② Function : Mechanical loss, pathogen invasion, fluid loss protection, environmental protection in the body, control of internal and external material exchange

③ One side anchored to the bottom, the other side exposed to body fluids or the environment

○ Protection, secretion and absorption function

○ Make up exocrine glands like sweat glands and digestive glands

④ Epithelial cells continue to fall off and are supplemented by cell division of stem cells in epithelial tissue

⑤ Kinds

○ Cubic epithelial tissue (e.g., Kidney tubule, thyroid gland, salivary gland) : Rounded surface layer

○ Tomographic columnar epithelium (e.g., Small intestine cells)

○ Faulty squamous epithelium (e.g., Alveoli)

○ Multilayer squamous epithelium : Well worn surfaces, mainly keratinized in the skin, and non-keratinized in the mouth, esophagus, vagina and anus

○ False multilayered ciliated columnar epithelium (e.g., Oviduct cilia, bronchial cilia) : Fault

⑥ Function

○ Exchange : Monolayer squamous epithelium

○ Characteristic : Molecules exchange smoothly with holes between cells

○ Location : Lung, vascular endothelium

○ Carrying : Cubic epithelium, monolayer columnar epithelium

○ Characteristic : Tight joints prevent exchange between cells, cell membranes fold to form villi and increase surface area

○ Location : Small intestine, kidney, some exocrine glands

○ Cilia : Cubic epithelium, monolayer columnar epithelium

○ Characteristic : One side is covered with cilia, so the flow moves along the surface

○ Location : Nose, bronchial and upper respiratory tract, female reproductive system

○ Protect : Multilayer squamous epithelium

○ Characteristic : Cells are firmly connected by many desmosomes

○ Location : Skin exposed to the external environment, such as the inner side of the mouth and the surface of the wound.

○ Secretion : Tomographic columnar epithelium, cubic epithelium, polygonal epithelium

○ Characteristic : Protein-secreting cells filled with membrane-enclosed secretory particles and multiple rough endoplasmic reticulum;

○ Location : Exocrine glands such as pancreas, sweat glands, and salivary glands, endocrine glands such as thyroid gland and gonads

⑷ Type 2. Connective tissue

① Function to bind or support organs and tissues, composed of cells embedded in substrates, and also act as physical barrier

○ Substrate consists of fiber and tissue fluid

② Coarse connective tissue (e.g., Subcutaneous)

○ Consists of universal connective tissue, fibroblasts and substrates

○ Matrix : Gels; More matrix than fibers and cells

○ Substrate : Collagen and elastin fibers are loosely interwoven and also contain reticulated fibers

○ Supports epithelial tissue and holds underlying tissues and organs

○ Location : Skin, around blood vessels and organs, under epithelium

③ Fibrous connective tissue

○ Forms tendons and ligaments, composed of fibroblasts and substrate

○ Substrate : Dense collagen fibers arranged in parallel

○ Matrix : Most of the fiber rather than the matrix

④ Adipose tissue

○ Store fat in the form of fat droplets

○ Function : Connect skin to infrastructure, support trachea, insulate, save energy

○ Class 1. White fat

○ Large fat droplets exist

○ Has a small amount of protoplasts, few substrates and fibers

○ Low organelles, little blood supply

○ Function : Fat storage

○ Class 2. Brown fat : Brown due to blood flow

○ mitochondria, rich in blood supply

○ Function : Non-vibration heat production

○ Brown fat is observed in the armpit and neck area of infants

○ It gradually degenerates as an adult and increases with low temperature acclimation.

○ 1^st. Sympathetic norepinephrine works GPCR

○ 2^nd. Increased cAMP and PKA during signal transduction

○ 3^rd. PKA acts on ligase to oxidize fatty acids

○ 4^th. cAMP and oxidized fatty acids produce thermogenin

○ 5^th. Thermogenin is uncoupled respiration in mitochondria. 3-⑵-⑤Heat with)

○ Obesity : Born with a similar number of mast cells at birth

○ Childhood obesity : Mast Cell Number Increase

○ Adult obesity : Mast cell enlargement

○ Fat location varies by age and gender

Figure. 2. White fat (left) and brown fat (right). (A) indicates droplets

⑤ Blood

○ Cell composition : Red blood cells, neutrophils, platelets

○ Substrate : Plasma

○ Oxygen and nutrient transport, immune function to cope with infection

⑥ Cartilage

○ Chondrocytes Differentiate into Soft oesteocytes

○ Soft oesteocyte Secretes Substrate

○ Cartilage supports fertilization and has fluidity

○ Blood vessels are not distributed, so much time is needed to repair the damage

○ Cartilage Substrate (Gel State) : Consists of water (70%), type II collagen, hyaluronic acid, chondroitin sulfate, glucosaminoglycans, proteoglycans, etc.

