Organization of the Animal Body 2024 PDF

ORGANIZATION OF THE ANIMAL BODY animals are made up of trillions of specialized cells tissues these are organized into _________________: each tissue composed of dozens to billions of structurally similar cells that act in concert to perform a p...

ORGANIZATION OF THE ANIMAL BODY animals are made up of trillions of specialized cells tissues these are organized into _________________: each tissue composed of dozens to billions of structurally similar cells that act in concert to perform a particular function organs tissues are the building blocks of ________________________________ e.g. stomach, small intestine, bladder organs are composed of several tissue types (at least two) systems organs are in turn organized into _____________________________________ e.g. digestive system includes stomach, small intestine, large intestine etc. How Do Tissues Differ? All the different tissue can be grouped into four types: Epithelial -__________________________________________________ Muscular -___________________________________________________ Nervous -___________________________________________________ Connective -___________________________________________________ Epithelial tissue also called epithelium cavities form sheets that cover the body and line body ____________________ such as the mouth, the stomach and the bladder →______________ oral nasal and __________________________ surfaces are covered Functions: protection _________________________________________ facilitate gas exchange regulate movement of nutrients and waste secrete may ________________________________ substances Characteristics: free have a _______________________ surface facing outside or inside of a “cavity” thin lack blood vessels ciliary action →gas exchange etc. via _________________________________ regenerate can _____________________________________ cells closely packed together and firmly attached to each other Two kinds of epithelial tissue Simple 1. _______________ Epithelium ____ one cell thick  Stratified or Compound 2. ________________ Epithelium ____________________ two or more than two layer in each: tissue named according to cell shape: squamous (flat, thin), cuboidal (cube-shaped) or columnar (elongated) may be ciliated (causing particles/fluids to move) specialized ___________________________________ for role Examples of Simple Epithelium Simple squamous epithelium may lines lung air sacs (thin, flat cells allow for fast gas exchange) Simple columnar ciliated epithelium digestive and upper respiratory tract lines ___________________ Examples of Stratified Epithelium Epidermis (of skin) extra thickness helps endure much “wear and tear” during development, the cells of some epithelial tissues change shape and function to form glands → clusters of cells that are specialized to secrete substances 2 broad categories of glands: endocrine and exocrine Exocrine Glands passageway (duct) stay connected to the epithelium by a _________________________________ secrete ______________________ substances through the duct e.g. sweat glands, salivary glands Endocrine Glands become separated from the epithelium that produced them hormones most produce __________________ which are secreted into the extracellular fluid that surrounds the glands and then diffuse into nearby capillaries Examples: ovaries, testes, thyroid, pituitary Connective Tissue diverse group functions include: support – ____________________ and strengthen other tissue bind – ____________________________ cells of other tissues together has a large amount of extracellular matrix that can be any of the below: – thin and watery gelatinous – _____________________  – stretchy – tough and flexible – Rigid ___________________ Loose Connective Dense Connective Specialized Connective abundant most ______________ most are tightly packed diverse flexible collagen with _______________ supports and cushions (strength); some have other tissue irregular collagen forms internal meshes (flexibility) framework __________________ and membranes Loose Connective adipose Example: ______________________ tissue (fat) acts as a cushion, energy store and insulation Dense Connective Example: tendon muscle connect _____________________ to bone strength parallel collagen fibres secreted by cells provide _____________________ Specialized Connective cartilage Example: ______________________ found at bone ends, ears and nose, supports respiratory passages cells widely spaced matrix has collagen and elastic fibres flexible Muscle Tissue long, thin cells contract (shorten) when stimulated and then relax passively three types of muscle tissue: skeletal, cardiac, and smooth 1. skeletal voluntary stimulated by nervous system →generally under _________________ control functions to move the skeleton Under the microscope: many large cells with ________________________ nuclei regular arrangement of fibrous proteins makes it appear striped or striated “__________________________” 2. cardiac located in the heart only not spontaneously active and _____________ under voluntary control interconnected cardiac muscle cells are __________________________ → “intercalated discs”: allow electrical signals to spread rapidly through the heart dark bands between adjacent cells Under the microscope: also striated discs visible as dark bands between cells one each cell has _____________ nucleus 3. smooth is embedded in the walls of digestive tract, uterus, bladder, and large blood vessels involuntary produces slow, sustained contractions that are normally _________________ Under the microscope: spindle ________________-shaped cells no striations proteins not consistently aligned (no striations visible) each cell has one nucleus Nerve Tissue brain makes up the ____________________, spinal cord and the nerves that travel from them to all parts of the body composed of two types of cells: neurons and glial cells neurons electrical – are specialized to generate __________________ signals and to conduct these signals to other neurons, muscles or glands – has four major parts: dendrites _____________ (receive signals for other neurons or environment) body cell ______________ (directs maintenance and repair of the cell) axon _______________ (conducts the electrical signal to its target cells) synaptic ________________ terminals (transmit the signal to the target cell) glial cells – ______________________________, surround support and protect ______________________ neurons and regulate the composition of the extracellular fluid, allowing neurons to function optimally How are tissues combined into organs? two or more tissue types form organ Example: Skin  comprised of all four tissue types Epidermis _______________________ (outer layer of skin) is a specialized epithelial tissue -covered by protective layer of dead cells (produced by underlying living cells) -dead cells are packed with keratin to keep skin airtight and waterproof dermis under epidermis is a layer of connective tissue called the ___________________ blood -loosely packed cells are permeated by _______________ vessels and lymph ________________ vessels, and nerves -packed with glands derived from epidermal tissue: hair follicles (produce hair); and sweat glands (produce watery secretions that cool the skin and excrete substances such as salts and urea; sebaceous glands secrete oily substances) muscle some areas of skin may also contain ____________________ tissue: tiny muscles stand-on-end attached to hair follicles can cause hair to “__________________” in response to neurons signals from ___________________ Organ Systems consist of 2 or more individual organs that work together to perform a common function coordinated the body’s organ systems all work together in a ________________________ manner to maintain the internal environment in the range required for life