Skin Anatomy Quiz

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Questions and Answers

What is the primary function of hair on the scalp?

To protect against injury, sunlight, and heat loss (correct)

To provide color to the hair

To facilitate growth of the hair

To monitor temperature

What does the structure of the hair bulb primarily contribute to?

Protecting the scalp

Determining hair color

Nourishing the hair shaft and promoting growth (correct)

Conducting sensory signals

Which of the following statements about nails is incorrect?

Nails help in grasping small objects

Nails are highly keratinized

Nails cover and protect the dorsal surface of digits

Nails are composed of soft, flexible cells (correct)

Which part of the hair determines its curliness?

The shaft Signup and view all the answers

Where is hair densely distributed on the human body?

Scalp and underarms Signup and view all the answers

What role do eyelashes and eyebrows primarily serve?

They protect against foreign particles Signup and view all the answers

What is the primary function of the papillary layer of the dermis?

To bring blood vessels near the epidermis Signup and view all the answers

What type of receptor are Pacinian corpuscles?

Pressure sensitive receptors Signup and view all the answers

Which cells are found in the stratum basale layer of the epidermis?

Keratinocytes, melanocytes, and Merkel cells Signup and view all the answers

The hair root is encased within which types of sheath?

Epithelial and connective root sheaths Signup and view all the answers

What components are primarily found in the dermis of the skin?

Elastic and collagenous fibers Signup and view all the answers

What is the primary role of the hypodermis?

To connect the dermis to underlying organs Signup and view all the answers

Which of the following best describes arrector pili muscles?

They create goosebumps in response to cold or fear Signup and view all the answers

What is the function of Meissner’s corpuscle?

Detects light touch Signup and view all the answers

The reticular layer of the dermis is characterized by which of the following features?

It is composed of dense and stretchable connective tissues Signup and view all the answers

How do hair follicles contribute to sensory perception?

Bending the hair stimulates nerve endings Signup and view all the answers

What is the primary function of ligaments in the skeletal system?

Connect bones and stabilize joints Signup and view all the answers

Which part of the human skeleton contains the highest number of bones?

Shoulder girdle Signup and view all the answers

How many total bones are in the adult human skeleton?

206 Signup and view all the answers

Which type of tissue is cartilage classified as?

Connective tissue Signup and view all the answers

What is the role of the thoracic cage in the human skeleton?

Protect the heart and lungs Signup and view all the answers

Where is cartilage primarily found in the human body?

At the ends of bones and between vertebrae Signup and view all the answers

Which of the following is not a component of the skeletal system?

Tendons Signup and view all the answers

How many bones make up the vertebral column?

33 Signup and view all the answers

Which type of bone is typically longer and found in the limbs?

Long bones Signup and view all the answers

What shape are short bones typically classified as?

Cube-shaped Signup and view all the answers

What is the overall prevalence of sarcopenia among Japanese community-dwelling older adults?

9.9% Signup and view all the answers

Which age group is primarily associated with the increased reduction in lower limb muscle cross-sectional area?

50 to 60 years Signup and view all the answers

Flat bones are generally related to which of the following?

Protection of organs Signup and view all the answers

How are bones classified according to their size and shape?

By size and shape Signup and view all the answers

What structural change in muscle composition is typically observed with aging?

Increased non-contractile structures Signup and view all the answers

Which type of muscle fiber is most significantly reduced with age?

Type II fast-twitch glycolytic fibers Signup and view all the answers

Which of the following is NOT an example of flat bones?

Femur Signup and view all the answers

What characteristic is commonly associated with long bones?

They play a role in movement and support Signup and view all the answers

What is the effect of aging on the total number of muscle fibers?

It begins to decline around age 25. Signup and view all the answers

What factor is associated with increased intramuscular adipose tissue in older inpatients?

Inability to walk independently Signup and view all the answers

Which type of bone would you NOT find in the ankle?

Long bones Signup and view all the answers

Flat bones can be found in which of the following locations?

Skull Signup and view all the answers

What is the typical contribution of lean muscle mass to total body weight in young adults?

