BSC2011 Exam 4 Study Guide

which animal groups exhibit the different types of symmetry?

• bilateral = most animals

• radial = cnidarians, ctenophores

• asymmetry = sponges

how do unicellular and multicellular organisms differ in regards to getting nutrients to the cells?

• unicellular organisms = get nutrients through diffusion

• multicellular organism = must provide nutrients and oxygen to all cells w/ specialized cells, organs, and organ systems

how does the BMR differ between animals of different sizes

smaller endothermic organisms have higher BMR than larger ones per gram of body weight

how does homeostasis maintain internal conditions?

if conditions stray from set point, homeostasis mechanisms kick in

what are the general differences between negative and positive feedback + examples of each?

• negative feedback = counteracts internal changes. ex. change in glucose

• positive feedback = strengthens response to stimulus. ex. birthgiving

4 mechanisms of heat transfer

radiation, conduction, convection, evaporation

radiation

the transfer of heat by electromagnetic (infrared) radiation. ex. sun shining on lizard

conduction

direct transfer of heat between two objects. energy transferred from hotter objects to colder ones. ex. lizard sitting on hot sidewalk

convection

transfer of heat brought about by the movement of a gas or liquid. ex. atmospheric air warming lizard

evaporation

heat of vaporization or the amount of energy needed to change them from a liquid to a gas phase… always heat loss. ex. lizard skin water loss

ectotherms

regulate temperature using behaviors. ex. snakes, lizards

endotherms

create internal metabolic heat. conservation or dissipation heat transfer controlled by amount of blood flow to animal surface. ex. mouse

4 tissue types

epithelia, connective, muscles, neurons

epithelia funciton

line cavities, open spaces, and surfaces

connective tissue function

connect tissues together, provide support

muscle function

generate movement

neurons

generate and send electrical signals

simple squamous epithelium

flat, irregular round shape. single layer.

location: lung alveoli, capillaries

stratified squamous epithelium

flat, irregular round shape. multiple layers.

location: skin, mouth, vagina

simple cuboidal epithelium

cube shaped, central nucleus. simple layer.

location: glands, kidney (renal) tubules.

some gland ducts are stratified

simple columnar epithelium

tall, narrow, nucleus toward base. single layer.

location: digestive tract (unciliated), bronchi (ciliated), intestinal lining w/ microvilli

pseudostratified columnar epithelium

tall, narrow, nucleus along cell. appear to be stratified by isnt.

location: upper respiratory tract

different types of connective tissue

blood, adipose tissue, loose connective tissue, dense connective tissue, bone, cartilage

blood

has RBCs (erythrocytes) and WBCs (leukocytes). fluid portion = matrix, the plasma. transports material through the body to bring nutrients to cells and remove waster material form them

adipose tissue

made up of adipocytes that collect and store fat in the form of triglycerides for energy metabolism. also serve as insulation to help maintain temperatures and act as cushioning. ex. fat under skin, visceral fat (around organs). no fibroblasts or real matrix

loose connective tissue

has sampling of all components of matrix: fibroblasts, macrophages, some lymphocytes, some neutrophils. fibers: collagen, elastic, reticular. found in every blood vessel, helps keep vessel in place. found around and between most body organs. tough, yet flexible. anchors epithelia

dense connective tissue

cells: fibroblasts, macrophages. large amounts of collagen fibers, few cells or matrix material. fibers arranged regularly or irregularly.

irregular arrangement = areas where body stress occurs in all directions, like skin dermis

regular arrangement - tendons (muscles to bone) and ligaments (bone to bone_

bone

cells: osteoblasts, osteocytes, osteoclasts. dual matrix: organic (collagen/elastic → flexibility) + inorganic (calcium salts → hardness)

types: compact and spongy

provide structural support + tendon attachment points.

location: vertebrate skeletons

cartilage

large amount of matrix. cells, chondrocytes, make matrix and fibers of the tissue. few collagen and elastic fibers = hyaline cartilage.

fibrocartilage = large amount of collagen

location: shark skeleton, fetal bones, human ears, invertebral discs

different types of muscle tissues

smooth, skeletal, cardiac

smooth muscle

no striations + single, centrally located nucleus. involuntary

location: visceral organs, walls of blood vessels, tubes of digestive system, tubes of reproductive systems

skeletal muscle

has striations. relatively long w/ multiple nuclei along the edge.voluntary

cardiac muscle

has striations + single, centrally located nucleus. involuntary but can be influenced by the autonomic nervous system to speed up or slow down. intercalated disc = assists in passing electrical impulse from one cell to the next and maintains strong connection between nearby cardiac cells.

location: heart

what are the different cellular components of nerve tissue?

neurons, neuroglia

neurons

generate and transmit electrical impulses

neuroglia

support and insulate neurons and eliminate foreign materials in and around neurons

what are the different parts of a neuron?

