Anatomy & Physiology: Tissue Types, Histology, and Organ Systems

What are the 4 types of general tissues

1. Epithelial

2. Connective

3. Muscle

4. Nervous

Epithelial tissue function

Covers structures - forming layers over organs and lining cavities. Rests on basement membrane

simple v stratified

Simple: one layer of epithelial cells

- functions include diffusion/ osmosis, filtration, secretion/absorption

Stratified: more than one layer

- function is protection

Simple squamous

("one layer; flat")

Function: diffusion/osmosis/filtration

- the thin structure allows for movement of nutrients

Simple Cuboidal

("one layer; cube")

function: secretion and absorption of substances. Also contains ACTIVE transport (more controlled movement than simple squamous)

Lumen

inside space of a cellular structure

follicle

cluster of cells (epithelial in this case) that surrounds and protects something

Simple Columnar

("single layer; tall and skinny columns")

function: protection (layers are thicker because of cell height), they sometimes have microvilli on top to increase nutrient absorption and cilia for material movement

goblet cell

produces mucus. It appears as the white gaps between epithelial cells

- found in simple columnar and pseudostratified columnar

pseudostratified columnar

("false multilayered; column")

all cells connect to the basement membrane

ciliated to move materials

Transitional epithelium

Shape depends on state of tissue (appears simple squamous when full and stratified/cuboidally columnar when empty)

Function: Allows for stretch of organs

Stratified Squamous

("multilayered; flat")

Function: Provides PROTECTION - may lose top cells and the ones below are safe

Stratified cuboidal

("multi-layered; cube")

functions: protection; controlled secretion

Stratified columnar

("multi-layered; column")

function: protection against abrasion

location: sclera of the eye for protection against infection

sometimes has goblet cells

Connective Tissue

3 components: specialized cells, ground substance, protein fibers (collagen, reticular, elastic)

Fibroblasts

principal structural cells of CT

Specialized CT

bone, blood, cartilage

Loose CT

- allows for expansion of organs and forms protective coverings on muscles, vessels and nerves

- has open spaces

areolar

adipose

reticular

areolar loose CT

not known for strength. Cells are fibroblasts, macrophages and lymphocytes (last two are for immune) and these cells are found between the fibers (mostly collagen some elastin). Provides support and nourishment for the structures it is associated with.

Reticular loose CT

made of irregularly reticular fibers. Provides structure for the lymphatic and hemopoietic tissues.

Adipose loose CT

Fat cells that are full of lipids for storage. nucleus at the periphery.

It acts as a thermal insulator, energy storage and protects organs

Dense CT

no open spaces

regular vs irregular (fibers go same direction vs fibers dont go same direction)

dense regular can be collagenous or elastic

dense irregular: collagenous or elastic

Dense regular collagenous

tight arrangement of collagen fibers in same direction (same direction gives strength)

Locations: tendons (muscle to bone), ligaments (bone to bone)

VERY STRONG

Dense regular elastic

collagen and elastic fibers

- capable of stretch and recoil (elastin)

- strength with the fibers in same dir.

FLEXIBILITY

Dense irregular collagenous

has strength to be stretched, pulled, and bent is all different directions

composed of collagen fibers that run in all different directions

Dense irregular elastic

made of bundles of collagen and elastin fibers going in multiple directions

Capable of strength and stretch and recoil

matrix for bone and cartilage

the matrix is exactly what sits between the cells

Supportive connective tissue

Cartilage and bone --more specialized

Cartilage

Made of chondrocytes and surrounded by solid matrix (flexible) produced by the chondrocytes. chondrocytes are found in lacuna spaces. There are three types.

Hyaline Cartilage

Composed of collagen fibers. Covers the ends of bones. Becomes bone over time.

Elastic Cartilage

Has elastic fibers.

Allows for structures to stretch and return to normal position.

More open spaces than other types of cartilage.

Fibrocartilage

NO elastin - toughest kind of cartilage

HIGH pressure areas to support the skeleton

very dense with few open spaces

Bone

solid matrix

made up of osteocytes (bone cells) and others as well as collagen fibers

Also functions as a calcium storage for body

what are the two types of bone?

spongy (lattice structure, inner part of bones. holds red and yellow bone marrow)

compact (dense, hard and shiny)

epiphysical plate/line

plate: children and it is cartilage for lengthwise growth

line: adults and stops growing

Blood (fluid CT)

Made up of RBCs/WBCs/ platelets, plasma

It carries nutrients and oxygen throughout the body

removes waste and carbon dioxide

Aids in thermoregulation and electrlyte balance

Lymph (Fluid CT)

Flows through the bodies lymphatic system and brings to lymph nodes to be filtered.

