chapter 12 Flashcards
Abomasum
the true stomach of ruminant or cud-chewing mammals, which have a four-chambered stomach
Absorption
the main role of the digestive system; the taking up of digested molecules
Alimentary canal
the specialised pathway food takes in complex animals; it includes the passage from mouth to anus, with all the organs food passes through
specialisation of alimentary canals is related to diet,
Alveoli
(singular alveolus) the tiny air sacs located on the end of the bronchioles
Amylase
an enzyme that digests starch; present in saliva and secreted from salivary glands near the base of the tongue
Aorta
the largest artery; it carries blood that is leaving the heart to flow to all parts of the body (i.e. the systemic circulation)
Aortic valve
the valve between the left ventricle and aorta
Arteriole
a small artery
Artery
a blood vessel that takes blood away from the heart
Atrium
(plural atria) a thin-walled chamber of the heart into which blood from the body arrives
Atrioventricular valve
the valve between the atrium and ventricle
Bile
a substance produced by the liver that moves into the duodenum; it has a detergent-like action that helps in mechanical digestion of fats
Bowman’s capsule
The Bowman’s capsule is a cup-shaped structure in the kidneys that surrounds the glomerulus, a network of tiny blood vessels. It is part of the nephron, the functional unit of the kidney. The primary role of the Bowman’s capsule is to filter blood. Blood enters the glomerulus under high pressure, forcing water, ions, glucose, and small molecules (but not large molecules like proteins or blood cells) into the Bowman’s capsule. This filtrate then passes through the nephron for further processing into urine.
Bronchi
(singular bronchus) the branches of the trachea that lead to the lungs
Bronchiole
a smaller tube of the bronchus
Capillary
a very small blood vessel, found between arteries and veins
Carbonic acid
the substance to which most of the carbon dioxide produced in respiration is converted in the plasma
Carnivore
an animal whose diet consists of animal flesh
Chyme
the ‘soupy’ contents of the stomach (partially digested food)
Chemical digestion
a process whereby complex substances are broken down into their simplest forms via enzyme action
Circulatory system
the heart, blood and blood vessels that ensure nutrients and wastes are carried around the body as needed
Closed circulatory system
a type of circulatory system in which blood is circulated inside vessels; more efficient than an open circulatory system
Dentition
the type of teeth of an animal, which is specialised and reflects the animal’s diet
Diaphragm
the muscular organ that, along with the muscles between the ribs, moves air into and out of the lungs
Digestion
the breaking down of complex organic molecules mechanically and chemically
animals break down nutrients acquired in the form of large, complex macromolecules into molecules that are small enough to be absorbed into the bloodstream (by moving them across the cell membrane and into the internal environment)
Distal tubule
the portion of the nephron between the loop of Henle and the collecting duct
. Even though it is short, it plays a key role in regulating extracellular fluid volume and electrolyte homeostasis.
Digestive system
the series of organs where digestion takes place; also known as the gastrointestinal tract
Double circulatory system
a circulatory system that has two circuits: the pulmonary circuit, which transports blood to the lungs and then back to the heart, and the systemic circuit, which pumps blood around the body and back to the heart
Egestion
the removal of waste food materials from the body
Endothermic
describes animals that are able to maintain relatively constant body temperature using heat by metabolism
Epiglottis
a small flap of tissue that closes off the trachea, ensuring food travels down the oesophagus to the stomach, and not into the lungs
Erythrocyte
a red blood cell that is non-nucleated when mature; contains haemoglobin pigment that transports oxygen from the lungs to the tissues
Faeces
the waste material eliminated from the body through the anus
Filament
a component of gills; each contains numerous gill plates to greatly increase the surface area of the gill
Filtrate
the fluid filtered from blood that passes through the nephron
Filtration
a separation technique used by kidneys to remove metabolic wastes from the blood and form urine
Gall bladder
the organ that stores bile if there is no food to digest in the small intestine
Gas exchange
(in animals) the diffusion of oxygen from the external to the internal environment and carbon dioxide from the internal to the external environment
Gastrovascular cavity
a central cavity with a single opening that functions to transport substances and in digestion; occurs in simple animals
Gastric juice
a substance produced when food is in the stomach; contains mucus, water, hydrochloric acid, and pepsin and protease enzymes
Gill
the respiratory organ of fish, and some amphibians, in which oxygen is extracted from water flowing over internal surfaces
Glomerulus
a network of capillaries located in the Bowman’s capsule of the kidney, where the first step in filtering the blood through the nephron occurs
Haemoglobin
the respiratory pigment of most vertebrates and some invertebrates; contains iron
Haemoglobin is a protein found in red blood cells that is responsible for carrying oxygen from the lungs to the rest of the body and transporting carbon dioxide back to the lungs to be exhaled. It plays a crucial role in the body’s ability to function by ensuring oxygen is delivered to tissues and organs that need it.
