A&P Lecture exam 1

What are the influencers of homeostatic balance

Nutrients

Oxygen (needed for chemical reactions)

Body temp (regulates chemical reactions)

Water (Blood pressure)

How is homeostasis maintained

Organ systems working together

1. Changes in environment or body (STIMULUS) recognized by RECEPTOR

2. CONTROL CENTER determines response

3. EFFECTOR preforms response to stimuli

Describe negative feedback loop

Response counters stimuli

1. Towards homeostasis

Describe positive feedback loop

Response intensifies stimuli

1. Away from homeostasis

*Most of the time positive feedback loop means something is going wrong (ice melting example)

Define tissues

Groups of cells similar in structure and preform common function

What does the epithelium tissue do?

Protection

Absorption

Filtration

Excretion

Sensory reception

What is thick epithelial tissue (covering and lining) good for and bad for

Good for protection

Bad for excretion and secretion

What is thin epithilal tissue (covering and lining) good for

Good for excretion, secretion, and absorption

What is cilia on apical surfaces good for

Help with movement (respitory track)

What is microvilli on apical surfaces good for

Increases surface area

Good at absorption and secretion

Ex: In gut to have as much surface area to come in contact with food and absorb nutrients

What is secretion

Something produced by cells and released

What is excretion

removal of waste from the body

What is a gland

One or more cells that make or secrete a product called a secretion

What are endocrine glands

Secretion enters the blood though the basel surface

What are exocrine glands

Secretion exits the apical surface

Describe exocrine glands

Apical release

Local effect

Short lived

Describe endocrine glands

Basel release

Always into blood

Always a hormone

Global effect that is typically last long

Name exocrine gland types

Unicellular

Multicellular (Merocrine, Holocrine)

Describe unicellular exocrine

Uses exocytosis to release secretion (fuses with cell for release)

Describe merocrine exocrine

Cells live

Uses exocytosis

Ex: sweat glands

Lots of cells excreting together

Describe Holocrine exocrine

Cells die

Store product until they swell and burst

Ex: Sebaceous oil glands of the skin

What glands have a Duct (tunnel to surface)

Multicellular exocrine glands

What gland has a Secretory unit (cells that make and release product)

Multicellular exocrine glands

What do hormones regulate

Reproduction

Growth/development

Electrolyte/nutrient balance

Cellular metabolism/energy usage

Immune response

Name each type of hormone

Amino acid based

Steroidal

Describe Amino Acid based hormones

Cannot enter cells because very weak soluble

Describe Steroidal hormones

Made from cholesterol (cholesterol is fatty)

Can cross cell membrane

What do hormones require to influence

Receptors

No receptor? No Influence (lock and Key)

Ex: Hormone=testosterone

1. Only influences cells that have receptors for testosterone

Where are hormone receptor locations

On plasma membrane (outside the cell)

1. Amino Acid based- Cannot enter cell

Inside the cell

1. Steroidal- Can enter cell

What happens when hormones bind (5)

Change membrane permeability (make membrane leaky)

Synthesis of enzymes (proteins)

Activate or deactivate enzymes

Increase rate of gland release elsewhere

Induce mitosis (cell division to growth)

*Need receptor to do these*

What regulates hormone release

Changes in chemical levels

Nervous system

A hormone from another gland

What is Humoral regulation

Regulation of hormones in response to chemical changes

What is Neural regulation

Regulation of hormones from the nervous system

What is Hormonal regulation

Hormonal regulation in response to another hormone

What is the growth hormone made by

Pituitary glands

What is the pituitary gland controlled by

By the hypothalamus

What does the hypothalamus make

Growth hormone releasing hormone (GHRH)

Growth Hormone Inhibiting hormone (GHIH)

What regulates blood sugar levels

The endocrine system

1. The Pancreas

What does the pancreas contain to regulate blood sugar

Endocrine and exocrine glands

How does endocrine glands regulate blood sugar levels

They contain pancreatic islet cells

1. Alpha cells- secrete Glucagon (hormone)

2. Beta cells- Secrete insulin (hormone)

What does Glucagon do

Binds to receptors on fat cells

Increases blood sugar

(Alpha Cells)

What does Insulin do

Binds to receptors on fat cells

Decreases blood sugar

(Beta cells)

What is Diabetes Mellitus

Insulin not made by Beta cells (Type 1)

Insulin present but not effective because of receptors (Type 2)

What does high blood sugar cause

Polyuria

Polydipsia

Polyphagia

What is Polyuria

Excess urine production —> dehydration

What is Polydipsia

Excessive thirst

What is Polyphagia

Excessive hinger/weight gain

*Leads to more sugar in the blood*

What is the integument composed of

Connective tissue

Epithelium

What are the tissues of the human body

Connective

Epithelial

Muscle

Nervous

What are connective tissue components

Ground substance

1. Fluid with dissolved molecules

Protein Fibers

Cells (Formed elements) <50% material

What are the 5 major functions of connective tissue

Binding and supporting other tissues

Transporting nutrients (blood)

Physical protection (compact bone)

