Arrector Pili Muscle – This is a tiny muscle that attaches to the base of a hair follicle at one end and to dermal tissue on the other end. In order to generate heat when the body is cold, the arrector pili muscles contract all at once, causing the hair to “stand up straight” on the skin.
Where are capillary loops found?
Papillary Layer – A loose mat of fibers, lots of blood vessels. It is characterized by dermal papillae, little bumps that protrude up into the bottom of the epidermis. In these papillae are capillary loops, and nerve endings (for pain reception) and Meissner’s corpuscles (touch receptors).
Which type of connective tissue is responsible for shock absorption?
Loose connective tissue is found between many organs where it acts both to absorb shock and bind tissues together. It allows water, salts, and various nutrients to diffuse through to adjacent or imbedded cells and tissues.
What is dense irregularly arranged fibrous connective tissue?
Dense irregular connective tissue has fibers that are not arranged in parallel bundles as in dense regular connective tissue. Dense irregular connective tissue consists of mostly collagen fibers. It has less ground substance than loose connective tissue.
What is part of skin that thickens markedly when one gains weight?
Sudoriferous gland. Dense irregularly arranged, fibrous connective tissue. Region that thickens markedly when one gains weight. Where capillary loops are found.
What are capillary loops?
Minute blood vessels in the papillae of the dermis. See also: loop.
What makes up the papillary layer?
The papillary layer is defined by rete ridges (i.e. papillae) which are finger-like structures extending into the epidermis and contains thin collagen fibres, sensory nerve endings, cytoplasms and a rich network of blood capillaries.
What structure secures a hair follicle?
The hair follicle is surrounded by two main structures below the surface of the skin – the inner root sheath and the outer root sheath. The inner root sheath is quite thin and the outer root sheath is quite thick. These two sheaths wrap around the hair follicle like blankets.
What is specialized connective tissue?
Specialised connective tissue includes tendons and ligaments, Bone and Cartilage, haemopoetic tissue, blood and adipose tissue. Bone contains Osteocytes, and osteoblasts (osteo – bone) which secrete the type of extracellular matrix material (ECM) that makes up bone.
Which tissue types are described as excitable?
Nervous and muscular tissue are both described as excitable tissue.
What is loose tissue?
Loose connective tissue is a category of connective tissue which includes areolar tissue, reticular tissue, and adipose tissue. Loose connective tissue is the most common type of connective tissue in vertebrates. It holds organs in place and attaches epithelial tissue to other underlying tissues.
What produces the collagen fibers in dense irregular connective tissue?
Dense irregular connective tissue
It contains molecules such as proteoglycans and adhesive glycoproteins, and like collagen fibers are produced by fibroblasts.
Does fibrocartilage contain dense irregular connective tissue?
Fibrocartilage is a transitional tissue between dense regular connective tissue and cartilage or bone. It consists of rows or lines of rounded chondrocytes in lacunae between parallel bundles of collagenous fibers (Fibrocartilage 1).
Where is the thickest skin found on the body?
Skin is thickest on the palms and soles of the feet (1.5 mm thick), while the thinnest skin is found on the eyelids and in the postauricular region (0.05 mm thick). Male skin is characteristically thicker than female skin in all anatomic locations.
What is a hypodermis?
Your hypodermis is the bottom layer of skin in your body. It has many functions, including insulating your body, protecting your body from harm, storing energy and connecting your skin to your muscles and bones.
How does the skin continually renew itself?
The epidermis constantly renews itself: New cells are made in the lower layers of the epidermis. These move to the surface within four weeks. This constant renewal serves to replace the cells that are lost and fall to the ground as tiny flakes of skin when the skin is rubbed.
What is the dermal papillae?
The dermal papilla consists of mesenchymal cells in the hair follicle, which plays the main role in the regulation of hair growth. Maintaining the potential hair inductivity of the DPCs and the dermal sheath cells during cell culture is the most important factor in in vitro hair follicle morphogenesis and regeneration.
