Respiratory and Urinary review notes

Billy Staggs Cahill

Nursing Student

Onondaga Community College


Notes by: Billy Staggs Cahill


Respiratory and Urinary (Renal) Systems

Abstract notes 

    When we think of the respiratory and urinary systems, we think of only breathing and urination. However, these systems are not so simplistic! There’s many cycles and functions, that are vital for human life. 

Let us take a deeper look beginning with the respiratory system:

The conducting portion of the respiratory system carries air to the lungs.

Gas exchange occurs in the alveoli.

O2 and CO2 are transported using different mechanisms. 

Air is inhaled actively and exhaled passively.

Breathing rate is controlled by the RESPIRATORY CENTER of the brain.


Assuming that you already know most of the basics of the respiratory system, let us take an extensive look into gas exchange:




The alveoli of the respiratory zone, is the site where gas exchange occurs.

External Respiration:

Note: The PCO2 is noted here, because the process is cyclic, as we know.

Diffusion of O2 occurs at a PO2 104 (give or take) → PO2 100, and PCO2 46 → PCO2 40. The O2 will then travel in the bloodstream via Hb (hemoglobin) / pulmonary circuit. 

Internal Respiration:

The RBC will reach the tissues, and the PO2 has equilibrated to PO2 104 and will diffuse into the tissues: PO2 104 → (PO2 40, inside tissue). Coming from cellular respiration, is the CO2, which is waste. It will have a PCO2 46 → (PCO2 40, inside RBC). 

As we know, there’s three ways CO2 is transported to the lungs / alveoli:

  1. 70% is transported buffered with water as carbonic acid.
  2. 20% CO2 bound to proteins, particularly Hb.
  3. 10% via plasma.


70% :

Pick up  CO2 → CO2 + H2O (H2O from RBC)  → H2CO3 (carbonic acid) → HCO3 and H+Hb (Hb in RBC)

Note: HCO3 diffuses into plasma

20% :

CO2 → CO2 + Hb (Hb in RBC) 


10% :

CO2 → CO2 in plasma

Arrival at alveoli  

HCO3 diffuses back into RBC

H+Hb → H → Hb 

H → HCO3 → H2CO3 → CO2 and H2O 


All CO2 diffuses into alveoli at a PCO2 46 → PCO2 40

All via systemic circuit / deoxygenated blood.

Our gas exchange is complete. The cycle will continue repetitively!


The next concept is the pleural cavity.

Note: These notes are abstract and review, and not in particular order.


Pleura is a serous membrane, that surrounds the lung, doubled layered:

parietal and visceral

parietal pleura is attached to the chest wall, and the visceral pleura covers the surface of the lungs.

Between these layers of pleura is a potential space; a space that doesn’t exist but it could exist, if something goes wrong.

There’s a small amount of fluid in this potential space, this serous fluid acts like a lubricant.

The purpose for the pleura is to move inside the body cavity without friction, as friction would cause damage to the lungs. The pressure inside the pleura membrane is – 4 mmHg, intrapleural pressure is 756 mmHg, as we know atmospheric pressure is 760 mmHg. The pressure keeps the lungs ‘stuck’ to the chest wall so they don’t collapse. 


Lung Compliance:

Ease at which lungs can be stretched . . . elasticity.

More ELASTIC → greater the compliance

surface tension of lungs

Greater tension → less compliant

distensibility  of thoracic cavity: deformities of thorax, ossification of costal cartilages, paralysis of intercostal muscle – hinder thoracic expansion

Airway resistance: 

  1. chronic inflammation, infections – scar tissue – fibrosis.
  2. decrease of surfactant.


lung compliance


Spirometry Measurements :




Vt  – tidal volume – normal respiratory cycle

IRV – inspiratory reserve volume – after a normal inspiration

ERV – expiratory reserve volume – after a normal expiration

RV – risidual volume – after maximal exhalation 

Why is a PFT given?

To test your lung function before surgery. To help diagnose lung conditions or diseases such as asthma, emphysema, chronic bronchitis, or pulmonary fibrosis. To check the extent of lung disease or to help explain new breathing symptoms. To find out if your breathing medicine is working.



Diffusion capacity/DLCO tests

This test determines how well the oxygen in your lungs is able to move to the bloodstream.  You will be asked to keep a tight seal on a mouthpiece with a clip on your nose and breathe normally.  After several breaths, you will take in as deep a breath as possible and blow it out slowly.  You will keep blowing out until you are told to take a deep breath in and hold it for 10 to 15 seconds.  Then, you will blow out again through the mouthpiece.

