Bio exam 1

• Understand homeostasis 


  -A state of balance among all the body systems needed for the body to survive and function correctly

  -Constancy of internal environment

  -the ability of the body to maintain a stable internal environment despite changes in external conditions.

  
• how do negative feedback loops work in Homeostasis

  - A system of control in the body that responds to a stimulus to oppose the change made by it, to get back to a set point.

  -reverses the change from a set point

  -reverses the set point

  -In a negative feedback loop, feedback serves to reduce an excessive response and keep a variable within the normal range. Examples of processes controlled by negative feedback include body temperature regulation and control of blood glucose.

  
• what is positive feedback loop?

  -is accelerating the change from set point; moving further and further from a set point

  -blood clotting, oxytocin, and uterine contracting, and hyperventilate

  -positive feedback loops amplify their initiating stimuli, in other words, they move the system away from its starting state.
• Muscle Tissue

  three types:

  -Skeletal muscle- providing structural framework and movement to the body. There are two types of skeletal tissues; Bones and Cartilages.

  -Cardiac muscle- makes up the thick middle layer of the heart.

  -Smooth muscle- Smooth muscle is present throughout the body, where it serves a variety of functions. It is in the stomach and intestines, where it helps with digestion and nutrient collection. It exists throughout the urinary system, where it functions to help rid the body of toxins and works in electrolyte balance.
• Cardiac muscle tissue 


  -found only in the heart

  -fibers are short, branched, and interconnected both physically and electrically

  -Striated, but very different than skeletal muscle

  -striated and involuntary

  -Cardiac muscle tissue is only found in your heart. It performs involuntary, coordinated contractions that allow your heart to pump blood through your circulatory system. 
• smooth muscle tissue

  -Found in walls of digestive, urinary, and reproductive organs, blood vessels, and bronchioles of the lungs (other hollow organs)

  -Not striated, involuntary

  -generally found in layers that run in different directions

  -Smooth muscle is a type of tissue found in the walls of hollow organs, such as the intestines, uterus, and stomach. You can also find smooth muscle in the walls of passageways, including arteries and veins of the cardiovascular system.
• Nervous Tissue

  -Brain, spinal cord, and nerves

  -Composed of neurons and neuroglia

  -Neurons conduct impulses

  -Neuroglia are supporting cells that do not conduct nerve impulses

  -tissue made up of neurons and supportive cells

  -Neurons, or nerve cells, carry out the functions of the nervous system by conducting nerve impulses. They are highly specialized and amitotic. This means that if a neuron is destroyed, it cannot be replaced
• Epithelial tissue 


  -forms membranes that cover body surfaces, line inside of hollow organs, and glands

  classified by the number of layers

  -simple-is one layer of epithelial

  -stratified- is like bricks of epithelial(protection)
• Skeletal muscle


  -skeletal muscle is attached to bone(moving bones) and voluntary control

  -an overlap that can cause light and dark bands--> striations

  -skeletal muscles are huge cells, and multinucleate(many nuclei)

  -with skeletal muscle, we can have a graded response (dictate the level of force that our muscles exert)
• Simple squamous epithelium:

  • Allows for rapid diffusion
  • Present at sites where filtration (e.g., blood filtration in the kidneys) or diffusion (e.g., oxygen diffusion into blood vessels of the lungs) occur
• Simple cuboidal epithelium:

  • Allows for the secretion of substances in various glands
  • Main function: absorption, excretion, and secretion
  • Found in small collecting ducts of the kidneys, pancreas, and salivary glands
• Simple columnar epithelium:

  • Allows for absorption, as found in the wall of the small intestine
  • secretion and provides protection
  • when we eat food there is going to be some kind of contaminate that we don't want in the bloodstream so we depend on our immune system and epithelial cells. so simple columnar is ideal for protection when nutrients go from the intestine to the bloodstream.
• Stratified Epithelial tissue


  -provide protection

  -no blood vessels, nourished by connective tissue

  -Epithelial tissues are attached to connective tissue by a "basement membrane"

  -Has two or more layers of cells. Because of this, it is more durable and can better protect underlying tissues.
• simple and stratified epithelial tissue

  
• what is non-keratinized epithelium?

