15.43 环境卫生结构和功能 -- -- 高级
章节大纲
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An ? Really?
::真的吗?Yes. This is a feather star, one of 550 of crinoids . Crinoids are animals that make up the class Crinoidea of the . Feather stars use their grasping “legs” to perch on , corals (as shown here), or other surfaces and feed on drifting microorganisms, trapping them in their sticky arm grooves.
::是的,这是一个羽毛星,是550个类类动物之一。类类动物是构成Crinoidea类的动物。羽毛恒星使用其抓抓的“腿”到孔上,珊瑚(如此处所示)或其他表面,并食用漂浮的微生物,把它们困在粘粘的手臂槽中。Structure and Function in Echinoderms
::杂质中的结构和功能Echinoderms have a distinct endoskeleton , an unusual organ system called the water vascular system , and a number of other less unique features. How is the endoskeleton organized? What are the components of the water vascular system, and how do they function to move the organism ? This section will answer these questions and will examine the other organ systems found in echinoderms.
::Echinodems有一个独特的内骨骼,一个称为水血管系统的不寻常器官系统,以及其他一些不那么独特的特征。内骨骼是如何组织起来的?水血管系统有哪些组成部分,它们如何运作以移动有机体?本节将回答这些问题,并将检查在脑电图中发现的其他器官系统。Endoskeleton
::底骨骼The echinoderm endoskeleton consists of a meshwork of plates and spines connected by mesodermal tissue . The plates are called ossicles. The organization of the ossicles that compose the endoskeleton of a sea star is shown in Figure . The ossicles are made up of microscopic networks of calcium carbonate crystals that form a unique structure referred to as the stereom. The ossicles may be tightly packed together, as they are in sea urchins, or they may be more loosely connected, as they are in sea stars. The same is true for the spines. Sea urchin spines are often quite loosely attached (despite the tight packing of the ossicles), and it is not uncommon to find a sea urchin alive and well but lacking most of its spines.
::内骨骨骼的内骨质由板块和脊柱组成,由中间体组织连接的板块和脊柱组成。板块称为。构成海星内骨骼的卵蛋组织在图中显示。由微小的碳酸钙晶体网络组成,形成一种被称为立体的独有结构。卵块可能紧紧地包装在一起,就像它们在海胆中一样,或者它们可能像在海星中一样松散地连接在一起。对脊椎来说也是如此。海胆的脊椎往往被松散地附着(沉没着卵壳的紧凑包装 ) , 找到一个活的海胆和精密但缺乏大部分脊椎的海胆并不罕见。An X-ray of a sea star, showing the endoskeleton. Notice the many tiny plates (ossicles) that are arranged in a clear pattern throughout the body of the organism. There are several specialized aspects of the echinoderm endoskeleton that vary between species. One example is the presence of pedicellariae on species of sea stars and sea urchins. Pedicellariae, shown in Figure , are spines modified as pincer-like structures that can be used to thwart predators . Another example of a modified endoskeletal feature is a feeding organ called Aristotle’s lantern (discussed in the Echinoderms: (Advanced) concept), which are found in sea urchin species.
::不同物种之间有不同物种的内分泌骨骼内分泌蛋白的若干特殊方面,其中一个例子是海星和海胆物种中存在小化石。如图所示,Pedicellariae的脊椎被改造成可以用来挫败食肉动物的针刺状结构。一个经过修改的内骨骨骼特征的另一个例子是一种喂养器官,叫做亚里士多德的灯笼(在Echinoderms中讨论过 : ( 高级)概念),在海胆物种中可以找到。The pedicellariae found on sea stars and sea urchins. Pedicellariae are modified spines that have a pincer-like structure at one end, as shown in this drawing. They may be used for self-defense against predators. The pedicellariae is shown both closed (left) and open (right). Water Vascular System
::水血管系统The water vascular system of echinoderms is essentially a system of fluid-filled canals that extend along each of the body regions and have many external projections called tube feet . There are several functions of the system, one of which is to use water pressure to mediate movement and assist in feeding. It also carries out respiratory, excretory, and some circulatory functions within the animal. The individual components of the water vascular system are the following:
::脑电流系统基本上是一个装满液体的运河系统,分布在每个身体区域,有许多外部预测,称为管脚,该系统有几个功能,其中之一是利用水压调节运动和帮助进食,它还在动物体内进行呼吸、排泄和一些循环功能。-
Madreporite.
