exam 2 Flashcards
(227 cards)
1
Q
What are the three categories of muscle, based on microscopic appearance? What sets them apart from one another?
A
Skeletal:multinucleate with striations (voluntary, bones and cartilage), Cardiac: only occurs in the heart (involuntary, cells are branching, intercalated disks), Smooth: lack striations (involuntary, devoted to visceral functions such as digestive tract blood vessels and lungs)
2
Q
How are muscle cells organized to form a muscle?
A
Each muscle cell is encased in a sarcolema which inside are myofibrils made up of myofilaments. Myofibrils consist of chains of repeating sarcomeres, which include thick and thin myofilaments. Myofilaments are made of actin (thin, dark straitions) and myosin (thick, light striations) proteins and anchored to Z disks
3
Q
How do muscles contract?
A
Skeletal muscle and cardiac muscles contract by nerves stimulating muscle to contract with generates tensile forces, electrical impulses travel by way of calcium ion channels in cell membrane, sliding of thick and thin filaments overlap to shorten muscles
Smooth muscles: acin and mysoin filaments are much fewer, calcium ions come from extracellular fluid nearby, thick filaments pull on thin ones which pull on network of dense bodies (force is transferred to plasma membrance and the entire cell shortens), slower contractions but can remain contracted a longer time, less resistant to fatigue because actin and myosin filaments do not detach right away- uses less ATP than skeletal muscle
4
Q
How does the tendon act in an elastic way to store energy?
A
Energy is stored within a muscle and tendon, stretching like a rubber band and releasing during repetitive events. Ex) in running 33% of energy is recycled per each stride
5
Q
extensors vs flexors
A
Bending and straightening
Flexors: bend one body part relative to another about a joint
Extensors: straighten a part of the body
Ex) elbows towards/away from biceps
6
Q
adductors vs abductors
A
In and out
Adduction: draw limb towards ex) lower arm from T-pose
Abduction: move limb away from midline ex) raise arm to T-pose
7
Q
levators vs depressors
A
Levators and depressors are a special kind of abduction/adduction
Levators: close jaws
Depressors: open jaws
8
Q
protractors vs retractors
A
Projecting away and back
Protractor: project a part out ex) moving shoulder forward
Retractor: bringing a part back ex)pulling shoulder backward
9
Q
supinators vs pronators
A
Rotating
Supinators: rotate palm or sole up
Protonators: roate palm or sole down
10
Q
Sphincters
A
Opening and closing
Sphincters: close tubes, circular muscles ex)pupil
Dialators: open tubes
11
Q
What are the myomere shapes and trends in axial muscle evolution across fishes? What about axial muscle trends in tetrapods?
A
There is a trend from cephalochordates and jawless fishes going to gnathostomes that there are increasingly complex myomeres and myosepta. V-shaped muscle bocks become W shaped in gnathostomes which helps distribute muscle forces and myosepta act as little tendons that direct forces to specific muscle fibers. Axial muscles are reduced in tetrapods since appendicular muscles are doing more work. Axial muscles also become specialized; exert more control over vertebral column flexion, rib cage movement. In salamanders epaxial muscles are on segmented muscle and hypaxial muscles divided into 3 layers. In lizards epaxial muscles differentiated and reduced, hypaxial muscle form body wall, horizontal septum lost. In birds axial muscles are reduced due to fusion in vertebral column. In mammals additional subdivisions, hypaxial muscles become recus abdominis which supports ventral body wall.
12
Q
What are some muscular adaptations for running?
A
Bunching of appendicular muscles proximally in limb, reduces mass carried by limb, most extreme examples in perissodactyls (horses) and artiodactyls (deer) also seen in bipedal archosaur
13
Q
What muscular adaptations are seen in flying birds?
A
Axial muscles diminished, appendicular muscles expanded. Also keep muscle mas close to body, pectoralis muscles become huge (to depress wings) supracoracoideus now inserts on coracoid through tendon to lift wing, long tendons give precision, patagialis keeps wing shape aerodynamic.
14
Q
What is the difference between intrinsic and extrinsic eye muscles?
A
Intrinsic: muscles that move or shape the lens to focus light on the retina
Extrinsic: rotate eyeball within the orbit to direct the eye’s gaze
15
Q
What are some novel functions that muscles have evolved to do, aside from contracting?
A
Sound producing, drumming muscles on swim bladder, bird syrinx is a muscular organ at split of trachea and lungs that allows birds to sing continuously on in and out breath, electrically producing muscels that depolarize using sodium and potassium ions.