  -not waterproof, so some moisture or movement the cells stay alive, they get nourished

  -ex: your esophagus, urethra, anal connel, and vaginal connel
• what is Keratinized epithelium?

  -provides a waterproof surface, ridget, dry, and a bit more protective

  -skin is keratinized stratified epithelial (outer layer) (dry membrane) water does not go into the body or leave the body(except in certain places)
• Exocrine glands 


  -derived from epithelial tissue

  -secretions transported by ducts

  -Epithelial tissue is a boundary layer between two environments

  -glands make hormones, sweat, oil, tears, enzymes, etc.

  -A gland that makes substances such as sweat, tears, saliva, milk, and digestive juices, and releases them through a duct or opening to a body surface.
• endocrine glands (within)

  -Derived from epithelial tissues

  -Endocrine glands are ductless and instead secret into capillaries within the body

  -release hormones into the bloodstream

  -This lets the hormones travel to cells in other parts of the body. The endocrine hormones help control mood, growth and development, how our organs work, metabolism, and reproduction. The endocrine system regulates how much of each hormone is released.
• Connective tissue 


  -characterized by a matrix of protein fibers, extracellular material, and specialized cells

  -two major functions of connective tissue are to support and join other tissues
• Connective tissue proper

  -composed of protein fibers and a gel-like substance

  -loose-collagen fibers scattered loosely with room for blood vessels and nerves

  -Dense regular-Densely packed collagen fibers with little room for ground substance

  -they connect epithelia to underlying body structures, link muscles to bones, and hold joints together. However, connective tissues provide the body with more than structural connections and form—they play vital roles in defense, repair, storage, and nutrition.
• Cartilage connective tissue 


  -is strong but flexible

  -for example, our ears have cartilage

  • cartilage functions as a flexible, boneless skeleton
  • cartilage has no blood vessels, so any injuries to it tend to heal slowly
  • a strong, flexible connective tissue that protects your joints and bones. It acts as a shock absorber throughout your body. Cartilage at the end of your bones reduces friction and prevents them from rubbing together when you use your joints.
• Bone connective tissue

  -is a rigid connective tissue with a dense matrix of collagen fibers hardened with deposits of calcium salts. this combination makes bone hard without being brittle
• Why is water so unique and important to life on this planet?

  -Water: most abundant molecule in organisms, 70% of total body weight. Water is highly mobile and holds tremendous amounts of heat

  -Water's extensive capability to dissolve a variety of molecules has earned it the designation of “universal solvent,” and it is this ability that makes water such an invaluable life-sustaining force. On a biological level, water's role as a solvent helps cells transport and use substances like oxygen or nutrients. Everything water can do blood can do too b/c your blood contains water
• Bioenergetics (first law of thermodynamics, coupled reactions, release of energy)

  -The First Law of Thermodynamics states that energy cannot be created or destroyed; it can only be converted from one form to another.

  -energy is not created but more destroyed and it is not fully conserved. Thermal energy rises and escapes out into the atmosphere

  -when solar energy lands on the planet, plants harness only 1% of energy from the sun. while 99% escapes into the atmosphere.

  • The sun heats things up--> thermal energy--> escapes and heat moves out into space
• Bioenergetics (first law of thermodynamics, coupled reactions, release of energy)(continued)


  -Plants utilize solar energy and make sugar (glucose)

  -An organism is gonna eat the plant and going to consume some energy from the sun. Eats the glucose and releases the energy

  -at each trophic level each organism loses 90% of its energy

  -energy becomes more chaotic and less useable as it moves from trophic level to trophic level.

  -the energy that was released from glucose is used to build ATP
• what is an Endergonic reaction?


  -a chemical reaction that infuses energy into a system, input energy

  -what comes out of the chemical reaction has more useable energy, than what went into it

  -products contain more free energy than reactants

  - An endergonic reaction is a reaction that requires energy to be absorbed in order for it to take place. These reactions are not spontaneous. They require work or an input of force - often in the form of energy 
• what is an Exergonic reaction?

