Tissues

Epithelial tissue

Tissue that lines the surfaces of the body and organs.

Exocrine glands

Glands that release substances onto body surfaces or into body cavities.

Connective tissue

Tissue that provides support, protection, transportation, energy storage, and immune system response.

Cell arrangement

The way cells are organized within a tissue.

Connective tissue proper

Type of connective tissue that includes loose connective tissue and dense connective tissue.

Epithelial tissue functions

Protection, absorption, and secretion.

Skeletal muscle

Type of muscle responsible for voluntary movement and locomotion.

Neuron

Basic unit of nervous tissue responsible for transmitting and processing nerve impulses.

Epidermis layers

Stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and stratum basale.

Keratinization

Process of cells becoming filled with keratin as they move to the outermost layer of the epidermis.

Skin color differences

Variation in the amount and type of melanin produced by melanocytes in the skin.

Hair anatomy

Hair follicle, root, shaft, and bulb.

Sebaceous glands

Glands that produce sebum and are connected to hair follicles.

Sweating

Process of releasing watery sweat for temperature regulation.

Skin temperature regulation

Mechanisms like sweating, vasodilation, and piloerection.

Skin functions

Protection, regulation of body temperature, sensation, secretion, and absorption.

Endocrine glands

Secrete hormones into the bloodstream to regulate bodily functions. Examples include pituitary, thyroid, adrenal, and pancreas glands.

Squamous

A type of epithelial cell characterized by its thin, flat shape. Found in the skin, respiratory tract, and lining of blood vessels.

Cuboidal

________ tissues are a type of epithelial tissue found in organs and glands. They are cube-shaped with a central nucleus and provide protection, secretion, and absorption. Examples include kidney tubules and salivary glands.

Columnar

_________ tissues are specialized epithelial tissues composed of tall, elongated cells with their nuclei located at the base. They line the inner surfaces of organs, such as the digestive tract and respiratory system. _________ tissues provide protection, absorption, and secretion, and are characterized by their column-like shape.

Epithelial Tissue vs Connective Tissue

Epithelial Tissue:

• Covers body surfaces and lines body cavities

• Functions in protection, absorption, and secretion

Connective Tissue:

• Supports and connects body structures

• Functions in providing structure, strength, and flexibility

3 major types of connective tissue

Connective tissue proper, fluid connective tissue, supporting connective tissue

connective tissue proper

Connective tissue proper is a type of tissue that supports and connects different structures in the body. It includes loose and dense connective tissue. Loose connective tissue provides cushioning and flexibility, while dense connective tissue offers strength and stability. Examples include adipose tissue, which stores fat, and tendons, which connect muscles to bones.

fluid connective tissue

• Type of tissue found in the circulatory system

• Composed of cells suspended in a liquid matrix called plasma

• Functions include transportation of nutrients, gases, and waste products

• Examples include blood and lymph

• Plays a crucial role in maintaining homeostasis in the body

supportive connective tissue

Provides structural support and protection to various body parts. Composed of cells called fibroblasts that produce collagen fibers, which give strength and flexibility. Examples include cartilage and bone.

functions of epithelial tissue

1. Protection: Acts as a barrier to protect underlying tissues from injury, pathogens, and dehydration.

2. Absorption: Allows for the absorption of nutrients, water, and ions from the external environment.

3. Secretion: Produces and releases substances such as hormones, enzymes, mucus, and sweat.

4. Sensation: Contains specialized cells that detect and transmit sensory information.

5. Excretion: Helps eliminate waste products from the body, such as urine and sweat.

6. Filtration: Filters and regulates the passage of substances across epithelial layers.

7. Diffusion: Facilitates the exchange of gases and nutrients between different body compartments.

skeletal muscle function

Skeletal muscles are responsible for voluntary movements, such as walking and running. They provide support, maintain posture, and generate heat. Skeletal muscles contract and relax to produce movement by pulling on bones through tendons. They are under conscious control and enable activities like lifting, pushing, and pulling.

