Comparative Anatomy Final

Front 1

Dorsal aorta (paired)

Back 1

Carries oxygenated blood from the aortic arches.

Front 2

Dorsal aorta (single)

Back 2

Distributes blood to the posterior part of the body and eventually extends into the tail as the caudal artery.

Front 3

Aortic arches

Back 3

vessels braching off ventral aorta which pass dorsally within the branchial arches between pharyngeal slits.

Front 4

Ventral aorta

Back 4

vessel leaving conus arteriosus (ventricle in hagfish). First thing blood enters when leaving heart and course foward below the pharynx.

Front 5

Internal carotids

Back 5

sprouts from anterior end of the dorsal aorta and carries blood forward into the head and usually penetrate the braincase to supply the brain.

Front 6

External carotids

Back 6

divides the anterior ventral aorta and carries blood into the ventral region of the head.

Front 7

Pulmonary artery

Back 7

carries blood from the heart to the lungs. They are the only arteries that carry deoxygenated blood.

Front 8

Pulmonary vein

Back 8

carries oxygenated blood from the lungs to the left atrium of the heart. They are the only veins in the post-fetal human body that carries oxygenated blood.

Front 9

Ductus arteriosus

Back 9

Connects the most posterior aortic arch (gives rise to the pulmonary artery) to the dorsal aorta.

Front 10

Systemic arches (IV)

Back 10

Left systemic arch consists of left aortic arch and the curved section of the left dorsal aorta. Right systemic arch includes the same components on the right side of the body. Two systemic arches unite behind hte heart to form the common dorsal aorta

Front 11

Subintestinal veins

Back 11

upaired vessel originating in the caudal vein. Loops around the anus and extends forward, running along the ventral wall of the intestine from which it collects blood.

Front 12

Hepatic portal vein

Back 12

Collects blood from the intestines, stomach, pancreas, and spleen and delivers it to the vascular sinusoids within the liver. Transports nutrients directly from the digestive tract to the liver for storage or processing of many end products of digestion.

Front 13

Postcava

Back 13

(posterior vena cava) drains the posterior part of the body

Front 14

Renal portal system

Back 14

Transports blood returning from capillary beds within the tail or hindlimbs through the renal portal veins. Function not well understood, suggested to have direct route for delivering metabolic by-products to the kidneys that result from active locomotion involving the caudal musculature or a way to improve kidney filtration.

Front 15

Renal portal vein

Back 15

A part of the renal portal system; empties blood into capillaries within the kidneys.

Front 16

Common cardinal vein

Back 16

major vein that receives blood returning from the anterior cardinal vein and the posterior cardinal vein.

Front 17

Anterior cardinal vein

Back 17

Drains the anterior region of the body.

Front 18

Posterior cardinal vein

Back 18

Drains the posterior region of the body.

Front 19

Subcardinal vein

Back 19

Arise ventral to the kidneys, drain them, and run forward to empty into the posterior cardinal vein.

Front 20

Lateral abdominal vein

Back 20

Empties blood from veins from the lateral body wall and posterior appendage into the common cardinal vein.

Front 21

Ventral abdominal vein

Back 21

In amphibians, left and right lateral abdominal veins may unite into this single median vein, which runs along the floor of the body coelom.

Front 22

Inferior jugular vein

Back 22

Drains head along with anterior cardinal veins; joins the common cardinal veins just before they empty into the sinus venosus of the heart. (in fishes)

Front 23

Internal jugular vein

Back 23

Derived from the anterior cardinal; works with external jugular vein and lingual vein (from tongue) to return blood from the head.

Front 24

External jugular vein

Back 24

Works with internal jugular vein and lingual vein to return blood from the head.

Front 25

Nephron

Back 25

Functional unit of kidney; unique to vertebrates. Adult kidney has thousands to millions nephrons in each kidney. Forms urine.

Front 26

Mesomere

Back 26

Anterior part forms the paired nephrotome which is often segmented; eventually becomes the nephric tubule. Posterior part forms the nephric ridge which is not segmented and protrudes slightly from the dorsal wall of the body cavity.

