
Lymph ducts function
- return filtered lymph fluid back into the blood stream to help regulate fluid levels and support immune function
- carries lymph to the heart
45
Lacteal function
- absorbs lipids from the intestine and helps transport them into the bloodstream
46
How does lymph go back into the bloodstream?
the lymph is dumped into the large veins near the heart and circulates the body again
47
Digestive system functions
- digestion
- absorption
- movement of food
48
Digestion
the breaking down of organic molecules
49
Absorption
- passage from digestive system to circulatory system
50
What occurs in the mouth (buccal cavity)?
- ingestion
- mastication
- saliva secretion
- absorption of monosaccharides
- bolus is formed and passed to pharynx then to esophagus
51
Saliva Secretion
- amylase
- mucins
- lingual lipase
52
Amylase
- digestive enzyme
- carbohydrate digestion
53
Mucins
- makes things slimy for easy transportation
54
Lingual Lipase
- lipid digestion
55
What keeps food from going down trachea?
- when we swallow, the epiglottis closes
56
Esophagus
- surrounded by circular smooth muscles
- lumen is lined with stratified squamous epithelia
- bolus is pass through by peristalsis
57
Peristalsis
- wave of circular smooth muscle contractions passing down a tube
- all or none phenomenon (peristalsis and action potential)
58
Stomach
- contains cardiac sphincter and pyloric sphincter
- secretes gastrin
- some absorption
- forms chyme
59
How does the bolus drop into the stomach?
- a peristaltic wave causes cardiac sphincter to relax and bolus drops into stomach
60
What does the bolus in the stomach do?
- it causes the cell linings to mesh and secrete gastrin
61
What does gastrin do?
- causes secretion of HCL from stomach lining and denatures proteins
- causes secretion of pepsin
- causes peristaltic waves to pass over stomach (mixes stuff together which later turns into chyme)
- mucus secretion
62
Chyme
acidic mixture of gastric juices and partially digested food
62
What does the stomach absorb?
- small non-polar molecules
- ethanol
- NSAIDS
63
Pyloric Sphincter
- valve that regulates the passage of chyme out of the stomach into the small intestine
63
Cardiac Sphincter
- valve between esophagus and stomach
- allows bolus to go into stomach
64
What is the 3/4 life of food in stomach?
3 hours
65
Small Intestine
- where most digestion occurs
- where most absorption occurs
66
How does chyme flow from stomach to small intestine?
- peristaltic waves gradually push small amounts of chyme through the pyloric sphincter into the small intestine
67
What does the arrival of chyme in the small intestine cause?
- causes endocrine cells to secrete secretin and cholecystokinins
68
How does adrenaline affect the digestive system?
- causes the pyloric sphincter to relax and empty the digestive system
69
Secretin
- causes pancreas to secrete HCO3- (bicarbonate) and neutralizes chyme
- slows down gastrin secretion
70
Cholecystokinins
- causes secretion of pancreatic enzymes
- causes gall bladder to secret bile
71
Bile
- toxic fluid that contains bile salts and bile pigments
72
How does digestion occur in the small intestine?
- peristalsis pushes food and enzymes down the small intestine, mixes them, and causes digestion
73
What is the small intestine lined with?
- columnar epithelia
74
What are beneath the columnar epithelial cells in the small intestine?
- capillaries that transported the digested molec throughout the body
75
Efficiency of digestion
- time = length of small intestine
- diet: proteins and lipids digest easily; complex carbohydrates are hard to digest
76
What enzyme do herbivores have that allow for the digestion of cellulose?
cellulase
77
Why do rabbits have longer small intestines than carnivores?
- their diet is harder to digest, so they need more time to digest it = longer small intestine
78
Efficiency of absorption
- surface area
- greater the surface area = greater the absorption
- 3 types
a. plicae
b. villi
c. microvilli
79
Plicae
- circular folds within the small intestines lining
80
Villi
- small, finger-like projections that line the inner surface of the small intestine
81
Microvilli
- folds on membrane of columnar epithelia in the small intestine
82
How does waste move from the small intestine to the large intestine?
peristaltic waves gradually pushes the waste through the ileocecal sphincter into the large intestine
83
Ileocecal sphincter
- sphincter muscle that controls the flow of waste into the LI
84
Ceacum
- blind sack at the end of the LI
- absorbs water and salts and solidifies the waste
85
Appendix
- houses beneficial bacteria
- synthesizes vitamin K
86
What happens as blood leaves the digestive system?
