exam 1 (review slides + some content) Flashcards
list some of the body’s responses to the fight or flight response
- increased heart rate
- dilation of airways (airways in lungs dilate for more air intake)
- dilation of pupils (to improve vision)
- increased blood pressure (ensure adequate blood flow to muscles and vital organs)
- stored energy gets broken down (glycogen in the liver and fatty acids in adipose tissue)
- suppression of digestive functions
- increased sweating
- heightened mental awareness
epithelial tissue + the different types
covers outside of the body and lines organs and cavities within the body
- contains cells that are closely packed
cuboidal: dice-shaped cells specialized for secretion, makes up the epithelium of kidney tubules and many glands, including thyroid glands and salivary glands
simple columnar: large, brick shaped cells, found where secretion or active absorption is important (ex. intestines)
simple squamous: single layer of platelike cells found in areas where exchange of material by diffusion (ex. lungs, blood vessels)
stratified squamous: multilayered and generates rapidly, common to areas subject to abrasion, such as outer skin, lining of mouth, anus, and vagina
pseudostratified columnar: single layer of cells that look like multiple layers because vary in height and position of nuclei, found in mucuous membranes such as respiratory tract
negative and positive feedback in homeostasis
negative feedback: “damps” a stimulus, plays major role in homeostasis
- ex. body temperature goes up so body brings it back down
positive feedback: amplifies stimulus, helps drive a process to completion, does not play major role in homeostasis
- ex. childbirth, contractions increase
endothermic vs ectothermic animals
endothermic: “self heating” creatures, regulate body temperature internally, regardless of environmental temp
- ex. mammals and birds
ectothermic: “environmentally heated” animals, rely on external sources like the sun or their surroundings to heat them
- ex. reptiles, amphibians, fish
- need to consume less food than equally sized endotherms
- tolerate greater variation in internal temperature
endothermy is more energetically expensive than ectothermy
great example of homeostatic processes for thermoregulation
endotherms and ectotherms - vasodilation nd vasoconstriction
- many endotherms and some ectotherms can alter the amount of blood flowing between the body core and skin
vasodilation: widening of blood vessels = blood flow in skin increases, facilitating heat loss decreases blood pressure
vasoconstriction: narrowing of blood vessels = blood flow in skin decreases, lowering heat loss increases blood pressure
countercurrent exchange
- mechanism used by animals to efficiently transfer substances, such as heat or oxygen, between 2 flowing fluids that are moving in opposite directions, reduces heat loss
- example of circulatory adaptations
explain cooling by evaporative heat loss
- process by which heat is removed from the body through the evaporation of water from the skin or respiratory tract
- sweating or bathing moistens skin = hells cool animal down
- panting increases cooling effect in birds and many mammals (moisture from airway linings evaporates with each exhale)
what is brown fat
- type of fat tissue in the body that generates heat to help keep you warm
- contains high number of mitochondria = helps dissipate energy as heat rather than storing it when activated - why called “good fat”
- primarily found in infants and hibernating animals
- mainly located around the neck, shoulders, and spine
thermogenesis & non shivering thermogenesis
adjustment of metabolic heat production to maintain body temperature in endotherms
- increased by muscle activity such as moving or shivering
non-shivering thermogenesis: takes place when hormones released in response to cold cause mitochondria to increase their metabolic activity and produce heat instead of ATP
metabolic rate (BMR & SMR)
metabolic rate: sum of all the energy an animal uses in a unit of time
determined by:
- animal’s rate of heat loss
- amount of oxygen consumed or carbon dioxide produced by animal’s cellular respiration
