Animal Body Plans PDF

2. Radial Symmetry GRADES OF ORGANIZATION AND ANIMAL BODY PLANS - Applies to forms that can be divided into similar halves bu...

2. Radial Symmetry GRADES OF ORGANIZATION AND ANIMAL BODY PLANS - Applies to forms that can be divided into similar halves but with more than two planes passing through the longitudinal axis Usually recognized as five (5) major grades of - The shapes of animals are often tubular, vase-like, organizations or bowl-shaped 1. Protoplasmic - Can be placed amongst sponges and hydra, - Confined amongst unicellular organisms jellyfish, urchins, and other groups - A type of organization where all life functions are confined within the boundaries of a single cell 3. Bilateral Symmetry - Fundamental unit of life - Applies to animals that can be divided along a - Protoplasm is differentiated into organelles within a sagittal plane into two (2) portions (right and left cell and are capable of performing specialized functions halves) - Has a ciliate known as paramecium - Its appearance is considered to be a major innovation as these animals are better fitted for 2. Cellular directional or forward movement than radially - An aggregation of cells that are functionally symmetrical animals differentiated - Often associated with cephalization (differentiation - Division of labor—cells concerned with reproduction and cells concerned with nutrition of the head; the connection of nervous tissues) - Flagellates examples: - Since organs in the head bestows obvious Volvox Species advantages to an animal moving through its ○ have distinct somatic and environment head first reproductive cells - Produces an efficient position of organs for sensing ○ Placed at the cellular grade or level the environment and likewise the response of the organization organism (stimuli) 3. Cell-Tissue - An aggregation of similar cells into definite patterns or layers - Organized to perform a common function to form a tissue - Sponges or poriferans are considered (by some authorities) to belong in this grade - Jellyfish and cnidarians demonstrate the tissue plant - Both groups (sponges and cnidarians) are largely of this cellular grade of organization, as most cells are often not organized into tissues - Example among cnidarians: Nerve Net ○ Nerve cells and their processes form a definite tissue structure with the function of coordination REMEMBER 4. Tissue-Organ - Aggregation of tissue into organs Protostomes = blastopore becomes mouth - A step further into complexity - Usually composed of more than one kind of tissue Deuterostomes = blastopore becomes anus - Have specialized functions than that of a tissue - The organizational level of platforms or those from Diploblastic = two germ layers the phylum platyhelminthes in which well-defined organs like eye spots, the proboscis, and other Triploblastic = + mesoderm reproductive structures and organs are present - Amongst flatworms, the reproductive organs transcend tissue organ grade and are organized into the reproductive system 5. Organ - Organs work together to perform a function, producing the highest level of organization—-the organ system - Systems are associated with body functions such as circulation, respiration, reproduction, and digestion - Most animal phyla demonstrate this type of organization BODY SYMMETRY METHODS OF MESODERM FORMATION Refers to balanced proportions or correspondence in size Will dictate the type of body cavity present in a certain and, likewise, shape of parts and opposite sides of a animal median plane There are three (3) types of symmetry 1. Spherical Symmetry - Any okane passing through the center that divides a body into equivalent or mirrored halves - Occurs amongst unicellular forms or eukaryotes and is rare among vertibrates or higher animals - Best suited for floating and, likewise, rolling  DEVELOPMENT SEQUENCE OF ANIMALS SIMPLE EPITHELIA A single layer of cells Occurs mainly in all metazoans Classified based on shape and function a. Squamous - has a presence of flattened cells forming a continuous lining of capillaries, lungs, and surfaces allowing diffusion and transport SEGMENTATION Metamirism (segmentation) is a common feature of b. Cuboidal - short boxeed like cells lining the ducts and metazoans tubials, kidneys, salivary glands, and other excretory ○ Serial repetition of body segments along the systems longitudinal axis of the body Metamere or somite - contains internal and external structures ○ Mobility and complexity of