16
Q
Epimesium
A
muscle tissue membrane around the entire muscle organ
17
Q
Perimysium
A
muscle tissue membrane around groups of cells
18
Q
Endomysium
A
muscle tissue membrane around a single fiber/cell
19
Q
Sarcolema
A
cell membrane that encases each muscle cell
20
Q
Intercalated discs
A
in cardiac muscles intercalated discs join togehter short cells. specialized junctions between cardiac muscle fibers (cardiomyocytes) that allow for rapid electric transmission, called an action potential, and nutrient exchange.
21
Q
desmosomes
A
anchors intercalated disks, consist of protein plaques with root-like fibers
22
Q
fascia adherens
A
span space in between muscle cells
23
Q
gap junctions
A
how electrical impulses are sent between two muscle cells, small pores in between each cell
24
Q
aponeuroses
A
thin, flat, and tough sheets of muscle tendons, ex) abdominal
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fascia
sheets of fibrous connective tissue that wrap and bind muscles together (tendons) ex) fingers have tendons conneting them to arms
26
multiunit smooth muscle
motor units come from autonomic nervous system and synapse with individual cells, seen in large arteries, airways, iris, and arrector muscles
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single unit smooth muscle
cells are connected to eachother by gap junctions (much fewer neurons), inner circular layer and outer longitudinal layer, found in most blood vessels, digestive, respiratory, urinary, and reproductive tracts
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tonic muscles
slow contracting and produce little force, but can sustain contraction for a long time, used for postural support, coomon in axial and appendicular muscles, common in amphibians and reptiles (not seen in humans/mammals)
29
Twitch
Twitch (phasic) fast contraction, used for rapid movements, found commonly in all vertebrates
Slow twitch: take longer to reach maximum force, more resistant to fatigue
Fast twitch: thick and strong fibers adapted for quick responses, not fatigue resistant
30
Morphological vs physiological cross section
Morphological cross section: ara of a muscle perpendicular to it’s longitudinal axis at the widest part
Physiological cross section: area of all muscle fibers perpendicular to thier longitudinal axis
Morphological and physiological are same if muscle fibers run parallel, different if they run obliquely
31
Muscle origin vs insertion
Origin: (relatively fixed point of attachement, site of origin is the head, where muscle anchors to
Insertion: mobile point of attachment, site of insertion is the slip, origin stays still and insertion moves AKA slips during muscle contraction
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epaxial muscles
part of axial musculature, used for locomotion, dorsal
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hypaxial muscle
part of axial musculature, used for locomotion, ventral
34
horizontal septum
part of axial musculature, used for locomotion, absent in cyclostomes
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myomeres
muscle blocks
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myosepta
connective tissue separating muscles
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hypobranchial muscles
ventral, below jaws and gill arches, contriubutes to tongue
38
branchiomeric muscles
sides of gill arches, each arch has its own dorsal and ventral superficial constricors, interarcuals (dorsal and lateral), adductor, and interbranchial (between gill rays) began as a water pump, modified for jaws/feeding
39
What is unidirectional vs bidirectional respiration?
What is unidirectional vs bidirectional respiration?
40
Which taxa have external gills? Why do they have them?
External gills are filamentous capillary beds that protrude into surrounding water, seen in many vertebrate larvae and some adults (lungfish, amphibians, some actinopterygians, chondrichthyans) water currents flow across their surface to aid in exchange (passive!)
41
What are some cutaneous respiratory organs? How do they work? Which vertebrate groups do cutaneous respiration?
Cutaneos respiratory organs are where skin supplement breathing, seen in fish amphibians and reptiles, plood circulates near surface of the skin and establishes countercurrent exchange system, often accompanied by increases in surface area (skin folds)
42
Dual pump
Buccal and opercular cavities expand, while operculum is closed (water drawn in through mouth), mout closes and buccal and opercular cavities are compressed (water pushed out trhough operculum)
43
Buccal pump (two- vs four-stroke)
Two stroke: Bidirectional and in tetrapods, expansion of buccal cavity mixes old air from the lungs with fresh air in the mouth, upon compression the mixed air is forced into lungs and excess air is expelled through the nares
Four stroke tetrapods (amphibians):1) buccal cavity expands to draw fresh air in through open nares 2) the glottis opens rapidly, relaeasing spent air from the elastic lungs through the open nares 3) the nares close and the floor of the buccal cavity rises, forcing the fresh air held in this cavity into the lungs through the open glottis 4) the glottis closes retaining the air that has just filled the lungs and nares open agian
44
Aspiration pump
amniotes and birds, air is sucked in by low pressure created in lungs (lungs located within pump) pump includes rib cage and muscular diaphragm, mouth no longer involved (feeding and ventilation are decoupled) useful for mammals who do a lot of chewing
45
How do lampreys and hagfish ventilate their gills?