- it goes to the liver through the hepatic portal system/vein
87
Liver
- detoxifies harmful compounds in blood
- turns ammonia into urea
- stores glycogen
- destroys worn out RBC and produces bile
88
Glycogen
intermediate energy source found in liver
89
Bile salts
- emulsifies and allows for the digestion of fats
90
Bile pigments
- toxic to the body
- bilirubin and biliverdin (yellow when combined)
91
What happens when the liver malfunctions?
- build up of bile = build up of bile pigments = jaundice
92
What are the three versions of the respiratory system?
- cutaneous
- gills
- lungs
93
Cutaneous Respiration
- gas exchange occurs through the skin
- aquatic animals with a thin epidermis and a high vascularized dermis
- supplement for fish
- some amphibians
94
Gills
- organs that extract oxygen from water and release carbon dioxide
- water goes through mouth and is pumped through gills
95
Parts of the gill respiratory system
- gill arch
- gill filament
- gill lamellae
96
Gill arch
series of bony arches behind the throat that support the gills
97
Gill filament/lamellae
- contains capillaries
- where gas exchange occurs
98
What are the four aspects that enhance gill efficiency?
1. ram ventilation
2. lamella surface area
3. diffusion distance
4. countercurrent exchange
99
Ram ventilation
- one way path of water into gills
- constant flow of oxygen
100
Lamellae surface area
- larger surface area = more gas exchange
- 2.5 square feet/lb
101
Diffusion distance
- as the lamellae gets thinner, gas exchange is faster
102
Countercurrent Exchange
- diffusive exchange between two fluids flowing in close proximity and opposite directions
- maintains a concentration gradient and prevents equilibrium
- 80% of oxygen from water
103
Lungs
- respiratory surface = alveoli
- each alveoli is surrounded by a capillary
- negatives:
a. half time inhaling half time exhaling
b. lungs are never fully emptied
104
O2 + Hemoglobin <--> oxyhemoglobin
- affected by pH
- Bohr effect
- keeps O2 concentration in body low, which allows for constant diffusion
- when pH=7.4, forward rxn occurs
- when pH=7.2 reverse rxn occurs
105
Bohr effect
hemoglobin loses its affinity to oxygen as pH decreases
106
CO2 + Hb <--> carbaminoHb (CHb)
- governed by equilibrium dynamics
- acts as a pH buffer
107
CO2 + H2O <--> HCO3- + H+
- catalyzed by carbonic anhydrase
- forward rxn lowers pH
- reverse rxn increase pH
108
Step of Gas Exchange of Tissues
1. CO2 from tissue diffuses into RBC
2. CO2 reacts with water and lowers pH
3. OHb becomes O2 and Hb
4. O2 diffuses out of RBC
5. CO2 and Hb bind to form CHb and prevents pH from decreasing
109
Gas Exchange at the Lungs
1. Low [co2] in the lungs causes CO2 diffuses out of the RBC
2. Chb breaks down into CO2 and Hb, and CO2 continues diffusing outward
3. CO2 concentration decreases, so HCO3- and H+ react to form CO2 and H2O, which increases the pH
4. Due to the higher pH, Hb and O2 bind to form OHb which maintains a low oxygen concentration in blood
5. Due to low concentration, continues to O2 diffuse into RBC
110
Excretory system function
- excretion of liquid waste
111
What makes up liquid waste?
- ammonia/urea from proteins and deamination
- excess water and salts
- other harmful compounds in the blood
112
Kidney
- composed of nephrons
- each kidney contains about 1 million nephrons
113
Nephron definition
- functional unit of the kidney used for excretion and osmoregulation
114
Excretion
- 3 processes:
1. filteration
2. tubular reabsorption
3. tubular secretion
115
Filteration
- high hydrostatic pressure in glomerulus forces water and dissolved molec from blood into Bowman's capsule = filtrate
- produces 200 liters of filtrate per day
116
what dissolved molecules are in blood?
