Virginia Tech BMSP 2135 RAT #4: 1.5, 7.2-7.3, 3.1-3.2

*this* is a basic concept that is revisited repeatedly in the textbook

1. Feedback loops

2. relationship of structure and function

3. gradients

4. cell-cell communication

core principle

*this* is the maintenance of the body's stable internal environment

homeostasis

*this* is the disturbance in homeostasis; can result in disease or death if not corrected

example: having too much sugar in the blood on a long-term basis can cause damage of nerves, blood vessels, kidneys, and eyes

homeostatic imbalance

*these* are variables in the internal environment that are controlled so they stay close to a particular normal value; to prevent homeostatic imbalances

regulated variables

a ____________ _________ is a homeostatic control mechanism in which a change in a regulated variable causes effects that feed back and affect that same variable

made of a series of events that lead to effect our output of some sort, which then influences the events of the loops themselves

feedback loop

a ________________ feedback loop is one that opposes the initial change and reduces the output; a change in a regulated variable in one direction results in actions that cause changes in the variable in the opposite direction

negative

in a negative feedback loop, the ____________ activity shuts off when conditions return to the normal range

effector

each regulated variable has its own *what*, or normal value

not really an exact value but rather a normal range

set point

when a regulated variable is outside its normal range, this information (stimulus) is picked up by a cellular structure called a ______________ (sensor)

receptor

once the receptor receives the stimulus, the receptor then sends this stimulus to a _____________ __________ by a variety of mechanisms, usually requiring the use of cells of the nervous or endocrine system

control center

the control center is often cells in the brain or an endocrine organ called a ___________

gland

If the control center determines that the variable is out of the normal rang, it sends signals to cell or organs, called _____________, which cause physiological responses that return the variable to the normal range.

effectors

a ______________ feedback loop is when the effector's activity increases, reinforcing the initial stimulus and amplifying the response of the effector; less common

positive

effects in a positive feedback loop (do/do not) continue indefinitely

every correctly functioning positive feedback loop eventually reaches a point at which positive feedback shuts off in response to an external stimulus (an event that is not part of the loop); also can shut down when some end point is reached or some outside event intervenes

do not

1. negative feedback loop is not bad for the body

2. homeostasis does not mean that the body's internal environment is static

3. feedback loops are constantly engaged in some degree of activity

4. not all physiological variables can be controlled; a physiological variable can be controlled through feedback loops only if cells with receptors exist to detect changes in a set point; also, changes in an _______________ variable can disrupt the homeostasis of a regulated variable

unregulated

complementarity of structure and function: ________ ___________ _____________; a core principle of anatomy and physiology; states that the structure of a chemical, cell, tissue, or organ is always such that it best suits its function

form follows function

*examples of complementarity of ___________ and _____________*

1. blood vessels are hollow tubes that can transport blood through the body

2. hard and strong bones support and frame the body

3. the lung tissue is extremely thin, which allows its function of allowing gases such as O2 and CO2 to cross

structure, function

a _____________ is a condition in which more of something exists in one area than in another, and these two areas are connected

gradient

*3 types of gradients*

1. temperature gradient

2. _______________ gradient

3. pressure gradient

concentration

cell-cell communication is important in the body to ensure that ________________ of the entire organism is maintained

homeostasis

cell-cell communication comes in form of electrical signals or ____________ ___________________, in which one cell triggers a response from another cell

chemical messengers

*2 major methods of cell-cell communication*

1. electrical signals: transmitted directly between ________________ cells

neighboring

*2 major methods of cell-cell communication*

2. chemical messengers: may be released from one cell directly onto another cell or into the fluid surrounding another cell, or they may reach another cell after traveling through *what*; main way cells of the nervous system communicate with other cells of the body

the blood

what passes through the foramen magnum to enter the vertebral cavity?

spinal cord

the _________ articulates at the occipital condyles

atlas

what articulates with the mandibular fossa?

mandible

what does the external acoustic meatus lead to?

middle ear

what surface is considered the petrous region?

internal or medial surface of the temporal bone

how is the sphenoid bone unique?

it articulates with every other cranial bone

what pass through the cribriform foramina of the ethmoid bone?

tiny nerves that detect smell

what is the role of the crista galli of the ethmoid bone?

attachment point for membranes that surround the brain

what structure is formed in part by the perpendicular plate of the ethmoid bone?

nasal septum

what substance drains through the lacrimal fossa?

tears

what is a common name for zygomatic bones?

cheekbones

the palatine bones are shaped like what letter of the alphabet?