In lampreys oral disk is suctioned onto surface, so water flows both in and out of pharyngeal pores, muscle compression in pharynx drives ventilation
In hagfish adults scroll and unscoll velum and contract branchial pouches to produce a unidirectional water current
46
How are snake lungs specialized for breathing during feeding?
Asymmertrical paired lungs in many snakes (left smaller) left lung lost entirely in some. When swallowing prey snakes compress saccular (posterior) portion to continue ventilation.
47
How are bird lungs organized? How do they route air across their parabronchi?
Two lungs connected to a trachea and ventilated by an aspiration pump, the trachea splits into two primary bronchi that do not enter the lung but extended to the posterior air sacs, nine avascular air sacs are connection to the lungs and extend into the cores of most large bones, instead of blind-ended alveoli they have one-way parabronchi that permit air to flow through the lungs, small air capillaries open off the walls of each parabronchus and gas exchange with the blood occurs in the air capillaries. During exhalation 2 air from posterior air sacs moves to parabronchi and faveoli, plus air in anterior air sacs flow out through bronchi.
48
How do fish regulate the amount of water that flows over their gills? Why do they do this?
Rather than breathin in and out through the mouth, fish use a one-way system, passing water in one direction over their gills. Water goies in the mouth, acoss the gills, and out through the opercula (the bony covering protecting their gills). A large amount of water needed to pass over the gills to get enough oxygen out of the environment
49
branchial arches
series of bony loops present in fish which support the gills, all vertebrate embryos develop pharyngeal arches as an evolutionary byproduct, start with 6
50
branchial rays
fine cartilaginous rods that articulate at their bases with the branchial arch
51
primary lamellae
part of internal gills, branchial arches support gill filaments, support secondary lamellae
52
secondary lamellae
part of internal gills, contain capillary beds
53
countercurrent exchange
blood in secondary lemellae flows in one direction and water flows in the opposite direction
54
faveoli
internal compartments that open into the central chamber and contain capillaries in the lung, internal subdivisions of the lung wall that open to a common central chamber found in amphibians and reptile lungs
55
bronchi
mammals, within lungs, two bronchi (each lobe of the lung)
56
Bronchioles
smaller branches off of the bronchi in the lungs
57
trachea
where lungs are connected to the environment, glottis forms the entrance
58
surfactant
reduces surface tension at air-water interface, alveoli are covered by mucus, need help to break tension so they can inflate
59
ram ventilation
fish swims forward with its mouth open taking in water that passes over the gills. The drawback to ram ventilation is that the fish has to swim continuously to be abble to continue breathing, occurs in active fishes swimming through the water
60
holobranch
arch with lamellae on anterior and posterior sides
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hemibranch
arch with lamellae only on one side
62
phsostomus swim bladder
connected to the pharynx through the pneumatic duct, air volume controlled by fish swallowing air and pushing it through pneumatic duct
63
Physoclsitorous swim bladder
not connected to the digestive tract so that fish with these swim bladders must diffuse gas from the blood to fill and collapse them.
64
limiting membrane
in turtles, connects to the abdominal muscles that contract or relax, allows lungs to open/close by acting as alternative to aspiration pump because of shell
65
parabronchi
in bird lungs, an alternative to blind-ended alveoli, parabronchi permit air flow through the lungs
66
air capillaries
in bird lungs, small air capillaries open off the walls of each parabronchus, and gas exchange with the blood occurs in the air capillaries
67
ventilation
rate of fluid passing over respiratory surface
68
perfusion
rate of blood moving through respiratory organ
69
How do arterioles route blood to or from a capillary bed?
Most capillaries drain into venule or end of metarteriole (most goes back to heart) most control involves constriction of upstream arterioles. Arterioles connect with even smaller blood vessels called capillaries. Through the thin walls of the capillaries, oxygen and nutrients pass from blood into tissues and waste products pass from tissues into blood.
70
How do pressure gradients contribute to blood flow through the vessels? What happens to pressure as blood flows away from the heart?
Pressure gradient determines the flow of blood back to the heart depends upon pressure in the veins is much lower than in arteries, drives blood back into the heart. As blood moves from the venules to veins the average blood pressure drops, but the blood velocity increases, this pressure gradient drives blood back towards the heart.
71
How does resistance affect blood flow?
Resistance is the force that opposes the flow of a fluid. In blood vessels, most of the resistance is due to vessel diameter (vasoconstriction and vasodilation) as vessel diameter decreases the resistance increases and blood flow decreases, increasing resistance decreases blood flow
72
What are the similarities and differences between blood vessels/flow and lymphatic vessels/flow?