○ Location : Articular surface, spine, ear, nose, pharynx

○ Arthritis

○ 1^st. Substrate of cartilage has -OH group (OH glycoprotein) and has elasticity while holding moisture

○ 2^nd. Reduction of Substrate in Old Age

○ 3^rd. Inflammation of joints after loss of elasticity and injuries

⑦ Bone

○ Hard connective tissue due to calcium salts

○ Osteoblast : Secrete substrate composed of collagen fiber and calcium phosphate

○ Osteoclast : Decompose bone

○ Oesteocyte : Maintain Solid Goal Substrate

○ Lack of dietary calcium uses calcium in bone

⑸ Type 3. Muscle tissue

① Contractile tissue, composed of muscle cells (muscle fibers)

② Actin and myosin protein interact to muscle contraction

③ 3 types : Skeletal muscle, heart muscle, smooth muscle

○ Skeletal muscle : Voluntary movement, equilibrium, horizontal pattern, multicore, non-differential

○ Heart muscle : Involuntary movement, pruning arrangement, horizontal pattern, nucleus, differential

○ Smooth muscle : Involuntary movements, fusiform, flat pattern, nucleus, differential

○ Eradication degeneration, no T tract

⑹ Type 4. Nerve tissue

① Transmitting nerve signals from one part of the animal to another

② Composed of neurons. Brain and spinal cord composition

③ Neurons : A sense of stimulation. Stimulus information processing. Send exercise command

④ Nerve : Nourishing neurons. Insulator. Involved in neuronal formation

⑤ Most nervous system cells do not divide

3. Organ

⑴ Composed of several (≥ 2) organizations for independent functions

⑵ Exists in all animals except sponges

⑶ One organ can belong to multiple organ systems

① Example : Interest plays an important role in both the endocrine and digestive systems

⑷ Example : Heart, stomach, lungs, etc.

4. Organ System

⑴ Example : Digestive system, respiratory system, circulatory system, endocrine system, nervous system, exercise system, immune system

5. Individual : Homeostasis

⑴ Animal classification according to the internal environment control method

① regulator (regulator) : Use internal control mechanisms to reduce internal changes caused by external fluctuations

② conformer (conformer) : Change the internal environment according to the external environment

⑵ Negative feedback control : Mechanisms of change reduction to eliminate the causes of environmental changes in the body

① Class 1. Feedback inhibition : Feedback circuits interfere with enzyme and metabolic mechanisms

② Collaborative feedback inhibition

○ Each final product must be above a certain concentration to inhibit the enzyme

○ Enzyme has more than one allosteric site

③ Cumulative feedback inhibition

○ Each final product partially inhibits the enzymes involved in the initial reaction

○ If the sum of each amount of the final product exceeds a certain level, the total enzyme is inhibited

④ Class 2. Feedback repression : Feedback circuitry interferes with gene transcription (↔ induction)

⑶ Positive feedback : Changes in the environment do not contribute to the mechanism of expansion, homeostasis

① Example 1. Blood clotting

② Example 2. Uterine contractions at birth

③ Example 3. Reproductive cycle : Estrogen

④ Example 4. Neuronal action potential

⑷ Homeostasis

① Set points and normal ranges for homeostasis may vary for different environments

○ Example : Most animals have lower body temperatures when they are sleeping than when they are awake

② One way to change the normal range of homeostasis is to purify it (the process of adapting to changes in the external environment).

○ Example : Physiological Changes in Mammals Ascending From Sea Level to Highlands. Increased blood flow to the lungs. Increased red blood cell production

6. Individual : Metabolic regulation

⑴ Bioenergy : Limit the behavior, growth, and reproduction of living things and determine how much food an animal needs

① Metabolic rate : The amount of energy used per unit time, the amount of energy required for the entire biochemical reaction for a given time

② Energy strategy

○ In general, the metabolic rate of warm-temperature animals is much higher than the metabolic rate of warm-temperature animals.

○ Warm animals have a longer period of intense exercise (eg. Long distance running, active flight)

○ In general, temperature resistant animals are less resistant to fluctuations in internal temperature and more food intake than external temperature animals.

⑵ Effect on metabolic rate

① Size and metabolic rate

Figure. 3. Correlation between BMR and Body Size

○ Excessive size of the animal limits mobility

○ Larger animals increase energy cost per body mass

○ The larger the animal, the more adequate the exchange system for exchanging material (eg : Circulatory system)

Figure. 4. Each part of the body with increased surface area for mass exchange

○ body mass index (BMI)

○ Defition : Weight (kg) divided by height (m) squared

○ BMI ≥ 30 : Obesity. BMI <18.5 : Low weight

② Activity

○ Maximum metabolism rate : Occurs during intense activity and is inversely proportional to duration of activity

○ Minimum metabolic rate : Promote life-sustaining functions such as cell maintenance, respiration, and heart rate, divided into basic metabolic rate and standard metabolic rate

○ Basal metabolic rate (BMR) : The metabolic rate of a tolerant animal that is resting, has an empty stomach, and does not grow under stress, as determined within the environmental temperature range.