amino acids, electrolytes, glucose, amino acids, fatty acids
117
Tubular reabsorption
- cells lining the nephron will actively reabsorbing the good stuff back into the blood through peritubule capillaries
118
Tubular secretion
- harmful compounds are secreted into the nephron through peritubule capillaries = urine
119
Osmoregulation
- regulating the tonicity of cells
- 5 steps:
1. proximal convoluted tubule
2. descending limb of loop of henle
3. ascending limb of loop of henle
4. distal convoluted tubule
5. collecting duct
120
Osmoregulation: Proximal Convoluted Tubule
- sodium pumps pump sodium from nephron into the peritubule capillaries
- water follows by osmosis
- 66% of blood volume is recovered here
121
Osmoregulation: Descending limb of loop of henle
- water is drawn out nephron due to high salt concentration in the surrounding tissues
- 25-50% of blood volume is recovered
122
Osmoregulation: Ascending limb of loop of henle
- not permeable to water
- sodium is pumped into surrounding area
123
Osmoregulation: Distal convoluted tubule
- sodium pumps pump sodium into peritubule capillary
- water follows by osmosis
- this step is controlled by hormones
124
Osmoregulation: collecting duct
- permeable to water
- surrounding area is salty, so water is drawn out
- controlled by hormones
125
Collecting duct permeability vs urine volume
- high permeability due to high vasopressin levels = concentrated/hypertonic urine = low urine volume
- low permeability due to low vasopressin levels = diluted/hypotonic urine = high urine volume
126
Hormonal Control of Osmoregulation
- baroreceptors
- osmoreceptors
127
Baroreceptor function
- monitors blood pressure
- present in carotid arteries
128
Osmoreceptor function
- monitors salinity
129
Rapid drop in blood pressure
- adrenal glands secrete aldosterone
130
Aldosterone function
- increases sodium pump activity in the distal convoluted tubule which pulls in sodium and water
- increase in blood volume = increase in blood pressure
131
Increase in salinity
- pituitary gland secretes vasopressin
132
Vasopressin function
- makes the collecting duct more permeable to water
133
Parts of the male reproductive system
- 2 testes
- epididymis
- ductus deferens
- urethra
- semen
- sperm
134
What are the testes houses in? why?
- the scrotum
- scrotum is outside the body cavity so temperature is cooler
- cooler temp = increase in viability of sperm
135
Testes
- contains seminiferous tubules that produce sperm
- endocrine gland that produces testosterone
136
What are some functions of testosterone?
- skeletal growth
- muscle development
- facial hair
137
Epididymis
- coiled tube on testes that stores sperm
138
Ductus deferens
- muscular tube that carries sperm from the epididymis to the urethra
139
Urethra
- muscular tube that carries sperm and urine to penis
140
Inguinal canal function
- serves as a passage way for structures between the intra and extra abdominal structures
141
Semen
- contains sperm and glandular secretion
- seminal vesicles
- prostate gland
- cowper's gland
142
Seminal vesicles
- secretes mucoid base
- secretes fructose
- secretes prostaglandins
- 60-70% of semen volume
143
Mucoid base function
- neutralizes the acidity of the urethra and vagina to protect the sperm
- provides lubrication through the urethra
144
Prostaglandins function
- causes smooth muscle contraction
- induces peristalsis in the female reproductive system
145
Prostate gland
- contains citric acid
- contains zinc that kills bacteria and cleans out urethra
- 25-30% of semen volume
146
Cowper's gland
- pre-ejaculate
- cleans out urethra/kills bacteria
- lubricant
147
Sperm
- contains head, neck, and tail
148
What are fructose and citric acid used for in the male reproductive system?
- used as energy for the mitochondria in the sperm to move the flagella/tail
149
What is the tail of a sperm cell made of?
flagella
150
Acrosome
- cap-like structure on the head of a sperm cell that contains enzymes involved in fertilization
151
What is the neck/midpiece of a sperm cell made of?
mitochondria
152
What are the main parts of the female reproductive system?
- 2 ovaries
- Uterus
- cervix
- vaginal canal
153
Ovaries
- 1-2 million primary oocytes that have started M1 are stored in the ovaries
154
Where do the primary oocytes sit?
- in the graafian follicle
155
What happens in the ovaries during ovulation?
