Physiology - CH.1 - Intro + homeostasis/feedback control/anatomy

Scientific method/process

observations, questions, hypothesis, research, experiment, analysis, conclusion

Hypothesis

has to be testable, looking for cause/effect

Importance of Following scientific method/process

Prevents false conclusions, misinformation, bias, enables repeatability,

Homeostasis

state of dynamic constancy, keeping the body in balance

Homeostasis Importance

must be maintained for normal body functioning and to sustain life

Negative Feedback (loop)

- The major physiological response to stimuli

- Opposes stimulus

ex: body temp, blood sugar/pressure

Positive Feedback (loop)

- Causes a system to change further in the same direction

- Action of effectors amplifies the changes that stimulated the effectors

- Moves further away from set point

ex: blood clotting, shiver, sweating

Physiology

- study of biological function

- how the body works to maintain life

Intrinsic control

- Local, built into the organs being regulated

Autoregulation

utilize intrinsic control mechanisms to maintain a relatively constant blood flow

Extrinsic Control

- Regulation comes from outside the organ

- from nervous system/endocrine system (hormones)

Components of Homeostasis

Stimulus, receptor, Integrating center, effector

Stimulus

- cause a high change in balance

- causes the organism to react

Sensor

- Notices stimulus

- sends info (afferent pathway) to Integrating center

Afferent Pathway

Sensory pathway, sends info to CNS

(sensor --> Integrating Center)

Integrating Center

- recieves info from sensor

- Establishes set point

- Analyzes + sends out info by efferent pathway

Efferent pathway

Used by Integrating center, sends to effector

Effector

the organ that carries out the directions given by the integrating center

Set point

the point at which one's body tries to maintain the average range

Normal range

range that moves around set point

Primary Tissues

muscle, nervous, epithelial, connective

Muscle tissue

3 types - skeletal, muscle, smooth

- Contraction and movement

Skeletal muscle

- forms by fusion of embryonic myoblasts

- lines up parallel, forms bundles

Cardiac Muscle

- branched in a continuous fabric

- Intercelated disks, gap junctions for electrical interconnections

Smooth Muscle

- Found in many internal organs

- Controlled by ANS

Nervous Tissue

- Glial cells + neurons

- conduct electrical signals

cell body, dendrites, axons

Supporting/Glial cells

provide physical and functional support for neurons•

5X more abundant than neurons

Cell body

Contains nucleus, is metabolic center

Dendrites

- highly branched extensions off cellbody

- Receive inputs from other neurons

Axon

- single, long extension off cell body

- Conducts nerve impulses to other cells

P feedback examples

blood clotting, shiver, sweating

Neg feedback examples

body temp, blood sugar/pressure

Connective tissue

- Has lots of extracellular material deposited inspace between its cells

- Connective tissue proper -collagen, tendons, ligaments, adipose

.-Cartilage

- Bone

- Blood

Epithelial Tissue

Lines/covers body surfaces

cells that form membranes and glands

Continously replaced

found in - skin, digestive/respiratory/respiratory tracts

True stem Cells

- zygotes are are totipotent

Their cells can become any cell.

Organism - organization

cell - tissue - organ - organ sysyem - organism

Organ Systems

DRCRUSMILEN, 11

Integumetary

Skin, hair, nails

protection and thermoregulation

Nervous

regulates other body systems

Brain, spinal cord, nerves

Endocrine

Hormone secreting glands (pituitary, thyroid, adrenal)

Secretion of hormones (regulatory molecules)

Skeletal

Bones, cartilage

Support and movement

Muscular

Skeletal muscles

movement of the skeleton

Circulatory

Heart, blood vessels, lymphatic vessels

moves the blood and lymph

Immune

bone marrow, WBCs

defends the body from invaders/pathogens

Respiratory

lungs, trachea, pharynx

Gas exchange

Urinary

Kidneys, ureters, bladder, urethra

Regulates blood volume/composition

Digestive

Pancreas, gallbladder, liver, intestines, stomach, mouth

Breaks down food molecules

Reproductive

gonads, genetalia,

Continuatiuon of species

Exocrine glands

- from epithelial cells, secrete onto epithelium

- secretion controlled by myoepithelial cells

- tubular, acinar, branched acinar

Endocrine glands

release hormones IN bloodstream

Intracellular compartment

the fluid part of the body contained within cells

separates w extracellular via PM

Extracellular compartment

Blood plasma + intersitial fluid

refers to the fluid outside the cell

Cell Organelles

centrosome, ribosomes, Rough ER, Smooth ER, Golgi apparatus, lysosomes, Peroxisomes, Mitochondira, nucleus,

Centrosome

- made of centrioles, which are made of microtubules

-

Rough Endoplasmic Reticulum (RER)

makes glycoproteins and phospholipids

Smooth Endoplastic Reticulum (SER)

makes fatty acids and steroids, has NO ribosomes)

Golgi apperatus

- sorts + packs proteins from ribosmes/rough ER

uses vesicles

Lysosomes

digestive enzyme- breaks down molecules

Mitochondria

Powerhouse, makes ATP

Nucleus

Nuclear envelope with pores for move in/out

- Nucleoli - makes ribosomes-

Chromosomes - contains genes and DNA

DNA

Building blocks = Nucleotides

Nucleotide structure =5 carbon sugar, nitrogen base and phosphate group

Nucleotide

5 carbon sugar, nitrogen base and phosphate group

Ribosomes

The central Dogma

DNA -> RNA -> Protein

Antagonistic effctors

help maintain homeostasis by moving opposite directions to keep balance

Dynamic constancy

maintaining conditions within a certain normal range

lymph

attack foreign invaders,

prokaryotic cell

cell lacking a nucleus and most other organelles

(bacteria)

Eukaryotic cell

cell that has a nucleus and other membrane-bound organelles

(animals/plants)

What makes something alive?

Cells, growth/develop, stimuli response, metabolism, reproduction, cell division