○ Example : Adult men 1600-1800 kcal / day, adult women 1300-1500 kcal / day

○ SMRl standard metabolic rate : Metabolic rate varies depending on metabolic rate and environmental temperature of thermophilic animals resting at a certain temperature, not eating, and not stressed

③ Animal form

○ Streamlined animal body design reduces frictional resistance when moving

○ The flat body design has a large surface area per unit volume, which is advantageous for mass exchange.

⑶ Energy balance : Percentage of items where energy is used

Figure. 5. Annual energy expenditure for each animal

① Resistant Animal Energy Balance

○ Significantly consumes a large percentage of energy

○ The proportion of energy spent on size and temperature control is the opposite

② Thermoplastic Animal Energy Balance

○ Very low percentage of energy spent on thermoregulation

○ Significantly less energy expenditure than temperature-resistant animals of the same size

⑷ Dormancy and energy conservation

① Hibernation : Adaptation to winter cold and food shortage

○ Example : Hibernating Ground Squirrel : Lowers body metabolism by lowering body temperature

② If : Adaptation to long periods of high temperature and insufficient water supply

③ Intraday sleep : The body size of all dormant animals that are dormant is considered to be a biometric cycle controlled by a biological clock.

○ Example : Bats dormant during the day even if they feed on the night, sleep during the day, and continue to feed

7. Individual : Thermoregulation

⑴ Thermoregulation

① Necessity of thermoregulation⑴ : The temperature at which the enzyme is active is limited, so most cell functions are limited to a narrow temperature range.

② Necessity of thermoregulation⑵ : Heat continues to develop in life.

○ Adult male standard, 87 W for sleep, 115 W for rest or office work, 230 W for bowling, 440 W for severe physical labor

○ Adult women produce about 15% less heat because their bodies are smaller than in adult men

③ Necessity of thermoregulation⑶ : Heat exchange between the skin and the external environment (conduction, convection, radiation, evaporation)

○ The key to thermoregulation is to equalize heat gain and heat loss.

○ Animals perform thermoregulation to reduce heat exchange as a whole

④ Temperature resistant animal

○ Endotherm : Creature that regulates body temperature by heat generated in the body

○ A warm-blooded animal : Creature that regulates body temperature by heat generated in vitro

○ Homeotherm : Generally temperature-resistant animals, animals with constant temperature

○ Poikilotherm : Generally thermophilic animals, animals whose body temperature varies within a certain range

○ Body temperature control by controlling blood flow in both warm and warm animals

⑵ Thermoregulation of Temperature-Resistant Animals

① Active heat generation of temperature resistant animals

○ Generate shivering heat : Heat generated by muscle activity, such as moving or trembling

○ Generate non-shake heat : Brown Fat (See. 2-⑶-④)

○ Thyroxine and Metabolic Fever

② Heat and adaptation

○ Surface area : Species living in cold areas have a small surface area

○ Insulation : Reduces heat flow between animals and the environment

○ Example : Hair, feathers, fat layer

○ Circulatory system adaptation : Changes the amount of blood flowing inside the body and between skin in response to changes in environmental temperature

○ Vascular Relaxation : Increased blood flow to the skin surface to increase the rate of heat loss into the body

○ Vasoconstriction : Reduced blood loss to the skin surface to reduce heat loss rate

○ Countercurrent heat exchange : System to reduce heat loss

Figure. 6. Example of Backflow Heat Exchange

○ Adjacent blood flow in opposite directions to maximize heat transfer rate

○ Part of the heat in the arterial blood flows into the venous blood and becomes a mechanism to maintain the temperature in the center of the body

○ Cooling by evaporation

○ Gasping

○ Sweating : Observed in many terrestrial animals, with sweat glands controlled by the nervous system

○ Saliva : Some kangaroos, observed in rodents

○ Evaporative cooling control through changes in the amount of mucus on the body surface

⑶ Thermoregulation of Thermophilic Animals

① Generate shivering heat : Some large reptiles increase metabolic rate through tremor

② Behavioral response

○ Outside animals rely more on temperature control by behavior

○ Bee : Density and heat production in cold days by using thermoregulatory mechanisms dependent on social behavior ↑

⑷ Purification in thermoregulation

① Purification of temperature resistant animals

○ Controlling the degree of insulation

○Example : Grows thick fur in winter and takes off in summer

○ Seasonal Changes in Metabolic Heat Production Capacity

② Purification of Thermophile Animals : Often includes adjustment at the cellular level

○ Generation of enzyme variants with the same function but with different optimum temperatures

