Bio Last unit

purpose of digestion

reduce food particles to molecules that can be absorbed into the blood

chewing

mechanical breakdown of food

HCl in the stomache, enzymes

chemical breakdown of food

incomplete digestion

saclike digestive cavity, food enters and waste leaves through one single opening

complete digestion

a tube with an opening at each end, one for taking in food and one for elimination

monogastrics

one simple stomach

ruminants

four compartment stomach

ruminant animals

capable of digesting material with high fiber concentration, uses microbial fermentation

cattle, sheep, goats, deer

examples of ruminant animals

four compartment stomach

Rumen, Reticulum, omasum, abomasum

85%

Rumen and reticulum hold what % of the stomach

Rumen

largest of 4 part stomach, filled with bacteria and other microbes, converts large amounts of roughage to amino acids 

Reticulum

compartment where liquid goes, honeycombs in structure, interacts with rumens to mix contents

Omasum

grinds and squeezes, many folds, removes some liquid

Abomasum

“true” stomach, enzymes and acids

Rumination

continuous regurgitation, chewing and swallowing

Mechanical processing and motility, secretion, digestion, absorption, elimination

five tasks of a complete digestive system

mechanical processing and motility

physical manipulation that breaks up, mixes, and propels food

secretion

release of digestive enzymes and other substances from lining oftract and accessory organs

digestion

chemical breakdown of food into molecules small enough to be absorbed

absorption

passage of digested nutrients and fluid across the tube wall and into body fluids

elimination

expulsion of undigested, unabsorbed residues from the end of the gut

human digestive system

consists of a muscular tube extending from mouth to anus, and its associated organs

accessory organs

salivary glands, liver, gallbladder, pancreas

salivary glands

secrete saliva( with carb digesting enzymes, buffers, and mucus to moisten food)

liver

secretes bile for emulsifying fat, also roles in fat, carbohydrate and protein metabolism

gallbladder

stores and concentrates bile from liver

pancreas

secretes digestive enzymes that break down all major food molecules, secretes buffers against HCL from stomach, and secretes insulin to control glucose metabolism

amylase enzyme, bicarbonate, mucins, and water

saliva includes

pharynx

common chamber for food and air

epiglottis

closes off trachea: breathing temporarily ceases

bolus

what is chewed up food called

peristalsis

wavelike contractions to move food down the esophagus

stomach

dimensions vary, can be narrow tube when empty or expanded into a sac that can hold almost ½ gallon

functions of the stomach

store ingested food, mixing ingest food(mechanical), digestion of proteins(chemical) using amino acids and enzymes, absorption of some substances, controlling passage of food into small intestine

small intestine

duodenum, jejunum, Ileum, most chemical digestion and nutrient absorption here, recives food called “chyme” from stomach, recieves secretion from liver, gallbladder, and pancreas

walls of small intestine

projections into the intestinal lumen increase the surface area available for absorption

remove and destroy toxins(alcohol and drugs), serves as large reservoir of blood, remove cell debris, pathogens, and damaged red blood cells

functions of the liver

gallbladder

muscular sac that stores bile produced by liver, bile produced in liver may flow directly into small intestine through common hepatic duct, or may back up through cystic duct to be stored

large intestine

holds and compacts undigested materials, absorbs water and vitamens produced by resident intestinal bacteria

break down remaining nutrients and synthesize vitamins

E. coli bacteria in large intestine

cecum

expanded chamber, receives chyme from small intestine

colon

longest portion, has characteristic series of muscular pouches, water is reabsorbed here, bacterial activity may produce hydrogen sulfide, flatus due to bacterial action on undigested plant polysaccharide

rectum

chamber at end of tract, usually empty, except when peristaltic contrations force feces into it from colon, triggers defecation reflect, extretion through anus

diarrhea

colon not effective in reabsorbing water(due to infection)