::疯婆子 -
Stone canal.
::石头运河 -
Circular ring canal.
::圆环运河 -
Radial canals.
::放射性运河。 -
Lateral canals.
::横向运河 -
Tube feet.
::管子脚
What does each of these components do, and how do they contribute to the functioning of the water vascular system? The madreporite is a sieve-like, calcified plate that connects the system to the environment. Water enters through the madreporite and flows through a tube, called the stone canal, that connects to the circular ring canal surrounding the mouth. From there, water can flow into five radial canals that branch off the circular ring. The radial canals each extend into a different ray, or arm, of the organism along a groove called the ambulacral groove. Numerous lateral canals, leading to rows of tube feet on either side of the ambulacral groove, branch from each side of the radial canals. The organization of the components of the water vascular system is shown in Figure .
::这些部件的每个部件都做什么? 它们如何促进水血管系统的运转? 疯疯疯癫癫地是一个将系统与环境连接起来的类似筛选的、石化的板块。 水穿透麻风花,流过一个管子,叫做石沟,连接到圆环环的河道上。 从那里,水可以流到圆环的分支的五道圆形运河中。 弧形运河每道延伸成一个叫做气流圆柱形的圆形形形形形形形形形形形形形形形形形形形形体的射线或臂形形形形体。 无数横向运河,从斜形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形形色色色色色色色色色色色色色色色色色色色色色图图示图示图示图示图示图示图图图示图图图图图图示图示图示图示图示图示图示图示图示图示图示图图图图示图图图图图图图图示图图示图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图图The components of the water vascular system of echinoderms. Water enters the system through the madreporite, flows through the stone canal, and enters the ring canal. A number of bulbous structures, called polian vesicles, that branch off of the ring canal serve as reservoirs to maintain extra water stores. From the ring canal, water enters the radial canals that extend into each of the arms, or rays. The lateral canals branch from the radial canal and bring the water into the ampullae and podia of the tube feet. The tube feet extend between the endoskeletal plates to reach outside of the organism. They are basically thin-walled cylinders with muscular bulb-shaped structures called ampullae on the internal end and suckered structures called podia on the external ends. The tubular canals that make up the water vascular system are lined with cilia . Cilia are small hair-like, cellular projections that beat back and forth repeatedly to help maintain water flow through the canals.
::管脚伸展到内骨板之间,伸展到生物体之外,基本上是薄壁圆柱形,内端有肌肉泡泡形结构,称为脉冲,外端有吸尘结构,外端有波形结构,构成水血管系统的管状运河与西里亚相连。So how do tube feet work to move the animal? When the of the ampullae contract, water is forced into the suckered podia, which then extend outward. As the podia stretch, they can use their suckers to attach to a location farther away from their previous point of attachment. This results in a slow but powerful form of movement. Extended tube feet can also be used to generate small waves of water current toward the mouth region to assist in food collection. A close-up view of the tube feet of an echinoderm is shown in Figure .
::管子脚是如何移动动物的呢?当脉冲断裂时,水被迫进入被吸食的囊囊中,然后伸向外边。在脉部伸展时,它们可以使用吸管将吸管连接到距离先前的附着点更远的地方。这导致一种缓慢但强大的运动形式。扩展管脚也可以用来向嘴部区域产生小波水流,以帮助收集食物。图中显示了对脑电极管脚的近视。The tube feet of a sea star. If you look closely, you can see the suckered podia at the end of the tube feet protruding from the bottom (or oral) surface of the animal. In addition to the mechanical work it conducts, the water vascular system also provides respiratory and excretory functions. Most echinoderms do not have respiratory or excretory organs, so the thin walls of the tube feet serve this purpose by allowing oxygen to diffuse in and waste to diffuse out.
