Connective, Muscle, and Nerve Tissue

Connective Tissue - Recall

Epithelial Tissue (yesterday’s material)

Basement Membrane

Connective Tissue

Three common types of cells found in connective tissue matrix:

1. Mast cells – prevent blood clots

2. Macrophages – first line of defense of immune system to fight microorganisms

3. Fibroblasts – most abundant cells, produce fibers

Connective Tissue

Main types of fibers: (1) collagenous –

thick, composed of protein, appear in large parallel bundles. Functions to be strong, flexible, but not very elastic (EX: bones, ligaments, tendons)

(2) elastic – not as strong, but elastic (EX: respiratory, vocal cords)

Connective Tissue

Properties of Connective Tissue General characteristics include: (1) Most abundant type of tissue found

throughout body (2) Binds/connects structures together (3) Functions to provide support, act as a

framework, fill space, store fat, produce blood cells, fight infection, and repair tissue

(4) Composed of more scattered cells with abundant intracellular matrix

(5) Most connective tissue is vascular (good blood supply)

Connective Tissue

Consists of 3 main types:

(1) Proper (2) Fluid (3) Supporting

Proper Connective Tissue

Includes: (1) Areolar

(Loose) (2) Dense

(Regular/ Fibrous) (3) Reticular (4) Adipose

Areolar (Loose) Connective

Contains lots of fluid-filled space

Located beneath the skin and around blood vessels, muscles and nerves

Functions to bind one tissue to another (as skin connects to muscle), protection and nourishment to the organs and structures it binds, and stores "body fluid"

Fibroblast

Collagen Fibers

Elastic Fibers

Dense (Regular) Connective

Contains tightly packed, parallel collagenous fibers

This fiber contains few cells, and poor blood supply, which leads to longer healing time

Located in the tendons and ligaments

Functions to provide strong flexible support

Fibroblasts

Collagen fibers

Reticular Connective Tissue

Form a network or lattice shape

Located in the spleen, lymph nodes, liver

Functions to give support to soft organs

Fibroblast

Reticular Fibers

Adipose Connective Tissue

Known as fat cells called adipocytes

Located beneath the skin, around kidneys, eyeballs, and in abdominal membranes.

Functions to provide a protective cushion, insulate and preserve body heat, and stores energy

Fluid Connective Tissue

Consists of blood and lymph

Blood is found throughout the body in blood vessels

Functions to provide oxygen and nutrients to tissues and remove wastes and CO2

Supporting Connective Tissue

Tissue that provides support. Consists of:

(1) Hyaline cartilage (2) Elastic cartilage (3) Fibrocartilage (4) Bone Tissue All cartilaginous cells

are called chondrocytes Contains small cavities

that chondrocytes are found in, called lacunae

Hyaline Cartilage

Most common cartilage Located around the

ends of bones and joints, connects ribs to sternum, and respiratory passages

Functions to withstand both pulling and compressive forces from bone movement in the respiratory system, as well as support the moveable joints between bones

Chondrocyte (inside the lacunae)

Lacunae (space)

Ground Matrix

Elastic Cartilage

Contains elastic fibers (hairy looking)

Functions to provide more flexibility and elasticity

Located in the external ear and larynx

Fibrocartilage

Very tough cartilage, composed of large amounts of collagenous fibers

Functions to provide tough support

Located in the intervertebral disks and meniscus of the knee

Collagenous fibers

Lacunae

Chondrocyte

Bone Tissue

Two main types of bone tissue: 1. Ground bone – need to recognize on slide 2. Spongy bone – don’t need to recognize

Spongy bone inside

Ground, compact

bone outside

Ground (Compact) Bone Tissue

Tough, outer layer of bone

Bone cells called osteocytes

Contain longitudinal Haversian canals used for small blood vessels to flow through

Canaliculi look like tiny hairs that allow osteocytes to branch out and obtain nutrients and even form contacts to communicate with other osteocytes

Muscle Tissue

Three main types of muscle tissue: 1. Skeletal 2. Smooth 3. Cardiac

Skeletal Muscle

Skeletal muscles function to perform conscious, voluntary movements (you can control)

Composed of bundles of fibers and have striations (stripes)

Multi-nucleated

Striations

Smooth Muscle Smooth muscle controls

involuntary movements Able to contract in long,

wavelike motions Found in blood vessel

walls to help maintain blood pressure, stomach and intestine walls to propel food through digestive tract, and in the bladder

Nonstriated, single nucleus present

Cardiac Muscle

Cardiac muscle (as name implies) is found in the heart

Functions to control involuntary contractions of the heart

Contains striations and branching

Contains intercalculated disks to separate one cell from the next

Nervous Tissue

Found in the brain, spinal cord, and nerves

Functions to send messages to the organs, muscles, glands, and to maintain homeostasis of the body

Neurons function to send messages

Neuroglial cells function to provide support