L

the top of the perpendicular plates of the palatine form a small piece of what structure?

the orbit

the horizontal plates of the palatine form in part what structure?

hard palate

the ____________ __________ of the mandible is the attachment site for a major muscle of mastication

coronoid process

the mandibular condyles articulate with the ______________ __________ of the temporal bone

mandibular fossa

the _____________ _____________ is the bottom of the mandibular condyle

condylar process

what is the singular form of maxillae?

maxillary

the _____________ nasal conchae is part of the ethmoid bone

middle

the singular form of conchae is ___________

concha

the vertebral column is the spine, consisting of _______ bones called vertebrae

33

there are ____ cervical vertebrae, _____ thoracic vertebrae, and ____ lumbar vertebrae, ____ fused sacral vertebrae, and _______ coccygeal vertebrae

7, 12, 5, 5, 3-5

an _________________ _____________ is the space between most of the moveable (unfused) vertebrae; spinal cord is visible through these foramina; location where spinal nerve roots emerge

intervertebral foramen

the spine is a vaguely __-shaped vertebral column

S

the cervical and lumbar vertebrae are ___________

concave

the thoracic and sacral vertebrae are ____________

convex

both the convex thoracic curvature and the convex sacral curvature are present in fetal life as part of the fetus's original C-shaped vertebral column, so they are known as ____________ ______________

primary curvatures

the concave cervical and lumbar curvatures are called ____________ ___________________ because they develop after the fetal period; this development is critical to our ability to walk upright

secondary curvatures

*this abnormal spinal curvature* is lateral curvatures in vertebral column that give it a C or S shape when viewed from the posterior or anterior side

scoliosis

*this abnormal spinal curvature* is described as "swayback"; exaggerated cervical and lumbar concave curvatures

lordosis

*this abnormal spinal curvature* is when thoracic convex curvature is exaggerated, giving a "hunchback" appearance; caused by joint conditions such as arthritis, bone conditions such as osteoporosis and vertebral fractures, and developmental abnormalities of the skeleton

kyphosis

the plural form of vertebra is *what*

vertebrae

the body of the vertebrae is the most anterior structure; also called the _____________; primary weight-bearing structure

centrum

the vertebral foramen is posterior to the body; the spinal cord and its associated tissues pass; the vertebral foramina of the entire vertebral column form the ____________ ___________ (vertebral canal)

vertebral cavity

the vertebral foramen is bordered anteriorly by the body, laterally by two _____________ that project from the body, and most posteriorly by the ___________

pedicles, laminae

together, the pedicles and laminae form the _____________ ________; the pedicles merge into the laminae, which enclose the posterior part of the vertebral foramen

vertebral arch

the superior and inferior ____________ _____________ are found at the junctions of the pedicles and laminae

articular processes

the surfaces of the superior and inferior articular processes contain smooth regions known as _________ that are covered by hyaline cartilage; the superior articular facets of one vertebra form joints with the inferior articular facets of the vertebra above it.

facets

_________________ ___________ project from the lateral sides of the vertebral arch; serve as attachment sites for muscles

transverse processes

the _____________ ____________ is the posterior projection from the vertebral arch; site for muscle attachment; palpable along your back as your "spine"; helps protect the posterior spinal cord

spinous process

the _____________ vertebrae are the only vertebrae to have transverse foramina = holes in the transverse processes that allow passage of the vertebral arteries and veins

cervical

the atlas (C1) is unique because it has no ______ or __________ ____________

body, spinous process

the axis (C2) is unique because it has the ________ (odontoid process) = superior projection from body; fits up into the vertebral foramen of the atlas where the body of the atlas would be located; this allows this joint to perform its function of rotational motion of the neck, such as shaking your head to indicate "no"

dens

*this type of vertebrae* has heart-shaped bodies, circular vertebral foramina, long spinous processes that point inferiorly

thoracic vertebrae

thoracic vertebrae have superior and inferior __________ __________ found on the lateral sides of the bodies

costal facets

T10-T12 have only a single costal facet on each side of the body

T1-T10 have two additional costal facets on the transverse processes called the _____________ __________ ___________ (these articulate with another portion of the ribs)

transverse costal facets

______________ vertebrae have large kidney-shaped bodies, thick spinous processes that point posteriorly, and vertebral foramina shaped like a flattened triangle; pedicles and laminae are thicker and shorter

lumbar

the sacrum's two lateral surfaces, the _____________ surfaces, articulate with the two pelvic bones

auricular

the sacrum's superior surface, the flattened bone, articulates with _____ at its superior articular processes