50% Signup and view all the answers

How does muscle strength change with age?

It declines due to reduced muscle fiber number. Signup and view all the answers

Study Notes

Epidermis Layers

Stratum spinosum is several layers thick, cells have dark nuclei and spiny projections.
Stratum basale is the deepest layer of the epidermis and is a single layer of actively dividing cells.
Keratinocytes, melanocytes, and Merkel cells are present in the stratum basale.

Dermis

Found below the epidermis, composed of elastic and collagenous fibers.
Contains sweat glands, sebaceous glands, nerve endings, and hair follicles.
Composed of two layers:
- Papillary layer is composed of loose connective tissues with many blood vessels.
- Reticular layer is deeper and thicker than the papillary layer and is composed of dense and stretchable connective tissues.
Papillae are fingerlike projections in the papillary layer that bring blood vessels near the epidermis and help to hold the two layers together.
The arrangement of the papillae determines fingerprints.

Hypodermis or Subcutaneous Layer

Not a part of the skin but connects the dermis to other organs.
Stores fat, is a shock absorber, and anchors the skin to underlying structures.

Specific Appendages inside the Skin Layer

Arrector pili muscles cause goosebumps.
Sensory nerve fibers protect the body and are sensitive to temperature.
Hair follicles contain nerve endings allowing a person to feel hair movement.
Sebaceous glands associated with each hair follicle produce oil to condition hair and skin.
Pores lubricate the skin.
Meissner’s corpuscles in the dermis monitor the duration and extent of touch.
Pacinian corpuscles are pressure sensitive receptors.

Hair

Found everywhere in the body except palms, soles, lips, penis, and parts of the female genitalia.
Dense distribution of hair on the scalp, face, pubic area, and underarms.
Functions for protection:
- from injury, sunlight, and heat loss (scalp hair)
- from foreign particles (eyebrows and eyelashes)
- from airborne particles (hairs in the nostrils).
Also functions as a sexual attractant.
Composed of the shaft, root, and bulb.
- The shaft determines the curliness of the hair: round shaft (straight hair), oval shaft (wavy hair), and flat shaft (kinky hair).
- The bulb is the enlarged base of the follicle.
- The root is encased in an internal or epithelial root sheath (derived from the epidermis), and an external or connective root sheath (derived from the dermis).

Nails

Composed of hard plates of highly keratinized cells.
Formed from the stratum corneum of the epidermis.
Cover and protect the dorsal surface of the fingernails and toenails.
Help in grasping and picking small objects.

Overview of Skeletal System

Bones are classified according to size and shape:
- Long bones are typically longer.
- Short bones are generally cube shaped.
- Flat bones are thin, flattened, and usually curved.
- Irregular bones have complex shapes.

The Skeletal System Consists of More Than Bones

The human skeleton is made up of bones, ligaments, and cartilage.
Ligaments are bands of dense and fibrous connective tissue that are essential for joint function.
Cartilage is more flexible than bone but stiffer than muscle, found in the larynx, nose, between vertebrae, and at the ends of bones.

The Adult Human Skeleton Is Made Up of 206 Bones

Skull - 22 bones
Shoulder Girdle/Upper Extremities - 64 bones
Thoracic Cage - 25 bones
Vertebral Column - 33 bones
Pelvic Girdle/Lower Extremities - 62 bones.

Lean muscle mass contributes up to 50% of total body weight in young adults, but this decreases to 25% by 75 to 80 years.

Typical Muscle Changes with Age

Reduced muscle mass and increased fat mass.
Reduced lower limb muscle cross-sectional area, beginning in early adulthood and accelerating after age 50.
Decline in the number of muscle fibers, primarily affecting type II fast-twitch glycolytic fibers.

Sarcopenia

Prevalence in Japanese community-dwelling older adults is 9.9% overall (9.8% among men, and 10.1% among women).

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Description

Test your knowledge on the layers of the skin, including the epidermis, dermis, and hypodermis. This quiz covers the structure and functions of these layers along with specific cell types and their roles. Perfect for students studying human anatomy and physiology.