Blood has RBCs, WBC's, platelets, and a fluid called plasma. Whereas lymph has WBC's and watery fluid. They both have immune and also circulatory functions in them. One of the major differences between them is that blood flows through blood vessels and lymph through lymphatic vessels
73
What are the major locations of collections of lymph nodes?
Cervical lymph nodes (head and neck), axillary lymph nodes (armpit, upper limb and female breast), thoracic (mediastinum, lungs, and airway), abdominal (urinary and reproductive), intestinal and mesenteric (mesenteris, digestive tract) inguinal (groin, entire lower limb), popliteal (back of knee, foot and leg)
74
How has the ancestral pattern of six aortic arches been modified in each major vertebrate group?
Basic 6-arch pattern at the base of jawed vertebrates
Cyclostomes: 8+ aortic arches
Chondrichthyans: have all 6 (first two/spiracular are highly modified and have few gill lamellae
Teleosts have 4 (first 2 lost/modified)
Lungfish have 5 (2-6) only arches 2,5,6 have gill lamellae, oxygenated blood from lungs goes to arches 3 &4 and directly to body, deoxygenated blood from veins goes through arches 5 & 6 and then to lung
Amphibians have 4 (3-6)
Squamates/turtles have 3 (3,4,6)
Birds have 3 (3,4,6) systemic arch goes to right
Mammals have 3 (3,4,6) systemic arch goes to left
75
How does the hepatic portal system work?
Hepatic portal vein receives blood specifically from the stomach, instestines, pancrease, and spleen and carries it into the liver through the porta hepatis. The porta hepatis serves as the point of entry for the hepatic portal vein and proper hepatic artery and is the point of exit for the bile passages
76
How is the heart organized in major vertebrate groups – how many chambers and any unique features?
*cyclostomes, chondrichthyans, and Teleosts have 1 atrium, 1 ventricle
Cyclostomes: Hafish and lamprey
Hagfish: branchial heart with sinus venosus, atrium, ventricle, vena cava (no bulbus/conus arteriosus) lots of simple accessory “hearts”- portal, caudal, cardinal
Lamprey: sinus venosus,atrium, ventricle, bulbus arteriosus (expands and absorbs P changes generated by ventricle)
Chondrichthyans: sius venosus, atrium, ventricle, conus arteriosus (muscular), special conal valves prevent backflow of blood
Teleosts: sinus venosus, atrium, ventricle, bulbus arteriosus (not muscular), bulbus arteriosus helps to absorb large increases in blood pressure (depulsation)
Lungfish: (2 chambers, walls partially separate) Partially divided atria and ventricles: interatrial septum, atrioventricular plug, interventricular septum, when lungfish breathe air left channel receives oxygenated blood from lungs, right channel carries deoxygenated systemic blood, spiral valve in conus arteriosus helps keep blood separate
Amphibians: 3 chambers, complete interatrial septum, one ventricle, conus arteriosus with spiral valve to separate blood streams
Reptiles: 3 chambers, 2 atria, 1 ventricle, 3 sub chambers in ventricle (cavum venosum, cavum pulmonale, cavum arteriosum)
Crocodilians: 4 chambers (2 atria, 2 ventricles), in crocodilians the foramen of panizza normally connects the two sides of the systemic circuit, birds, mammals: 4 chambers (2 atria, 2 ventricles)
77
How do crocodilians use a cardiac shunt when diving?
they do a cardiac shunt when diving and holding their breath- they constrict blood vessels and use special valves to route blood away from the pulmonary trunk
in crocodiles, shunts blood away from lungs when diving, vasoconstriction in lungs obstructs pulmonary circulation- cog tooth valves close trunk, pressure higher in R ventricle=deoxygenated blood exits mostly through systemic arch (recycle systemic blood and monitor pH in dive
78
plasma matrix
fluid portion of blood, mostly water + protein + nutrients
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erythrocytes
red blood cells, used in gas exchange
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leukocytes
white blood cells, used in immune system regulation
81
platelets
component of blood that are not true cells, involved in clotting
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arteries
carry blood away from heart, usually oxygen rich, red
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veins
carry blood back to heart, usually oxygen poor, blue
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capillaries
connect smallest arteries to smallest veins to create a circuit
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tunica interna
endothelium, lines the blood vessel and is exposed to blood, secretes chemicals that stimulate dilation or constriction, normally repels blood cells and platelets to prevent clotting
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tuninica media
middle layer, contains smooth muscle, collage, elastic, contracts vessels
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tunica esterna
outer layer, consists of loose connective tissue, anchors vessels in place (vessel wall)
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arterioles
control the amount of blood flowing to organs through capillaries (smallest arteries are capillaries, arterioles are slightly larger)
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metarterioles
throughfare channels that link arterioles to directly to venules (bypass capillary bed)
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precapillary sphincters
control flow in capillary beds supplied with metarterioles, when sphincters are relaxed capillaries have more blood, when sphincters contract they constrict the entry to the capillary and blood bypasses the capillary
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venules
smallest veins, receive blood from capillaries, very porous, no muscle in vessel wall
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circulatory routes