L5

the sacrum's inferior surface, the _______, articulates with the coccyx

apex

the _______ (lateral to the sacral promontory) of the sacrum are relatively smooth

alae

_______________ _________ of the sacrum are where the vertebrae fused

transverse lines

on the posterior surface of the sacrum in the opening to the _________ _________, a continuation of the vertebral canal, which contains nerve roots from the spinal cord and surrounding connective tissue membranes

sacral canal

___________________ ________ are fibrocartilage pads between 2 vertebrae that absorb shock, bind the vertebral column together, and help support the weight of the body

intervertebral discs

*2 components of intervertebral discs*

1. _____________ ___________: soft, inner, jelly-like substance; resilient shock absorber

2. annulus fibrosus: outer ring of fibrocartilage that surrounds the nucleus pulposus; holds both the nucleus pulposus in place and the vertebrae together

nucleus pulposus

the thoracic cage is composed of the....

sternum, ribs, thoracic vertebrae

3 portions of the sternum

_______________, body, ____________ __________

manubrium, xiphoid process

the notch on the superior surface of the sternum is called the...

suprasternal notch

the two notches on the lateral surface of the sternum are called the ________________ _______, which articulate with the clavicles of the pectoral girdles

clavicular notches

the ___________ ________ is where the manubrium and the body meet; where the cartilages of the second ribs attach

sternal angle

how many ribs are there in a typical adult human?

24 (12 pairs)

what is the term for the space between ribs?

intercostal space

ribs 1-7 are considered *what* because they attach directly to the sternum via their own costal cartilage

true ribs

ribs 8-12 are considered *what* because they do not attach to the sternum directly

false ribs

ribs 11-12 are ____________ ribs (subset of false ribs) because they lack any attachment to the sternum

floating

*Basic Processes of Cells*

1. ________ _______________: the chemical reactions that a cell carries out to maintain life; include anabolic, catabolic, redox reactions

Cell metabolism

*Basic Processes of Cells*

2. _________________ ____ ______________: compounds it has produced or ingested to a variety of destinations, either out of the cell or to a different location in the cell

transportation of substances

*Basic Processes of Cells*

3. _______________ with itself, with its surrounding environment, and with other cells in the body; involves chemical and electrical signals

communication

*Basic Processes of Cells*

4. ______ ________________: many cell types can reproduce themselves via cell division, which is necessary for growth and development, as well as for replacement of old and damaged cells

cell reproduction

*Basic components in human cells*

1. _________ _____________: "fence" of the cell; structural support, communication with other cells, regulation of transport into and out of the cell, and cell identification

plasma membrane

*Basic components in human cells*

2. _____________: inside the plasma membrane; consists of both the fluid cytosol and the structures embedded within it (the organelles and the cytoskeleton)

cytoplasm

*Basic components in human cells*

3. ___________: surrounded by a membrane similar to the plasma membrane called the nuclear envelope; contains most of the cell's DNA and is primary location for RNA synthesis (transcription)

nucleus

*Structural variations in human cells*

- tiny, concave RBCs that lack _________ and most organelles measure only 6-8 micrometers

- long, branching nerve cells measure from 1 mm to over a meter

nuclei

structural variations in human cells is an example of which type of core principle?

structure-function

*examples of cell ____________________*

- cells of the liver serve critical detoxification functions, so they contain a large number of the organelle that carries out detoxification reactions

- cells of the skeletal muscles, whose cytoplasm is filled with contractile proteins that enable the cells to contract and generate movement

specialization

cell specialization is achieved by a unique __________________ of organelles, proteins, and other structures in each cell type

composition

molecules of the plasma membrane must have parts that can interact with the water in both these fluid compartments (ECF & cytosol), in addition to having parts that do not interact with water to keep the water in the ECF and cytosol separated

phospholipids have these properties

the membrane's hydrophilic regions that interact with water must have *what type of bonds*, whose polar ends can form H bonds with surrounding water molecules

polar covalent bonds