BIOL 1306 Exam #3

what is the structural hierarchy of animals

cell, tissues, organs, organ systems, organismal level

what are the characteristics of epithelial tissues and where are they?

-line the heart chambers
-prevent leaks
-form a smooth surface for blood flow
-they cover the outside of the body and line the inner surface of many organs
-form glands

what are the characteristics of connective tissue and where are they?

-make the heart elastic and strong
-under skin and connect muscles, bones, and organs

what are the characteristics of muscle tissues and where are they?

-responsible for movement, pumping the heart, and mixing of food

what are they characteristics of nervous tissues and where are they?

-consist of nerve cells called neurons

What does the circulatory system do?

-delivers oxygen and nutrients to the body cell
-transports co2 to lungs
-carries metabolic wastes to kidneys

What does the respiratory system do?

-exchanges gases with the environment
-supplies blood with oxygen
-disposes co2

What does the urinary system do?

-removes wastes products from the blood
-excretes urine
-regulates chemical makeup, pH, and water balance of blood

What does the digestive system do?

-ingests and digests food
-absorbs nutrients
-eliminates undigestible material

what does the endocrine system do?

-secretes hormones that regulate body activities

what does the reproductive system do? (and specifically female reproductive system?)

-produces gametes and hormones
-the female reproductive system: produces milk and supports developing embryo

What does the integumentary system do?

protects against:
-physical injury
-infection
-excessive heat or cold
-drying out

what does the nervous system do?

coordinates body activities by:
-detecting stimuli
-integrating information
-directing responses

what do they lymphatic and immune system do?

-protect body from infection and cancer
-the lymphatic system also returns excess body fluid to the circulatory system
-innervates the gut

What does the skeletal system do?

-supports the body
-protects organs such as the brain and lungs
-provides framework for muscle movement

what does the muscular system do?

-moves the body
-maintains posture
-produces heat

What do animals do to interact with the environment and meet the demands of cells?

they develop structural adaptations (large folds or increased surface area)

how do animals regulate their internal environment?

by homeostatic mechanisms and negative feedback control mechanisms (like a thermostat)

what are the different types of skeletons?

-hydrostatic skeleton
-exoskeleton
-endoskeleton

what are hydrostatic skeletons?

they consist of fluid under pressure in a closed body compartment

where are hydrostatic skeletons found?

in worms and cnidarians

what are exoskeletons?

rigid, external structures

where are exoskeletons found?

arthropods and carbonate shells in molluscs

what are endoskeletons?

-hard or leathery supporting elements situates along the soft tissue

where are endoskeletons found?

amphibians, birds, reptiles, and mammals

what do all vertebrates have?

-axial skeleton
-appendicular skeleton

describe axial skeletons?

-supports axis of body
-consists of skull, vertebrates, and ribs

describe appendicular skeletons?

-includes appendages and bones that anchor the appendages
-consists of arms, legs, shoulder girdle, and pelvic girdle

what is at the ends of bones and where joints are?

cartilage

what does cartilage do?

-cushions joints
-reduces frictions of movements

how are muscle connected to bones?

by tendons

How do muscles contract?

when muscles contract they require an opposite muscle to reverse

what are inside sarcomeres?

-thick filaments (primarily composed of the protein myosin)
-thin filaments (primarily composed of the protein actin)

what is the sliding sarcomere model?

a sarcomere contracts when its thin filaments slide along the thick filaments

where is ATP used in a sarcomere?

in the myosin head of thick filaments they bind to ATP

what are the different type muscle fibers?

-slow twitch
-fast twitch
-intermediate

describe slow twitch muscle fibers?

can sustain multiple contractions and are slow to fatigue, but contractions are less forcefull

describe fast twitch muscle fibers?

rapid and powerful, but fibers fatigue quickly

describe intermediate muscle fibers?

have some characteristics of slow and fast twitch muscle fibers

what are the kinds of diets animals can have and describe them? which animals have these type of diets?

-herbivore: eat plants (cattle, gorillas, sea urchins, and snails)

-carnivore: eat other animals (lions, owls, whales, and spiders)

-omnivore: eat plants and other animals (human, roaches, raccoons, and crows)

what are the steps of food to be processed? describe them.

1. ingestion: act of eating

2. digestion: breaking down of food (mechanical and enzymatic) into molecules small enough for the body to absorb

3. absorption: take up of the products of digestion, usually by cells lining digestive tract

4. elimination: removal of undigested materials from digestive tract

what are essential nutrients that animals cant live without?

-amino acids
-fatty acids
-vitamins

what is an incomplete digestive tract?

having one opening for ingestion of food and elimination of food

what is a complete digestive tract? what are the advantages of this tract?

-have two openings: one for ingestion and one for elimination
-advantages:
-different chemical and physical processes confined to different compartments
-occur independently and in a confined sequence
-one way flow of food and waste (no interruption)

what does the alimentary canal depend on? what is an example of this?

-depends on diet
-example: enlarged cecum, which contains cellulose digesting bacteria, is found in animals that eat a lot of plants

what is the path of human digestion?

pharynx (throat) →esophagus → crop (food is soften and stored) →gizzard (food is ground and stored) →stomach (food is ground and stored) →intestines (chemical digestion and nutrient absorption) →anus

Describe processes of nutrient absorption of carbs, lipids, and proteins.