Simplest: heart-> arteries-> arterioles->capillaries->venules->veins, in this route blood passes through only one network of capillaries from the time it leaves the heart until it returns
Portal: blood flows through two consecutive capillary networks before returning to heart, between hypothalamus and anterior pituitary, between intestines to liver
Anastomosis: convergence between two vessels other than capillaries, arteriovenous anastomosis (shunt), artery flows directly into vein bypassing capillaries
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vasoconstriction
vessels get smaller, smooth muscle of tunica media contracts, increasing pressure
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vasodilation
vessels get larger, brought about by muscular passivity, smooth muscle relaxes, blood pressure expands vessel
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systolic BP
during ventricular contraction
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diastolic BP
during ventricular relaxation
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myocardium
the muscular tissue of the heart, pump deoxygenated blood from the right ventricle to the lungs to allow for oxygenation in the alveoli, pump oxygenated blood from the left ventricle into the aorta for distribution to the rest of the body
98
lymphatic capillaries
terminal lymphatics, penetrate nearly every tissue of the body, cells of capillary wall overlap like roof shingles, closed at one end, endothelium creates valve-like flaps that open when interstitial fluid pressure is high, close when it is lowl
99
lymphatic trunks
jugular, subclavian, trunk (bronchomediastinal, intercostal, intestinal), and lumbar trunk
100
lymphatic ducts
Right lymphatic duct: receives lymph from right arm, right side of head and thorax, empties into right subclavian vein
Thoracic duct: larger and longer, begins as a sac in abdomen called the cisterna chyli, receives lymph from below diaphragm, left arm, left side of head, neck and thorax, empties into left subclavian vein
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lymph nodes
cleanse the lymph
102
Single vs double circulation
in single circulation, blood flows to and from the heart through a single pathway, whereas in double circulation there are two separate pathways that are connected to the heart through which oxygenated and deoxygenated blod flows
103
Afferent vs efferent arteries:
afferent arterioles carry blood to glomerulus and efferent arteriole carry blood away from the Glomerulus (the filtering unit of the kidney, is a specialized bundle of capillaries that are uniquely situated between two resistance vessels)
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cardinal veins
veins that drain into the sinus venosus during embryonic development, mainly receives vessels that drain the head and the forelimbs
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lateral abdominal veins
drains above mainly into the axillary vein via the lateral thoracic vein and below into the femoral vein via the superficial illiac vein, transports venous blood to the liver for processing
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pericardium
the membrane enclosing the heart, consisting of an outer fibrous layer and an inner double layer of serous membrane
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sinus venosus
cardiac chamber with myocardial walls located upstream of the right atrium in tetrapod's and the single atrium in fish
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atrium
one of the upper chambers in the heart that receives blood from the circulatory system, pumped into the heart ventricles through the atrioventricular mitral and tricuspid heart valves
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ventricle
two lower chambers of the heart, receive blood from the atria and pump it to the rest of the body
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Conus/bulbus arteriosus
Conus arteriosus contains myocardium in its walls and has two rows of valves, the bulbus has no myocardium and is rich in elastin, transport deoxygenated blood from the right ventricle to the pulmonary trunk and onto the lungs
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sinoatrial valve
develop from two lateral infoldings of cardiac wall, in the upper wall of the right atrium, used as pacemaker
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atrioventricular valve
separate atria from ventricles, tricuspid on R side, bicuspid/mitral on L side
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conal valves
4 valves, the separation between the conus and the ventricular junction
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semilunar valves
Separate ventricles from aorta and pulmonary trunk, pulmonary valve on R side, aortic valve on L side
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branchial heart
accessory hearts in hagfish that serves as pumps to circulate the blood, high volume low pressure simple heart
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truncus arteriosus
remnant of ventral aorta, receive blood from different sides of spiral valve
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cavum venosum
receives blood from right atrium (deoxygenated) sends it to cavum pulmonale
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cavum pulmonale
receives blood from cavum venosum; sends it out pulmonary arch
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cavum arteriosum
receives blood from left atrium (oxygenated) routes it across muscular ridge to cavum venosum and out systemic arch
120
cardiac shunt
in crocodiles, shunts blood away from lungs when diving, vasoconstriction in lungs obstructs pulmonary circulation- cog tooth valves close trunk, pressure higher in R ventricle=deoxygenated blood exits mostly through systemic arch (recycle systemic blood and monitor pH in dive.