Haemolymph
the fluid in open circulatory systems
Herbivore
an animal whose diet consists of plant or plant products
Ingestion
the taking in of nutrients
Internal environment
(of a cell) all material contained within the cell membrane
Kidney
an organ that excretes the urea dissolved in the blood out of the body via the bladder
Interstitial fluid
the fluid between the cells of a multicellular organism
Larynx
the voice box
Large intestine
the final length of the gut, consisting of the colon and the rectum; functions to compact undigested food material, and absorb water and some salts back into the body
Leukocyte
a type of white blood cell that forms in both lymph glands and bone marrow, and defends the human body against infectious diseases and foreign particles; the number circulating increases when injury or infection occurs
Loop of Henle
the portion of a nephron that connects the proximal convoluted tubule to the distal convoluted tubule
Lymph vessel
Gases and small molecules entering the internalenvironment are not the only substances to pass through capillary walls. Blood pressure forces some fluid and some small protein molecules out of the capillaries at the arterial end. Most of the water from this fluid passes back into the capillaries at the venous end, where the blood pressure is lower, by osmosis.However, some water and proteins would be left in the spaces between the cells if it were not for the lymph vessels. Lymphatic capillaries are small, blind-ending tubes that allow the fluid and protein to enter through tiny flaps between the cells in their walls that act as one-way valves. The fluid flows in the lymph vessels towards the heart to re-join the blood circulation. It is pushed along in much the same way as blood in the veins is moved, by contracting muscles. Valves in the lymph vessel walls maintain a unidirectional flow to the heart.
Mechanical digestion
the process whereby large pieces of food are broken down through chewing or muscular movement in the stomach
The aim of this is to increase the surface area of the food so it can be acted on more effectively by enzymes in chemical digestion.
Nephron
the structure of the kidney where filtration of the blood occurs
Oesophagus
a vessel that transports food from mouth to stomach
Omnivorous
describes a diet consisting of both animal and plant foods
Open circulatory system
a circulatory system in which transport liquid washes freely over the internal organs; less efficient than a closed circulatory system
Operculum
a protective covering over the gills in bony fish
Opercular cavity
the cavity in which the gills of bony fish are located
Pancreatic juice
the secretions released by the pancreas into the small intestine via the duodenum; contains amylase, trypsin and lipase
Peristalsis
the unidirectional muscular contractions that enable food to move down the oesophagus
Plasma
the pale-yellow liquid component of the blood that holds blood cells, proteins and nutrients in suspension
Platelet
a small cell fragment involved in the clotting property of the blood
Proximal tubule
the section of the tubule in the nephron that leads from the Bowman’s capsule to the loop of Henle
Pulmonary circulation
the system of vessels that carries blood to and from the lungs
Pulmonary valve
the valve between the right ventricle and the pulmonary artery
Reabsorption
the movement of molecules, ions and water needed by the body, from the filtrate, through the nephron and capillary walls, back into the blood
Renal artery
the branch of the aorta that brings blood (containing nitrogenous waste and water, blood proteins, red blood cells and minerals dissolved in the blood plasma) to the kidneys
Renal pelvis
the section of the kidney where urine is collected and directed to the ureter
Stomach
a muscular part of the gut that holds food and releases protein-digesting enzymes and hydrochloric acid
Secretion (
general) the release of certain substances from cells to their external environment; also, the substances secreted; (in excretion) the transfer of substances into the collecting duct of the nephron, adding to a collection of substances that form urine
Single circulatory system
a circulatory system that has only one circuit, such as is found in fish; the heart pumps blood to the respiratory surface to be oxygenated and it then flows to the rest of the body under low pressure
Rumen
the largest chamber of the four-chambered stomach of ruminant or cud-chewing mammals
Sphincter
a small, muscular opening that surrounds tube-like organs and controls the passage of material from or to an organ by contracting and relaxing
Systemic circulation
the system of blood vessels that circulate blood to most of the body
Tongue
an organ that helps to move the food around the mouth and increases food contact with the teeth
Trachea