○ Maintain membrane fluidity at various environmental temperatures by varying the saturated fat / unsaturated fat ratio

○ Life at very low environmental temperatures creates antifreeze and lowers freezing point

⑸ Vertebrate thermostats : Thalamus lower part, Thalamus lower part of the brain

Figure. 7. Thermostatic mechanism under the Thalamus

① Use feedback information

○ Lower Thalamus perception of cold → contraction of blood vessels in the skin → reduction of blood flow and shaking in the skin → heat generation

○ Lower Thalamus perception of heat → skin and blood vessel expansion → increased blood flow and panting → heat loss

○ Thalamus lower part stimulates autonomic nervous system and pituitary gland

② Fever defends against infection

○ Fever factor rises set point

○ Macrophage secretion during infection → Thalamus lower setpoint ↑ → Temperature rise → Immune system activity and microbial growth ↓

③ Energy savings can be achieved by lowering the set point

⑹ Drosophila and heat shock proteins

① HSF (heat-shock factor) induces the expression of HSP70 by binding to the heat-shock element (HSE) located above the HSP70 gene

② HSF protein is bound to HSE by thermal shock

8. Individual : Osmotic control

⑴ Osmotic Control Challenge : Moisture Balance of Various Animals

① Classification according to the method of maintaining water balance

○ Osmosis : Animals Not Actively Controlling Osmolarity In The Body, Net Migration Of Water ×

○ Osmotic regulator : Animals that maintain an internal osmolarity different from the external osmolarity, energy is constantly required

② Osmotic Control of Seawater and Freshwater Animals

○ Sea animals : Water intake with high salt concentration, water leaks from the body surface by osmosis → Salt discharge from gills, small amount of urine with high salt concentration

○ Freshwater animals : Water intake with low salt concentration, water inflow from body surface by osmosis → Salt intake from gill, large amount of urine with low salt concentration

③ Water bear : Trehalos protects cell membranes and proteins during dehydration

⑵ Energy Science of Osmotic Control : Saving energy

① Adapts body fluids to the salinity of the habitat to save energy consumed to balance water and solutes

② Transport epithelium : Take saline as an example.

○ Carrier epithelial cells in charge of solute transport consist of one or several layers

○ Large surface area in the form of complex tubes

○ Example. Seagulls consume 80% of the water they drank through the saline while removing 80% of salt

③ Backflow Exchange

○ Direction of blood flow and discharge of salinity in the lumen of the secretory canal

○ This countercurrent system maintains the concentration gradient of salt throughout all sections, facilitating the transfer of salt from the blood to the tube

⑶ Osmoticity of the human body

① Water inflow (/ day)

○ Drink Intake : 1250 mL

○ Water of food : 1000 mL

○ Metabolic generation : 350 mL

○ Total inflow : 2600 mL

② Moisture Spill (/ day)

○ Unconscious loss (lungs, skin) : 900 mL

○ Sweat : 100 mL

○ Credit : 100 mL

○ Urine : 1500 mL

○ Total runoff : 2600 mL

③ Osmotic homeostasis

Table. 1. Osmotic concentration of various ions in the human body

④ Fluctuations in fluid volume and osmolarity

Table. 2. Fluctuations in fluid volume and osmolarity

○ Extracellular fluid volume (ECF) : Increasing fluid volume increases ECF, decreasing decreases ECF

○ Intracellular Fluid Volume (ICF) : Increasing osmolality reduces ICF, decreasing decreases ICF

⑷ Edema

① Defition : Swelling caused by the movement of water from the blood into tissue fluid

② Cause 1. Sleep after eating high salt : Ramen broth)

○ 1^st. The kidneys do not work and no salt is released

○ 2^nd. Salin accumulation in the blood

○ 3^rd. Blood delivers salt to tissues for osmolality

○ 4^th. Osmotic pressure increases tissue content

○ 5^th. Edema occurs

③ Cause 2. Kidney disease

○ 1^st. Kidney does not function smoothly and cannot release salt

○ 2^nd. Salin accumulation in the blood

○ 3^rd. Blood delivers salts to tissues for osmolality

○ 4^th. Osmotic pressure increases tissue content

○ 5^th. Edema occurs

④ Cause 3. Fast

○ 1^st. Reduced concentration of albumin, a temporary energy source in the blood

○ 2^nd. Blood Osmotic Reduction Effect

○ 3^rd. The presence of net water from the blood to tissue fluid

○ 4^th. Edema occurs

⑤ Cause 4. Exercise

○ 1^st. Increased blood pressure

○ 2^nd. The presence of net water from the blood to tissue fluid

○ 3^rd. Edema occurs

Input : 2015.7.16 09:46

revisions : 2019.9.14 23:04

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Chapter 12. Systematic Level of Animals

1. Cell

**2. Tissue