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Animal principles, functions, and nutrition - Coggle Diagram
Animal principles, functions, and nutrition
Chapter 40: Principles and function of animal forms
40.1 How does animal form and function help them adapt
If all animals share the same requirements in order to live what makes their anatomy so different?
Natural selection favors those variations in a population that increase relative fitness
The body plan of an animal is the result of a pattern of development programmed by the genome which is the product of millions of years of evolution
Evolution of animal size and shape
Dolphins and fish are an unrelated species but still have similar morphologies why?
They both have to adapt to the same environmental challenges which in this case was overcoming the drag during swimming
Exchange with the Environment
Occurs as substances dissolved in an aqueous solution move across the plasma membrane of each cell
Rate of exchange is proportional to the membrane surface area involved in exchange
The amount of material that must be exchanged is proportional to the total body volume
A multicellular organism only works if every cell has access to a suitable aqueous environment
Many animals with simple internal organization have body plans that enable direct exchange between almost all their cells and the external environment
Increasing the number of cells decreases the ratio of outer surface area to total volume
Evolutionary adaptations that enable sufficient exchange with the environment are specialized surfaces that extensively branched or folded
Exchange surfaces lie within the body that's whole purpose is to protect their delicate tissues from dehydration
The branching or folding increases surface area
Internal body fluid link excahnge surfaces to body cells
Space between cells are filled with a liquid known as interstitial fluid
Complex body plans
Include a circulatory fluid such as blood
Exchange between interstitial fluid and the circulatory fluid enables cells through the body to obtain nutrients and get rid of waste
Advantageous for animals living on land
Hierarchical Organization
Cells are organized into tissues
Different types of tissues are further organized into functional units called organs
Group of organs that work together providing additional level of organization and coordination make up and organ system
Four main types of animal tissues
Epithelial
Cover the outside of the body, line organs, and cavities within the body
Connective
A sparse population of cells scattered through an extracellular matrix hold many tissues and organs together and in place
Muscle
Responsible for nearly all types of body movement
Nervous
The recipt, processing, and transmission of information
Coordination and Control
For an animal's tissues and organ system to function effectively they must act in concrt with one another
The Endocrine System
Signal travels everywhere via the bloodstream
Hormones
Long-lasting since hormones can remain in the bloodstream for minutes or even hours
Only cells that have receptors for a particular hormone respond
Well adapted for coordinating gradual changes that affect the entire body
The Nervous System
Signal travels along axon to a specific location
Transmission is extremely fast with nerve impulse taking only a fraction of a second to reach the target and last less than a second
Can act on other neurons, on muscle calls, and on cells and glands that produce secretions
Well suited for directing immediate and rapid responses to the environment
40.2 Feedback control
Regulating and Conforming
An animal is a regulator for an environmental variable if it uses internal mechanisms to control internal change in the face of external function
An animal is a conformer if it allows its internal mechanisms to control internal conditions to change in accordance with external conditions changes in the particular variable
Homeostasis
The maintenance of internal balance
Animals maintaining a steady state a relatively constant internal environment even when the external environment changes
Mechanisms of Homeostasis
Requires a control system
In animals helps maintain a variable such as body temperature within a set point
Fluctuation in the variable above or below the set point serves as the stimulus detected by a sensor
Sensor signals a control center which triggers a response that helps return the variable to the set point
Moderates but does not eliminate changed in the internal environment
Feedback Control in Homeostasis
Negative Feedback
Control mechanism that damps its stimulus
Plays a major role in homeostasis in animals
A change in a variable triggers a response that counteracts the initial change
Positive Feedback
Control mechanism that amplifies the stimulus
Helps drive processes to completion
Alterations in Homeostasis
Set point of homeostasis can chage under various circumstances
Regulated changes in the internal environment are essential to normal body functions
In all animals' certain cyclic alterations in metabolism reflect a circadian rhythm
Set of physiological changes that occure roughly every 24 hours
Acclimatization
Animals' physiological adjustment to changes in its external enviroment
40.3 Homeostatic processes for thermoregulation
Thermoregulation
Process in which animals maintain their body temperature within the upper and lower limits of the set point
Depends on an animal's ability to control the exchange of heat with its environment
Insulation
Reduces the flow of heat between an animal's body and its environment
Found in both the body's surface and beneath
Circulatory Adaptations
Provide a major route for heat flow between the interior and exterior of the body