• cell body (soma) = contains nucleus

• dendrites = highly branched extensions. conduct electrical impulses toward cell body

• axon = sign cytoplasmic extension. conducts impulses away from cell body

what is the function of the myelin sheath of neurons?

insulate the axon so the electrical impulse is transferred more efficiently

what are the main organs of the vertebrate digestive system and their general functions?

• mouth and pharynx = entry

• esophagus = delivers food to stomach

• stomach = preliminary digestion

• small intestine = digestion and absorption

• large intestine/colon = absorption of water or minerals

• cloaca or rectum = expel waste

how do the digestive systems of humans and rabbits differ (both with monogastric stomachs)?

• rabbits small intestine and cecum are enlarged to allow more time to digest plant material + more surface area for nutrient absorption

• rabbits digest food 2x: food passes through system and passes as cecotrophs. rabbit re-ingests cecotropes

what are the primary accessory organs of the vertebrate digestive system and their general functions?

• liver = produces bile

• gallbladder = stores and concentrates bile

• pancreas = produce “pancreatic juice.” digestive enzymes and bicarbonate buffer

how does the avian digestive system differ from other vertebrates?

• have crop in esophagus, which stores good

• 2 stomachs: (1) proventriculus contain digestive juices to break down good. (2) gizzard grinds food

• wastes are excreted from cloaca - dont have separate opening for urine and feces

in general, how does the ruminant digestive system differ from other mammals? give examples of ruminants

ruminant examples: cows, goats, sheep, deer

• multi-gastric = have 4 stomachs - rumen, reticulum, omasum, and abomasum

what is the function of each chamber of the ruminant stomach?

• rumen and reticulum = contain prokaryotes that are able to digest cellulose fiber

• omasum = remove water from cud

• abomasum = where cud is digested by enzymes produced by the ruminant

follow the digestive process of a piece of food (bolus) through the digestive system. least each organ and its energy function, in order, from mouth to anus

how does peristalsis work to move a bolus of food through the alimentary canal?

alternating contractions of circular and longitudinal smooth muscle bands pushes bolus along the digestive track

how does the oblique muscle layer of the stomach help mechanical digestion?

it helps mix food with gastric juices

what are the functions of the different cells lining the stomach?

• mucus-secreting cells = lubricates food bouls

• parietal cells = secrete HCI and intrinsic factor (for Vitamin B 12 absorption)

• chief cells = secrete pepsinogen (inactive form of pepsin) for protein digestion

what are the functions of the villi and microvilli

both have functions in the small intestine

• villi = folds on the small intestine lining that increase the surface area to facilitate the absorption of nutrients

• microvilli = projections of the epithelial lining to further increase surface area for absorption

in a balanced diet, what different food groups should be included?

fruits, vegetables, grains, and protein

how are carbohydrates digested and absorbed?

• starch and glycogen are broken down into glucose by amylase and maltase

• sucrose and lactose are broken down by sucrase and lactase, respectively

• monosaccharides are absorbed by Na+ - cotransporters or facilitated diffusion across the brush boarder

how are proteins digested and absorbed?

digestion begins in the stomach and continues through the small intestines where amino acids are absorbed

• pepsin in stomach breaks down proteins → peptides

• various peptidases from pancreas and small intestine → amino acids in small intestine

• these are transported to the liver via the hepatic portal vein

• liver regulates distribution of amino acids to the rest of the body

how are lipids digested and absorbed?

digested in the mouth, stomach, and mostly the small intestine

• bile emulsifies lipids to breakup globules for more effective lipase action in small intestine

• gastric and pancreatic lipases breakdown lipids → fatty acids and monoglycerides

  • packaged as micelles to move through microvilli

• reformed triglycerides w/ cholesterol, coated w/ proteins → chylomicrons → lymph vessels → circulatory system

what are the four essential nutrients + examples?