constipation

feces moves along too slowly, becomes too compacted

mouth to crop

bird esophagus connects what to what

bird crop

stores and softens food is a dilation of the esophagus

gizzard

crushes food, often contains grit and gravel, mixes food with digestive juices

malnourished

lacking in one or more essential nutrients

undernourished

lack of sufficient calories

carbohydrates

body’s main energy source, foods high in this are also high in fiber

vitamins

organic nutrients, need to be in diet, used in metabolic reactions

minerals

inorganic nutrients required for many body functions

fat soluble vitamins

excess accumulates in tissue, can be toxic

water soluble vitamins

excess excreted

respiratory system function

oxygen into blood, carbon dioxide out of blood

cutaneous respiration

some more primitive organism can “breathe” through their skin

countercurrent flow

water flows over gills in one direction while blood flows in the opposite direction through gill capillaries

respiration

movement of an oxygen-containing medium so it contacts a moist membrane overlying a blood vessel

positive pressure breathing

inflate lungs by filling its mouth with air ex. frogs

negative pressure breathing

inflate and deflate by the bellow-like expansion and contraction of the muscles in the ribcage  ex: reptiles

two breath cycles

how birds lungs work to make them lighter

Upper(nasal cavities) lower(trachea)

what makes up mammalian respiratory tract

asthma

disease of bronchi and bronchioles marked by wheezing, breathlessness, cough, mucus

cilia that remove mucus

what tobacco smoking remove in the lungs

circulatory system/cardiovasular

internal transport of gases, nutrients, and waste

Cnidarians

gastrovascular cavity that exposes inner cells to water for nutrient and gas exchange

Flatworms

gastrovascular cavity also small size and flattened shape for a higher surface to volume ratio for better absorption

open circulatory system

antropods, most mollusks- blood is pumped from heart through blood vessels then leaves and enters body cavities where organs are bathed in blood

closed circulatory system

all vertebretes, annelids, and cephalopod mollusks, blood remains within blood vessels, pressure is high, and blood is pumped faster

Vertebrate hearts

contain muscular chambers called atria and ventricles, contraction of a chamber forces out blood, blood flows in one direction due to valves that prevent backflow

atria

recieve blood returning to the heart, contract to pump blood

ventricles

main pumping chamber of the heart, contract to pump blood away from the heart to body, lungs, or gills

fish

what species has a two chambered heart

amphibians

what group of animals have three chambered hearts (2 atria and 1 ventricle)

birds, mammals, and crocodilians

what animals have four chambered hearts, acting as two seperate pumps

single circulation

2 chambered hearts have what kind of circulation

double circulation

3 and 4 chambered hearts have what kind of circulation

human heart

moves blood by rhythmic contractions, controlled by a specialized region of cardiac muscle in right atrium calledthe SA node

SA node

pacemaker of the heart, sends signal to the AV node, causes ventricles to contract

pulmonary circulation

right ventricale to lungs through pulmonary arteries, returns with O2 to left atrium through pulmonary veins

systemic circulation

left ventricl to body through aorta, returns withoutO2 to right atrium through vena cava

heart attacks

cardiac muscle tires or dies due to blocked coronary arteries

blood vessels

heart to arteries to arterioles to capillaries to venules to veins to heart

arteries

carry blood away from heart to capillaries

capillaries

extremely narrow, permit exchange of material with tissues

veins

return blood from capillaries to heart

varicose veins(spider veins)

valves don’t function correctly, blood remain in vein, can pool and bepainful

capillaries

diameter so small small that red blood cells travel single file… specialized for exchange of substances with interstitial fluid

liquid(plasma) and cells

blood made of two parts

plasma

water mainly, also protein, salts, hormones, gases

Red blood cells

transport oxygen(by hemoglobin), help transport CO2, most numberous cells in body…120 day lifespan

White Blood cells

fight infection

platelets

aid in blood clotting-not true cells but fragments…produced in bone marrow

lymphatic system

secondary circulatory system that collects fluid and cells and returns them to the cardiovascular system

cholesterol

combination of steroid and alcohol, found in all cell membranes and transported in the blood

low density lipoprotein

bad cholesterol, build up on walls of arteries

high density lipoprotein

good cholesterol, protects against heart attack