Taken from UPMC, life changing medicine. 

Lung Capacities: 

4200 female capacity

6000 male capacity

Acidosis and Alkalosis

Acidosis – abnormal physiological state characterized by a plasma PH below 7.35.

Alkalosis – A condition of a plasma PH above 7.45; deficiency oh hydrogen ions or an excess of bicarbonate ions.

Respiratory response to acidosis –

Increased respiratory rate lowers PCO2 effectively converting carbonic acid molecules to water.

H2CO3 → H2O

Respiratory response to alkalosis –

Decreased respiratory rate elevates PCO2 effectively converting CO2 molecules to carbonic acid.

CO2 → H2CO3


Renal response to acidosis –

Kidney tubules respond by secreting H ions, removing CO2, Reabsorbing HCO3 to help replenish bicarbonate reserves.

Renal response to alkalosis –

Kidney tubules respond by conserving H ions and secreting HCO3.


Capsule cells:


Factors Controlling Glomerular Filtration:


55 mm Hg  –  (30+15)

55 mm Hg – 45 mm Hg

= 10 mm Hg

If at ZERO = No Filtration









Respiratory System Notes / exam prep


Notes By Billy Staggs Cahill

Fall / 2017

Onondaga Community College

Anatomy & Physiology / Nursing





















  • forceful  exhalation:  active  process
  • muscles  of  exhalation  contract

+  rectus  abdominis

+  internal  intercostals

Factors  influencing  pulmonary  ventilation

  • factors  effecting  rate  of  airflow  and  ease  of  pulmonary  ventilation:
  1. surface   tension
  2.  compliance  of  lungs
  3.  airway  resistance

+  surface  tension

  • must  be  overcome  for  inhalation
  • SURFACTANT :  mix  of  phospholipids  and  lipoproteins  prevents  total  alveolar  deflation  during  exhalation
  • respiratory  distress  syndrome

Factors  influencing  pulmonary  ventilation

+  compliance

  • how  much  effort  needed  to  stretch  lungs  and  chest  wall
  • high  compliance:  chest  wall  expands  easily


  • surface  tension:  surfactant  increase  compliance
  • elasticity:  increase  compliance
  • pulmonary  fibrosis,  scoliosis,  emphysema  

+ airway  resistance  

  • some  resistance  normal
  • narrowing  of  airway  or  obstruction  ↑  resistance  and  more  pressure  needed  for  airflow:  asthma 



lung v1


lung v2

lung v3

lung v4

  • At  rest

+  average  respiratory  rate:  12  breaths  /  minute

+ adapts  to  O2  needs

+  adults  (rest):  12  –  18  br  /  min

(exercise):  40

+  child  (rest):  18  –  20  br  /  min

(exercise):  60

Tidal  volume  (Vt):  volume  of  one  breath:  500  ml  /  breath

Respiratory  minute  volume:  total  volume  of  air  moved  in  /  out  each  minute

(resp  rate  (BPM))  x  (Vt)

=  600  ml  /  min  or  6  L  / min





alve lec

Visual Notes:







Neuromuscular Junction (NMJ)

Notes by: Billy Staggs Cahill

Nursing Student RN / Fall Semester  / A&P


Control  of  skeletal  muscle  activity in summary:

  1.  Controlled  by  the  nervous  system
  2. Communication  between  the  nervous  &  muscular  systems  via  neurotransmitters
  3. Communication  between  nervous  system  and  muscle  occurs  @  NMJ  (Neuromuscular  Junction)
  4. Excitation  —  contraction  coupling  –  link  between  action  potential  and  start  of  muscle  contraction
  5. The  key  to  the  action  potential  is  the  links  between  the  nervous  and  muscular  systems




Exam 3 Prep and Notes / Anatomy & Physiology Nursing Notes / Quick Summary / EKG Intro

Billy Staggs

Fall Semester / 2017

Nursing Student – RN

Instructor: Dr. Vera Mcilvain

Anatomy and Physiology

Notes by: Billy Staggs


 Three types of muscle tissue:

  • skeletal muscle
  • smooth muscle
  • cardiac muscle

muscle tissue 1


  1. Body movement / integration of muscles, bones and joints / work together 
  2. Stabilize body position / continual contraction
  3. Organ volume regulation.
  4. Moving substances within body.
  5. Heat production


Study notes:tissues1








RECAP summary again w/ more detail:

  1. CONTRACTION CYCLE BEGINS: the  contraction  cycle  which  involves  a  series  of  interrelated  steps,  begins  with  the  arrival  of  calcium  ions  within  the  zone  of  overlap.
  2.  ACTIVE  –  SITE EXPOSURE: calcium  ions  bind  to  troponin,  weakening  the  bond  between  actin  and  the  troponin  –  tropomyosin  complex.  The  troponin  molecule  then  changes  position,  rolling  the  tropomyosin  molecule  away  from  the  active  sites  on  actin  and  allowing  interaction  with  the  energized  myosin  heads.
  3.  CROSS  –  BRIDGE FORMATION: once  the  active  sites  are  exposed,  the  energized  myosin  heads  bind  to  them,  forming  cross  –  bridges. 
  4. MYOSIN HEAD PIVOTING: after  cross  –  bridge  formation,  the  energy  that  was  stored  in  the  resting  state  is  released  as  the  myosin  head  pivots  toward  the  M  –  line.  This  action  is  called  the  power  stroke;  when  it  occurs,  the  bound  ADP  and  phosphate  group  are  released.
  5.  CROSS  –  BRIDGE DETACHMENT: when  another  ATP  binds  to  the  myosin  head,  the  link  between  the  myosin  head  and  the  active  site  on  the  actin  molecule  is  broken.  The  active  site  is  now  exposed  and  able  to  form  another  cross  –  bridge.
  6.  MYOSIN REACTIVATION: myosin  reactivation  occurs  when  the  free  myosin  head  splits  ATP  into  ADP  +  P.  The  energy  released  is  used  to  recock  the  myosin  head. 


Taken from Martini A&P text






EKG Intro:





Lab Practical Prep / Lab # 2

Billy Staggs Cahill

Nursing Student – RN

Fall 2017

Instructor: Dr. Vera Mcilvain PhD 

Anatomy & Physiology


Nurses notes / fractures and dressings: 




This patient’s open fracture has been stabilized c external fixation and the wound has been partially closed c antibiotic beads. . . 
Antibiotic Beads:



The skeletal system includes:

Bone (hardest connective tissue) 

  • cells, collagen fibers, dense mineralized ground substance 



Ligaments connect bone – to – bone

Tendons connect skeleton muscle to bone

Other connective tissues

Blood supply and nerves run through the bone




structural support – site for attachment of tissues and organs

storage of minerals and lipids – calcium salts, yellow bone marrow 

blood cell production – red, white platelets produced in red bone marrow

protection – heart, lungs, brain, spinal cord, reproductive organs 

leverage / movement (together w / skeletal muscle)

bone marrow

Notes and study guide 


tib fib 3

Intercondylar eminence, Lateral condyle, Medial malleolus of tibia, Anterior border, Tibial tuberosity, Lateral malleolus, Head of fibula

  • Do not get tuberosity and tubercle confused! Tubercle is the ribs NOT THE FIB – TIB!
  • A and P view — head of fibula same name / fibula head is head of fibula posterior / anterior — SAME!
  • fibula is the smaller bone, TIBIA IS THE LARGER BONE


tib fib4

tib fib5


Recall: Sisters — TIB – FIB. “Mrs. Tib and Miss Fib

foot 1

D ⇒ M ⇒ P

  • Distal / Middle / Proximal

    Phalanges – x – X – x

    foot 2

  • I, II, III, IV, V — x – x – x – x – x
  • Toe is I

3 circ


Cuneiform — cUnee – form

  1. Medial cuneiform
  2. Intermediate cuneiform
  3. Lateral cuneiform

THEY ARE SIDE – SIDE – SIDE @ top foot, starting below toe. 


M I L 

medial — INTERMEDIATE — lateral 

In feet — Metatarsal, in hand / fingers — Metacarpal 



L and R scapula / both birds peaking out (A, B , F, G) and lower curves inward (D)  > < 













a to b


Repetitive patterns, mapping, points and memorization OF the skeletal system


Recall notes:

Femur – upper leg next to gluteal, below gluteal, has sockets, longish neck and ONE bone. 

