Animal Biology and Homeostasis

Flashcards based on College Physics and Biology lecture notes covering animal tissues and homeostasis.

Tissue

A group of closely associated, similar cells that carry out specific functions.

Four kinds of animal tissues

Epithelial, connective, muscle, and nervous tissue.

Parazoa

Sponges - lack defined tissues and organs; cells can disaggregate and aggregate.

Eumetazoa

All other animals with distinct and well-defined tissues.

Epithelial Tissues

Line cavities, open spaces, and surfaces.

Connective Tissues

Connect tissues together, provide support.

Muscle Tissues

Generate movement.

Nervous Tissues

Generate and transmit electrical signals.

Simple Epithelium

Single layer of epithelial cells.

Stratified Epithelium

Multiple layers of epithelial cells.

Connective Tissue Function

Used to connect different tissues or give the body structure.

Connective Tissue Composition

Cells (fibroblasts) embedded in a non-cellular matrix.

Collagen fibers

Tough fibrous proteins that remain intact when stretched.

Elastic fibers

Found in structures that expand and contract, such as in lungs and arteries.

Reticular fibers

Form a supporting framework in many organs, including liver, spleen, and lymph nodes.

Cells in Loose/Areolar Connective Tissue

Fibroblasts, macrophages, some lymphocytes, some neutrophils.

Location of Loose/Areolar Connective Tissue

Around blood vessels; anchors epithelia.

Cells in Dense, Fibrous Connective Tissue

Fibroblasts, macrophages, connective tissue.

Location of Dense, Fibrous Connective Tissue

Skin (irregular), tendons, ligaments (regular).

Cells in Cartilage

Chondrocytes, chondroblasts.

Location of Cartilage

Shark skeleton, fetal bones, human ears, intervertebral discs.

Cells in Bone

Osteoblasts, osteocytes, osteoclasts.

Location of Bone

Vertebrate skeletons.

Cells in Adipose Tissue

Adipocytes.

Location of Adipose Tissue

Adipose (fat).

Cells in Blood

Red blood cells, white blood cells.

Location of Blood

Blood.

Loose Connective Tissue

Composed of loosely woven collagen and elastic fibers.

Dense Fibrous Connective Tissue

Contains large amounts of collagen fibers and few cells or matrix material.

Cartilage

A connective tissue with a large amount of the matrix and variable amounts of fibers.

Chondrocytes

Cells that make the matrix and fibers of cartilage.

Lacunae

Spaces within cartilage tissue where chondrocytes are found.

Bone

Predominant skeletal tissue of vertebrates other than sharks and rays.

Osteocytes

Bone cells that secrete calcium salts and collagen.

Canaliculi

Contain cytoplasmic extensions for communication between osteocytes.

Adipose Tissue

Connective tissue made up of cells called adipocytes.

Red blood cells function

Oxygen transport.

White blood cells function

Defense.

Platelets function

Clotting.

Plasma

Liquid matrix of blood, consisting of water, proteins, salts, and soluble chemical messengers.

Three kinds of Muscle Tissue

Skeletal, Smooth, and Cardiac.

Skeletal Muscle

Voluntary; striated; multinucleated; mainly connected to the skeleton.

Smooth Muscle

Involuntary; no striations; spindle-shaped cells; found in hollow muscular organs.

Cardiac Muscle

Involuntary; striated; have intercalated discs between cells; found only in heart.

Neurons

Receives and transmit signals.

Glial cells (neuroglia)

Support and nourish the neurons, destroy pathogens, and modulate transmission of impulses.

Dendrites

Receive and transmit signals to the cell body.

Axon

Transmits signals away from the cell body.

Homeostasis

Aims to keep internal conditions around a set point.

Acclimatization

Changes in one organ system to maintain a set point in another organ system (altitude example).

Negative Feedback Loop

Counteracts any internal changes (reverses the direction of the change).

Positive Feedback Loop

Maintains and potentially strengthens the response to a stimulus.

Examples of Negative Feedback

Temperature, Glucose, pH, Blood calcium.

Example of Positive Feedback

Birth of a human infant.

Hypothalamus

Thermoregulatory control by this region of the brain.

Four Mechanisms of Heat Exchange

Radiation, Evaporation, Convection, Conduction.

Ectotherms

Animals that depend on the environment for their body heat.

Endotherms

Generate body heat metabolically, and have adaptations for thermoregulation.

Structural adaptations for thermoregulation

Insulating feathers, hair, and fat.

Physiological mechanisms for thermoregulation

Regulation of heat production and heat exchange with the environment.

Production of heat

Muscle contractions, shivering.

Loss of heat

Panting, dilation of skin capillaries, and sweating.

Acclimatization

Changes in one organ system to maintain a set point in another organ system.

Acclimatization

Changes in one organ system to maintain a set point in another organ system.

Acclimatization

Changes in one organ system to maintain a set point in another organ system.

Acclimatization

Changes in one organ system to maintain a set point in another organ system.

Acclimatization

Changes in one organ system to maintain a set point in another organ system.

Acclimatization

Changes in one organ system to maintain a set point in another organ system.

Acclimatization

Changes in one organ system to maintain a set point in another organ system.

Acclimatization

Changes in one organ system to maintain a set point in another organ system.

Acclimatization

Changes in one organ system to maintain a set point in another organ system.

Acclimatization

Changes in one organ system to maintain a set point in another organ system.

Acclimatization

Changes in one organ system to maintain a set point in another organ system.

Acclimatization

Changes in one organ system to maintain a set point in another organ system.

Acclimatization

Changes in one organ system to maintain a set point in another organ system.

Acclimatization

Changes in one organ system to maintain a set point in another organ system.

Acclimatization

Changes in one organ system to maintain a set point in another organ system.

Acclimatization

Changes in one organ system to maintain a set point in another organ system.

Acclimatization

Changes in one organ system to maintain a set point in another organ system.

Acclimatization

Changes in one organ system to maintain a set point in another organ system.

Acclimatization

Changes in one organ system to maintain a set point in another organ system.

Acclimatization

Changes in one organ system to maintain a set point in another organ system.