Front 27

Glomerulus

Back 27

Outgrowth of vessels from dorsal aorta; high pressure. Arterial vessels at both ends.

Front 28

Renal capsule (Bowman's capsule)

Back 28

Surrounds wall of glomerulus; collects filtrate. With the glomerulus, considered the first part of the nephron.

Front 29

Renal tubule

Back 29

2nd part of the nephron; has regional differentiation, selective absorption and secretion. Mammals have the Loop of Henle to concentrate urine.

Front 30

Collecting duct

Back 30

Part of the uriniferous tubule. Affects the concentration of urine and conveys it to the minor calyx, the beginning of the excretory duct.

Front 31

Pronephros

Back 31

Most anterior (1-12 pairs of nephrotomes); first to develop; gives rise to “pronephric” duct that induces development of posterior tubules; duct develops even if tubules degenerate; found in all vertebrates (at least in rudimentary form).

Front 32

Mesonephros

Back 32

Arise in middle of nephric ridge. Do not produce a new duct but instead taps into the preexisting pronephric duct; duct is renamed the “mesonephric: duct; usually becomes functional in embryo

Front 33

Metanephros

Back 33

Formation of metanephric duct appears as ureteric diverticulum arising at the base of the preexisting mesonephric duct. Grows dorsally into the posterior region of the nephric ridge. Becomes the adult kidney of amniotes and the metanephric duct is usually called the ureter.

Front 34

Pronephric duct

Back 34

Usually persists and drains the mesonephros or extended opisthonephros. In some males, this duct transports sperm and is called the vas deferens; in females, the wolffian duct. Most general term is archinephric duct.

Front 35

Opisthonephros

Back 35

Extended mesonephric kidney with additional posterior tubules is termed the opisthonephros (found only in adult fishes and mammals).

Front 36

Ureter

Back 36

Also known as the metanephric duct. Goes from the kidney to the urinary bladder.

Front 37

Indifferent gonad

Back 37

Gonad shows neither male nor female characters during embryonic development.

Front 38

Cortex (of indifferent gonad)

Back 38

Residence of germ cells (in females). Thick outer layer of gonad.

Front 39

Medulla (of indifferent gonad)

Back 39

Residence of germ cells (in males); develops into the seminiferous tube. Deeper layer of gonad.

Front 40

Ovary

Back 40

female gonad; produces both hormones and mature ova.

Front 41

Testis

Back 41

; paired; two functions: sperm production and hormonal secretion. Hormones of the testes are steroids collectively called the androgens.

Front 42

Neuron

Back 42

Nervous system cell. Specialized for long-distance transmission of electrical stimuli throughout the body. Structural and functional unit of the nervous system. Consists of the nerve cell body and thin cell processes called nerve fibers.

Front 43

Neuroglia

Back 43

nervous system cell. Do not transmit impulses; they support, nourish, and insulate neurons. Bind together nervous tissue and can be specialized. Swann cells wrap around axons to form myelin sheath. Increases speed of action potential.

Front 44

Axon

Back 44

One of the nerve processes. Usually one per neuron. Carry impulses AWAY from the nerve cell body of the neuron.

Front 45

Dendrites

Back 45

One of the nerve processes. Usually one or many dendrites per neuron. Transmit incoming electrical impulses toward the nerve cell body of the neuron.

Front 46

Synaptic bulb

Back 46

a part of the axon. Holds neurotransmitters.

Front 47

Synapse

Back 47

When action potential reaches synaptic bulb, causes release of neurotransmitters. Diffuse across synaptic cleft and stimulate membrane of next neuron. Site of action; gaps between junctions of neurons.

Front 48

Multipolar

Back 48

Has many processes associated with the cell body. Efferent or motor information.

Front 49

Unipolar

Back 49

Have a single stem that divides into a dendrite and axon. General Sensory.

Front 50

Bipolar

Back 50

Have two processes, usually at opposite ends. Special sensory; cells found in retina, olfactory.

