Unit 9 AP BIO TEST HHS going over Chapters 32-35 in AP Biology Textbook- vocab and questions

Tissues

groups of cells with similar appearance and common function

Organs

structures made of two or more tissue types that work together to perform specific functions.

Organ systems

groups of organs that work together to perform complex functions in an organism.

Digestive system

main function: food processing (ingestion, digestion, absorption, elimination

main components: mouth, pharynx, esophagus, stomach, intestines, liver, pancreas, anus

Circulatory system

main function: transport of nutrients, gases, hormones, blood cells, internal distribution of materials

main components: heart, blood vessels, blood

Respiratory system

main function: gas exchange (oxygen intake and carbon dioxide removal) main components: nose, pharynx, larynx, trachea, bronchi, lungs, diaphragm

Immune and lymphatic systems

main function: defense against pathogens and disease

main components: white blood cells, lymph nodes, lymphatic vessels, spleen, thymus.

Excretory system

main function: elimination of waste products and regulation of water and electrolyte balance

main components: kidneys, ureters, bladder, urethra.

Endocrine system

main function: regulation of body functions through hormones

main components: glands such as the pituitary, thyroid, adrenal, and pancreas.

Reproductive system

main function: production of offspring and sex cells
main components: ovaries, testes, fallopian tubes, uterus, epididymis.

Nervous system

main function: coordination of body activities through electrical signals and neurotransmission

main components: brain, spinal cord, and peripheral nerves.

Integumentary system

main function: protection of the body from external damage and regulation of temperature

main components: skin, hair, nails, and associated glands.

Skeletal system

main function: support and protection of body organs, movement facilitation

main components: bones, cartilage, ligaments, and joints

Muscular system

main function: movement of the body and maintenance of posture

main components: muscles, tendons, and fascia.

animal tissue— Epithelial

— covers body surfaces, lines cavities/ organs

— involved in protection, secretion

animal tissue—Connective

— Supports and binds other tissues, provides strength and elasticity

— Main components include loose connective tissue, dense connective tissue, adipose tissue, blood, and bone.

animal tissue—Muscle

— responsible for movement through contraction

— Includes skeletal, cardiac, and smooth muscle types.

animal tissue—Nervous

— nervous tissue functions in the receipt, processing, and transmission of information

— neurons are the basic units of this system

Regulator (regulating/ conforming)

— an animal that is a regulator uses internal mechanisms to control internal change despite external fluctuation

Regulators use metabolic processes to control their internal environment.

Conformer (regulating/ conforming)

— an animal that is a conformer allows its internal condition to change in accordance with external changes

an animal may regulate some internal conditions and not others

Interstitial fluid

ex. a fish may conform to surrounding temperature in the water, but it regulates solute concentrations in its blood and interstitial fluid (the fluid surrounding body cells)

Homeostasis

what organisms use to maintain a “steady state” or internal balance REGARDLESS of EXternal environment

ex. In humans, body temp, blood pH, and glucose concentration are each maintained at a constant level

regulation of room temperature by a thermostat is analogous to homeostasis

Set point

— how animals achieve homeostasis by maintaining a variable at or near a particular value or set point

Stimulus

fluctuations above or below the set point to serve as a stimulus, these are detected by a sensor and trigger a response, the response returns the variable to the set point

Negative feedback

homeostasis in animals relies largely on negative feedback, a control mechanism that reduces the stimulus

—homeostasis moderates, but does NOT eliminate, changes in the internal environment

Thermoregulation

process by which animals maintain an internal temperature within a tolerable range

Endothermic

animals generate HEAT by metabolism

ex. birds/ mammals are endotherms

—endotherms can maintain a stable body temp in the face of large fluctuations in environmental temperature

Ectothermic

animals GAIN heat from EXternal sources, ectotherms include most invertebrates, fish, amphibians, and nonavian reptiles

— ectotherms may regulate temperature by behavioral means

—ectotherms generally need to consume less food than endotherms, bc their heat source is largely environmental

Organisms exchange heat through these 4 processes:

Radiation, Evaporation, Convection, Conduction

Radiation

emission of electromagnetic waves by all objects warmer than absolute zero

Evaporation

the removal of heat from the surface of a liquid that is losing some of its molecules as gas

Convection

transfer of heat by the movement of air or liquid past a surface

Conduction

the direct transfer of heat between molecules of objects in contact with each other