What is papillary layer of dermis?
The papillary dermis is the superficial layer, lying deep to the epidermis. The papillary dermis is composed of loose connective tissue that is highly vascular. … The dermis houses blood vessels, nerve endings, hair follicles, and glands.
What is the importance of the capillary loops in the hair papilla?
1 Blood Supply
Arteriovenous anastomoses are found, especially in areas where thermoregulation occurs. Opening and closing of these shunts provides a means of varying the cutaneous blood flow over a wide range, while blood flowing through the capillary loops provides uninterrupted nourishment of the epidermis.
What is unique about the papillary layer?
The papillary layer is a layer of the dermis, directly underneath the epidermis. This layer contains (endings of) capillaries, lymph vessels and sensory neurons. It has a loose network of connective tissue, this characteristic separates it from the reticular layer underneath.
What are keratinocytes?
Keratinocytes are the most prominent cell within the epidermis. Keratinocytes are ectodermally derived and can be distinguished from melanocytes and Langerhans cells in the epidermis by their larger size, intercellular bridges, and ample cytoplasm. Keratinocytes are present in all four layers of the epidermis.
What do Vellus hairs lack?
Each hair follicle contains a gland that secretes sebum, an oil that lubricates the skin and hair. However, unlike terminal hair, vellus hair does not typically have a medulla. The medulla is a portion of the hair’s core that strengthens it, allowing it to grow longer.
What is the shaft of hair?
Your hair shaft is the part of your hair that can be seen above your scalp. It is made of a protein called keratin, compacted and fused together. Keratin is the same material that nails, hoofs, feathers and claws are composed of.
Is hair made out of keratin?
Hair is made of a tough protein called keratin. A hair follicle anchors each hair into the skin. … In the hair bulb, living cells divide and grow to build the hair shaft.
What is the hair follicle made up of?
The hair follicle is made of multiple layers of cells that form from basal cells in the hair matrix and the hair root. Cells of the hair matrix divide and differentiate to form the layers of the hair. Watch this video to learn more about hair follicles.
What is elastic cartilage?
Elastic cartilage, which is yellow in appearance, is more pliable than the other two forms because it contains elastic fibres in addition to collagen. In humans it makes up the external ear, the auditory tube of the middle ear, and the epiglottis.
What is a cartilage?
Cartilage is the main type of connective tissue seen throughout the body. It serves a variety of structural and functional purposes and exists in different types throughout our joints, bones, spine, lungs, ears and nose.
What is a fibroblast?
Fibroblasts are the most common cell type of the connective tissues found throughout the body and the principal source of the extensive extracellular matrix (ECM) characteristic of these tissues. … We now recognize many common fibroblast-related features across various physiological and pathological protracted processes.
What are the excitable cells of the nervous system called?
Neurons, also called nerve cells, are electrically excitable cells that are the main functional units of the nervous system. Their function is to transmit nerve impulses. They are the only type of human cells that can carry out this function.
How does the embryological origin of these tissues help us understand their function?
Embryonic Origin of Tissues
The first embryonic cells generated have the ability to differentiate into any type of cell in the body and, as such, are called totipotent, meaning each has the capacity to divide, differentiate, and develop into a new organism.
What is a histological section?
Most histological sections are 2D slices, from a 3D piece of tissue. Exactly what will be seen on the microscope slide depends on the plane of the section, that is, the position of the microtome cut, in relation to the anatomical structures in the tissue.
Where can loose connective tissue be found?
Loose connective tissue is found around every blood vessel, helping to keep the vessel in place. The tissue is also found around and between most body organs. In summary, areolar tissue is tough, yet flexible, and comprises membranes.
What type of collagen is in loose connective tissue?
Loose connective tissue is also found in and around other organs. In the optically transparent vitreous body of the eye, fibroblasts produce a highly hydrated gel of hyaluronan and proteoglycans, supported by a loose network of type II collagen.
Where is loose connective tissue located?