::除了机械工作外,水血管系统还提供呼吸和排泄功能,大多数脑外科没有呼吸或排泄器官,因此管脚的薄壁有助于达到这一目的,允许氧气散入和废物散出。When discussing the bilaterally symmetrical phyla, we have been able to use terms such as anterior, posterior, dorsal, and ventral to refer to the front, back, top, and bottom of the animal. With radially symmetrical animals, such as echinoderms, it is more difficult to specify which region of the animal you are talking about. Generally, the surface of the animal with the mouth opening is called the oral surface, and the one without the mouth opening is called the aboral surface. The madreporite opens into the aboral surface. Because the madreporite is one of the few non-repeating structures of echinoderms and is not directly in the center of the animal, it is used as an orientation point to distinguish between the various radial projections (arms/rays) of echinoderms. For example, echinoderm rays are named A through E in a counter-clockwise direction, and A is defined as the ray opposite the position of the madreporite. This is illustrated in Figure .
::当讨论双边对称的植物时,我们能够使用诸如前额、后端、面部和通风等术语来指动物的前部、背部、顶部和底部。在对称动物(如脑电极)的辐射性动物中,更难确定你所说的动物的哪个区域。一般而言,张嘴的动物表面被称为口腔表面,而没有张嘴的动物表面则被称为口腔表面。疯人院打开的表面进入了腹部表面。因为疯人院是少数非重复的脑电介质结构之一,并不直接位于动物中心,因此它被用作区分各种脑电极射线(武器/射线)的取向点。例如,在反时针方向,将脑电极射线命名为A到E,A被定义为与麻风球位置相对的射线。图中说明了这一点。Describing the body parts of an echinoderm. The rays, or units of pentameral symmetry, of an echinoderm are labeled A through E. The ray located opposite the madreporite is called A, and subsequent rays are labeled B, C, D, and E in a counterclockwise direction. Other Organ Systems
::其他机构系统Almost all echinoderms have a simple but complete digestive tract. Although most species lack respiratory and excretory organs, echinoderms do have a . They generally have an open circulatory system but lack a distinct heart. In an open circulatory system, circulating is not entirely contained within . The is not centralized and usually consists of a network of interconnected nerve distributed throughout the body. There is a nerve ring surrounding the mouth in the central region and nerves that extend from the ring into each arm. Echinoderms are able to sense chemical and physical stimulation using sensory cells located on the surface of their bodies. Some of these cells have chemoreceptors that bind to molecules called pheromones . Individuals within a species secrete pheromones that bind to the receptors found on other individuals as a means of . One example of this is the signaling of metamorphosis . Pheromones secreted by a cluster of adult echinoderms may indicate to larvae swimming nearby that they have found a good place to settle. The larvae sense the pheromone and respond by settling and initiating the process of metamorphosis (changing from a free-swimming larval form to a more sedentary adult form). In the next section we will examine the of echinoderms and the nature of their metamorphic changes.
::虽然大多数物种缺乏呼吸和排泄器官,但是它们确实有一个。它们一般有一个开阔的循环系统,但缺乏独特的心脏。在开放的循环系统中,循环并非完全包含在其中。它们不是集中的,通常由分布在整个身体的相互连接的神经网络组成。在中央区域的口部和神经圈周围有一个神经环环,从圆圈延伸到每个手臂。在它们身体表面的感官细胞中,它们能够感知化学和物理刺激。有些细胞有与分子结合的乳房感应器,叫做球素。在一种开放的循环系统中,它们并不完全包含在其中。它们不是集中的,而且通常由分散在身体中分布的相互连接的神经网络组成。在中间有一个神经环环环环环环环环环绕着每个手臂,而神经从圆向每个手臂伸伸展。在周围的神经激素可能表明它们找到了一个适合其身体表面表面的感官细胞游泳的地方。这些细胞中有些细胞的乳腺感应器被粘合起来,这些细胞的感应与分子联结在一起,叫做球质。在一种叫做球形体细胞内的个人感官会感官的感官会感官会感官,从一个更形的状态中将进入一个形态的状态中,从一个形态的形态的形态的形态的状态中将进入一个形态的形态的形态。Reproduction and Development
::复制和发展Most echinoderms reproduce by through the fusion of and eggs . They generally have separate sexes, and is usually external. Sea cucumbers, for example, release sperm and eggs into the open ocean where they may come in contact and undergo fertilization. The majority of echinoderm species undergo indirect development with a free-swimming bilaterally symmetrical larval stage. The bilateral symmetry of the larvae is strikingly different from the radial symmetry of the adult stage. Larvae undergo a process called metamorphosis, in which the organization of the body shifts from bilateral to radial symmetry. Some species, however, undergo direct development, where the young are simply smaller, sexually immature versions of their parents. There are also a few species, particularly among those living in extreme environments such as polar regions, that exhibit behavior. They nurture the young until they are old enough to fend for themselves. Some species of sea stars and brittle stars are also capable of by fission. In this process, the animal splits itself into two parts and each part regenerates the missing regions to produce a complete individual.