Greater and lesser trochanter / curvature / angular neck / 

  • fovea capitis above head / head / neck / 

  • @ bottom → ” the condyles” – lateral/ medial

  • → epicondyle and condyle

  • EPI →  UPPER, condyle is just condyle below epicondyle

  • “wrap” →  patellar surface Anterior / Posterior→  intercondyler fossa, which is where a socket / “dip” is.

  •  A → patellar surface / P → “socket in back” → intercondylar fossa. INTER → “enter bone” place for bone to join.

  • Intercondylar Fossa!

  • medial → “middle” Lateral /   \ Lateral condyle, epicondyle

  • ———— ↑ (line above) intercondylar fossa is LINEA ASPERA, ASPERA! LINEA ASPERA! LINEA ASPERA! 

  • gluteal tuberosity ↑ linea aspera

  • GREATER and lesser trochanter! G and L TROCHANTER



Tibia and Fibula – bottom leg before feet / malleolus! NOT condyle! MALLEOLUS! Lateral & Medial

  • head of fibula bot A and S / tibial tuberosity is ANTERIOR always front q x no matter what! TIBIAL TUBEROSITY!

  • ^^ ← Intercondylar eminence / two @ top →→ Intercondylar eminence /

  • lateral malleolus is the bottom of fibula / point outwardly / medial malleolus is middle and bottom tibia! Medial MALLEOLUS is the tibia and Lateral MALLEOLUS is the fibula 

  • ANTERIOR BORDER is the tibia ↑ medial malleolus


tib and fib 1

tib and fib 2



Sacrum → APEX – top of coccyx

Body @ top / posterior — sacral promontory @ top / anterior

MEDIAN SACRAL CREST / NOT medial, but median!

Radius and Ulna








E  head of radius  D → neck of radius C → radial tuberosity  F → olecronon G → trochlear notch H → coronoid process I → proximal radioulnar joint K → interosseous membrane B → radius J → ulna A → radial styloid process N → distal radioulnar JOINT! (DO NOT THINK NOTCH! IT IS A JOINT) M → ulnar styloid process L → head of ulna

radius and ulna

  • 1 → distal radioulnar joint

  • 2  → ulnar styloid process

  • 3 → olecronon

  • 4 → trochlear notch

  • 5 → coronoid process (notice the triangular top)

  • 6 → radial styloid process

  • 7 → radial tuberosity

  • 8 → head of radius (think of nail head for identification in lab)

  • 9 → radial notch of the ulna / proximal radioulnar JOINT

  • 10 → lateral epicondyle

  • 11 → olecronon fossa

  • 12 → coronoid fossa 


Radius: Thumb Side, Ulna: Little Finger Side.

radius frac

FEMUR (the condyle and trochanter bone)


1 → head of femur

2 → lesser trochanter

3 → medial epicondyle

4 → linea aspera

5  →  lateral epicondyle

6 → greater trochanter

7 → lateral condyle

8  → medial condyle

9 → patellar surface

10  → neck of femur 




  1. Recall:
  2. FEMUR — condyle and epicondyle , lateral & medial
  3. TIBIA AND FIBIA — malleolus, medial and lateral
  4. FEMUR — lesser and greater trochanter
  5. RADIUS AND ULNA — styloid process, radial and ulnar, also distal and proximal radioulnar joints
  6. FEET — cuneiforms, medial, intermediate and lateral + calcaneus, cuboid, talus, navicular
  7. HAND — “ates”, hamate, lunate, capitate + triquetrum, pisiform, trapezium, trapezoid, scaphoid

FEET — tarsals

HANDS — carpals 

w / feet — recall cuboid:


  • the sides and top, etc look like a cuboid, not exact, but close

cuboid 2

CUBOID is aligned w/ the cuneiforms (medial —  intermediate — lateral) → CUBOID

navicular and calcaneus are below and appear bigger / longer (to me anyway)



R and L hints:

  1. Humerus – hold the bone so that the capitulum and trochlea face YOU (anterior)

-if the head faces left – it is a left humerus

  1. Ulna – face the trochlear notch away from you (U-shaped process) and look at the olecranon

-ask yourself – on what side is the radial notch?
-if it is on the right – it is a right ulna

3. Radius – orient the bone with the round head UP and the distal end DOWN
-look at “bumps” at the distal end
-look for the styloid process at the distal end
-if it is on the right side – it is a right radius