smooth muscle function

Involuntary muscle found in organs and blood vessels. Contracts slowly and rhythmically to control movement of substances, such as food in the digestive tract or blood in the arteries. Regulates organ functions like digestion, breathing, and blood flow. Not under conscious control.

cardiac muscle function

• Responsible for pumping blood throughout the body

• Involuntary muscle, meaning it contracts without conscious control

• Exhibits rhythmic contractions and relaxations to maintain a steady heartbeat

• Highly resistant to fatigue due to a rich blood supply and numerous mitochondria

• Coordinates with the electrical conduction system of the heart to ensure proper heart function

anatomy of neuron

• Dendrites: Branch-like structures that receive signals from other neurons.

• Cell Body: Contains the nucleus and controls cell functions.

• Axon: Transmits electrical signals away from the cell body.

• Myelin Sheath: Fatty covering that insulates and speeds up signal transmission.

• Nodes of Ranvier: Gaps in the myelin sheath for efficient signal conduction.

• Axon Terminal: Releases neurotransmitters to communicate with other neurons.

• Synapse: Junction between the axon terminal of one neuron and the dendrites of another.

• Neurotransmitters: Chemical messengers that transmit signals across synapses.

• Receptors: Proteins on the dendrites that receive neurotransmitters from other neurons.

• Action Potential: Electrical impulse that travels along the neuron to transmit signals.

function of nervous tissue

Transmit and process information through electrical impulses. Coordinates body movements, regulates bodily functions, and allows for sensory perception and cognitive processes.

layers of epidermis

1. Stratum corneum - outermost layer, composed of dead skin cells

2. Stratum lucidum - found only in thick skin, transparent layer

3. Stratum granulosum - contains granules that help form keratin

4. Stratum spinosum - spiky layer with cells connected by desmosomes

5. Stratum basale - deepest layer, actively dividing cells, contains melanocytes

sebaceous glands vs sweat glands

Sebaceous glands:

• Found in the dermis layer of the skin

• Produce sebum, an oily substance that lubricates the skin and hair

• Helps to moisturize and protect the skin

Sweat glands:

• Found in the dermis and subcutaneous layers of the skin

• Produce sweat, a watery substance that helps regulate body temperature

• Plays a role in excreting waste products and maintaining electrolyte balance

anatomic parts of a hair

• Shaft: Visible part of the hair above the skin's surface

• Root: Part of the hair embedded in the skin

• Follicle: Structure that surrounds the root and produces new hair cells

• Bulb: Base of the hair follicle where cells divide and hair growth occurs

• Papilla: Small, nourishing structure at the base of the hair follicle

• Cuticle: Protective outer layer of the hair shaft

• Cortex: Middle layer containing pigment that gives hair its color

• Medulla: Innermost layer, often absent in fine hairs

• Sebaceous Gland: Gland that produces oil to moisturize the hair and scalp

sweating cooling effect explained

The body's natural mechanism to cool down through the evaporation of sweat. As sweat evaporates from the skin's surface, it absorbs heat, reducing body temperature. This process helps regulate body temperature during physical activity or in hot environments.

vasodilation explained

Widening of blood vessels, increasing blood flow and decreasing blood pressure. It occurs when smooth muscles in the vessel walls relax, allowing the vessels to expand. Vasodilation can be caused by various factors, such as exercise, heat, certain medications, and the release of certain chemicals in the body.

piloerection explained

The involuntary reflex in which the muscles at the base of hair follicles contract, causing hairs to stand on end. This response is commonly known as "goosebumps" and is triggered by cold temperatures, fear, or strong emotions.

functions of skin

Protection: Skin acts as a barrier, shielding the body from harmful substances and pathogens.

Temperature regulation: It helps maintain body temperature through sweating and blood vessel dilation or constriction.

Sensation: Skin contains sensory receptors that detect touch, pressure, pain, and temperature.

Excretion: Small amounts of waste, such as salts and water, are eliminated through sweat.

Vitamin D synthesis: Skin produces vitamin D when exposed to sunlight, aiding in calcium absorption.

Appearance: Skin contributes to our physical appearance and plays a role in social interactions.