  -Releases energy in the form of heat

  -what comes out of an explosion has less available energy than when we started

  -blowing something up, allows the building of something new. to break something down, so we can build something different

  -Typically, this energy is released when bonds are broken. More specifically, in humans, these reactions are called catabolic, which means that the molecules are being broken down into smaller
• coupled reaction from Bioenergetics

  
• What is ATP

  -The energy that is released from glucose is used to build ATP

  -ATP is the currency of energy in your body

  -we can't use any of the energy until it is converted into ATP(universal token of energy)

  -Breaking down ATP is an exergonic reaction

  • glucose--> build ATP--> cell(breaks down ATP)--> builds protein--> you eat this protein(from animal)--> break it down--> build ATP--> build your own protein
  • for ATP power, is the release of the phosphate at the tip of the triphosphate tail that makes energy available to working cells
• what is ATP(continued)


  -when ATP drives work in cells by being converted to ADP, the released phosphate groups don't just fly into space. ATP energies other molecules in cells by transferring phosphate groups to those molecules

  -when a target molecule accepts the third phosphate group, it becomes energized and can then perform work in the cell

  -when that little bit of energy is released we can build protein, we can power our muscles, move ions, and do other things
• what is passive transport: diffusion across membranes

  -passive transport -passive because no energy is needed for the diffusion to happen.

  -Molecules move from higher to lower concentration without metabolic energy. A substance diffuses down its concentration gradient, from where the substance is more concentrated to where it is less concentrated

  -oxygen moves by passive transport from the air into the bloodstream
• what is diffusion

  -the movement of molecules spreading out evenly into the available space.

  -the overall diffusion of a population of molecules is usually directional, from a region where the molecules are more concentrated to a region where they are less concentrated
• what is Facilitated diffusion?

  -Passive transport that does not require the cell to expend energy

  -substances that do not cross membranes spontaneously or otherwise cross very slowly can be transported by proteins that act as corridors for specific molecules

  -molecules diffuse across the plasma membrane with assistance from membrane proteins, such as channels and carriers. A concentration gradient exists for these molecules, so they have the potential to diffuse into (or out of) the cell by moving down it.
• How do cells interact with their environment?

  -Cell signaling

  -A binding site fits the shape of a chemical messenger. The messenger may cause a change in the protein that relays the message to the inside of the cell.

  -to detect and respond to cues in their environment. This process not only promotes the proper functioning of individual cells but also allows communication and coordination among groups of cells
• Active Transport: the pumping of molecules across membranes

  -requires that a cell expend energy to move molecules across a membrane.

  -cellular energy (usually provided by ATP) is used to drive a transport protein that pumps a solute against the concentration gradient -that is, in the direction that is opposite the way it naturally flows

  -allows cells to maintain internal concentrations of small solutes that differ from environmental concentrations.

  -the plasma membrane pumps sodium out of the cell and potassium into the cell. ATPase enzyme pumps 3 Na+ out of celland 2 K+ into cell
• why the plasma membrane is such a dynamic andan integral component of cellular function

  -The plasma membrane, or the cell membrane,provides protection for a cell. It also provides a fixed environment inside the cell, and that membrane has several different functions. One is to transport nutrients into the cell and also to transport toxic substances out of the cell.
• Sensory neurons (afferent)

  -Neuron that transmits impulses from a sensory receptor into the CNS

  -sensory neuron, a nerve cell that carries information about changes in external and internal environments to the central nervous system (CNS). Such neurons are part of the peripheral nervous system, which lies outside the brain and spinal cord.
• Motor neurons(muscles and glands; efferent)


  -Neuron that transmits impulses from the CNS to an effector organ; for example a muscle

  - cells in the brain and spinal cord that allow us to move, speak, swallow, and breathe by sending commands from the brain to the muscles that carry out these functions.

  • A nerve cell that conveys command signals from the CNS to receiving cells, such as muscle cells or gland cells
• Somatic motor neurons

  -reflexes and voluntary control of skeletal muscle

  -has one neuron from spinal cord to effector
• Autonomic motor neurons 


  -Nerve that stimulates contraction(or inhibits contraction) of smooth muscle and cardiac muscle and that stimulates glandular secretion

  -innervate involuntary targets