4. Scapula – hold the bone with the spine facing YOU and the apex facing DOWN
-if the acromion faces left – it is a left scapula
-NOTE: the corocoid process is spelled with a “c” and so is “scapula”

5. Femur – the head must face IN and the lesser trochanter must be on the BACK side of the bone
-so hold the bone so that the head is on top and the trochanters are on the BACK surface of the bone
-if the head faces left – it is a left femur

6. Tibia – hold the bone so that the intercondylar eminence is towards the top and you are looking at the tibial tuberosity
-if the medial malleolus on the distal end is on the left side – it is a left tibia

7. Clavicle – a. point the flat sternal end toward the midline
b. the clavicle bulges OUT then IN
c. the conoid tubercle must point DOWN


  1. Cervical – three holes, forked spinous process
  2. Thoracic – one hole, long, thin spinous process
  3. Lumbar – one hole, processes are thick and large
  4. Atlas – looks very different, almost like a circle
  5. Axis – look for the “dens” near the body

Corocoid – “c” in scapula
Coronoid – “n” in ulna (or mandible)
Conoid – is the clavicle



Microsoft Word - Frontiers Manuscript 061513 Revised Manuscript

Ossification — Bone formation 





It’s all transitory


Origin of bone cells


osteogenic cell develops into an osteoblast:

osteogenic cell →→ osteoblast →→ osteocte

bone cell


OSTEOCLAST is from white blood cell lineage



  • most numerous
  • mature bone cells / non – dividing
  • develop from osteoblasts
  • one osteocyte / lacuna (space)
  • connected by canaliculi 


canaliculi — small canal or tubular passage

can –  a – lick – u lie



x – bone maintenance nutrients / waste exchange

x – turnover of matrix components

x – repair damage

x – “strain sensors”

x – can convert back to osteoblasts or osteoprogentetor if needed





Metabolism / Triglycerides

Notes by: Billy Staggs Cahill

Nursing Student – RN

A&P Instructor: Dr. Vera Mcilvain PhD / Adjunct Professor 

Fall 2017

Onondaga Community College 

tri info




  • Are lipoproteins
  • they consist of 95% triglycerides (core, inside)
  • They transport dietary lipids from the intestines to other parts of the body


Adipose Tissue





Lipid Panel

Checks for different types of cholesterol. There are good and bad kinds of fats.

It is recommended by the American Heart Association, anyone 21 and older get checked frequently / have a lipid panel done every 5 years.

There should be an overnight fast before the lipid panel is given. 

There are hardly any symptoms when triglycerides are high.  “silent but can be deadly” 

lipid panel

Dieting for triglycerides:

  • Target: To decrease triglyceride levels
  • Remember: Eating before a lipid panel is given can influence the results

The patient must be informed of a good diet to help lower triglyceride levels / cholesterol.

There are many different diets, ways, routes to target levels.

Quick Notes:

A good breakfast with milk, fruit and wheat toast is a start, eat a light weight meal q 2 – 4 hrs.

Cut sugars — replace c fruit, this can eliminate the craving for sugars / carbs

Eat fiber

Limit fructose

moderately low – fat diet

omega -3 fatty acids

Exercise regularly


Replace x sugar craving c fruit: if a desire for a piece of cake / replace c  apple or orange (any fruit desired).

x – breakfast → fruit, wheat toast, no more than 1 egg

x lunch →  fruit or vegetable c tuna, wheat bread, chicken or anything healthy that cuts fat. Take vitamin in between meals.

x dinner →  vegetable, replace starch, flour c sweet potatoes, green beans, &c. fish, chicken, wheats, fruit snacks, peanut butter, &c. All good / limit serving / maintain good eating habits c nutrition.

q d / take vit / omega / exercise / eat healthy / watch carb intake along c sugars / glucose &c.

  • Sensible decisions to maintain good triglycerides.
  • Once back to normal, keep practicing good health

tri food




Integument II / nurse notes

Notes and writing by Billy Staggs Cahill 

Nursing – RN 

Fall 2017

Anatomy and Physiology

Instructor: Dr. Vera Mcilvain


Why it’s important for a nurse to know the Integumentary System.

By: Billy Staggs Cahill (Nursing Student)

     Like most anatomy, the epidermis and dermis is very complex and has physiological cycle to it. It’s important for a nurse to know about about skincare, vitamins, nutrients, and learning about the subcutaneous layer — the hypodermis is important, since hypodermic syringes are part of nursing. It’s all relative and accumulative knowledge; the more a nurse knows, the better she / he is on the career front.