Regulate the extent of blood flow near the body surface or that trap heat within the body core
Nerve signals that relax the muscles of the vessel walls result in vasodilation
Reducing heat loss from the body relies on countercurrent exchange
Transfer of heat between fluids that are flowing in opposite directions
Cooling by evaporative Heat Loss
If environmental temperature is above body temperature
Animals exhibit adaptations that greatly facilitate evaporative cooling
Swaet glands
Panting
Pouch richly supplied with blood vessels in the floor of the mouth
Behavioral Responses
When cold they seek warm places
When hot they bathe, move to cool areas
Social behavior is used by both endotherms and ectotherms
Endothermy and Ectothermy
Endothermic
Are warmed mostly by heat generated by metabolism
Humans, mammals, and birds
In cold they generate enough heat to keep their body substantially wemer than its surrounding
In hot weather they have a mechanisms for cooling their bodies
Vasodilation usually increases the transfer of body heat to the environment by radiation, conduction, and convection
Ectothermy
Gain most of their heat from external sources
Non-avian reptiles and fishes
Adjust their body temperature by behavioral means such as seeking out shade or basking in the sun
The amount of food they consume is way less than the amount of a endotherms do
Variation in Body Temperature
Poikilotherm
Animal body temperature varies with its enviroment
Homotherm
Relatively constant body temperature
Misconception that ectotherms are cold-blooded and endotherms are warm-blooded
40.4 The amount of energy an animal needs is due to their size and more
Animal use chemical energy for growth, repair, activity, and reproduction
Bioenergetics determines the nutritional needs and is related to the animal's size, activity, and environment
Energy Allocation and Use
Autotrophs
Harness light energy to build energy-rich organic molecules and then use those molecules for fuel
Heterotrophs
Obtain their chemical energy from food, which contains organic melecules synthesized by other organisms
Quantifying Energy Use
Sum of all the energy an animal uses in a given time interval is called metabolic rate
Metabolic rate can be measures by monitoring an animal's rate of heat loss
Can also be determined from the amount of oxygen consumed
To calculate metabolic rate over long er periods researchers record the rate of food consumption, the energy content of the food, and the chemical energy
Minimum Metabolic Rate and Thermoregulation
Basal metabolic rate
Nongrowing endotherms that is at rest, has an empty stomach, and is not experiencing stress
Standard metabolic rate
Ectotherms minimum determined at a specific temperature because changes in the environmental temperature alter body temperature and therefore metabolic rate
Rate of fasting, nonstresses ectotherm at rest at a particular temperature
Influences on Metabolic Rate
Size
The larger the animals the more body mass it had therefore it requires more chemical energy
Affects energy consumption by body cells and tissues
Energy it takes to maintain each gram of body mass is inversely related to body size
The smaller the animal is the higher the metabolic rate per gram demands a higher rate of oxygen delivery
As body size increases energy costs per gram of tissue decrease however an ever-larger fraction of body tissue is required for exchange, support, and locomotion
Activity
The maximum metabolic rate an animal can sustain is inversely related to the duration of activity
Torpor and Energy Conservation
Major adaptation that enables animals to save energy in the face of such difficult conditions is torpor a state in which decreases activity and the metabolism
Endotherms that exhibit daily torpor are small and when active they have high metabolic rates and therefore high rates of energy consumption
Hibernation
Long-term torpor that is an adaptation to the winter
Body temperature declines as its body's thermostat is turned down
Metabolic rate during this process can be 20 times lower than if the animal attempted to maintain normal body temperature
Slow metabolism and inactivity of estivation/ summer torpor enable animals to survive long periods of high temperatures and scarce water
Chapter 41: Animal nutration
41.1 What must a animals diet consist off?
Animals must consume food for both energy and the organic molecules used to assemble new molecules, cells, and tissues
Adequate diet must satisfy chemical energy for cellular processes, organic building blocks for macromolecules and essential nutrients
All of an animal's activities depend on sources of chemical energy in the diet
Carbohydrates, proteins, and lipids
Chemical reactions of cellular respiration use this energy to produce ATP which powers processes ranging from DNA replication and cell division
Essential Nutrients
Include certain amino acids, fatty acids, and vitamins and minerals
Animals can get these by feeding on plants or other animals
Amino Acids
All organisms require a standard set of 20 amino acids to make a complete set of proteins
Animals have the enzymes to synthesize half of the amino acids the other half they need to get through the animal's food in prefabricated form
Animals and humans require eight amino acids which are isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine
Proteins in animal products like meat, eggs, and cheese are complete which means they provide all the essential amino acids
Plant proteins are" incomplete" which means they are deficient in one or more essential amino acid
Fatty Acids
Animals require them to synthesize a variety of cellular components including membrane phospholipids, signaling molecules, and storage fats
An unsaturated fatty acid that an animal needs but cannot make.