Insulation (Adipose)

Fuel storage (adipose)

What are connective tissue types

Connective tissue proper

Cartilage

Bone

Blood

*CT is the only tissue that is not mostly cellular*

What are the types of CT proper

Areolar

Adipose

Reticular

Dense Irregular

Dense Regular

Sense Elastic

What are the layers of the skin

Epidermis

Dermis

*Hypodermis is not apart of the skin it anchors the skin to things bellow*

Describe the hypodermis

Adipose tissue

Cushions, insulates, and anchors dermis to muscle beneath

Highly vascular (blood vesscles go through dermis)

Describe the Epidermis

Visible skin

Stratified squamous epithelium

Dry, tough

Avascular (no blood flow to epidermis)

Describe the Dermis (Reticular layer)

Lower 80%

Composed of dense Reticular CT

Vascular!!

Pacinian Corpuscles

Deep Pressure sensors

Describe the Dermis (Papillary layer)

Top 20%

Composed of Areolar CT

Dermal papillae contain

1. Capillary loops

2. Free nerve endings

3. Meissner’s Corpuscles- Light touch

What do Papilla create

More surface area (more nutrients)

More stability

What are the 4 primary cell types in epidermis

Dendritic cells

Tactile (Merkel cells)

Keratinocytes

Melanocytes

What are dendritic cells

Scavengers

Part of the immune system

What are tactile cells (Merkal cells)

Cover neuron “endings” = light touch sensation

what are keratinocytes

Epithelial cells that produce keratin- part of the protective scaffolding

What are melanocytes

Make a pigment- Melanin

What are the Keratinocyte layers

Statum basale

Statum Spinosum

Stratum Granulosum

Stratum Lucidum

Stratum Corneum

Describe the Stratum basale layer

Stem cell layer

Melanocytes

Describe the stratum spinosum layer

Lots of desmosomes

Dendritic cells (immune cells)

Describe the stratum granulosum layer

Lots of granules to store glycolipids (glue)

Cells are dying

Describe the Stratum Lucidum layer

Only visible in thick skin

Cells dead but held together by “glue”

Describe the Stratum Corneum layer

Very thick

All dead

What do desmosomes do

Hold cells together by “linking them together”

How do melanocytes work

UV activates Keratinocytes

Keratinocytes activate melanocytes

Melanocytes make melanin

Melanin released

Melanin taken up by Keratinocytes

Binds to the “sunny” side of the keratinocyte nucleus

Blocks UV light from hitting DNA

What does each skin color produce

Brown

1. Melanin

Orange

1. Accumulates in fats and oils

Pink

1. Hemoglobin

2. RBC’s binds O2 (why blood is red)

What does hair do for the body

Sensation

Warmth

Protection

Filteration

What are the hair color pigments

Melanin

1. Yellow to black

Pheomelanin

1. Red

2. Type of melanin

Air bubbles

1. Grey

Describe the stages of hair development

Vellus hair

1. Peach fuzz

Terminal hair

What hormone controls hair development

Androgens

What are factors that influence hair growth

Nutrition

Blood flow

Irritation/Inflammation

What factors that influence hair loss

Follicles don’t regenerate forever

Replacement slower than “shedding”

Describe male pattern baldness

Genetic

Shorter growth cycle

Sheds before it reaches skin

What is Alopecia

Autoimmune- Attacks follicle

Describe the development of skin cancer

UV causes mutations = dimmers

C-C = cysteine dimmer

T-T = Thymine dimmer

50-100 occur ever second in every keratinocyte

*Only One mutation can cause cancer*

What are a cells defense mechanism for skin cancer

Repair enzymes- fix mismatches

Pro-apoptosis

1. Cell told to commit suicide (apoptosis) when overwhelmed trying to fix mismatches

What are the types of skin cancer

Benign tumor

1. Cells are not cancerous and won’t spread

Malignant tumor

1. Cells are cancerous and can spread to other tissues and organs

How does cancer spread

Cells escape their tumor mass into the blood vessel and create their own other mass

What is Basal cell carcinoma

Most Common form 8/10

Least malignant

Excision cures 99%

What is Squamous cell Carcinoma

Often malignment

Grows and metastasizes

Excision and radiation

What is melanoma

Cancer of melanocytes

Grows and metastasizes very quickly

Diagnose

1. Asymmetry

2. Bonder irregularity

3. Color

4. Diameter

5. Evolving

How does scaring work

Just epidermis- scar free

Epidermis- scar

Name and describe the 3 kinds of burns

1st- damage only to epidermis (sunburn)

2nd- Damage to epidermis and upper dermis (blisters)

3rd- Damages through dermis

1. - No initial skin swelling or pain because nerves are burned

2. - Biggest threat is fluid loss

Name and describe Burn outcomes

1st- Reddening

1. - Heal

2. 
   

2nd- Pain + swelling, and blistering

1. - Pigmentation changes

3rd- infection

1. - loss of accessory structures (hair follicles)

2. - pain

3. - swelling later

2. - Scar formation/ loss of function