Heat is ALWAYS transferred from an object of _______ to ______ temperature

HIGHer to lower

Vasodilation

the widening of diameter of superficial blood vessels, promotes heat LOSS

-this is what an animal can do in response to changes in environmental temperature, they can alter blood (and heat) flow between their body core and their skin

Vaso-CONSTRICTION

the narrowing of the diameter of superficial blood vessels, reducing heat loss

--this is what an animal can do in response to changes in environmental temperature, they can alter blood (and heat) flow between their body core and their skin

Countercurrent exchange

the arrangement of blood vessels in many marine mammals and birds allows for countercurrent exchange

-countercurrent heat exchangers transfer heat between fluids flowing in opposite directions and reduce heat loss

Acclimatization

birds and mammals can vary their insulation to acclimatize to seasonal temperature changes

-acclimatization in ectotherms (ex. amphibians-get heat source from environment) often includes adjustments at the cellular level

Unsaturated lipids

help keep membranes FLUID at lower temperatures

Antifreeze compounds

Some ectotherms that experience subzero temperatures can produce “antifreeze” compounds to prevent ice formation in their cells

Hypothalamus

thermoregulation in mammals is controlled by this region of the brain, the hypothalamus triggers heat loss or heat-generating mechanisms

-FEVER is a result of a change to the set point (animals maintaining a variable at/ near particular value) for a biological thermostat

Two major systems for controlling and coordinating responses to stimuli

The Endocrine & Nervous systems

Endocrine system

signaling molecules released into the bloodstream by endocrine cells reach ALL locations in the body

-the endocrine system is well adapted for coordinating gradual changes that affect the entire body

Nervous system

neurons transmit signals along dedicated routes, connecting specific locations in the body

-signals, called nerve impulses travel along communication lines consisting mainly of axons

-other neurons, muscle cells, and endocrine and exocrine cells can all receive nerve impulses

nerve impulse + chemical signal

Hormones

signaling molecules sent out by the endocrine system are called hormones

pH control in the duodenum

digestive juices in the stomach are extremely acidic and must be neutralized before the remaining steps of digestion take place, coordination fo pH control in the duodenum relies on a endocrine pathway

-the release of acidic stomach contents into the duodenum stimulates endocrine cells there to secrete the hormones secretin

-this causes target cells in the pancreas to raise the pH in the duodenum

Pituitary gland

signals from the hypothalamus travel to a gland located at its base, called the pituitary gland

Anterior pituitary

hormone signals from the hypothalamus triggers synthesis and release of hormones from the anterior pituitary

Posterior pituitary

an extension of the hypothalamus that secretes oxytocin

Oxytocin

regulates release of milk during nursing in mammals

Antidiuretic hormone (ADH)

also known as vasopressin, is a hormone that plays a crucial role in regulating fluid balance in the body. 

Positive feedback

Reinforces a stimulus to increase the response

-during childbirth, where uterine contractions stimulate the release of oxytocin, which in turn intensifies contractions, leading to a rapid progression of labor. 

Negative feedback

a regulatory mechanism where a stimulus triggers a response that opposes the initial stimulus, bringing the system back to a stable state or "set point". 

Epinephrine

secreted by the adrenal glands and can raise blood glucose levels, increase blood flow to muscles, and decrease blood flow to the digestive system

Thyroid hormone

plays a role in metabolism across many lineages, but in frogs it has taken on a unique function: stimulating the resorption of the tadpole tail during metamorphosis

Prolactin

mammals- stimulates mamary gland growth and milk

birds- regulates fat metabolism and reproduction

amphibians- delays metamorphosis

freshwater fish- regulates salt and water balance

Osmoregulation

general term for the processes by which animals control solute concentrations in the interstitial fluid and balance water gain and loss

Osmolarity

the solute concentration of a solution, determines the movement of water across a selectively permeable membrane

Iso-osmotic

if 2 solutions are isosmotic, the movement of water is = in both directions

-if 2 solutions differ in osmolarity, the net flow of water is from the hypoosmotic to the hyperosmotic solution

Osmoconformers

consisting of some marine animals, are isosmotic with their surroundings and DO NOT regulate their osmolarity

Osmoregulators

expend energy to control water uptake and loss in a hyperosmotic or hypoosmotic environment

-Marine fish drink LARGE amts of seawater to balance water loss and excrete salt through their gills and kidneys