     There are many nursing and pre – nursing students who look at anatomy and physiology as a mountain to climb on their way to success. In all that is sacred of science and useful in the medical field — anatomy and physiology should be a main focus at the time it’s studied by the student. It’s very important for a good nurse to know and study anatomy and physiology thoroughly. 

“A fine perceptive of the human anatomy is clinically significant to members of the health care team, including nurses. It is important to know the human body and how it functions in its healthy state. By knowing such, it will be easier to learn about pathophysiology, clinical assessment and many other nursing procedures. Those are exact reasons why we, nurses, have this subject as a prerequisite for other nursing subjects.” Nursing Crib — Why You Should Know Your Anatomy is a good online article and source that sums up why it’s important for all the health team should know anatomy, including nurses! Of course — this is relating to your own medical knowledge.

In what ways is it good for a nurse to know about the Integumentary System?

Why should we know about the skin? 


Vitamins and oils?

How about nutrition, and what our skin needs?

 It’s good for nurses to take care of themselves, maintaining a healthy lifestyle and diet. Let’s get one thing straight! There’s no such thing as perfect! However, there is theory and practice. What works best for each individual’s skin may not be for everyone. This doesn’t mean go out and spend all your money on some secret anti – aging cream or drops. It simply means to know the Integumentary System is to know how our skin works — what’s best for our skin and good hygiene. 

Let’s focus on skincare:

skin care1

 People are always looking at ways to help their skin, and sometimes they may ask a nurse. Most likely not, but as nurses ( female or male), we should focus on ways helping ourselves and maintaining a good example of health. It doesn’t take a “skin genius” Dermatologist to maintain good skin. 

According to WebMD, the following are the vitamins and antioxidants to maintain skin health:

  • Vitamin A, also known as retinol, is important for helping to keep skin healthy
  • Vitamin C, also known as ascorbic acid, helps protect cells and tissue and aids wound healing.
  • Vitamin E helps to maintain cell structures and protect cell membranes.
  • Selenium is a mineral that helps prevent damage to cells and tissues.
  • Vitamins C and E, and selenium are antioxidants that may help protect skin from sun damage.

There are numerous products that can be used for different types of skin. Everyone varies when it comes to using skin products. We may use a new lotion or soap that has hit the market, while our mothers’ use Oil of Olay. Some people invent their own skin products by fruits, herbs, lotions and all kinds of x, y, z potions. Whatever you find works best for your integument is what’s best for you — it’s really that simplex. Personally, I find a combination of Vit. E & A to work wonders. Also many different lotions seem to work best for skin. It doesn’t have to be a specific, expensive lotion from Eden. It can be as simplex as baby lotions, coconut oils or Argon. There’s so many different names and varieties, it’s all sample, test and game. 

     Many people, including nurses have a bad habit of biting their nails. There’s ways of stopping and breaking this bad habit! It’s called a clear coat of nail hardener, even men can use this technique to stop biting their nails. It makes you think twice about biting your nails with a chemical layered on top of it. Who wants a nurse with nails like Dr. Jekyl? I certainly wouldn’t! 

     Good hygiene and skincare IMO is a big PLUS for nurses, doctors and anyone who desires to be a good example of health. This is ONLY one reason it’s good to know the Integumentary System and all anatomy of our bodies. It’s not only critical for a health team, but also good measure in taking care of ourselves! 



Side notes (compilation) to the Integumentary System:

Langer’s Lines:

Important for surgeons to know, not so much nurses.

langer's lines

  • In certain areas of the body
  • Collagen fibers in reticular region orient more in one direction than in others
  • Knowledge of lines important for surgeons, however on Integ. Exams for all medical students.



  • Functions:
  • Protects and insulates
  • Guards openings (nose, ears) against particles and insects
  • Is sensitive to very light touch
  • Hair follicle: produce hair
  • Invagination of epidermis into dermis
  • Wrapped with dense Connective Tissue
  • Surrounded by root hair plexus
  • Arrector pili – smooth muscle cells. “goosebumps”
  • Hair color (melanocytes) grey hair: melanocytes produce less melanin


Microscope slides / Melanocytes and other / Epidermis & Dermis












Hypodermic syringes:

hypodermic needle2