121
foramen panizza
connects L and R systemic arches
122
Coronary sulcus
atrioventricular sulcus, boundary between, separates atria and ventricles
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Interventricular sulcus
overlies interventricular septum that divides (boundary between)the right ventricle from left
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interatrial sepctum
wall that separates atriai
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nterventricular septum
muscular wall separating ventricles
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pectinate muscles
internal ridges of myocardium in right atrium and both auricles
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trabeculae carneae
internal ridges in both ventricles, may prevent ventricle walls from sticking together after contraction
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sinoatrial (SA) node
modified cardiomyocytes (heart muscle cells) pacemaker in right atrium, initiates each heartbeat and determines heart rate, signals spread throughout atria
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Atrioventricular (AV) node
near right AV valve at lower end of interatrial spetum electrical gateway to the ventricles
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atrioventricular bundle
forks into right and left branches that pass through interventricular septum
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subendocardial connecting networks
nerve-like processes spread throughout ventricular myocardium, cardiomyocytes then pass signal from cell to cell through gap junctions
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umbilical vein
part of fetal circulation, carries oxygenated blood from placenta to developing liver
133
How are different methods of mastication (chewing vs slicing) adapted for different foods?
Soft and sinewy foods are best broken down by bladelike teeth, fibrous foods are best broken down by grinding, gizzards also break down food by griding it up with stones
134
What are the major divisions of the digestive tract?
Tubular passageway that goes from the mouth to the anus/cloaca. Made of buccal cavity (capturing food and chewing; contains teeth, tongue, palate), pharynx (swallowing), and alimentary canal (chemical and mechanical digestion, divided into esophagus stomach small intestine and large intestine)
135
How do birds regurgitate food for their young?
Birds can hold food in the crop which can then be brought back to young and regurgitated
136
How are the digestive tracts generally organized in fishes vs amphibians vs tetrapods?
Fishes have esophagus , stomach and intesting that open into cloaca or rectum, may contain rectal gland, pyloric cecum, and spiral valve
Amphibinas have a shor esophagus, double layer of mucus cells, gradual transition into coiled small intestine, short straight large intestine
Tetrapods have a more elaborate digestive tract, stomach is thicker and muscular, cloaca differentiated into coprodeum (large intestine empties into) and urodeum (urogenital system empties into
137
How does hindgut fermentation work and how is the digestive tract arranged?
Hindgut fermentation is digestion of cellulose that happens in intestine, extensive elongation of intestine and large ceca increase volume for fermentation, large cecum projects off intestine-small intestine junction, usually smaller animals, fermentation occurs at the end of digestion
138
Which non-ruminant mammals also do foregut fermentation?
Psuedo ruminants like camals have 3-chambered stomachs (no omasum), other animals do foregut fermentation by increasing compartments, hoatzin is only bird that does fermentation in large crop
139
How do animals with long periods between feeding up-regulate and down-regulate their metabolism?
Up-regulation (intestinal mucosa increase in size in response to feeding after fasting), down-regulation: once a meal has been digested, intestinal mucosa returns to resting state. Cell proliferation within the intestine proliferates at different rates, up and down regulation are metabolically expensive and animals only do this if there are predicatble and long periods of fasting
140
What three tissue layers surround the kidneys in mammals?
Renal fascia: binds kindey to abdominal wall, perirenal fat capsule: cushions kidney and holds it into place, fibrous capsule: encloses kidney protecting it from trauma and infection, collagen fibers extend from fibrous capsule to renal fascia
141
What is housed within the renal corpuscle?
Blood filtering component of the nephron of the kidney, consists of glomerulus and glomerular capsule. Houses parietal (outer layer), visceral (inner layer), casular space, vascular pole, and urinary pole
142
What are the different components of the renal tubule in mammals?
Renal (urinferous tubule) duct leading away form glomeular capsule and ending at tip of medullary pyramid
Proximal convoluted tubule (longest and most coiled region
Nephron loop: U shaped portion with thick and thin segments to transport salt/water
Distal convuluted tubule: begins after ascending limb reenter the cortex, water reabsorption
Collecting duct: receives fluid from the DCTs of several nephrons as it passes back into the medulla
143
How are kidneys different between fishes/amphibians and amniotes?
Fishes: pronepheros degenerate and more tubules are added to leave adult with opisthonephros (kidney), tubules also transport sperm
Amphibians: pronephros replaced with mesonephros and optisthonephros, neprons degenerate into anterior and posterior regions, andterior tubes transport sperm and posterior tubes drain urine using achinephric duct
144
What are the three ways that ammonia is excreted from the body, and which groups use each mechanism?