Loose connective tissue (areolar) is located directly beneath the epidermis of the skin. Dense irregular connective tissue forms most of the dermis below the loose connective tissue.
What is hyaline cartilage?
Hyaline cartilage, the most widely distributed form, has a pearl-gray semitranslucent matrix containing randomly oriented collagen fibrils but relatively little elastin. It is normally found on surfaces of joints and in the cartilage making up the fetal skeleton.
What produces the elastic and collagen fibers?
Fibroblasts synthesize most components of connective tissue, including collagen, elastic fibers and proteoglycans.
What are the three fiber types found in fibrous connective tissue?
The three types of connective tissue fibers are:
- Collagen fibers – most are type I collagen (most abundant protein in the body)
- Elastic fibers – contain elastin and fibrillin.
- Reticular fibers – contain type III collagen.
What fibers are found in fibrocartilage?
Fibrocartilage contains large bundles of collagen fibres made up of Type I collagen. These bundles run linearly through the tissue separated by a cartilage matrix containing chondrocytes.
Does fibrocartilage have elastic fibers?
Fibrocartilage is the tough, very strong tissue found predominantly in the intervertebral disks and at the insertions of ligaments and tendons, it is similar to other fibrous tissues but contains cartilage ground substance and chondrocytes. Elastic cartilage, which is yellow in appearance, is more pliable…
Does fibrocartilage contain connective tissue?
Fibrocartilage is a specialized form of connective tissue in which the ground substance is cartilage. The fibrous and cartilaginous components render this tissue extremely tough and resilient. The cell types found in this connective tissue include both fibroblasts/cytes and chondroblasts/cytes.
What is the largest organ in the body?
The skin is the largest organ of the body. The skin and its derivatives (hair, nails, sweat and oil glands) make up the integumentary system. One of the main functions of the skin is protection. It protects the body from external factors such as bacteria, chemicals, and temperature.
Which of the following is present in skin lacking hair follicles?
The dead cells at the skin surface are ultimately sloughed, or desquamated. In thick, glabrous skin lacking hair follicles, such as that on human palms and soles, a clear layer, called the stratum lucidum, can be distinguished between the stratum granulosum and the stratum corneum.
Does thick skin have hair follicles?
Thick skin has a thicker epidermal layer that includes the stratum lucidum and thick skin lacks hair follicles.
What is Hypoepidermis?
Definition of hypodermis
1 : the tissue immediately beneath the epidermis of a plant especially when modified to serve as a supporting and protecting layer. 2 : the cellular layer that underlies and secretes the chitinous cuticle (as of an arthropod) 3 : superficial fascia.
What is the difference between the hypodermis and fascia?
The hypodermis is that part of the skin underlying the epidermis. Under the hypodermis there mostly lies a membranen called a fascia, mostly some fraction of a millimeter. Under the fascia mostly we find the muscles. The fascia is thus a fibrous membrane between the skin/hypodermis and the muscle.
Where is the papillary layer located?
The papillary layer is the superficial layer of the dermis that projects into the stratum basale of the epidermis to form finger-like dermal papilla (plural = dermal papillae) (see Figure 5.6).
Can dermis grow back?
The cells in the superficial or upper layers of skin, known as the epidermis, are constantly replacing themselves. This process of renewal is basically exfoliation (shedding) of the epidermis. But the deeper layers of skin, called the dermis, do not go through this cellular turnover and so do not replace themselves.
How can I regenerate my skin?
5 tips to regenerate your skin after the summer
- Say goodbye to dead skin. The first thing you need to do is remove dead cells to help the new ones regenerate more quickly. …
- Good hydration. …
- Care from within. …
- Always protect yourself from the sun. …
- A little help.
What is the difference between sebaceous glands and sebaceous follicles?
Simple sebaceous glands secrete an oily substance into the hair follicles of your skin. They’re found almost all over your body, well, wherever you have hair, at least, while sebaceous follicles are found mostly on your face, back, chest, nipples and genital regions.