- release of oocyte into the oviduct (takes about 3-5 days to get to uterus)
156
Uterus
- myometrium layer
- endometrium layer
157
Endometrium function
- spongy, vascularized tissue is the uterus that supports the young embryo
158
Cervix
- tight opening that secretes:
a. mucus to enhance sperm movement
b. wax to create a plug for the opening to block bacteria
159
Where does copulation occur?
the vaginal canal
160
Female Reproductive Cycle phases
- 28 day cycle
- 3 parts
a. menstrual cycle
b. proliferative phase
c. secretory phase
161
Menstrual cycle
- days 1-5
- pituitary gland secretes follicle stimulating hormone (FSH), which causes one primary oocyte to complete meiosis one, and the graafian follicle to enlarge and start secreting hormones
- thick endometrial lining of uterus degenerates and is expelled off (mensis)
162
Proliferative Phase
- day 5-14
- graafian follicle is secreting estradiol
- on day 11, estradiol levels peak, which causes the pituitary gland to secrete luteinizing hormone (LH)
163
Follicle Stimulating Hormone (FSH) function
- causes primary oocyte to complete meiosis one
164
Luteinizing hormone (LH)
- causes ovulation of secondary oocyte around day 14
165
Estradiol function
- causes the thickening and vascularization of endometrial lining
166
Secretory Phase
- day 14-28
- graafian follicle becomes corpus luteum, which secretes estradiol and progesterone
- secretion of estradiol and progesterone causes more thickening and vascularization of endometrium and the deposition of glycogen in endometrium
- 2 possibilities
167
Progesterone function
- blocks secretion of FSH (prevents another primary oocyte from ovulating)
- prevents endometrial lining from degenerating
168
What if the embryo does not implant in the endometrium?
- the corpus luteum degenerates and stops secreting estradiol and progesterone
- endometrial lining degenerates
- pituitary gland secretes FSH
- cycle restarts
169
What happens if the embryo is implanted in the endometrium?
- the embryo secretes human chorionic gonadotropin, which prevents the corpus luteum from degenerating
170
What does the corpus luteum secrete?
- estradiol and progesterone
171
Fertilization
- sperm encounters the zone pellucide and releases acrosomal enzymes that digests a path through the ZP
- sperm encounters and fuses with the membrane
172
What happens when the sperm encounters and fuses with the membrane of the secondary oocyte?
- sperm chromosomes enter oocyte
- oocyte membrane undergoes a confirmation change which prevents other sperm from fusing
- oocyte completes meiosis 2
= embryo
173
Where does successful fertilization occur?
in the upper regions of the oviduct
174
Zone pellucide function
- reduces the chance of polyspermy by slowing the sperm down
175
After fertilization
- embryo goes through cleavage and then becomes a blastocyst
176
Cleavage
- repeated mitotic division of embryo without growth for 7 days and then becomes a blastocyst
177
Blastocyst
- hollow ball of cells that implants in the endometrium
- composed of trophoblast and inner cell mass
178
What does the inner cell mass of a blastocyst become?
becomes the blastula
179
Implantation
- trophoblast secretes enzymes that digest the endometrium and burrows into it
- embryo can now grow
180
What are the four extraembryonic membranes a developing embryo grows?
- develops with 4 extraembryonic membranes
a. amnion
b. chorion
c. allantois
d. yolk sac
181
Amnion
- forms fluid filled sac around embryo
- uses as protection
182
Chorion
- derived from the trophoblast
- surrounds everything
- secretes hCG
- at 3 months it forms the placenta
183
Allantois
- forms the umbilical chord and bladder
- waste removal
184
Yolk sac
- vestigal structure
185
Placenta
- develops from the chorion at 3 months
- interface between fetal and maternal circulatory systems
- endocrine gland
186
What does the placenta secrete?
a. estradiol
b. progesterone
c. at 6 months, relaxin
d. at 9 months, a surge of estradiol
187
Relaxin function
- softens dense connective tissue
- allows pelvic bone to widen
188
What does the surge of estradiol from the placenta cause?
- causes the uterus to secrete prostaglandins
189
Prostaglandin at 9 months pregnancy
- causes contractions of the myometrium and leads to pain
- pain causes the pituitary gland to secrete oxytocin
- oxytocin causes stronger contractions