Ammonotelism: direct excretion through gill epithelium, water animals
Uricotelism: ammonia is converted to uric acid and excreted, birds and reptiles
Ureotelism: ammonia converted to urea and excreted, mammals
145
How do mammals and birds conserve water?
Large numbers of nephron loops allow for more extraction of water and highly concentrated urine
146
Which kinds of fish can switch from freshwater to saltwater? What about saltwater to freshwater?
Anadromous fish hat in freshwater, migrate in saltwater, spawn in freshwater
Catadromous fish start in saltwater, migrate in freshwater, spawn in saltwa
147
oral glands
release saliva into the mouth during feeding (exocrine glands), contain enzymes like amylase to break down food, specialized in many vertebrates for venom production
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pancreas
present in all vertebrates, one or two ducts empty into duodenum of intestine, release pancreatic juice (lots of enzymes), pancreatic islets produce hormones insulin and glucagon to regulate blood glucose levels
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liver
present in all vertebrates, removes toxic substances from blood, produces bile adn releases it into intestines to emulsify fat
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mastication
chemical breakdonw
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gizzard
break down food by grinding it up with stones, muscular region of stomach
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oropharyngeal cavity
the mouth, includes soft palate and hard palate
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lingula feeding
protract tongue out of mouth at prey, possibly represents major feeding innovation of tetrapods moving to land ex) salamanders and woodpeckers
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epiglottis
depressed during swallowing to cover the opening to the trachea and ensure food makes its way from pharynx to the esophagus, flap of cartilage at base of the tongue
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esophagus
connects pharynx with stomach
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stomach
mechanical and chemical digestion of food
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small intestine
divided into duodenum, jejunum, and ileum
Nearly all chemical digestion and nutrient absorption, add secretions to food being digested, selectively absorb amino acids carbohydrates and fatty acids
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large intestine
reduces indigestible residue, re-absorbs water and electrolytes, absorbs vitamins, propels feces toward rectum for excretion
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layers of alimentary canal tissue
Mucosa: epithelium that lines lumen, smooth muscle, and loose connective tissue, innermost layer
Submucosa: loose connective tissue and nerves
Muscularis externa: circular and longitudinal sheets of smooth muscle
Adventitia: fibrous connective tissue
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ruggae
internal wall relaxed into folds
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cardia
narrow part of stomach, only in mammals
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fundus
largest part of stomach, contains fundic glands (type of gastric gland) that secrete mucus
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pylorus
narrow, contains pyloric glands that neutralize acid, pyloric sphincter passes food from stomach to intestines
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gastric glands
glandular epithelium, secrete mucus, branched and tubular, empty into gastric pits
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villi
ingerlike protrusions in small intestine used to increase surface area
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microvilli
up to several thousand on each epithelial cell, also used to further increase surface area of small intestine
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cloaca
receives products from urinary/reproductive systems
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rectum
only receives products from alimentary canal
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peristalsis
waves of contractions that move food along
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typhlosole
prominent longitudinal fold that projects from one wall of the intestine of lamprey larvae, increases surface area for absorption of digestive products
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rectal gland
opens into cloaca, eliminates excess salt
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pyloric cecum
opens into duodenum (junction between stomach and intestine) and increases surface area
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spiral valve
opens into cloaca, eliminates excess salt and who has it: adds surface area and increases time food is spent in intestines, many fish and non-telosts (chondrichthyans, bowfin, gar, ect.)
