Major Anatomical Themes and Terminology

Question 1

what are the 4 basic tissue types?

Answer 1

1. connective tissue
2. epithelial tissue
3. muscle tissue
4. nervous tissue

200 unique types of cells in the human body combine to form one of the four basic tissue types

Question 2

what is an organ?

Answer 2

an organ is formed when two or more anatomically and functionally distinct “communities” of tissues combine to perform a specific function

heart, liver, lungs, kidneys, stomach - which are composed of varying amounts of epithelium, muscle, and connective tissue

Question 3

what are the 11 organ systems in the body?

Answer 3

1. integumentary
2. skeletal
3. muscular
4. cardiovascular
5. lymphatic
6. nervous
7. endocrine
8. respiratory
9. digestive
10. urinary
11. reproductive

Question 4

what are membranes?

Answer 4

a combination of an epithelial layer and an underlying CT layer

they are NOT one of the four basic tissue types

Question 5

what are the 4 types of membranes?

Answer 5

1. mucous membranes
2. serous membranes
3. synovial membranes
4. cutaneous membranes

Question 6

what are mucous membranes?

Answer 6

mucous membranes line body cavities that are open to the exterior and provide protection and aid in the movement of substances

ex. respiratory, digestive, reproductive, urinary tracts

Question 7

what are serous membranes?

Answer 7

serous membranes line body cavities that DO NOT open to the exterior and ensheath the organs that lie within those cavities

they secrete serous fluid, a watery lubricating fluid that allows organs to glide easily against one another or against the walls of cavities

ex. thoracic and abdominopelvic

Question 8

what are the two layers of a serous membrane?

Answer 8

1. visceral
   portion that covers and attaches to the organ inside a cavity (inside)
2. parietal
   portion of serous membrane attached to the wall of a cavity (outside)

these two layers of serous membranes are continuous with each other at some point

Question 9

what are 3 examples of serous membranes?

Answer 9

1. pleura
2. pericardium
3. peritoneum

Question 10

what is the pleura?

Answer 10

serous membrane

lines the thoracic cavity (parietal) and covers the lungs (visceral)

Question 11

what is the pericardium?

Answer 11

serous membrane

lines the heart cavity (parietal) and covers the heart (visceral)

Question 12

what is the peritoneum?

Answer 12

serous membrane

lines the abdominal cavity (parietal) and covers the abdominal organs (visceral)

Question 13

what are synovial membranes?

Answer 13

synovial membranes line cavities of freely movable joints not open to the exterior

synovial membranes secrete synovial fluid which lubricates cartilage at ends of bones during movement, nourishes the cartilage covering bones at joints, and cushions impact during joint articulation

ex. joint cavities, tendon sheaths & bursae

Question 14

what are cutaneous membranes?

Answer 14

cutaneous membranes are an organ of the integumentary system (skin)

they cover most of the body

skin = organ because it consists of different types of tissues joined to perform specific activities

Question 15

what is the function of cutaneous membranes?

Answer 15

cutaneous membranes form the most superficial layer of the body wall and helps to regulate body temperature (evaporate sweat), protection, sensation, excretion, immunity, blood reservoir, synthesis of vitamin D

Question 16

what are the two layers of the cutaneous membrane?

Answer 16

1. epidermis (most superficial)

the most superficial layers of the epidermis are shed or washed off, all cells of epidermis will be replaced about every 28 days (in psoriasis this turnover time is much more rapid, <7 days)

2. dermis

dermis contains rich capillary network of blood vessels that is involved with vitamin D conversion and thermoregulation

Question 17

what is subcutaneous tissue?

Answer 17

aka superficial fascia or hypodermis

it is NOT considered a layer of the integument

contains cutaneous blood vessels, nerves, lymphatics, and fat

Question 18

what is the function of the superficial fascia?

Answer 18

superficial fascia is present throughout the body to provide padding and insulation for structures found deep to it

fat cells are located throughout the superficial fascia EXCEPT in the auricles, eyelids, penis, and scrotum

adipose density depends on age, sex, geographic region of the body, and nutritional status

Question 19

why is the superficial fascia a common site for drug injections?

Answer 19

superficial fascia is common site for drug injections using hypodermic needles since it does not contain vital organs, but does contain the cutaneous plexus of blood vessels, which can transport drugs into the general circulation

Question 20

what are the two layers of the subcutaneous tissue?

Answer 20

1. fatty layer (superficial)

immediately deep to the dermis

2. membranous layer (deep)

Question 21

what is the deep investing fascia?

Answer 21

aka deep fascia or epimysium

the deep investing fascia is a thin layer of dense regular CT that ensheathes all skeletal muscles and can be thought of forming a system of connective tissue “sheets”

it is usually very difficult to separate the deep fascia from the skeletal muscle it ensheathes

the deep fascia attaches to the outer connective tissue layers of bone and cartilage

**the deep investing fascia is anatomically distinct from the deep layer of the superficial fascia; they are NOT the same histological entity

Question 22

what is the internal fascia?

Answer 22

aka subserosa fascia

the internal fascia is a barely discernible fibroelastic connective tissue lining of the thoracic and abdominopelvic body cavities

it’s named regionally or according to the muscles it is in contact with

internal fascia is only found in the trunk NOT in the limbs, head, and neck

Question 23

what is the functional of the internal fascia?

Answer 23

the internal fascia is a barely discernible fibroelastic connective tissue lining of the thoracic and abdominopelvic body cavities

its purpose is to affix the parietal layer of the serous membranes to the innermost aspect of the body cavity wall

Question 24

what are the layers that you would cut through to get to the appendix?

Answer 24

1. epidermis
2. dermis
3. superficial layer of the superficial fascia
4. deep layer of the superficial fascia
5. deep investing fascia of the anterolateral abdominal wall skeletal muscles
6. various layers of the individual anterolateral wall skeletal muscles all of which are ensheathed by deep investing fascia
7. internal fascia
8. parietal layer of the peritoneum which is the serious membrane of the abdominal cavity
9. fluid filled wafer-tin space between the parietal peritoneum and the visceral peritoneum of the appendix
10. visceral peritoneum of the vermiform appendix
11. the appendix

Question 25

what is a body cavity?

Answer 25

confined spaces within the body whose function is to cushion, protect, and permit changes in the shape and movement of internal (visceral) organs

Question 26

what are the two types of cavities?

Answer 26

1. ventral cavity (larger)
2. dorsal cavity

protects the CNS tissue and vessels

Question 27

what are the various ventral cavities?

Answer 27

1. thoracic cavity
   - pleural cavities = contain lungs
   - mediastinum = contains esophagus, trachea and major blood vessels
2. abdominopelvic cavity = contains the peritoneal sac and cavity
   - abdominal cavity = most of the digestive tract, kidneys and pancreas
   - pelvic cavity = badder, reproductive organs, rectum, very distal digestive tract

**all body cavities in the ventral cavity are lined by a single continuous serous membrane

Question 28

what are the two parts of the dorsal cavity?

Answer 28

1. cranial cavity

2. spinal cavity