Front 51

Somatic information pathway

Back 51

Target organ: sense organs in skin, tendons of skeletal muscle, skeletal muscle

Front 52

Visceral information pathway

Back 52

Target organ: Sense organs in walls of viscera (e.g. stretch receptors); smooth muscle in viscera.

Front 53

Sensory (afferent) information pathway

Back 53

Nerves carrying information from tissues to the central nervous system.

Front 54

Motor (efferent) information pathway

Back 54

: Nerves carrying information away from the CNS to effectors.

Front 55

Central nervous system

Back 55

Brain and spinal cord. Bundles of axons within CNS structures = tracts. Grouping of cell bodies = tract. Covred with meninges. Connective tissue membrane(s) partly derived from neural crest.

Front 56

Peripheral nervous system

Back 56

Nerves and ganglia to/from organs. Serve either somatic or visceral tissues and carry sensory or motor information.

Front 57

Tripartite brain

Back 57

Vertebrate brain; forms initially as three enlarged areas.

Front 58

Ventricles of the brain (lateral, third, fourth)

Back 58

Enlarged spaces in brain. Lateral has 2.

Front 59

Cerebral aqueduct

Back 59

Surrounded by the midbrain; not a ventrical. Tectum-floor; tegmentum-floor.

Front 60

Meninx

Back 60

Wraps the brain and spinal cord; derived from in part from neural crest. In mammals, there are 3 layers: dura mater (tough outermost), arachnoid (weblike), pia mater (innermost with blood vessels).

Front 61

Primary meninx

Back 61

(primitive) In fishes; meninges consist of a single membrane; wrapped around brain and spinal cord.

Front 62

Secondary meninx

Back 62

In amphibians, reptiles, and birds, the meninges include a thick outer dura mater derived from mesoderm and a thin inner secondary meninx. Cerebrospinal fluid circulates more effectively. In mammals, secondary meninx yields both the arachnoid and pia mater from ectomesoderm.

Front 63

Dura mater

Back 63

tough outermost layer of meninx

Front 64

Arachnoid

Back 64

middle weblike layer of meninx (only in mammals)

Front 65

Pia mater

Back 65

innermost layer with blood vessels of meninx (only in mammals)

Front 66

Prosencephalon

Back 66

Divided into Telencephalon and Diencephalon. Gives rise to the forebrain.

Front 67

Mesencephalon

Back 67

Gives rise to midbrain

Front 68

Rhombencephalon

Back 68

Divided into Cerebellum, Pons (mammals), and Medulla. Gives rise to hindbrain.

Front 69

Telencephalon

Back 69

Anterior region of brain. Sensory input from “lower” brain centers; integration; initiates descending information. Also called cerebrum or cerebral hemispheres (2 sides); surround lateral ventricles; includes olfactory bulbs. Relative size varies. 2 major regions: Pallium (medial, dorsal, lateral) and Subpallium (striatum, septum).

Front 70

Cerebrum/cerebral hemispheres

Back 70

known as Telencephalon.

Front 71

Pallium (medial, dorsal, lateral)

Back 71

Actinopterygians-eversion of pallium; all other vertebrates- inversion. Relative sizes of pallial regions: lateral pallium (birds); dorsal pallium (mammals)

Front 72

Subpallium

Back 72

has two subdivisions: striatum and septum. Below the pallium. A part of the Telencephalon.

Front 73

Dorsal ventricular ridge

Back 73

Believed to be derived from the lateral pallium (in birds, expands further). Dominates the central region of the cerebral hemisphere. Accounts for much of the relative increase in size of the cerebral hemispheres and crowds the lateral ventricle into a slit.

Front 74

Diencephalon

Back 74

Surrounds third ventricle. Source of the thalamus. Includes 4 regions: epithalamus, hypothalamus, ventral thalamus, and dorsal thalamus.

Front 75

Epithalamus

Back 75

Pineal gland. Non-amniotes: pigmentation; amniotes: biorhythms.