Look at picture in computer

how does the stomach digest food into chyme?

stomach contents are churned about every 20 seconds

what happens when the hormone gastrin is produced?

it stimulates the release of gastric juices by three different cell types

what are the three different cell types? and what do they do?

-mucous: secretes mucous (protects and lubricates stomach cells)
-parietal: secretes H and Cl (they combine and form HCl)
-Chief: secretes pepsinogen, which is inactive form of the enzyme pepsin

what are the reasons why the stomach doesnt digest itself?

-secretion of pepsinogen helps protects the cells of the gastric glands
-mucus protects the stomach lining against pepsin and acid
-new cells lining the stomach are produced every 3 days by mitosis and replace damaged ones
-gastric juice secretion is controlled by nerve signals and a hormone
-food stimulus causes your brains to stimulate gastric glands (gastric juice isnt produced all the time)

where is chyme delivered to after the stomach? describe the process (where it travels)

-the small intestine
-process: duodenum →jejunum →ileum

What occurs in the duodenum? why?

-bile is added to emulsify lipids
-pancreas adds an additional digestive enzyme and bicarbonate to neutralize the acidity of chyme

where does most of the absorption occur in the small intestine? how are they absorbed?

-occurs mostly in jejunum and ileum
-absorbed against their concentration gradient

what is passed into the capillaries? then where do they go

-amino acids, sugars, and lipids
-liver then bloodstream

what innervates the digestive tract?

immune vessels

describe the structure of the lining of intestines?

-they are covered with villi to increase the small intestines absorption area
-innervated with blood capillaries and lymph vessels

what is the purpose of the large intestine?

reclaims water from undigested food material

what is in the large intestine that helps with digestion?

large populations of various bacteria

what does gut microbiome contribute to?

-ability to metabolize certain types of nutrients
-protect against harmful pathogens
-ferment non-digestable substances
-maintain integrity of mucosal lining of gut

what does an imbalance in the gut microbiome cause?

variety of disease and maybe even cancer

what was discovered in the ulcer case study?

ulcers are associated with infections from the bacterium Helicobacter pylori

Where does gas exchange occur?

respiratory system

what does animals exchanging gases in the environment allow?

cellular respiration and release Co2 waste

how does gas exchange occur in fish, vertebrate, and insects?

-fish: gills
-vertebrates: lungs
-insects: tracheal systems

what is the process of gas exchange in animals?

breathing → exchange gas via alveoli (air sacs) and capillaries surrounding them

what is breathing?

ventilation of the lungs through alternation of inhalation and exhalation

what is maintained during breathing?

-high O2
-low Co2

where does gas exchange occur SPECIFICALLY?

alveoli

what occurs in the alveoli?

O2 diffuses into the blood and Co2 diffuses out the blood

What are surfactants?

secretions that keep the walls of alveoli from sticking shut from the surface tension of their moist surface

what is breathing controlled by? where is it?

medulla; brain

how does the medulla work?

keeps breathing in tunes with the body needs and senses and responds to Co2 levels in body

how does the brain know the Co2 levels in the body?

the heart has sensors that monitor the pH (Co2) levels in the blood and communicate with the brain

where do gases move? how?

move across capillaries by diffusion (down their pressure gradient)

What do arteries do?

carry blood away from the heart to body organs and tissues

what do veins do?

carry blood to the heart

what do capillaries do?

convey blood between arteries and veins within each tissue

what is single circulation? (what animal has this)

blood passes through the heart once in each circuit of the body (fish)

what is double circulation? (what animal has this)

blood is pumped a second time when it loses pressure in the lungs (land vertebrates)

What is the order of blood flow through circuits?

pulmonary circuit → systemic circuit

what does a pulmonary circulation do?

blood flows from the heart to the lungs (oxygen depleted) → lungs to heart (oxygen replete)

what does a systemic circuit do?

blood flows from the heart to body (oxygen replete) → then body to heart (oxygen depleted)

What is diastole?

resting portion of a heartbeat

what is systole?

contracting portion of a heartbeat

how is the cardiac cycle controlled?

the sinoatrial node (SA node) controls a heartbeat by passing electrical impulses to the atrioventricular node (AV node) and to cardiac muscle cells innervating the ventricles

which thin-layered cells transports blood though tissues and exchanges nutrients and gases into interstitial fluid

capillaires

what is the structure of capillaries?

elastic and smooth muscle

how is back flow of blood prevented?

the valves in veins prevent back flow

how does blood travel in veins?

travels *against* the pull of gravity

describe velocity, area, and pressure of blood in arteries?

velocity: high
area: low
pressure: highest

describe velocity, area, and pressure of blood in veins?

velocity: low to medium
area: low
pressure: lowest

describe velocity, area, and pressure of blood in capillaries?

velocity: low to none
area: high
pressure: low

how does distance from the heart affect blood pressure?

blood pressure decreases as blood moves away from the heart

what is cooperative binding?

as a molecule of oxygen binds to a hemoglobin subunit, it causes a conformational change that causes other subunits to more likely bind to oxygen

what does homeostasis mean?

maintaining a "steady state" internal balance regardless of the external enviroment

what does protein/enzyme function rely on?

-balance of pH
-temperature
-other chemical conditions

what is thermoregulation?

temperature balance in body regardless of external environment

describe endotherms

-derive body heat from mainly from metabolism
-birds and mammals

describe ectotherms

-gain most of heat from external sources
-reptiles, fishes, and most invertebrates