Chapter 32 – The Internal Environment of Animals (Vocabulary)

A comprehensive set of vocabulary flashcards covering key terms from Chapter 32 on the internal environment of animals, including anatomy, physiology, endocrine and nervous regulation, homeostasis, osmoregulation, and kidney structure and function.

anatomy

The structure of an organism.

physiology

The processes and functions of an organism.

tissue

An integrated group of cells with a common structure, function, or both.

organ

A specialized center of body function composed of several different tissue types.

organ system

A group of organs that work together to perform vital body functions.

epithelial tissue (epithelium)

Sheets of tightly packed cells that line organs, body cavities, and external surfaces.

connective tissue

Animal tissue that mainly binds and supports other tissues, with cells scattered through an extracellular matrix.

muscle tissue

Tissue consisting of long muscle cells that contract voluntarily or when stimulated by nerves.

nervous tissue

Tissue composed of neurons and supporting glial cells.

neurons

Nerve cells that transmit signals using electrical charges across their plasma membranes.

glial cells

Non-neuronal nervous-system cells that support, nourish, insulate, and protect neurons.

stimulus

A fluctuation in a variable that triggers a response in feedback regulation.

response

A physiological activity triggered by a change in a variable or a transduced signal.

endocrine system

Internal communication system of ductless glands, hormones, and target-cell receptors that maintains homeostasis with the nervous system.

nervous system

Fast-acting communication system of sensory receptors, neurons, and effectors that works with the endocrine system to regulate the body.

hormones

Secreted chemicals formed in specialized cells that travel in body fluids to target cells, causing functional changes.

endocrine glands

Glands that secrete hormones directly into the interstitial fluid and bloodstream.

exocrine glands

Glands that release products through ducts onto body surfaces or into body cavities.

hypothalamus

Ventral forebrain region that coordinates the endocrine and nervous systems and controls the pituitary gland.

negative feedback

Regulatory mechanism in which accumulation of an end product slows the process, counteracting initial change.

positive feedback

Regulatory mechanism in which an end product speeds up the process, amplifying the initial change.

pancreas

Gland with exocrine digestive functions and endocrine roles secreting insulin and glucagon for homeostasis.

pituitary gland

Endocrine gland at the brain’s base with a posterior lobe (stores hypothalamic hormones) and an anterior lobe (produces many hormones).

posterior pituitary

Extension of the hypothalamus that stores and releases oxytocin and ADH.

anterior pituitary

Pituitary portion of endocrine cells that synthesize and secrete several tropic and nontropic hormones.

oxytocin

Posterior-pituitary hormone that induces uterine contractions and milk ejection.

antidiuretic hormone (ADH)

Posterior-pituitary peptide that promotes water retention by kidneys; also called vasopressin.

vasopressin

Another name for antidiuretic hormone (ADH).

epinephrine (adrenaline)

Catecholamine hormone from adrenal medulla mediating fight-or-flight responses; also a neurotransmitter.

regulator

Animal that uses homeostatic mechanisms to moderate internal changes despite external variation.

conformer

Animal whose internal condition changes according to external environmental changes.

interstitial fluid

Fluid that fills spaces between animal cells.

homeostasis

Steady-state physiological condition of the body.

set point

Value maintained for a variable in homeostasis, e.g., body temperature.

sensor

Receptor that detects a stimulus in a feedback system.

control center

Component that compares sensor data to the set point and directs effectors to respond.

effector

Component that causes a change in the regulated variable (e.g., sweat glands).

thermoregulation

Maintenance of internal body temperature within a tolerable range.

endothermic

Describing organisms that generate heat from metabolism to maintain stable body temperatures.

ectothermic

Describing organisms that rely on external heat sources for temperature regulation.

gradient

Difference in a particular quality (concentration, electrical, thermal, pressure) between two regions.

countercurrent exchange

Exchange of heat or substances between two fluids flowing in opposite directions, maximizing transfer.

osmoregulation

Regulation of solute concentrations and water balance by an organism.

excretion

Disposal of nitrogenous metabolites and other wastes.

osmolarity

Solute concentration expressed as molarity.

osmoconformer

Animal isoosmotic with its environment.

osmoregulator

Animal that maintains internal osmolarity independent of the external environment.

ammonia

Small, toxic nitrogenous waste (NH3) from protein and nucleic acid metabolism.

urea

Soluble nitrogenous waste produced in the liver by combining ammonia with CO2.

uric acid

Relatively nontoxic, largely insoluble nitrogenous waste of insects, land snails, and many reptiles (including birds).

transport epithelia

Specialized epithelial layers that carry out and regulate solute movement.

filtration

Extraction of water and small solutes from body fluid in excretory systems.

filtrate

Cell-free fluid extracted from body fluid by the excretory system.

reabsorption

Recovery of solutes and water from filtrate back into body fluid.

secretion

Discharge of synthesized molecules or wastes into filtrate or out of the body.

kidney

Vertebrate excretory organ where blood filtrate forms and becomes urine.

ureter

Duct that carries urine from kidney to urinary bladder.

urinary bladder

Pouch that stores urine before elimination.

urethra

Tube releasing urine; also serves as exit for male reproductive system.

renal pelvis

Funnel-shaped chamber in kidney that receives processed filtrate from collecting ducts.

nephron

Tubular excretory unit of the vertebrate kidney.

glomerulus

Ball of capillaries in Bowman’s capsule where blood filtration occurs.

Bowman’s capsule

Cup-shaped nephron region receiving filtrate from the glomerulus.

proximal tubule

Nephron segment downstream of Bowman’s capsule that conveys and refines filtrate.

loop of Henle

Hairpin turn between proximal and distal tubules with descending and ascending limbs for water and salt reabsorption.

distal tubule

Nephron segment that further refines filtrate and empties into a collecting duct.

collecting duct

Kidney location where processed filtrate (urine) is collected from renal tubules.

peritubular capillaries

Network of tiny blood vessels surrounding proximal and distal tubules in the kidney.

aquaporin

Channel protein that specifically facilitates the diffusion of free water across cell membranes (osmosis).