BIG STUDY GUIDE

What is the definition of anatomy?

the structure of living organisms.

What is the definition of physiology?

is how living organisms function.

What is homeostasis?

Maintenance of relatively constant internal environment.

Give examples of factors maintained via homeostasis.

Body temperature, glucose, blood pressure, pH, oxygen levels, blood volume, waste levels, CO2 levels.

What is the difference between negative feedback and positive feedback?

Negative feedback is more common as it helps maintain homeostasis by reversing changes, while positive feedback enhances changes.

Why is negative feedback more common than positive feedback?

Because negative feedback loops are essential for maintaining homeostasis.

What triggers physiological processes in our bodies?

the mechanisms employed to accomplish negative feedback and maintain homeostasis.

What are the basic functions of the plasma membrane?

Defines cell boundaries, controls interactions with other cells, and regulates movement of materials in and out of the cell.

What types of membrane proteins exist?

Receptors, enzymes, channel proteins, carrier proteins, cell-identity markers, and cell-adhesion molecules.

What differentiates leak channels from gated channels?

Leak channels are always open while gated channels can be opened or closed under specific conditions.

What are carrier proteins' function in membranes?

They help move molecules across the plasma membrane, aiding diffusion down or transporting against concentration gradients.

What does selectively permeable mean in the context of plasma membranes?

Plasma membrane acts as both a barrier and a pathway for molecules between cytosol and extracellular fluid.

What distinguishes passive transport from active transport?

Passive transport occurs without energy, while active transport requires energy to move substances against their concentration gradient.

What is diffusion?

Movement of molecules from an area of high concentration to an area of low concentration.

What factors can affect the rate of diffusion?

Temperature, molecular weight, steepness of concentration gradient, and membrane permeability.

What is osmosis?

Movement of water across a membrane.

What are aquaporins?

Pores through which water moves during osmosis.

Define isotonic, hypertonic, and hypotonic solutions regarding water movement in cells.

Isotonic: no net water movement; Hypertonic: water moves out of the cell; Hypotonic: water moves into the cell.

What's the difference between facilitated diffusion and active transport?

Facilitated diffusion moves substances down their concentration gradient without energy, while active transport moves substances against it and requires ATP.

What is the sodium-potassium pump?

A pump that moves sodium out of the cell and potassium into the cell, important for regulating cell volume and membrane potential.

What happens during endocytosis?

The cell takes in materials by engulfing them in vesicles.

What happens during exocytosis?

The cell expels materials by fusing vesicles with the membrane.

What are two divisions of the nervous system?

The central nervous system (CNS) and peripheral nervous system (PNS).

What is the role of sensory neurons?

They receive information about the internal and external environments.

What does the central nervous system (CNS) consist of?

The brain and spinal cord.

How does the peripheral nervous system (PNS) function?

It links the CNS to the rest of the body through nerves.

What is a neuron?

a basic unit of the nervous system that transmits signals.

What are dendrites?

Branch-like extensions from the soma that receive signals from other neurons.

What is the function of the axon?

Conducts electrical impulses away from the cell body.

Define myelin sheath.

A fatty layer that insulates the axon and increases the speed of impulse conduction.

What is the role of the node of Ranvier?

Gaps between myelin segments that allow for faster nerve impulse transmission through saltatory conduction.

What is the resting membrane potential of neurons?

-70 mV.

What happens during depolarization?

The membrane potential becomes less negative, moving toward zero.

What occurs during hyperpolarization?

The membrane potential becomes more negative than the resting membrane potential.

What triggers an action potential in neurons?

A series of voltage changes across the membrane due to ion movement.

How do electrical signals travel along neurons?

Via action potentials that regenerate at nodes along myelinated axons.

What is a synapse?

The area where two neurons communicate with each other.