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gastrolilth
had objects like stones in gizzard
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Duvernoy’s gland in snakes
oral gland specialization, modified to form venom gland in some species
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crop
part of esophagus, temporarily holds food before being digested or regurgitated for nestlings
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appendix
reduces form of cecum, used to store food and break down cellulose, at junction between small and large intestine
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ruminants
hoofed, herbivorous grazing or browsing mammals that do fermentation in specialized stomach compartments
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rumen
large holding and fermenting vat with thin walls and papillae to increase surface area, develops from espohagus
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reticulum
small accessory chamber with honeycomb texture
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omasum
espophageal epithelium is folded into overlapping leaves
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abomasum
true derivative of the stomach
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grazers vs browsers
Grazer: eat grass and low growing herbaceous plants, coarse and fine food particles are physically separated in rumen and reticulum along with gas
Browsers: eat more woody vegetation, shrubs, leaves, reticulum collects finer particles and less fluid is present, gas is belched quickly, so rumen is smaller
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nephric ridge
part of kidney development, mesoderm on posterior body wall expands to form nephric ridge
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nephrotome
part of kidney development, formed after nephric ridge, extend length of the body
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nephrocoel
cavity of nephrotome
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glomerulus
medial end of nephrotome widens to form renal capsule that houses glomerulus (collection of arterial capillaries)
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archinephric duct
general term for the pair of tubes that carry urine from the kidneys to bladder
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opisthonephros
in fish and amphibians, adult structure that arises from mesonephros and acts as the kidney
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ureters
tubular continuation of pelvis, drains urine down to urinary bladder
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hilium
medial surface of kidney is concave and receives renal nerves, blood vessels, lymphatics, and urreters
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renal cortex and renal colums
idneys in mammals, renal cortex ix the columns between the pyramids nad renal colums are extensions of cortex, project inward toward sinus
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Renal medulla and its parts – pyramids, major and minor calyces, renal pelvis
Renal pyramid: broad base facing cortex and renal papilla facing sinus, 6 to 10
Minor calyx: cup that nestles papilla of each pyramid, collects urine
Major calyces: formed by convergence of 2+ minor calyx
Renal pelvis: formed by convergence of 2+ major calyx
All combine to urete
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podocytes
part of visceral layer of renal corpuscles, elaborate cells that wrap around capillaries of the glomerulus
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nephron
microscopic functioonal unit of the kidney composed of renal corpuscle and renal tubule
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urinary bladder
muscular sac located on floor of pelvic cavity, collects urine until excretion, made of parietal peritoneum, muscularis detrusor, and mucosa
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detrusor muscle
tree layers of smooth muscle within the bladder
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umbrella cells
in mucosa of bladder, on surface of epitheliuma nd protect it from hypertonic acidic urine
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Hyperosmotic vs hypoosmotic vs isosmotic
Hyperosmotic: body is saltier than surrounding water so water tends to flow in
Hyposmotic: body less salty than surrounding water so water flows out
Isosomotic: water concentratons approximately equal
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Stenohaline vs euryhaline
Stenohaline: can only tolerate a rarrow range of salinity
Euryhaline: can live in both fresh and salt water
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salt gland
salt is collected and excreted, can be nasal orbital or glands under tongue/mouth
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How do the gonads develop and differentiate?
Paired gonads arise form a genital ridge (thickening of splanchnic mesoderm) initially shows neither male nor female characteristics (indifferent gonad), contain germ cells (future sperm or eggs) which migrate from endoderm, in femails germ cells reside in cortex, in males they are housed in medulla. Gonad=mesoderm
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What is the difference between a uriniferous kidney and a reproductive kidney?
Uriniferous kidneys only drain urine, reproductive kidneys drain urine and sperm
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What different shapes can uteri take in mammals? In what groups do we see those shapes?
no true uterus in fish/amphibians often called ovisac, dublex uterus in eutherians (oviducts join vagina separately), bipartit and bicornuate uterus (uteri partly fuse) simplex uterus (uteri fuse completely)(humans)
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Which vertebrate groups have undescended testicles?
Monotremes, insectivores, manatees, elephants, sloths, cetaceans, armadillos
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How have duck penises and vaginas evolved to mimic each other in shape?
There is a genital arms race in ducks where aggressive males have caused the evolution of a spiral penis/vagina, corkscrew shape gives females more control, blind pouches in vagina block fertilization
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ovary
capsule that encloses eggs, wrapped in a layer of follicle cells
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ova
eggs
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follicle
Ovum+follicle cells=follicle
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oviduct
during ovulation, where ovum are relased from, connects overies into uterus
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uterus
supports embryos, muscular organ that houses fertilized egg
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testes
capsule enclosing seminiferous tubules
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Seminiferous tubules
location of sperm production, straighten and exit via efferent ductules
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epididymis
temporaily stores sperm before it is released
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vas deferens
tubules that are used to release sperm
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indifferent gonad
initially shows neither male nor female characteristics
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wolffian duct
EMBRYONIC females, aka mesonephric duct, drains embryonic mesonephros but regresses in adulthood, in males is used for sperm transport as part of epididymis
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mullerian duct
MBRYONIC, in females forms alongside the wolffian duct and becomes oviduct, uterus, and vagina, sometimes formed in makes but degenerates as adults
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oogenesis
process of egg maturation involving mitotic and meiotic cell divisions
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oogonia
germ cells in ovary
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Primary vs secondary oocyte
Mitotic division results in primary oocyte, meiotic division results in secondary oocyte
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shell gland
makes egg case, secretes albuman and mucus (stores sperm in some some)
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spermatogonium
OG cell, engulfed by connective tissue cells, become sertoli cells as maturation proceeds
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spermatocyst
nested clones of spermatogonia, develop in unison
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Primary vs secondary spermatocyte
Primary spermatocyte: Primordial germ cells (spermatogonia) divide by mitosis
Secondary spermatocyte: meiotic division of primary spermatocyte
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testicular duct
testes develop separately from kidneys, duct that sperm travels out of
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