Can obtain ample quantities of essential fatty acids from seeds, grains, and vegetables in their diets
Vitamins
Organic molecules that are required in the diet but in very small amounts
Vitamin C
Required for the productions of connective tissue; also waters-soluble
Vitamin B2
Water-soluble vitamin that is converted in the body to FAD
Coenzyme used in many metabolic processes including cellular respiration
Vitamin D
Aids in calcium absorption and bone formationd
VItamin A
Fat- soluble which is incorporated into visual pigments of the eye
Overconsumption of fat-soluble vitamins may cause them to accumulate to toxic levels
Minerals
Inorganic nutrients like iron, and sulfur which are required in small amounts
Diverse functions in Animal physiology
Some are assembled into the structure of proteins
Iron
The functioning of nerves and muscles and in maintaining osmotic balance between cells and the surrounding body fluid
Sodium, potassium, and chloride
Key function is serving as substrates of enzymes as coenzymes and as cofactors in biosynthetic reactions
Variation in Diet
Herbivores
Plants and algae
Carnivores
Eat other animals, meat
Omnivores
Eat both plants and meat
Most animals are opportunistic feeders broadening their diet when their usual foods aren't available
Deficiencies in Essential Nutrients
If there is not enough intake of essential nutrients it can cause deformities, disease, and even death
A diet with insufficient amounts of one or more essential amino acid can cause protein deficiency
Undernourishment
The body first uses up stored carbohydrates and fat then breaks down its own proteins for fuel
Causes the muscles to shrink and the brain to become protein-deficient
Can happen as a result of a eating disorder
Inadequate nourishment in humans is most common when droughts, wars, and other crisis disrupt the food supply
Can be caused by a diet that fails to provide enough chemical energy
41.2 Food processing
Can divide food processing into four 4 stages
Ingestion
Fist stage
The act of eating
Filter feeding
Substrate feeding
Fluid feeding
Bulk feeding
Digestion
Second stage
Food is broken down into small molecules small enough for the body to absorb
Mechanical and chemical processes are required
Mechanical works for chewing in order to break the food down into smaller pieces increasing the surface area
Chemical is necessary because animals cannot directly use the nucleic acids, fats, phospholipids, and most carbohydrates in food
Breaking down bonds through the addition of water
Enzymatic hydrolysis is when polysaccharides and disaccharides are split into simple sugars
Also releases fatty acids and other components from fats and phospholipids
Absorption
Third stage
The animals cells absorb small molecules such as amino acids and simple sugars
Elimination
Undigested materials passes out of the digestive system completes the process
Poop it out
Digestive Compartments
The evolutionary adaptation that allows animals to avoid self-digestion is the processing of food within specialized intracellular or extracellular compartments
Intracellular
Food vacuoles in which hydrolytic enzymes break down food
Simplest digestive compartments
The hydrolysis of food inside vacuoles begins after a cell engulfs solid food by phagocytosis
Newly formed vacuoles fuse with lysosomes, organelles containing hydrolytic enzymes
Fussion of organelles brings the food in contact with the enzymes which allow digestions to happen safely within a compartment enclosed by a protective membrane
Extracellular
The breakdown of food in compartments that are continuous with the outside of the animal's body
Having more than one extracellular compartment helps animals eat much larger pieces of food than can be ingested by phagocytosis
Animals with a simple body plan have a digestive compartment with a single opening which is called a gastrovascular cavity
Functions in digestion and in the distribution of nutrients through the body
Animals with complex body plans have a digestive tube with two openings a mouth and an anus called an alimentary canal
Can ingest food while earlier meals are still being digested
41.3 Organs specialized for sequential stages of food processing
Three pairs of salivary glands and three individuals' glands which are the pancreas, the liver, and the gallbladder
Oral cavity, pharynx, and esophagus
As soon as food enters your mouth the foos processing begins
Anticipation of food in the oral cavity triggers the release of saliva by the salivary glands
Saliva is a complex mixture of materials with a number of vital functions
Mucus is a viscous mixture of water, salts, cells, and slippery glycoproteins
Mucus lubricates food for easier swallowing, protects the gums against abrasion, and facilitates taste and smell
Saliva contains buffers which help prevent tooth decay by neutralizing acid, and antimicrobial aganets
Most abundant enzyme in saliva is amylase which breaks down starch and glycogen
Tongue
Tongue movements manipulate the mixture of saliva and food helping shape it into a ball called a bolus
Taste buds on the tongue help evaluate ingested materials by selecting which foods should be processed further and then enabling their passage
During swallowing helps by pushing the bolus to the back of the oral cavity and into the pharynx
Bolus of food is received by the pharynx which leads to two passageways which are the esophagus and the trachea
Esophagus
Muscular tube that connects to the stomach