Contains WBCs

Absorbs extracellular fluid and filters it

Muscle Tissue

Allows for movement by protein filaments (the lines/striations in the fibers) sliding across each other

Cells are called "fibers"

3 types: skeletal, cardiac, smooth

Properties of muscle

- excitable: stimulate to action

- extensible: able to stretch

- elasticity: able to recoil

- Contractibility: ability to become shorter to generate force

Skeletal

Voluntary control

multi-nucleated: No cytokinesis after mitosis. cells are the biggest out of all muscle cells and require more help. Peripheral nuclei.

striated: actin and myosin makes it look texturized

Cardiac Muscle

involuntary: self excite to cause contraction

single nucleus

striated

gap junctions for communication of contraction --- relates to the involuntary nature of contraction

Smooth Muscle

Found in GI tract

No striations

single nucleus

involuntary control

Nervous Tissue

Takes external cues and coordinates an internal response

Neurons and neuroglia

Neurons: generate and recieve electric impulses. Dendrites receive information, axons send it. Myelinated to increase speed of info.

Neuron function

receive input (afferent neurons - into CNS)

integrate information (CNS)

Motor output (efferent neurons - out of CNS)

Organ systems

organ: 2 or more tissues that carry out specific functions

Systems: organs working together to maintain homeostasis

Skeletal system

20% weight of body

support and protect organs

levers for movement

calcium storage

muscular system

excitable and contractible

allows for movement WHEN attached to bone

control circulation of blood and digestion

Integumentary

The Skin and assocaited structures.

This system acts as a protective barrier to the external environment. Contains sensory receptors (afferent pathways). Thermoregulation and produced vitamin D when in contact with sun.

Nervous system

quick communication system

responds to maintain homeostasis

PNS: nerves throughout body

CNS: brain and spinal cord

Digestive - GI tract and accessory organs (supportive but aren't actual part of the system)

This system breaks down and absorbs nutrients.

Path: mouth -->pharynx --> esophagus -->stomach -->small intestine --> large -->rectum -->anus.

Supportive: tongue, teeth, liver, gall bladder, pancreas, salivary glands

Urinary system

kidneys, bladder, ureters, urethra.

Rids the body of metabolic waste.

Related to thirst mechanism.

blood pressure - releases a hormone that increases RBC production

affects pH balance

Respiratory system

Lungs, mouth, nose, pharynx, larynx, trachea, bronchus, bronchioles

oxygen and carbon dioxide exchange through capillaries in alveoli of lungs

bronchus

pathway conducting air from airway to lungs

Cardiovascular system

heart, veins, arteries, blood

movement of oxygen and nutrients

hormone movement

immune cell movement

thermoregulation: vasoconstriction, vasodilation

Lymphatic system

tissues and organs that produce WBCs (lymphocytes) --spleen (hold WBCs), bone marrow (produce WBC) thymus (produce), lymph nodes (holds)

fluid is filtered before returned back into blood

defends against pathogens

It also absorbs fat and vitamins from GI tract

Immune system

includes Lymphatic system

skin also plays a critical role

Recognizes and destroys pathogens

Innate system: general defense (whatever is not human)

adaptive system: memory t certain pathogens for quicker and better defense

Endocrine system

glands throughout the body produce hormones that target areas of the body

regulate processes like growth, development, metabolism, water/ionic balance and reproductive function

Reproductive system

Ova or sperm produced in primary organs.

transport of gametes

Nurture of young

hormone production

ATP SYNTHESIS TOPIC 5

Glycolysis

IN CYTOPLASM

Energy consumption phase:

a glucose molecule uses an ATP to add phosphate. Then is adds another phosphate using ATP. Splits into two PGALs

Energy production phase:

Something in PGAL is oxidized and NAD+ is reduced to NADH. Energy is then produced by the removal of a phosphate - creating ATP. An additional phosphate removal to create pyruvate. This happens for BOTH PGALs.

Totals from glycolysis

2 ATP

2 NADH

2 pyruvate

THIS IS PER GLUCOSE

Pyruvate intermediate steps

Pyruvate is brought to the mitochondrial matrix and is broken down. Acetyl group attached to coenzyme A and waste products (additional NADH and CO2)

Kreb's cycle

Substrate: Acetyl CoA

Occurs in mitochondrial matrix

Oxidation and reduction of NAD+

- CO2 waste

Another Oxidation and reduction of NAD+

- CO2 waste

ATP produced!

oxidation FADH2 is reduced

oxidation and NADH is reduced

Totals for Kreb's cycle

1 ATP

2 CO2

3 NADH

1 FADH2

Electron transport chain

Electrons are transported down a series of protein sin the inner membrane of the mitochondria. USES ELECTRONS NOT ATP to provide energy in moving hydrogen. Hydrogen ions are pumped in the intermembrane space. The pumping of hydrogen ions to the intermembrane space sets up a high concentration and allows for faciliated diffusion of hydrogen ion through the ATP synthase, producing ATP.

Totals of ETC

30-34 ATP

Net yeild for entire process: 34-38 ATP

PER ONE GLUCOSE

Lipids for energy

GLUCOSE IS PREFERRED SOURCE OF ENERGY.

Beta bonds in lipids are oxidized and that energy is converted to ATP.