- measuring energy content of food consumed and energy lost in waste products
basal metabolic rate (BMR): amount of energy endotherm body needs to carry out basic functions at complete rest, with an empty stomach, and not experiencing stress
standard metabolic rate (SMR): similar to BMR but typically used for metabolic rate of aquatic animals (ectotherms)
ectotherms have much lower metabolic rates than endotherms of a comparable size
relation between size and metabolic rate
smaller animals have higher metabolic rates per gram than larger animals (bc they lose heat more quickly and need to generate more heat to maintain body temp bc of higher surface area to volume ratios)
- the higher metabolic rate of smaller animals leads to a higher oxygen delivery rate, breathing rate, heart rate, and greater (relative) blood volume, compared with a larger animal
adrenal gland
produce several important hormones called corticosteroids
- cortisol (stress hormone)
- aldosterone (regulates blood pressure and electrolyte balance by influencing reabsorption of sodium)
- sex hormones (for secondary sex characteristics)
thyroid gland
- regulates metabolism
- body temp
- heart rate & cardiovascular function
- regulation of reproductive hormones and menstrual cycles in women
bowman’s capsule & proximal convoluted tubule & concentrations of NaCl and HCO3
cup like structure in the kidneys that catches all the stuff your body wants to get rid of, responsible for filtering blood and producing urine
- collects initial filtrate
proximal convoluted tubule: twisty tube connected to the bowman’s capsule, next stop in the kidneys filtration process (recollects more nutrients and puts them back into the blood stream)
concentrations: NaCl is actively reabsorbed as it moves through the PCT, concentration of HCO3 may remain constant or decrease slightly to help regulate body’s acid-base balance
essential amino acids
- 8 amino acids that your body has to obtain, cannot be created
- all organisms require 20 amino acids (plants and microorganism produce all 20)
meat, eggs, and cheese provide all essential amino acids = “complete proteins”
most plant proteins are incomplete in amino acid composition
- deficient in 1 or more essential amino acid
- vegetarians can easily obtain all essential amino acids by eating a varied diet of plant proteins (ex. corn, beans)
mechanical vs chemical digestion
mechanical digestion: chewing or grinding, which breaks food into smaller pieces, increases surface area
chemical digestion: enzymes break the food into smaller particles that can pass through membranes
- enzymatic hydrolysis breaks bonds in molecules with addition of water
the 2 roles of stomach in digestion & chyme
storage & process food into liquid suspension
- secretes gastric juice and mixes it with food through a churning action
chyme: mixture of partially digested food and gastric juice formed in stomach (what goes to the small intestine for it to absorb)
once food arrives in the stomach, G cells in lining of stomach secrete ________
gastrin
- a peptide hormone that stimulates production of HCl and gastric acid
main difference between anterior and posterior pituitary gland
anterior produces its own hormones whereas posterior stores and releases hormones produced by the hypothalamus
- pituitary gland: growth hormone
loop of henle
- located in the renal medulla (inner part of kidney)
- function: main job is to help body conserve water and regulate concentration of urine by creating a concentration gradient
- as urine travels through the loop, passes through region with different levels of salt concentration, sets up a gradient where outer part of the loop has higher salt concentration than the inner part
the loops of henle create a concentration gradient in the interstitial fluid surrounding the loop, with the concentration higher in the ________ and lowest in the ______
inner medulla; cortex
thrombin gene
section of DNA that has instructions for making protein called thrombin
- thrombin causes the blood to clot when there is a cut so that bleeding stops
- mutation in this gene would cause blood to not clot effectively
why is the velocity of blood flow lowest in capillaries?