• vitamins (e.g. vitamin C and D)

• amino acids (e.g. valine, glutamine, glycine)

• long-chain unsaturated fatty acids (e.g. omega-3s, bs, and qs)

• minerals (e.g. calcium, iron, iodine)

what are the three general functions of circulating blood and a circulatory system?

transportation, regulation, protection

what are the components of blood plasma? what is the hematocrit?

nutrients, wastes, hormones, ions, proteins (albumin and fibrogen), 92% water. hematocrit = fraction of total blood volume occupied by red blood cells (RBCs)

what is the function of hemoglobin?

binds and transports oxygen from the lungs to the body’s tissues and organs. carries oxygen to cells and carbon dioxide to lungs

describe the steps of how a blood clot forms

1. stimulated by chemicals released from damaged tissue

2. vessels constrict near damage, reducing blood loss

3. injury site releases chemicals to activate and attract other platelets → become spiked and stick to each other and wound → platelet plug

4. coagulation → circulating fibrinogen converted to fibrin, forming mesh to trap more platelets and RBCs → clot

where do blood cells form? from what cells do they arise?

they come from the bone marrow from pluripotent stem cells

what are examples of the most basic types of circulation systems in animals?

• sponges = circulate water using incurrent pores and ine excurrent pore (osculum)

• hydra circulate water through a gastrovascular cavity

• nematodes are thin enough that the digestive tract can also be used as a circulatory system

open circulatory system

hemolymph (blood mixes with interestial fluid), no capillaries, animal movement → hemolymph back to heart through ostia. decreased energy, decreased O2 to organs. ex. arthropods, mollusks

closed circulatory system

blood separate from interestial fluid, unidirectional flow (enclosed in vessels- arteries → capillaries → veins), blood moved by heart. increased energy, increased O2 to organs. ex. annelids, vertebrates. more efficient at delivering oxygen to tissues

difference between hemolymph and blood

• hemolymph = blood mixed with interestial fluid

• blood = separate from interestial fluid

circulatory system of a bony or cartilaginous fish with a 2-chambered heart.

circulatory system of a lungfish or amphibian with a 3-chambered heart

how does a typical, non-crocodilian heart differ from that of amphibians and crocodilians?

they have a septum, which partially subdivides the ventricle, further reducing mixing of blood

path of blood flow through the 4-chambered human heart

describe the cardiac cycle (from diastole to systole back to diastole), including the diff components of the cycle, and how they function

• the cycle begins with diastole - the ventricles relax and fill with blood as the AV valves (tricuspid on the right, mitral on the left) open

• next, SA node (pacemaker in right atrium) fires electrical signal before sending it through the Bundle of His → Purkinje fibers, causing both ventricles to contrast simultaneously - this is systole. the AV valves close (“lub”) and the semilunar valves open, ejecting blood to the lungs and body

• finally, ventricles relax, the semilunar valves close (“dub”), and the cycle returns to diastole

what are the “heart sounds” and what do they indicate is happening within a beating heart?

• “lub” = AV valves closing

• “dub” = semilunar valves

• murmurs = defective valves

arteries structure

4 tissue layers: endothelium, elastic fibers, smooth muscle, and connective tissue. walls thick → no material exchange across wall. more elastic fibers in walls

veins structure

4 tissue layers: endothelium, elastic fibers, smooth muscle, and connective tissue. wall thick → no material exchange across wall. thinner layer of smooth muscle

capillaries structure

single layer of endothelial cells. greatest cross-sectional surface area → lowers blood pressure. about diameter of single RBC to enhance gas exchange

arteries function

recoil each time they receive blood from heart (pulse). helps to “smooth” out blood flow

veins

venous pumps helps blood return to heart. skeletal muscle contractions (body movements) and one-way venous valves. keeps one-way flow toward heart

how does blood and interstitial fluid flow at the level of the capillaries?

most fluid leaves at the arteriole end (higher blood pressure) of capillary and returns at venule end (lower pressure). fluid that does not return to capillaries is returned to circulation by the lymphatic system

major components of the lymphatic system and their functions

• lymph = continues into progressively larger vessels with one way valves (like veins, very low pressure)

• lymphatic vessels = drain into subclavian veins through thoracic duct

• lymph nodes = sites for immune system cells to filter and “sample” lymph for pathogens

• lymph organs = thymus and spleen

path of lymphatic fluid from capillary beds back to circulatory system

atherosclerosis

accumulation of fatty material within arteries - plaque. impedes blood flow

arterioscelosis

arterial hardening due to calcium deposition