::大部分的脑电离子通过聚变和卵体繁殖。 它们一般有不同的性别,通常是外部的。 例如,海参将精子和蛋释放到它们可能接触和受肥的开阔海洋中。 大多数脑电离子物种都通过一种自由的对称的双向幼虫阶段进行间接发育。 幼虫的双边对称与成年阶段的辐射对称非常不同。 拉尔瓦经历了一种叫作变形的过程, 身体的组织从双边向辐射对称转变。 但是, 一些物种直接发育, 在那里, 年轻人只是其父母的性不成熟型小。 还有少数物种, 特别是在生活在极地地区等极端环境中的物种中, 表现出行为。 它们培养幼虫直到它们老到足以养活活自己为止。 一些海洋恒星和小恒星也能够通过裂变。 在这个过程中, 动物本身分裂成两个部分, 每一个部位, 产生一个完整的单个区域。Echinoderms have the ability to regenerate a missing arm, or ray. The limb may be lost as the result of a bite from a predator, or in some cases it is purposely released by the echinoderm in a process called self-amputation, or autotomy. This is usually done to escape a predator that has a hold of that particular limb. Most echinoderms can only undergo regeneration if a certain portion of the animal remains intact, usually including the central disk region. However, sea stars have quite extensive powers of regeneration, and they can often produce an entire organism from a small segment such as an arm. A sea star in the process of regenerating a missing limb is shown in Figure .
::精密剂具有再生缺失的手臂或射线的能力,四肢可能因食肉动物的咬伤而丧失,或在某些情况下,在称为自我截肢或自爆的过程中,由脑电极有意释放。这通常是为了逃离掌握着该特定肢体的掠食动物。大多数脑电极只有在动物的某一部分保持完好,通常包括中央磁盘区域的情况下才能再生。然而,海洋恒星具有相当广泛的再生能力,而且往往能够从一个小部分如手臂中产生整个有机体。图中显示了正在重新生成一个缺失肢体的海洋恒星。A sea star in the process of regenerating a missing limb. Echinoderms, such as this sea star, have the amazing ability to regenerate lost limbs, and, in some cases, almost the entire body can be regenerated from one limb. Summary
::摘要-
The endoskeleton of echinoderms is composed of plates, known as ossicles, that are formed from networks of calcium carbonate crystals called the stereom.
::内骨骨骼 由金属板组成 叫做 由碳酸钙晶体网络组成 叫做立体管 -
The water vascular system of echinoderms is essentially a system of fluid-filled canals that extends along each of the body regions and has many external projections called tube feet.
::脑电图的水血管系统基本上是一个装满液体的运河系统,分布在每个身体区域,有许多外部预测,称为管脚。 -
Although most species lack respiratory and excretory organs, echinoderms do have a circulatory system and a digestive system. They generally have an open circulatory system and a complete digestive system.
::虽然大多数物种缺乏呼吸道和排泄器官,但脑电离层确实有一个循环系统和消化系统,一般都有一个开放的循环系统和完整的消化系统。 -
Most echinoderms reproduce by sexual reproduction through the fusion of sperm and eggs. They generally have separate sexes, and fertilization is usually external.
::通过精子和卵子的混合性生殖,大多数的精子和卵子通过性生殖而繁殖,它们通常有不同的性别,施肥通常是外部的。
Review
::回顾-
How do echinoderms use their water vascular system to move?
::脑电图如何使用水血管系统移动? -
What kind of functions does the water vascular system have other than movement?
::水血管系统除了移动之外还有何种功能? -
Describe the nervous system of an echinoderm.
::描述神经神经神经系统 脑电图。 -
What role do pheromones play in the metamorphosis of certain echinoderms?
::某些脑电介质的变形中 费洛蒙能起什么作用? -
How well can echinoderms regenerate?
::脑电介质再生能有多好?
-
Madreporite.
