Lecture 1

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Basic Definitions

Anatomy- the study of the structure of the body

Physiology- the study of the functional processes of the body

Microscopic Anatomy-the study of the structure of cells, tissues, and organs of the body as seen with a microscope.

Cytology- the study of cell structure and function

Histology- the study of microscopic structures of tissue and organs

Developmental Anatomy- The study of the structural changes of an individual from fertilization to adulthood.

Gross anatomy-the branch of anatomy that deals with the structure of organs and tissues that are visible to the naked eye.

Regional Anatomy- an approach to anatomic study based on regions, parts, or divisions of the body (the foot or the inguinal region), emphasizing the relationships of various systemic structures (muscles, nerves, and arteries) within that area

Surface Anatomy- deals with anatomical features that can be studied by sight, without dissection.

Systemic Anatomy-an approach to anatomic study organized by organ systems, the cardiovascular system, emphasizing an overview of the system throughout the body

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Homeostasis

Homeostasis- The ability of the body to maintain relatively stable internal conditions even though the outside world changes; indicates a dynamic

state of equilibrium

Homeostasis is a state of dynamic consistency. Homeostasis does not require variable to be constant at all times.

The compensating mechanisms that mediate responses are called homeostatic control systems.

Receptor- detects environmental change

Control Center- integrating center - the brain

Effector- the response of the system

Set point- the point in which homeostasis is set and which things are determined as in euilibrium

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Communication

Signals travel from the receptor and the integration center through an afferent pathway-afferent means to carry to

The output of the integration center to the effector travels through the efferent pathway-efferent as in exit

Effectors can be hormones -chemical messengers, neurons-electrical messengers, or neuroendocrine-combination of the two

There is the endocrine system, nervous system, and the neuroendocrine system- signaling is crucial for appropriate functioning of all systems.

Paracrine substances are chemical messengers involved in local communication between cells

Autocrine substances are chemical messengers secreted into the extracellular fluid and effects the cell that excreted the chemical.

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Feedback Loops

Negative feedback loop

Most systems act in this way

Positive feedback

Also known as partition

Most common example is birth

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Overcoming the Cell Barrier

Permeability determines what moves in and out of a cell

nutrients must get in

products and waste must get out

Selective permeability restricts materials based on

size

electrical charge

molecular shape

lipid solubility

molecules that are soluble in lipids travel quickly into and out of cells

3 Categories of Transport

Diffusion and Osmosis

Diffusion can be simple or channel mediated but it always requires a concentration gradient

Channel mediated diffusion- materials pass through the transmembrane protein channels

they are water soluable compounds

they are ions

Passage depends on

size

charge

interaction with the channel

Osmosis

Osmosis is diffusion of water across the cell membrane

The more solute molecules the lower the concentration of water

The membrane must be freely permeable to water and selectively permeable to solutes

Osmotic pressure- Is the force of a concentration gradient of water

osmosis can be prevented by resisting the change in volume and applying hydrostatic pressure equal to the of the osmotic pressure in the opposite direction

Tonicity

the osmotic effect of a solute on a cell

2 fluids may have equal osmolarity but different tonicity

Isotonic- same tonicity

Hypotonic-less than

Hypertonic-higher than

Carrier-mediated transport

transports ions and organic substrated

Facilitated diffusion

passive- goes down a concentration gradient

carrier mediated- carrier proteins transport molecules too large to fit through channel proteins- glucose and amino acids

Active transport

Active transport proteins move substrates against their concentration gradients- it requires energy like ATP

sodium potassium exchange pump

Secondary active transport

Sodium concentration gradient drives glucose transport

ATP energy pumps sodium back out

Contrasport

Counterrtransport

Characteristics of carrier mediated transport

specificity- only specific substances for specific carriers

saturation limits

regulation-

Vesicular transport

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Organic Molecules

Always contain carbon and hydrogen

Many contain large chains of covalently linked carbon

Many are water soluble

Four major classes

Carbohydrates

Lipids

Protein

Nucleic Acids

Carbohydrates

Contain a carbon, hydrogen, and oxygen

provide a ready and easily used source of cellular fuel

classes

monosaccharides

Disaccarides

Polysaccharides

Lipids

Contain a carbon, hydrogen, and oxygen

Purpose

insulate

energy storage

shock absorption

chemical messenger

steroid

Account for 10-12% of ur total body weight

5 classes

Fatty Acids

saturated and unsaturated

Eicosanoids

prostaglandins

leukotrines

Glycerides

neutral fats

Steroids

cholesterol

estrogen and testosterone

corticosteroids and calctrol

Bile salts

Phospholipids and Glycolipids

Where do lipids enter the metabolic pathway?

Protein

1000000 of kinds and 10-30% of total body weight

Most are macromolecules

Protein functions

support

movement

transport

buffering

metabolic regulation

coordination and control

defense

Structure of proteins

consist of long chains of amino acids joined by peptide bonds

Primary structure- polypeptide

Secondary structure- hydrogen bonds form spirals or pleats

Tertiary structure- secondary structure folds into a unique shape

Quaternary structure- proteins final shape

Specific types of protein

Fibrous

Globular

compact spherical proteins that have at least a tertiary structure

Water soluable

include chaperone and enzymes

Protein Combination

Glycoproteins- large protein with a small carbohydrate

Proteoglycans-large polysaccharides and polypeptides

Where do proteins enter the metabolic pathway?

Nucleotides

Long chains of nucleotides form RNA and DNA

DNA in the cell nucleus contains the information needed to construct all of the protein in the body

Nucleotides

Purines

Adenine

Guanine

Pyrdines

Cytosine

Thymine

Uracil (RNA only)

Forms of RNA

messenger RNA

transfer RNA

ribosomal RNA

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Metabolism

Aerobic

Anaerobic

ADP and ATP

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Phosphorylation

adding a phosphate group to ADP with a high energy bond to form the high energy compound ATP

ATPase- the enzyme that catalyzes phsphorylation

ATP- chemical energy stored in phosphate bonds

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