because they have a large cross-sectional area (size of the circle in them), because of this, the blood is more spread out and evenly distributed
capillaries are the connecting points for arteries and veins
SA (sinoatrial node)
natural pacemaker of the heart
- generates electrical signals that travel through the heart, telling it when to beat and how fast
- think of them as body’s orchestra = set the rhythm and coordinate the heartbeat to keep blood flowing smoothly
chambers in the hearts of:
- fish
- reptiles/amphibians
- mammals
- fish have 2 chambers (one atrium, one ventricle)
- reptiles/amphibians have 3 chambers (two atria, one ventricle)
- birds and mammals have 4 chambers
lymphatic system
body’s drainage system
- network of vessels and organs that helps to rid the body of toxins, waste, and other unwanted materials
parietal cells, goblet cells, and chief cells
parietal cells: produce stomach acid
goblet cells: produce mucus to protect the stomach lining
chief cells: produce pepsinogen, which is converted into pepsin to break down proteins in the stomach
rumen (fermentation chamber in cows)
- breaks down tough plant parts into smaller pieces
- when breaking down tough plants, produces chemicals called volatile fatty acids (energy packets) = cows absorb these packets and use them to keep themselves healthy
- rumen bugs convert nitrogen into protein
essentially allows cow to live off a plant based diet
duodenum
- first segment of the small intestine
- “mixing bowl” = chyme from stomach mixes with digestive juice from pancreas, liver, and small intestine itself
the 2 hormones produced by the small intestine
secretin: regulates acidity of digestive juices released by the pancreas and the liver
cholecystokinin (CCK): stimulates gall bladder contraction and releasing bile into duodenum
- pancreas also secretes a watery, alkaline buffer solution that contains bicarbonate (activated in lumen of duodenum to prevent auto digestion)
transport across epithelial cells can be _____ or ____
passive or active
- some nutrients can move passively across cells of small intestine by just following the concentration gradient (ex. fructose)
- other nutrients needs energy (ex. amino acids, glucose, and vitamins are co-transported into epithelial cells with Na+)
- Small intestine also reabsorbs water and ions (water reabsorbed by osmosis when Na + and other ions are pumped out of lumen of SI)
processing in large intestine (2 main parts)
cecum: aids in fermenting plant material
colon: leads to rectum and anus, reabsorbs water, produces feces
dentition & examples
dentition: animal’s assortment of teeth, example of structural variation reflecting diet
- carnivores have large pointed investors and canines used to kill prey and rip meat
- herbivores have premolars and molars with broad ridged surfaces that grind tough plant material
- omnivores are adapted to eating both plant and meat
mutualistic relationship between rabbits and rodents
- rabbits eat plants and poop out
- rodents eat the poop and get partially digested plant material
- the bacteria in the rodents digestive system breaks down the cellulose and extracts nutrients from the plant material
coprophagy = feeding on some of their feces and passing food through alimentary canal a second time to recover important nutrients
why do veins have valves?
to maintain unidirectional blood flow
2 opposing factors that control movement of fluid between capillaries and surrounding tissues
- blood pressure tends to drive fluid out of capillaries
- blood proteins tend to pull fluid back in (proteins responsible for much of the blood’s osmotic pressure bc of different in solute concentration)
coagulation
formation of a solid clot from liquid blood
- a cascade of complex reactions converts inactive fibrinogen into fibrin forming a clot
- a blood clot formed within a blood vessel is called a thrombus
pathway of air in the throat
pharynx → larynx → trachea → 2 bronchi (one leading to each lung) → bronchioles → alveoli
control of breathing in humans
breathing control centers found in medulla oblongata of brain
- sensors in medulla and in major blood vessels (carotid arteries and aorta) monitor O2 and CO2 concentrations (chemoreceptors)
osmoconforming in marine animals and freshwater animals
marine animals: hypoosmotic to seawater so they balance water loss by drinking large amounts of seawater and eliminating ingested salts through their gills and kidneys
freshwater animals: constantly take in water by osmosis from their hypoosmotic environment so they balance water by drinking almost no water and excreting large amounts of dilute urine
proximal tubule
site of reabsorption of ions, water, and nutrients
as filtrate passes thought proximal tubule, materials to be excreted become concentrated
descending and ascending loop of henle
descending reabsorbs water = filtrate becomes increasingly concentrated
ascending - salt but not water is able to diffuse from tubule into interstitial fluid (filtrate becomes increasingly dilute)
pheromones
how members of some animal species may communicate
chemicals that are released into the environment
serve many functions: marking trails leading to food, defining territories, warning of predators, and attracting potential mates
the same hormone may have different effects on target cells that have: (2 things)
- different receptors for hormone
- different signal transduction pathways
parathyroid hormone and calcitonin
parathyroid hormone: raises level of blood calcium
calcitonin: decreases level of blood calcium