This process occurs in the mitochondria matrix and REQUIRES OXYGEN.

Steps:

1. CoA attaches to COOH of fatty acid

- requires 2 ATP for this attachment

2. beta bond cleaves and forms two Acetyl CoAs

3. Remember that we oxidized the beta bond?? --> NAD+ and FAD+ are reduced for the ETC

****the lipids ultimately get cut at the beta bonds and results in a 2 carbon Acetyl CoA and a 16 carbon Acyl CoA for example that will go back to the beginning to get cleaved again.

Totals for Lipids for energy:

1 NADH

1 FADH2

beta oxidation of a single 18C fatty acid results in 146 ATP

**PER BETA-OXIDATION

Proteins for energy

DO NOT WANT THIS

In this process, proteins are broken down into amino acids.

Intermediates that are formed from removal of amino group enter Kreb's cycle or Glycolysis

Methods of using proteins for Energy

Transamination: amino group is transferred to a keto acid. The amino acid that gave up its amino group becomes a keto acid and that is what goes to the kreb's cycle.

- These products can sometimes be made into glucose to go through glycolysis

Oxidative deamination: amino group is removed and forms NH3 (ammonia). This is toxic and is excreted through urine.

NUTRITION, ENERGY & HUMAN HEALTH TOPIC 5 PT 2

Energy and cells

All living cells need energy

For consumers (animals), this energy is in chemical bonds in food

1. carbs --- 4 kilocals/gram

2. lipids --- 9 kilocals/gram

3. proteins --- 4 kilocals/gram

Macronutrients -- Carbs

preferred source of ATP

stored in liver at glycogen (which can be broken down into glucose)

Muscle has its own store of glycogen

Macronutrients -- Lipids

Largest ATP production

Macronutrients -- proteins

last resort for ATP

Consume protein --> broken down into amino acids which are used for new proteins in our cells

Energy output -- 2 forms

internal work: All other forms not involved in mechanical work. (REQUIRED TO SURVIVE)

1. shivering, chewing, posture

- chewing is considered internal because it provides food required for life

2. energy to sustain life: breathing, cardiac function

external work: energy expended when skeletal muscles contract (exercise)

Energy transfer

Energy cannot be created or destroyed, it is transformed.

- energy taken in that is not used is stored in adipocytes (fat cells)

1/3 of energy in food is used for work and by the body and the other 2/3 is released as heat.

Metabolism

It is ALL chemical reactions in the body

Metabolic rate: the rate at which energy is spent in the body over a period of time

- thyroid hormone can affect metabolic rate

Basal Metabolic rate

metabolic activity that is needed to maintain basic bodily functions under resting conditions

How is BMR measured

indirectly by oxygen uptake

Direct calorimetry measures heat produced by body

Conditions for BMR

- good room temp, no exercise, mentally calm, no food

Body weight

Energy input must equal energy output

negative: take in less than output

positive: take in more than output

Excess caloric consumption must be stored in adipocytes (fat storage cells)

- Energy in food consumed= external work + internal work + stored energy + heat

Metabolic resistance

With very large drops in caloric intake, your body try to match the calories are giving it by slowing down your metabolism and being able to run on that low level of calories. So, returning back to normal after your diet will potentially increase your body weight significantly.

Body Mass Index

flawed metric (muscle is denser than fat)

It is based on height, weight and sex

Underweight BMI

less than 18.5 BMI

Risks of underweight BMI

malnutrition, vitamin deficiency, decreased immune function, fertility issues, fatigue, anemia, fragile bones, developmental issues

Causes of underweight BMI

genetics, physical activity, mental illness, high metabolism

overweight BMI

BMI of 25-29

Pears vs apples (visceral fat is more dangerous - makes estrogen leading to fertility problems and fertility features in men)

Obesity

BMI of greater than 30

Hazard ratio = lower means lower health risk

What controls obesity?

Stress hormones

Insulin resistance (Type 2 diabetes)

Mutation of leptin receptor in brain

Increase in production of Neuropeptide Y

Hypothalamus role

controls food uptake, appetite, endocrine function, satisfaction (homeostasis)

neuropeptide Y

Hormone released by the hypothalamus that releases an "appetite signal"

Melanocortins

Hormone released by the hypothalamus that releases a "satiety" signal

Leptin

It acts to decrease food intake and increase metabolic rate

It is produced and released from adipocytes in the presence of INSULIN

- Leptin then decreases production of Neuropeptide Y (increases melanocortin)

Insulin

Pancreas releases insulin when glucose levels are too high

signals the adipocytes to release leptin.

Desensitization of insulin

Type 2 diabetes ---> decrease in receptor on cell for insulin which means more glucose in blood stream

Ghrelin

ONLY hormone to increase NPY (hunger)

It is released by stomach when empty

PYY

produced by large and small intestine

it is a satiety signal

Cholecystokin

released by small intestine

satiety signal

Factors affecting intake of food

stress, depression, socializing, taste and smell, culture, conditioning (free food)