structure and function ○ Ex. earthworm (phylum amelida) Metamirism is clearly represented through the segmental arrangement that includes external and internal structure of several systems c. Columnar - taller than cuboidla with elongated nuclei and Segmentation permits great body mobility and complexity of used mainly for increased absorption along the intestines structure and function Potential is amply displayed in phylum anthropoda (largest assemblage of animals on earth) Occurs amongst cordates in addition to those from the phylum anelida and likewise anthropoda VERTIBRATE TISSUE TYPES STRATIFIED EPITHELIAL TISSUE Is a group of similar cells specialized for performance of a common function The study of tissus is called histology or microanatomy All cells in the metazoan animals tend to form tissues (sometimes cells of a tissue may be of several kinds and some tissues may have much extra cellular material) During the embryonic development, the germ layers com A type of tissue wherein it has or bears two (2) or more cell differentiated into four (4) types of tissue: layers and are mostly restricted to vertibrates 1. Epithelial Tissue Is adapted to withstand mechanical abrasion, distortion - Epithelium is a sheet of cells that covers an internal or external part of the animal body Lines the oral cavity, esophagus, anal canal, and skin Internally , lining for all organs and ducts as well as all passageways Separated from underlying tissues from the presence of the ○ Allows transport of secretions basal layer that continues to divide and produce new cells ○ Mucus and specialized hormones and enzymes There is a presence of keratinized skin cells mainly found Externally, used for protection on the upper surface in terms of animals ○ Epithelial cells are classified based ○ Example on form and number of layers Reptiles, birds, mammals Simple stratified These skins/tissues are mostly stratified squamous  TRANSITIONAL EPITHELIAL TISSUE CARTILAGE AND BONE Type of stratified epithelium specialized for great stretching Cartilage is semi-rigid tissue of firm matrix cells (chonorocytes) with collagen and elastin Are mainly found in the urinary tract and the bladder of ○ Lacks blood supply so nutritients and waste have to vertibrates diffuse through the ground substance such that it heals very slowly after damage Allow enlargement while storing waste When stretched it appears to have only a few layers of extremely flattened cells CONNECTIVE TISSUE Connective tissue is widespread in body but contains relatively few cells, many fibers, and a ground substance or matrix that suspends fibers Bone is the strongest connective tissue made of calcified matrix (osteocytes) around collage fibers Two types of connective tissue proper occur in vertibrates ○ Blood vessels flow through tiny channels called ○ Loose connectivity canaliculi and large canals that allow for continuous ○ Dense connective tissue repair called remolding Other specialized connective tissues include blood, lymph, aadipose tissue, cartilage, and bone LOOSE CONNECTIVE TISSUE Also known as the areolar connective tissue Seves as a packing materials Anchors blood vessels, nerves, and organs DEVELOPMENT SEQUENCE OF ANIMALS Consists mainly of fibroblast that synthesize fibers, ground substance, and wandering macrophages that destroy Considered as the most abundant tissue in animals pathogens and damaged cells Originates mainly from the mesoderm There are mainly two types of muscle cells 1. Striated - a transversely striped muscle (skeletal, cardiac) a. Skeletal - Mainly long cylindrical fibers - Multinucleated - Considered to be as voluntary muscle in vertibrates or amongst vertibrates DENSE CONNECTIVE TISSUE Forms tendons, ligaments, and fascia ○ Fascia is arranged in sheats where spans of tissues surround the skeletal muscle b. Cardiac muscle - Short branch networks - Uninucleated - Connected by interconnected discs - Considered to be as involuntary muscle 2. Smooth - Non-striped - They are long tapering and unprimed with the presence of a central nucleus - Control is involuntary NEURON SRUCTURE It is specialized Receives stimuli Conducts impulses fromnone region to another Common parts of a neuron 1. Soma - nucleated body 2. Dendrites - they receive signals from receptors 3. Axon - carries signal away from the nerve body 4. Myelin sheath - Aka insulating sheath - Increases speed of signals during transmission 5. Synapse - specialized junctions between each neuron or effector organs