Front 76

Thalamus

Back 76

Lateral walls of diencephalon. Dorsal and ventral. Dorsal: major sensory area; input from all senses except olfactory; integration; relay to cerebrum.

Front 77

Hypothalamus

Back 77

Floor of diencephalons. Homeostasis of temperature, water balance, appetite, blood pressure, sexual behavior, and reproductive cycle, etc.

Front 78

Midbrain

Back 78

Mesencephalon. Surrounds cerebral aqueduct (not a ventricle).

Front 79

Tectum

Back 79

Roof of midbrain. Sensory input. Optic tectum-vision. Torus semicularis- auditory and lateral line. May be largest area of brain in fishes and amphibians.

Front 80

Tegutum

Back 80

Floor of midbrain. Origin of motor information; oculomotor nerve (III); Trochlear nerve (IV), both of which control eye muscles.

Front 81

Hindbrain

Back 81

Rhombencephalon. Surrounds fourth ventricle. Two subregions- Metencephalon (cerebellum, pons(mammals)) and Mylencephalon (Medulla oblongata).

Front 82

Medulla

Back 82

Origins of cranial nerves (Sharks V-X; mammals VII-XII). Ascending and descending pathways. Vital reflex centers (respiration, heartbeat, intestinal motility, etc.)

Front 83

Pons

Back 83

Only in mammals. Region of hindbrain consisting of enlarged pontine nuclei that convey information from cerebrum to cerebellum.

Front 84

Cerebellum

Back 84

Receives sensory and motor information from higher brain centers. Maintains positional equilibrium (muscle tone and balance) and refines motor action (does not initiate it). Variation in size relates to locomotion. May be enlarged hemispheres in birds and mammals.

Front 85

Cranial nerve

Back 85

Pairs of nerves connected to brain. Traditionally indicated by roman numerals (I-X or XII), anterior to posterior. Terminalis nerve (in all gnathostomes except birds) anterior to all tradinally numbered nerves- indicated by 0. Numbers vary: fishes and some amphibians: 0-X + up to 6 pairs of unnumbered laeral line nerves. Amniotes: 13 pairs (counting terminalis).

Front 86

Spinal nerve

Back 86

Connected to spinal cord. One pair/embryonic segment. Relationships to adjacent somites- myotomes, dermatomes.

Front 87

Dorsal root of spinal nerve

Back 87

information (both somatic and visceral); cell bodies of unipolar neurons in dorsal root ganglion; synapses in dorsal horn of spinal cord; each neuron extends the entire distance from source organ to spinal cord.

Front 88

Ventral root of spinal nerve

Back 88

somatic and visceral motor information in ventral root; cell bodies of multipolar neurons in ventral horn of spinal cord; each neuron extends entire distance from spinal cord to target organ (skeletal muscle).

Front 89

sympathetic system

Back 89

Paravertebral and Prevertebral ganglia;short length of preganlionic neuron; terminal neurotransmitter-epinephrine; extend of effect – widespread; nerves- thoraco-lumbar spinal nerves.

Front 90

parasympathetic system

Back 90

Visceral ganglia; long length of preganlionic neuron; terminal neurotransmitter- acetylcholine; extent of effect- organ specific, no innervation to skin; nerves- cranial and sacral spinal nerves.

Front 91

Autonomic nervous system

Back 91

Involuntary. Pathways differ from other information types; 2 neurons from spinal cord to target organ, synapse in autonomic ganglia; 2 divisions of autonomic information system- sympathetic and parasympathetic, visceral organs (except skin)-dual innervation with opposite effects.

Front 92

Paravertebral ganglion

Back 92

Sympathetic chain of ganglia; a paired series of linked ganglia adjacent to the vertebral column or notochord.

Front 93

Pervertebral ganglion

Back 93

Collateral ganglia; formed by other peripheral ganglia- paired cervicle, celiac, and mesenteric ganglia.

Front 94

Terminal ganglion

Back 94

Parasympathetic chain of ganglia; lie near or within the organs they innervate.