A & P - Ch 1

3 examples of organelles

-Mitochondria -centrioles -lysosomes

Organs

-definite anatomical boundaries -are visibly distinguishable from adjacent structures

What is the hierarchy of the human body

-organism is composed of organ systems -organ systems are composed of organs -organs are composed of tissues -tissues are composed of cells -cells are composed partly of organelles -organelles are composed of molecules -molecules are composed of atoms

2 examples of negative feedback

-vasodilation -vasoconstriction

Positive feedback cycle in child birth

1. Head of fetus pushes against the cervix 2. Nerve pulses from cervix transmit to the brain 3. Brain stimulates pituitary gland to secrete oxytocin 4. Oxytocin stimulates uterine contractions and pushes fetus towards cervix

The body is composed of only ____ primary classes of tissue: ____, ____, ____, ____

4, epithelial, connective, nervous, muscular

Stimulus

A chemical or physical agent in a cell's surroundings that is capable of creating a physiological response in the cell; especially agents detected by sensory cells, such as chemicals, light, and pressure.

Example of positive feedback

A woman giving birth

Homeostasis

Although the environment around an organism changes, the organism maintains relatively stable internal conditions. Ability to maintain internal stability

____ are the smallest units of an organism that carry out all the basic functions of life; nothing simpler is considered alive

Cells

Molecules

Composes organelles and other cellular components

Auscultation

During a physical examine, the act of listen to the sounds made by the body

down the gradient

If matter or energy moves from the point where this variable has a higher value to the point with a lower value, we say it flows

Metabolism

Living things take in molecules from the environment and chemically change them into molecules that form their own structures, control their physiology, or provide them with energy.

Up the gradient

Movement in the opposite direction is up the gradient

The fundamental mechanism that keeps a variable close to its set point is

Negative Feedback

There are _____ within ____—the large is visible to the naked eye often contain smaller ones visible only with the microscope

Oragans, organs

____ is especially obvious in animals because of nerve and muscle cells that exhibit high sensitivity to environmental stimuli, rapid transmission of information, and quick reactions.

Responsiveness

Example of effector

The effector is the heart: the restoration of normal blood pressure, is then sensed by the receptor, and the feedback loop is complete.

Vasoconstriction

a narrowing of the blood vessels in the skin, which serves to retain warm blood deeper in your body and reduce heat loss. If this is not enough, the brain activates shivering—muscle tremors that generate heat.

Negative feedback

a process in which the body senses a change and activates mechanisms that negate or reverse it.

Positive feedback

a self-amplifying cycle in which a physiological change leads to even greater change in the same direction, rather than producing the corrective effects of negative feedback

Organ

a structure composed of two or more tissue types that work together to carry out a particular function

Organelles

are microscopic structures in a cell that carry out its individual functions. Any structure within a cell that carries out one of its metabolic roles

molecule is a particle composed of at least two ____, the smallest particles with unique chemical identities

atoms

Effector

cell or organ that carries out the final corrective action

Example of integrating control center

comparing what the blood pressure is with what it should be and "makes a decision" about what the appropriate response should be

Plasma membrane

encloses a cell and is composed of lipids and proteins

Metabolism therefore requires ____, There is a constant turnover of molecules in the body; few of the molecules now in your body have been there for more than a year

excretion

examples of down the gradient

from a warmer to a cooler point, or a place of high chemical concentration to one of lower concentration.

A physiological gradient

is a difference in chemical concentration, electrical charge, physical pressure, temperature, or other variable between one point and another.

integrating (control) center

is a mechanism that processes this information, relates it to other available information

receptor

is a structure that senses a change in the body

positive feedback is a harmful or even life-threatening process. This is because

its self-amplifying nature can quickly change the internal state of the body to something far from its homeostatic set point.

Baroreceptors

large arteries near the heart

Macromolecules

largest molecules, such as proteins, fats, and DNA

By maintaining stability, ____ ____ is the key mechanism for maintaining health.

negative feedback

The skin is the body's largest ____

organ

A single ___ can belong to two ____ systems. For example, the pancreas belongs to both the ___and ___ systems.

organ, organ, endocrine, digestive

Most ____ and higher levels of structure are within the domain of gross anatomy.

organs

An example of a receptor

stretch receptors that monitor blood pressure

eponym

terms used to identify the discovery of a structure

Excretion

the separation of wastes from the tissues and their elimination from the body.

Vasodilation

the widening of blood vessels. When blood vessels of the skin dilate, warm blood flows closer to the body surface and loses heat to the surrounding air. If this is not enough to return your temperature to normal, sweating occurs; the evaporation of water from the skin has a powerful cooling effect

A ____ is a mass of similar cells and cell products that forms a discrete region of an organ and performs a specific function

tissue