Food is pushed along by peristalsis alternating waves of smooth muscle contraction and relaxation
The sphincter a ringlike valve of muscle regulates the passage of the ingested food into the next compartment, the stomach
Trachea (windpipe) leds to the lungs
Digestion in the Stomach
Two major roles which is storage and to process food into a liquid suspension
Digestive fluid called gastric juice and mixes it with the food through a churning action
Mixture of ingested food and gastric juiice is called chyme
Chemical digestion
Hydrochloric acid
Disrupts the extracellular matrix that binds cells together in meat and plants
High pH around 2
Pepsin
Breaking peptide bonds it cleaves proteins into smaller polypeptides and further exposes the contents of ingested tissues
Digestion in the Small Intestine
The alimentary canal is the longest compartment
First 25 cm of the small intestine forms the duodenum where chyme forms the stomach mixes with digestive juice from the pancreas, liver, and gallbladder
Arrival of chyme in the duodenum triggers release of the hormone secretin which stimulates the pancreas to secrete bicarbonate
Bicarbonate neutralizes the acidity of chyme and acts as a buffer for chemical digestion in the small intestine
Absorption in the small intestine
Large folds in the lining encircle the intestine and are studded with finger-shaped projections called villi
Epithelial microvilli have a brush-like appearance that is reflected in their name
Depending in the nutrient transport across the epithelial cells can be passive or active
Capillaries and vines that carry nutrient-rich blood away from the villi converge into the hepatic portal a blood vessel that leads directly to the liver
Processing in the Large Intestine
Alimentary canal ends
Small intestine connects to the large intestine at a T-shaped junction
One of their arms is a pouch called the cecum which is used for fermenting ingested material
Takes approximately 12-24 hours for materials to travel the length of the colon
Terminal portion is the rectum where the feces are stored before elimination
41.4 Evolutionary adaptations of digestive systems
Dental Adaptations
Animals assortment of teeth
Stomach and Intestinal Adaptations
Evolutionary adaptations to differences in diet are sometimes apparent as variations in the dimensions of digestive organs
Large expandable stomachs are common in carnivorous which must wait a long time between meals and must eat as much as they can when they catch pray
Adaptation is also apparent in the length of the digestive system
Longer digestive tract furnishes more time for digestion and more surface area for nutrient absorption
Mutualistic Adaptations
Coexistence of humans and many intestinal bacteria
Microbiome the collection of microorganisms living in and on the body along with their genetic material
Herbivores
Get much of the chemical energy they need from the cellulose of plant cell walls but they do not produce enzymes that hydrolyze
Host a large population of mutualistic bacteria and protists in fermentation chambers in their alimentary canals
have enzymes that can digest cellulose to simple sugars and fatty acids that the animal can absorb
41.5 Feedback circuits regulate digestion
Regulation of Digestion
As food reaches each new compartment it triggers the secretion of digestive juices for the next stage of processing
Arrival of food in the stomach triggers churning and the release of gastric juices
Enteric nervous system
Network of neurons dedicated to the digestive system
Plays a critical role in controlling digestion
Regulation of Energy Storage
When an animal takes in more energy-rich molecules than it needs for metabolism and activity it stores the excess energy
In humans the energy can be stored in the liver and muscle as glycogen a polysaccharide made up of many glucose molecules units or in adipose cells as fat
When fewer calories are taken in muscle cells draw on their stored glycogen and liver and adipose cells release glucose and fatty acids into the blood for use by the other body cells
Glucose Homeostasis
Synthesis and breakdown of glycogen are central not only to energy storage but also to maintaining metabolic balance through glucose homeostasis
Normal range of for the concentration of glucose in the blood is 70-110mg/100 mL
Relies predominantly on the opposing effects of two hormones insulin and glucagon
When blood glucose level rises above the set point increased secretion of insulin triggers the uptake of glucose from the blood into the body cells decreasing the blood glucose concentration
When blood glucose level drops below the set point increased secretions of glucagon promotes the release of glucose into the blood from energy stores increasing the blood glucose concentration
Diabetes Mellitus
A disease caused by a deficiency of insulin or a decreased response to insulin in target tissues
Blood glucose level rise but cells are unable to take up enough glucose to meet metabolic needs
Levels of glucose in the blood may exceed the capacity of the kidneys to reabsorb this nutrient
Type 1 Diabetes
Immune system destroys the beta cells of the pancreas
Usually appears during childhood and destroys the person's ability to produce insulin
Treatment consists of insulin injections typically given multiple times daily
Type 2
A failure of target cells to respond normally to insulin meaning they fail to take up glucose from the blood and so the blood glucose level remains elevated
Appears after age 40 but children can develop it as well