an organ that carries gases to the lungs via the bronchi and bronchioles; it is strengthened with rings of cartilage to stop it collapsing
Tracheal system
in insects, a system of tubes made of chitin that allows oxygen to pass in by diffusion; the mechanism for gas exchange in insects
Urea
a water-soluble nitrogenous waste product excreted by terrestrial mammals, including humans; formed by the breakdown of amino acids in the liver
Urine
the liquid excreted by animals that contains waste products filtered by the kidneys and stored in the bladder
Valve
a flap that ensures blood moves in one direction only through the heart and veins
Vein
a blood vessel that carries blood towards the heart
Vena cava
the vein that delivers deoxygenated blood from most of the body to the right atrium
Ventricle
a muscular chamber of the heart which pumps blood away from the heart
Venule
a small vein
Villi
the projections from the surface of the small intestine that increase its surface area and thus increase absorption
adipose
describes a type of connective tissue (e.g. cells containing fat droplets)
atom
the smallest fundamental particle of matter; composed of protons, neutrons and electrons
blood
a type of connective tissue (e.g. red blood cells)
bone
a type of connective tissue that provides support (e.g. skeleton)
cartilage
a type of connective tissue that holds parts of the body together (e.g. at the end of a bone)
cell
the basic structural unit of all life forms on Earth
cell membrane
the selectively permeable boundary of all living cells that maintains the contents of the cell and regulates movement of substances in and out of the cell
connective tissue
a basic tissue type in complex animals which provides support, strength and elasticity; it holds certain body parts together and includes bone, cartilage, tendons, blood and ligaments
cuticle
the non-cellular protective layer on the surface of a plant
cellular differentiation
the process by which an unspecialised cell develops into a specialised cell
cytosol
the fluid part of the cytoplasm, containing highly organised fluid material with dissolved substances; excludes the organelles
differentiation
the process by which cells become specialised in structure and function; occurs mostly during embryonic development in multicellular organisms
epidermis
the surface layer of plant or animal cells, generally responsible for separating and protecting the organism from its environment
epithelial tissue
a basic tissue type in complex animals whichcovers many surfaces, including the surface of the body and linings of body cavities such as airways,and acts as a protective layer and a barrier against infectious agents and water loss
eukaryote
a complex type of cell with a nucleus and membrane-bound organelles; a member of Domain Eukarya
meristem
a localised area of plant tissue in which cells actively divide to form new tissues; includes the growing tips of roots and stems
mitosis
a type of nuclear division that maintains the same number of chromosomes in daughter cells; it is the basis of bodily growth and asexual reproduction in many eukaryotic species
nervous tissue
a basic tissue type in complex animals which provides the means of communication between all body structures and includes neurons that transmit nerve impulses
molecule
the smallest particle of a chemical compound
multicellular
describes an organism consisting of more than one cell
muscle tissue
a basic tissue type in animals;made of thin and very long thread-like cells called muscle fibres which use ATP energy to perform movements; the fibres are capable of contracting when stimulated by nerve impulses
neuron
a nerve cell
organ
a collection of different types of tissues working together to perform a particular function
organelle
a specialised structure or compartment within a cell that has a specific function
specilaisation
(of cells) the possession of specific features that relate to a specific role or function
prokaryote
a simple type of cell that lacks a nucleus and membrane-bound organelles; a member of Domains Archaea or Bacteria
root hair
a tube-like outgrowth of a root epidermal cell that increases the surface area of the root; responsible for absorbing water and nutrients
specialised cell
a cell that has specific features that enable it to perform its specific function
stem cell
an unspecialised, immature cell capable of giving rise to different kinds of specialised, differentiated cells
system
a collection of organs that work together to perform a particular function
tissue
a group of specialised cells working together to perform a specific function
unicellular
describes an organism made up of a single cell
vascular
describes vessels that conduct fluid
vascular plants
(in plants) the plant tissue devoted to the bulk transport of water, nutrients, sugars and other substances, comprising the xylem and phloem