-Freshwater fish drink almost NO water and replenish salts through eating: some also replenish salts by uptake across the gills

Ammonia

NH3, some animals convert toxic ammonia to less toxic compounds prior to excretion

Urea and uric acid

Vertebrates secrete urea, a conversion product of ammonia, which is much LESS toxic

-Insects, land snails, and many reptiles including birds secrete URIC ACID as a SEMIsolid paste, it is less toxic than ammonia and generates very LITTLE water loss, but it is energetically more expensive to produce than urea

Transport epithelia

In most animals, osmoregulation and metabolic waste disposal rely on transport epithelia, these layers of epithelial cells are specialized for moving solutes in controlled amounts in specific directions

Filtrate

many animal species produce urine by refining a filtrate derived from body fluids

Key functions of most excretory systems

Filtration: filtering of body fluids

Reabsorption: reclaiming valuable solutes

Secretion: adding nonessential solutes and wastes from the body fluids to the filtrate

Excretion: releasing processed filtrate containing nitrogenous wastes from the body

Malpighian tubules

In insects and other terrestrial arthropods, Malpighian tubules remove nitrogenous wastes from hemolymph W/O a filtration step, insects produce a relatively dry waste matter, mainly uric acid

Capillaries/ Bowman’s capsule in kidneys

The capillaries and specialized cells of Bowmna’s capsule are permeable to water and small solutes NOT blood cells or large molecules, the filtrate produced their contains salts, glucose, amino acids, vitamins, nitrogenous wastes, and other small molecules

Proximal tubule

Reabsoprtion of ions, water, and nutrients takes place in the proximal tubule, molecules are transported actively and passively from the filtrate into the interstitial fluid and then capillaries

Descending limb of the loop of Henle w/ aquaporin

Reabsoprtion of water continues through channels formed by aquaporin proteins

-movement is driven by the HIGH osmolarity of the interstitial fluid, which is hyperosmotic (water moves outside cell) to the filtrate

-the filtrate becomes increasingly concentrated all along its journey down the descending limb

Ascending limb of the loop of Henle

the ascending limb has a transport epithelium that lacks water channels

-here, salt, but not water is able to move from the tubule into the interstitial fluid

-the filtrate becomes increasingly dilute as it moves up the cortex

Distal tubule

the distale tubule regulates the K+ and NaCl concentrations of body fluids

-the controlled movement of ions contributes to pH regulation

Collecting duct

the collecting duct carries filtrate through the medulla to the renal pelvis

-most of the water and nearly all sugars, amino acids, vitamins, and other nutrients are reabsorbed into the blood

-urine is hyperosmotic to body fluids

Adaptations of the Vertebrate Kidney to Diverse Environments

-Variations in nephron structure and function equip the kidneys of different vertebrates for osmoregulation in their various habitats

-Desert-dwelling mammals excrete the MOST hyperosmotic urine and have LONG loops of Henle

-Birds have shorter loops of Henle but conserve water by excreting uric acid instead of urea

-Mammals control the volume and osmolarity of urine

-The kidneys of the South American vampire bat can produce either very dilute or very concentrated urine

-This allows the bats to reproduce their body weight rapidly or digest large amounts of protein while conserving water

Homeostatic regulation of the kidney

-a combo of nervous and hormonal inputs regulates the osmoregulatory function of the kidney

-these inputs contribute to homeostasis for blood pressure and volume through their effect on amount and osmoregulatory of urine

Antidiuretic Hormone

ADH makes the collecting duct epithelium temporarily more permeable to water

-an INCREASE in blood osmolarity above a set point triggers release of ADH, which helps to conserve water

-decreased osmolarity causes a drop in ADH secretion and a corresponding decrease in permeability of collecting ducts

Renin-angiotensin-aldosterone system (RAAS)

-this system regulates kidney function

-a drop in blood pressure near the glomerulus causes the juxtaglomerular apparatus (JGA) to release the enzyme renin

-Renin triggers the formation of the peptide Angiotensin II

Angiotensin II

-raises blood pressure and decreases blood flow to capillaries in the kidney

-stimulates the release of the hormone Aldosterone, which increases blood volume and pressure

-ADH and RAAS BOTH INCREASE water reabsoprtion

-ADH responds to changes in blood osmolarity

-RAAS responds to changes in blood volume and pressure

Thus, ADH and RAAS are partners in homeostasis