HOW ANIMALS SURVIVE (1)

Innate immune system

Innate immune system

The body's first line of defense against foreign pathogens, characterized by nonspecific and rapid responses.

Acquired immune system

The immune system that develops over time and provides specific responses to specific pathogens.

Skin

The physical barrier of the body that helps prevent the entry of pathogens, with a pH of 3-5 and various protective enzymes and bacteria.

Mucous membranes

The moist linings of various body cavities that act as physical barriers and contain protective mechanisms such as cilia and antibacterial enzymes.

Phagocytes

Immune cells that engulf and destroy foreign cells, including macrophages, neutrophils, and dendritic cells.

Granulocytes

A type of white blood cell with granule staining patterns, including neutrophils, eosinophils, basophils, and mast cells.

Toll-like receptors (TLR)

Receptors on phagocytes that bind to pathogen surface molecules, triggering phagocytosis and the release of cytokines.

Inflammation

A local, nonspecific reaction to injury or infection characterized by increased blood flow, recruitment of phagocytes, and the release of cytokines.

Extravasation

The process by which phagocytes move from blood vessels to the site of infection.

Complement system

A group of circulating proteins that activate each other, leading to the formation of a membrane attack complex (MAC) that lyses bacteria and enhances phagocytosis.

Antibodies

Proteins produced by B cells that bind to specific pathogens and mark them for destruction.

Clonal selection

The process by which B cells are selected and differentiated based on their ability to bind to specific antigens.

Helper T cells

T cells that play a central role in coordinating the immune response and activating other immune cells.

Cytotoxic T cells

T cells that directly kill infected or abnormal host cells.

T cell receptor (TCR)

The receptor on T cells that recognizes and binds to antigens presented on major histocompatibility complex (MHC) molecules.

Antigenic drift

A mechanism by which pathogens, such as the flu virus, can change their surface proteins over time, evading memory T and B cells.

Tuberculosis (TB)

A bacterial infection caused by Mycobacterium tuberculosis that primarily affects the lungs and can be dormant or active.

Malaria

A parasitic infection caused by Plasmodium falciparum, transmitted through mosquito bites, and characterized by cyclical fevers and chills.

Nervous system

The complex network of cells and tissues that coordinates and controls the body's responses to internal and external stimuli.

Meninges

Three protective membranes that wrap around the spinal cord and brain.

Cerebrospinal fluid

Fluid that fills the spaces between the meninges, the central canal of the spinal cord, and the ventricles of the brain. It cushions the brain and spinal cord.

Gray matter

Consists of neuron cell bodies, dendrites, and unmyelinated axons in the brain and spinal cord.

White matter

Consists of bundles of myelinated axons in the brain and spinal cord.

CNS

which includes the brain and spinal cord.

Glia

Cells in the CNS that have numerous functions, including providing structural support, regulating ions and neurotransmitters, promoting circulation of cerebrospinal fluid, and protecting the nervous system from microorganisms.

Astrocytes

Type of glial cell that provides structural support for neurons, regulates extracellular ions and neurotransmitters, and induces the formation of a blood-brain barrier.

Radial glia

Type of glial cell that plays a role in the embryonic development of the nervous system.

Ependymal cells

Type of glial cell that promotes circulation of cerebrospinal fluid.

Microglia

Type of glial cell that protects the nervous system from microorganisms.

Oligodendrocytes

Type of glial cell in the CNS that forms myelin sheaths around axons.

Schwann cells

Type of glial cell that forms myelin sheaths around axons in the peripheral nervous system.

Forebrain

One of the three embryonic regions from which all vertebrate brains develop.

Midbrain

One of the three embryonic regions from which all vertebrate brains develop.

Hindbrain

One of the three embryonic regions from which all vertebrate brains develop.

Cerebrum

The largest and most complex part of the brain, consisting of the cerebral cortex, white matter, and basal nuclei.

Brainstem

The part of the brain that coordinates and conducts information between brain centers, consisting of the midbrain, pons, and medulla oblongata.

Cerebellum

Part of the brain responsible for coordination, error checking, and learning motor skills.

Diencephalon

One of the regions into which the forebrain develops, consisting of the epithalamus, thalamus, and hypothalamus.

PNS

transmits information to and from the CNS and regulates movement and the internal environment.

Afferent neurons

Neurons that transmit information to the CNS.

Efferent neurons

Neurons that transmit information away from the CNS.

Cranial nerves

Nerves that originate in the brain and mostly terminate in organs of the head and upper body.

Spinal nerves

Nerves that originate in the spinal cord and extend to parts of the body below the head.

Motor system

The functional component of the PNS that carries signals to skeletal muscles and is voluntary.

Autonomic nervous system

The functional component of the PNS that regulates the internal environment in an involuntary manner.

macrophages

“big eaters" patrol of the body

dendritic cell

skin and mm

neutrophils

abundant in blood; first to an infection

mast cells

release histamine contributing to allergies and inflamations

natural killer cells

only recognize/kill infected or abnormal host cells

phagocytes

detect surface molecules that are present on pathogen cells but not on host cells

sympathetic division

flight or flight response

parasympathetic division

rest and digest

enteric divison

controls activity of digestive tract