absorption
the movement of water and dissolved substances into a cell, organ or organism
active transport
the process whereby cells actively transport substances across a membrane from a low concentration to higher concentration of the substance; characterised by the fact that the process consumes energy
adaptation
any change in the characteristics of an organism that makes it better able to survive in its environment
cohesion
the strong forces that exist between water molecules
adhesion
the strong forces that exist between water molecules and other substances, due to the polar nature of the water molecules
arid
describes a climate that has little or no rain
capillary action
the combined forces of adhesion and cohesion which act to move water along a thin column
companion cell
a type of cell found in phloem next to the sieve tube cells; provides most of the cell functions of the sieve tube cells, which lack most organelles
epidermis
the surface layer of cells of a plant or animal; generally responsible for separating and protecting the organism from its environment
guard cell
pairs of cells surrounding and controlling the action of stomata
flaccid
describes a cell when it has shrunk due to loss of water
humidity
the concentration of water vapour in the air
humus rich soil
thecomplex organic material resulting from the decomposition of plant and animal debris (detritus)
lignin
a complex compound found in xylem cells; provides strength and structure to the cell wall and plant
mesophyll cell
a type of cell found in the middle of leaves, packed with chloroplasts and essential for photosynthesis
nitrogen fixing bacteria
bacteria found in the roots of certain plants that are able to capture atmospheric nitrogen and convert it to usable compounds
osmosis
the passive movement of water across a selectively permeable membrane from regions of low solute concentration to high solute concentration
non vascular
describes plants that do not have roots but do have simple leaves; they lack vascular tissue
nutrient
a substance required by living organisms, generally including dissolved salts and vitamins in the case of animals, rather than substances taken up to provide energy
palisade cell
an elongated cell packed with chloroplasts
phloem
a plant tissue that transports sugars, in the form of sucrose, and other photosynthesis products from one part of a plant (usually where they are made, the leaves, or where they are stored, the roots) to where they are needed; transport can therefore be in two directions; consists of conductive tissue composed of thin-walled cells
root hair
a tube-like outgrowth of a root epidermal cell that increases the surface area of the root; responsible for absorbing water and nutrients
root pressure
the force that pushes water up the stem from the roots
sieve tube cell
a long, tubular plant cell without a nucleus that is found in phloem and joins with others to form sieve tubes, through which sugar and other solutes travel
sink
a plant organ that uses sugar for active growth or stores sugar, such as growing roots, stems and fruits
source
a plant organ that produces (by photosynthesis) or releases sugar for translocation; leaves are the primary sugar source
stomata
(singular stoma) the openings in leaves, and some stems, that control the movement of gases into and out of the plant
tissue
a group of specialised cells working together to perform a specific function
translocation
the active, multidirectional movement of organic nutrients (sugars) in solution, from source to sink, through the phloem of vascular plants
transpiration
the loss of water vapour by evaporation from the surface of a plant, especially via stomata on the underside of leaves
Transpiration pull
the force arising from the evaporation of water from leaves which pulls water up through the xylem
Transpiration stream
a continuous column of water in the xylem that runs the length of the stem of a plant
turgid
describes a cell that is full of water and has a swollen appearance, such as a guard cell next to an open stoma
turgor
the state of a plant cell that is full of water
vascular bundle
a combined bundle of xylem and phloem tissues in a plant
vascular plants
plants that have vascular tissue, the tissue that transports water, nutrients, sugars and other substances around the plant body
vascular tissue
(in plants) the tissue devoted to the bulk transport of water, nutrients, sugars and other substances; comprises the xylem and the phloem
xylem
the plant tissue responsible for the transport of water, along with mineral nutrients, from the roots to the leaves; made of elongated, tubular dead cells
specialization
(of cells) refers to the possession of specific features that relate to a specific role or function
